diff --git a/src/ImageProcessor/Formats/Png/PngDecoder.cs b/src/ImageProcessor/Formats/Png/PngDecoder.cs index ca4af1338..7c97b6e24 100644 --- a/src/ImageProcessor/Formats/Png/PngDecoder.cs +++ b/src/ImageProcessor/Formats/Png/PngDecoder.cs @@ -31,7 +31,7 @@ namespace ImageProcessor.Formats /// Palette Index with alpha (8 bit). /// Palette Index without alpha (8 bit). /// - /// + /// /// public class PngDecoder : IImageDecoder { diff --git a/src/ImageProcessor/Formats/Png/PngDecoderCore.cs b/src/ImageProcessor/Formats/Png/PngDecoderCore.cs index aa0f37990..d0bdc8698 100644 --- a/src/ImageProcessor/Formats/Png/PngDecoderCore.cs +++ b/src/ImageProcessor/Formats/Png/PngDecoderCore.cs @@ -16,8 +16,8 @@ namespace ImageProcessor.Formats using System.Linq; using System.Text; - using ICSharpCode.SharpZipLib.Checksums; - using ICSharpCode.SharpZipLib.Zip.Compression.Streams; + //using ICSharpCode.SharpZipLib.Checksums; + //using ICSharpCode.SharpZipLib.Zip.Compression.Streams; /// /// Performs the png decoding operation. diff --git a/src/ImageProcessor/Formats/Png/PngEncoder.cs b/src/ImageProcessor/Formats/Png/PngEncoder.cs index 26f3fe89d..c747d934e 100644 --- a/src/ImageProcessor/Formats/Png/PngEncoder.cs +++ b/src/ImageProcessor/Formats/Png/PngEncoder.cs @@ -8,8 +8,8 @@ namespace ImageProcessor.Formats using System; using System.IO; - using ICSharpCode.SharpZipLib.Checksums; - using ICSharpCode.SharpZipLib.Zip.Compression.Streams; + //using ICSharpCode.SharpZipLib.Checksums; + //using ICSharpCode.SharpZipLib.Zip.Compression.Streams; /// /// Image encoder for writing image data to a stream in png format. diff --git a/src/ImageProcessor/Formats/Png/Zlib/Adler32.cs b/src/ImageProcessor/Formats/Png/Zlib/Adler32.cs new file mode 100644 index 000000000..0b9a54dea --- /dev/null +++ b/src/ImageProcessor/Formats/Png/Zlib/Adler32.cs @@ -0,0 +1,192 @@ +namespace ImageProcessor.Formats +{ + using System; + + /// + /// Computes Adler32 checksum for a stream of data. An Adler32 + /// checksum is not as reliable as a CRC32 checksum, but a lot faster to + /// compute. + /// + /// The specification for Adler32 may be found in RFC 1950. + /// ZLIB Compressed Data Format Specification version 3.3) + /// + /// + /// From that document: + /// + /// "ADLER32 (Adler-32 checksum) + /// This contains a checksum value of the uncompressed data + /// (excluding any dictionary data) computed according to Adler-32 + /// algorithm. This algorithm is a 32-bit extension and improvement + /// of the Fletcher algorithm, used in the ITU-T X.224 / ISO 8073 + /// standard. + /// + /// Adler-32 is composed of two sums accumulated per byte: s1 is + /// the sum of all bytes, s2 is the sum of all s1 values. Both sums + /// are done modulo 65521. s1 is initialized to 1, s2 to zero. The + /// Adler-32 checksum is stored as s2*65536 + s1 in most- + /// significant-byte first (network) order." + /// + /// "8.2. The Adler-32 algorithm + /// + /// The Adler-32 algorithm is much faster than the CRC32 algorithm yet + /// still provides an extremely low probability of undetected errors. + /// + /// The modulo on unsigned long accumulators can be delayed for 5552 + /// bytes, so the modulo operation time is negligible. If the bytes + /// are a, b, c, the second sum is 3a + 2b + c + 3, and so is position + /// and order sensitive, unlike the first sum, which is just a + /// checksum. That 65521 is prime is important to avoid a possible + /// large class of two-byte errors that leave the check unchanged. + /// (The Fletcher checksum uses 255, which is not prime and which also + /// makes the Fletcher check insensitive to single byte changes 0 - + /// 255.) + /// + /// The sum s1 is initialized to 1 instead of zero to make the length + /// of the sequence part of s2, so that the length does not have to be + /// checked separately. (Any sequence of zeroes has a Fletcher + /// checksum of zero.)" + /// + /// + /// + public sealed class Adler32 : IChecksum + { + /// + /// largest prime smaller than 65536 + /// + const uint BASE = 65521; + + /// + /// Returns the Adler32 data checksum computed so far. + /// + public long Value + { + get + { + return this.checksum; + } + } + + /// + /// Initializes a new instance of the class. + /// Creates a new instance of the Adler32 class. + /// The checksum starts off with a value of 1. + /// + public Adler32() + { + this.Reset(); + } + + /// + /// Resets the Adler32 checksum to the initial value. + /// + public void Reset() + { + this.checksum = 1; + } + + /// + /// Updates the checksum with a byte value. + /// + /// + /// The data value to add. The high byte of the int is ignored. + /// + public void Update(int value) + { + // We could make a length 1 byte array and call update again, but I + // would rather not have that overhead + uint s1 = this.checksum & 0xFFFF; + uint s2 = this.checksum >> 16; + + s1 = (s1 + ((uint)value & 0xFF)) % BASE; + s2 = (s1 + s2) % BASE; + + this.checksum = (s2 << 16) + s1; + } + + /// + /// Updates the checksum with an array of bytes. + /// + /// + /// The source of the data to update with. + /// + public void Update(byte[] buffer) + { + if (buffer == null) + { + throw new ArgumentNullException("buffer"); + } + + this.Update(buffer, 0, buffer.Length); + } + + /// + /// Updates the checksum with the bytes taken from the array. + /// + /// + /// an array of bytes + /// + /// + /// the start of the data used for this update + /// + /// + /// the number of bytes to use for this update + /// + public void Update(byte[] buffer, int offset, int count) + { + if (buffer == null) + { + throw new ArgumentNullException("buffer"); + } + + if (offset < 0) + { + throw new ArgumentOutOfRangeException("offset", "cannot be negative"); + } + + if (count < 0) + { + throw new ArgumentOutOfRangeException("count", "cannot be negative"); + } + + if (offset >= buffer.Length) + { + throw new ArgumentOutOfRangeException("offset", "not a valid index into buffer"); + } + + if (offset + count > buffer.Length) + { + throw new ArgumentOutOfRangeException("count", "exceeds buffer size"); + } + + //(By Per Bothner) + uint s1 = this.checksum & 0xFFFF; + uint s2 = this.checksum >> 16; + + while (count > 0) + { + // We can defer the modulo operation: + // s1 maximally grows from 65521 to 65521 + 255 * 3800 + // s2 maximally grows by 3800 * median(s1) = 2090079800 < 2^31 + int n = 3800; + if (n > count) + { + n = count; + } + count -= n; + while (--n >= 0) + { + s1 = s1 + (uint)(buffer[offset++] & 0xff); + s2 = s2 + s1; + } + s1 %= BASE; + s2 %= BASE; + } + + this.checksum = (s2 << 16) | s1; + } + + #region Instance Fields + uint checksum; + #endregion + } +} diff --git a/src/ImageProcessor/Formats/Png/Zlib/Crc32.cs b/src/ImageProcessor/Formats/Png/Zlib/Crc32.cs new file mode 100644 index 000000000..f476143fe --- /dev/null +++ b/src/ImageProcessor/Formats/Png/Zlib/Crc32.cs @@ -0,0 +1,194 @@ +// +// Copyright © James South and contributors. +// Licensed under the Apache License, Version 2.0. +// + +namespace ImageProcessor.Formats +{ + using System; + + /// + /// Generate a table for a byte-wise 32-bit CRC calculation on the polynomial: + /// x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x+1. + /// + /// Polynomials over GF(2) are represented in binary, one bit per coefficient, + /// with the lowest powers in the most significant bit. Then adding polynomials + /// is just exclusive-or, and multiplying a polynomial by x is a right shift by + /// one. If we call the above polynomial p, and represent a byte as the + /// polynomial q, also with the lowest power in the most significant bit (so the + /// byte 0xb1 is the polynomial x^7+x^3+x+1), then the CRC is (q*x^32) mod p, + /// where a mod b means the remainder after dividing a by b. + /// + /// This calculation is done using the shift-register method of multiplying and + /// taking the remainder. The register is initialized to zero, and for each + /// incoming bit, x^32 is added mod p to the register if the bit is a one (where + /// x^32 mod p is p+x^32 = x^26+...+1), and the register is multiplied mod p by + /// x (which is shifting right by one and adding x^32 mod p if the bit shifted + /// out is a one). We start with the highest power (least significant bit) of + /// q and repeat for all eight bits of q. + /// + /// The table is simply the CRC of all possible eight bit values. This is all + /// the information needed to generate CRC's on data a byte at a time for all + /// combinations of CRC register values and incoming bytes. + /// + public sealed class Crc32 : IChecksum + { + const uint CrcSeed = 0xFFFFFFFF; + + readonly static uint[] CrcTable = new uint[] { + 0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, + 0x706AF48F, 0xE963A535, 0x9E6495A3, 0x0EDB8832, 0x79DCB8A4, + 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, + 0x90BF1D91, 0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, + 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7, 0x136C9856, + 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9, + 0xFA0F3D63, 0x8D080DF5, 0x3B6E20C8, 0x4C69105E, 0xD56041E4, + 0xA2677172, 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B, + 0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, + 0x45DF5C75, 0xDCD60DCF, 0xABD13D59, 0x26D930AC, 0x51DE003A, + 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, + 0xB8BDA50F, 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, + 0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D, 0x76DC4190, + 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, + 0x9FBFE4A5, 0xE8B8D433, 0x7807C9A2, 0x0F00F934, 0x9609A88E, + 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01, + 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, + 0x1B01A57B, 0x8208F4C1, 0xF50FC457, 0x65B0D9C6, 0x12B7E950, + 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, + 0xFBD44C65, 0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, + 0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB, 0x4369E96A, + 0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5, + 0xAA0A4C5F, 0xDD0D7CC9, 0x5005713C, 0x270241AA, 0xBE0B1010, + 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F, + 0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, + 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD, 0xEDB88320, 0x9ABFB3B6, + 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF, 0x04DB2615, + 0x73DC1683, 0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, + 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1, 0xF00F9344, + 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB, + 0x196C3671, 0x6E6B06E7, 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, + 0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5, + 0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, + 0xA6BC5767, 0x3FB506DD, 0x48B2364B, 0xD80D2BDA, 0xAF0A1B4C, + 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, + 0x4669BE79, 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, + 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F, 0xC5BA3BBE, + 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, + 0x2CD99E8B, 0x5BDEAE1D, 0x9B64C2B0, 0xEC63F226, 0x756AA39C, + 0x026D930A, 0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713, + 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, + 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21, 0x86D3D2D4, 0xF1D4E242, + 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, + 0x18B74777, 0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, + 0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45, 0xA00AE278, + 0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7, + 0x4969474D, 0x3E6E77DB, 0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, + 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9, + 0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, + 0xCDD70693, 0x54DE5729, 0x23D967BF, 0xB3667A2E, 0xC4614AB8, + 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, + 0x2D02EF8D + }; + + internal static uint ComputeCrc32(uint oldCrc, byte value) + { + return (uint)(Crc32.CrcTable[(oldCrc ^ value) & 0xFF] ^ (oldCrc >> 8)); + } + + /// + /// The crc data checksum so far. + /// + uint crc; + + /// + /// Returns the CRC32 data checksum computed so far. + /// + public long Value + { + get + { + return (long)this.crc; + } + set + { + this.crc = (uint)value; + } + } + + /// + /// Resets the CRC32 data checksum as if no update was ever called. + /// + public void Reset() + { + this.crc = 0; + } + + /// + /// Updates the checksum with the int bval. + /// + /// + /// the byte is taken as the lower 8 bits of value + /// + public void Update(int value) + { + this.crc ^= CrcSeed; + this.crc = CrcTable[(this.crc ^ value) & 0xFF] ^ (this.crc >> 8); + this.crc ^= CrcSeed; + } + + /// + /// Updates the checksum with the bytes taken from the array. + /// + /// + /// buffer an array of bytes + /// + public void Update(byte[] buffer) + { + if (buffer == null) + { + throw new ArgumentNullException("buffer"); + } + + this.Update(buffer, 0, buffer.Length); + } + + /// + /// Adds the byte array to the data checksum. + /// + /// + /// The buffer which contains the data + /// + /// + /// The offset in the buffer where the data starts + /// + /// + /// The number of data bytes to update the CRC with. + /// + public void Update(byte[] buffer, int offset, int count) + { + if (buffer == null) + { + throw new ArgumentNullException("buffer"); + } + + if (count < 0) + { + throw new ArgumentOutOfRangeException("count", "Count cannot be less than zero"); + } + + if (offset < 0 || offset + count > buffer.Length) + { + throw new ArgumentOutOfRangeException("offset"); + } + + this.crc ^= CrcSeed; + + while (--count >= 0) + { + this.crc = CrcTable[(this.crc ^ buffer[offset++]) & 0xFF] ^ (this.crc >> 8); + } + + this.crc ^= CrcSeed; + } + } +} diff --git a/src/ImageProcessor/Formats/Png/Zlib/DeflateStrategy.cs b/src/ImageProcessor/Formats/Png/Zlib/DeflateStrategy.cs new file mode 100644 index 000000000..31a913609 --- /dev/null +++ b/src/ImageProcessor/Formats/Png/Zlib/DeflateStrategy.cs @@ -0,0 +1,26 @@ +namespace ImageProcessor.Formats +{ + /// + /// Strategies for deflater + /// + public enum DeflateStrategy + { + /// + /// The default strategy + /// + Default = 0, + + /// + /// This strategy will only allow longer string repetitions. It is + /// useful for random data with a small character set. + /// + Filtered = 1, + + /// + /// This strategy will not look for string repetitions at all. It + /// only encodes with Huffman trees (which means, that more common + /// characters get a smaller encoding. + /// + HuffmanOnly = 2 + } +} diff --git a/src/ImageProcessor/Formats/Png/Zlib/Deflater.cs b/src/ImageProcessor/Formats/Png/Zlib/Deflater.cs new file mode 100644 index 000000000..cbabedd90 --- /dev/null +++ b/src/ImageProcessor/Formats/Png/Zlib/Deflater.cs @@ -0,0 +1,555 @@ +namespace ImageProcessor.Formats +{ + using System; + + //using ICSharpCode.SharpZipLib.Zip.Compression; + + /// + /// This is the Deflater class. The deflater class compresses input + /// with the deflate algorithm described in RFC 1951. It has several + /// compression levels and three different strategies described below. + /// + /// This class is not thread safe. This is inherent in the API, due + /// to the split of deflate and setInput. + /// + /// author of the original java version : Jochen Hoenicke + /// + public class Deflater + { + #region Deflater Documentation + /* + * The Deflater can do the following state transitions: + * + * (1) -> INIT_STATE ----> INIT_FINISHING_STATE ---. + * / | (2) (5) | + * / v (5) | + * (3)| SETDICT_STATE ---> SETDICT_FINISHING_STATE |(3) + * \ | (3) | ,--------' + * | | | (3) / + * v v (5) v v + * (1) -> BUSY_STATE ----> FINISHING_STATE + * | (6) + * v + * FINISHED_STATE + * \_____________________________________/ + * | (7) + * v + * CLOSED_STATE + * + * (1) If we should produce a header we start in INIT_STATE, otherwise + * we start in BUSY_STATE. + * (2) A dictionary may be set only when we are in INIT_STATE, then + * we change the state as indicated. + * (3) Whether a dictionary is set or not, on the first call of deflate + * we change to BUSY_STATE. + * (4) -- intentionally left blank -- :) + * (5) FINISHING_STATE is entered, when flush() is called to indicate that + * there is no more INPUT. There are also states indicating, that + * the header wasn't written yet. + * (6) FINISHED_STATE is entered, when everything has been flushed to the + * internal pending output buffer. + * (7) At any time (7) + * + */ + #endregion + #region Public Constants + /// + /// The best and slowest compression level. This tries to find very + /// long and distant string repetitions. + /// + public const int BEST_COMPRESSION = 9; + + /// + /// The worst but fastest compression level. + /// + public const int BEST_SPEED = 1; + + /// + /// The default compression level. + /// + public const int DEFAULT_COMPRESSION = -1; + + /// + /// This level won't compress at all but output uncompressed blocks. + /// + public const int NO_COMPRESSION = 0; + + /// + /// The compression method. This is the only method supported so far. + /// There is no need to use this constant at all. + /// + public const int DEFLATED = 8; + #endregion + #region Local Constants + private const int IS_SETDICT = 0x01; + private const int IS_FLUSHING = 0x04; + private const int IS_FINISHING = 0x08; + + private const int INIT_STATE = 0x00; + private const int SETDICT_STATE = 0x01; + // private static int INIT_FINISHING_STATE = 0x08; + // private static int SETDICT_FINISHING_STATE = 0x09; + private const int BUSY_STATE = 0x10; + private const int FLUSHING_STATE = 0x14; + private const int FINISHING_STATE = 0x1c; + private const int FINISHED_STATE = 0x1e; + private const int CLOSED_STATE = 0x7f; + #endregion + #region Constructors + /// + /// Creates a new deflater with default compression level. + /// + public Deflater() : this(DEFAULT_COMPRESSION, false) + { + + } + + /// + /// Creates a new deflater with given compression level. + /// + /// + /// the compression level, a value between NO_COMPRESSION + /// and BEST_COMPRESSION, or DEFAULT_COMPRESSION. + /// + /// if lvl is out of range. + public Deflater(int level) : this(level, false) + { + + } + + /// + /// Creates a new deflater with given compression level. + /// + /// + /// the compression level, a value between NO_COMPRESSION + /// and BEST_COMPRESSION. + /// + /// + /// true, if we should suppress the Zlib/RFC1950 header at the + /// beginning and the adler checksum at the end of the output. This is + /// useful for the GZIP/PKZIP formats. + /// + /// if lvl is out of range. + public Deflater(int level, bool noZlibHeaderOrFooter) + { + if (level == DEFAULT_COMPRESSION) + { + level = 6; + } + else if (level < NO_COMPRESSION || level > BEST_COMPRESSION) + { + throw new ArgumentOutOfRangeException("level"); + } + + pending = new DeflaterPending(); + engine = new DeflaterEngine(pending); + this.noZlibHeaderOrFooter = noZlibHeaderOrFooter; + SetStrategy(DeflateStrategy.Default); + SetLevel(level); + Reset(); + } + #endregion + + /// + /// Resets the deflater. The deflater acts afterwards as if it was + /// just created with the same compression level and strategy as it + /// had before. + /// + public void Reset() + { + state = (noZlibHeaderOrFooter ? BUSY_STATE : INIT_STATE); + totalOut = 0; + pending.Reset(); + engine.Reset(); + } + + /// + /// Gets the current adler checksum of the data that was processed so far. + /// + public int Adler + { + get + { + return engine.Adler; + } + } + + /// + /// Gets the number of input bytes processed so far. + /// + public long TotalIn + { + get + { + return engine.TotalIn; + } + } + + /// + /// Gets the number of output bytes so far. + /// + public long TotalOut + { + get + { + return totalOut; + } + } + + /// + /// Flushes the current input block. Further calls to deflate() will + /// produce enough output to inflate everything in the current input + /// block. This is not part of Sun's JDK so I have made it package + /// private. It is used by DeflaterOutputStream to implement + /// flush(). + /// + public void Flush() + { + state |= IS_FLUSHING; + } + + /// + /// Finishes the deflater with the current input block. It is an error + /// to give more input after this method was called. This method must + /// be called to force all bytes to be flushed. + /// + public void Finish() + { + state |= (IS_FLUSHING | IS_FINISHING); + } + + /// + /// Returns true if the stream was finished and no more output bytes + /// are available. + /// + public bool IsFinished + { + get + { + return (state == FINISHED_STATE) && pending.IsFlushed; + } + } + + /// + /// Returns true, if the input buffer is empty. + /// You should then call setInput(). + /// NOTE: This method can also return true when the stream + /// was finished. + /// + public bool IsNeedingInput + { + get + { + return engine.NeedsInput(); + } + } + + /// + /// Sets the data which should be compressed next. This should be only + /// called when needsInput indicates that more input is needed. + /// If you call setInput when needsInput() returns false, the + /// previous input that is still pending will be thrown away. + /// The given byte array should not be changed, before needsInput() returns + /// true again. + /// This call is equivalent to setInput(input, 0, input.length). + /// + /// + /// the buffer containing the input data. + /// + /// + /// if the buffer was finished() or ended(). + /// + public void SetInput(byte[] input) + { + SetInput(input, 0, input.Length); + } + + /// + /// Sets the data which should be compressed next. This should be + /// only called when needsInput indicates that more input is needed. + /// The given byte array should not be changed, before needsInput() returns + /// true again. + /// + /// + /// the buffer containing the input data. + /// + /// + /// the start of the data. + /// + /// + /// the number of data bytes of input. + /// + /// + /// if the buffer was Finish()ed or if previous input is still pending. + /// + public void SetInput(byte[] input, int offset, int count) + { + if ((state & IS_FINISHING) != 0) + { + throw new InvalidOperationException("Finish() already called"); + } + engine.SetInput(input, offset, count); + } + + /// + /// Sets the compression level. There is no guarantee of the exact + /// position of the change, but if you call this when needsInput is + /// true the change of compression level will occur somewhere near + /// before the end of the so far given input. + /// + /// + /// the new compression level. + /// + public void SetLevel(int level) + { + if (level == DEFAULT_COMPRESSION) + { + level = 6; + } + else if (level < NO_COMPRESSION || level > BEST_COMPRESSION) + { + throw new ArgumentOutOfRangeException("level"); + } + + if (this.level != level) + { + this.level = level; + engine.SetLevel(level); + } + } + + /// + /// Get current compression level + /// + /// Returns the current compression level + public int GetLevel() + { + return level; + } + + /// + /// Sets the compression strategy. Strategy is one of + /// DEFAULT_STRATEGY, HUFFMAN_ONLY and FILTERED. For the exact + /// position where the strategy is changed, the same as for + /// SetLevel() applies. + /// + /// + /// The new compression strategy. + /// + public void SetStrategy(DeflateStrategy strategy) + { + engine.Strategy = strategy; + } + + /// + /// Deflates the current input block with to the given array. + /// + /// + /// The buffer where compressed data is stored + /// + /// + /// The number of compressed bytes added to the output, or 0 if either + /// IsNeedingInput() or IsFinished returns true or length is zero. + /// + public int Deflate(byte[] output) + { + return Deflate(output, 0, output.Length); + } + + /// + /// Deflates the current input block to the given array. + /// + /// + /// Buffer to store the compressed data. + /// + /// + /// Offset into the output array. + /// + /// + /// The maximum number of bytes that may be stored. + /// + /// + /// The number of compressed bytes added to the output, or 0 if either + /// needsInput() or finished() returns true or length is zero. + /// + /// + /// If Finish() was previously called. + /// + /// + /// If offset or length don't match the array length. + /// + public int Deflate(byte[] output, int offset, int length) + { + int origLength = length; + + if (state == CLOSED_STATE) + { + throw new InvalidOperationException("Deflater closed"); + } + + if (state < BUSY_STATE) + { + // output header + int header = (DEFLATED + + ((DeflaterConstants.MAX_WBITS - 8) << 4)) << 8; + int level_flags = (level - 1) >> 1; + if (level_flags < 0 || level_flags > 3) + { + level_flags = 3; + } + header |= level_flags << 6; + if ((state & IS_SETDICT) != 0) + { + // Dictionary was set + header |= DeflaterConstants.PRESET_DICT; + } + header += 31 - (header % 31); + + pending.WriteShortMSB(header); + if ((state & IS_SETDICT) != 0) + { + int chksum = engine.Adler; + engine.ResetAdler(); + pending.WriteShortMSB(chksum >> 16); + pending.WriteShortMSB(chksum & 0xffff); + } + + state = BUSY_STATE | (state & (IS_FLUSHING | IS_FINISHING)); + } + + for (;;) + { + int count = pending.Flush(output, offset, length); + offset += count; + totalOut += count; + length -= count; + + if (length == 0 || state == FINISHED_STATE) + { + break; + } + + if (!engine.Deflate((state & IS_FLUSHING) != 0, (state & IS_FINISHING) != 0)) + { + if (state == BUSY_STATE) + { + // We need more input now + return origLength - length; + } + else if (state == FLUSHING_STATE) + { + if (level != NO_COMPRESSION) + { + /* We have to supply some lookahead. 8 bit lookahead + * is needed by the zlib inflater, and we must fill + * the next byte, so that all bits are flushed. + */ + int neededbits = 8 + ((-pending.BitCount) & 7); + while (neededbits > 0) + { + /* write a static tree block consisting solely of + * an EOF: + */ + pending.WriteBits(2, 10); + neededbits -= 10; + } + } + state = BUSY_STATE; + } + else if (state == FINISHING_STATE) + { + pending.AlignToByte(); + + // Compressed data is complete. Write footer information if required. + if (!noZlibHeaderOrFooter) + { + int adler = engine.Adler; + pending.WriteShortMSB(adler >> 16); + pending.WriteShortMSB(adler & 0xffff); + } + state = FINISHED_STATE; + } + } + } + return origLength - length; + } + + /// + /// Sets the dictionary which should be used in the deflate process. + /// This call is equivalent to setDictionary(dict, 0, dict.Length). + /// + /// + /// the dictionary. + /// + /// + /// if SetInput () or Deflate () were already called or another dictionary was already set. + /// + public void SetDictionary(byte[] dictionary) + { + SetDictionary(dictionary, 0, dictionary.Length); + } + + /// + /// Sets the dictionary which should be used in the deflate process. + /// The dictionary is a byte array containing strings that are + /// likely to occur in the data which should be compressed. The + /// dictionary is not stored in the compressed output, only a + /// checksum. To decompress the output you need to supply the same + /// dictionary again. + /// + /// + /// The dictionary data + /// + /// + /// The index where dictionary information commences. + /// + /// + /// The number of bytes in the dictionary. + /// + /// + /// If SetInput () or Deflate() were already called or another dictionary was already set. + /// + public void SetDictionary(byte[] dictionary, int index, int count) + { + if (state != INIT_STATE) + { + throw new InvalidOperationException(); + } + + state = SETDICT_STATE; + engine.SetDictionary(dictionary, index, count); + } + + #region Instance Fields + /// + /// Compression level. + /// + int level; + + /// + /// If true no Zlib/RFC1950 headers or footers are generated + /// + bool noZlibHeaderOrFooter; + + /// + /// The current state. + /// + int state; + + /// + /// The total bytes of output written. + /// + long totalOut; + + /// + /// The pending output. + /// + DeflaterPending pending; + + /// + /// The deflater engine. + /// + DeflaterEngine engine; + #endregion + } +} diff --git a/src/ImageProcessor/Formats/Png/Zlib/DeflaterConstants.cs b/src/ImageProcessor/Formats/Png/Zlib/DeflaterConstants.cs new file mode 100644 index 000000000..1b9efbdb1 --- /dev/null +++ b/src/ImageProcessor/Formats/Png/Zlib/DeflaterConstants.cs @@ -0,0 +1,145 @@ +namespace ImageProcessor.Formats +{ + using System; + + /// + /// This class contains constants used for deflation. + /// + public class DeflaterConstants + { + /// + /// Set to true to enable debugging + /// + public const bool DEBUGGING = false; + + /// + /// Written to Zip file to identify a stored block + /// + public const int STORED_BLOCK = 0; + + /// + /// Identifies static tree in Zip file + /// + public const int STATIC_TREES = 1; + + /// + /// Identifies dynamic tree in Zip file + /// + public const int DYN_TREES = 2; + + /// + /// Header flag indicating a preset dictionary for deflation + /// + public const int PRESET_DICT = 0x20; + + /// + /// Sets internal buffer sizes for Huffman encoding + /// + public const int DEFAULT_MEM_LEVEL = 8; + + /// + /// Internal compression engine constant + /// + public const int MAX_MATCH = 258; + + /// + /// Internal compression engine constant + /// + public const int MIN_MATCH = 3; + + /// + /// Internal compression engine constant + /// + public const int MAX_WBITS = 15; + + /// + /// Internal compression engine constant + /// + public const int WSIZE = 1 << MAX_WBITS; + + /// + /// Internal compression engine constant + /// + public const int WMASK = WSIZE - 1; + + /// + /// Internal compression engine constant + /// + public const int HASH_BITS = DEFAULT_MEM_LEVEL + 7; + + /// + /// Internal compression engine constant + /// + public const int HASH_SIZE = 1 << HASH_BITS; + + /// + /// Internal compression engine constant + /// + public const int HASH_MASK = HASH_SIZE - 1; + + /// + /// Internal compression engine constant + /// + public const int HASH_SHIFT = (HASH_BITS + MIN_MATCH - 1) / MIN_MATCH; + + /// + /// Internal compression engine constant + /// + public const int MIN_LOOKAHEAD = MAX_MATCH + MIN_MATCH + 1; + + /// + /// Internal compression engine constant + /// + public const int MAX_DIST = WSIZE - MIN_LOOKAHEAD; + + /// + /// Internal compression engine constant + /// + public const int PENDING_BUF_SIZE = 1 << (DEFAULT_MEM_LEVEL + 8); + + /// + /// Internal compression engine constant + /// + public static int MAX_BLOCK_SIZE = Math.Min(65535, PENDING_BUF_SIZE - 5); + + /// + /// Internal compression engine constant + /// + public const int DEFLATE_STORED = 0; + + /// + /// Internal compression engine constant + /// + public const int DEFLATE_FAST = 1; + + /// + /// Internal compression engine constant + /// + public const int DEFLATE_SLOW = 2; + + /// + /// Internal compression engine constant + /// + public static int[] GOOD_LENGTH = { 0, 4, 4, 4, 4, 8, 8, 8, 32, 32 }; + + /// + /// Internal compression engine constant + /// + public static int[] MAX_LAZY = { 0, 4, 5, 6, 4, 16, 16, 32, 128, 258 }; + + /// + /// Internal compression engine constant + /// + public static int[] NICE_LENGTH = { 0, 8, 16, 32, 16, 32, 128, 128, 258, 258 }; + + /// + /// Internal compression engine constant + /// + public static int[] MAX_CHAIN = { 0, 4, 8, 32, 16, 32, 128, 256, 1024, 4096 }; + + /// + /// Internal compression engine constant + /// + public static int[] COMPR_FUNC = { 0, 1, 1, 1, 1, 2, 2, 2, 2, 2 }; + } +} diff --git a/src/ImageProcessor/Formats/Png/Zlib/DeflaterEngine.cs b/src/ImageProcessor/Formats/Png/Zlib/DeflaterEngine.cs new file mode 100644 index 000000000..15ae2ec8e --- /dev/null +++ b/src/ImageProcessor/Formats/Png/Zlib/DeflaterEngine.cs @@ -0,0 +1,757 @@ +namespace ImageProcessor.Formats +{ + using System; + + /// + /// Low level compression engine for deflate algorithm which uses a 32K sliding window + /// with secondary compression from Huffman/Shannon-Fano codes. + /// + /// + /// DEFLATE ALGORITHM: + /// + /// The uncompressed stream is inserted into the window array. When + /// the window array is full the first half is thrown away and the + /// second half is copied to the beginning. + /// + /// The head array is a hash table. Three characters build a hash value + /// and they the value points to the corresponding index in window of + /// the last string with this hash. The prev array implements a + /// linked list of matches with the same hash: prev[index & WMASK] points + /// to the previous index with the same hash. + /// + public class DeflaterEngine : DeflaterConstants + { + /// + /// ne more than the maximum upper bounds. + /// + private const int TooFar = 4096; + + /// + /// prev[index & WMASK] points to the previous index that has the + /// same hash code as the string starting at index. This way + /// entries with the same hash code are in a linked list. + /// Note that the array should really be unsigned short, so you need + /// to and the values with 0xffff. + /// + private readonly short[] previousIndex; + + /// + /// Hashtable, hashing three characters to an index for window, so + /// that window[index]..window[index+2] have this hash code. + /// Note that the array should really be unsigned short, so you need + /// to and the values with 0xffff. + /// + private readonly short[] head; + + /// + /// Hash index of string to be inserted. + /// + private int insertHashIndex; + + /// + /// Initializes a new instance of the class with a pending buffer. + /// + /// The pending buffer to use> + public DeflaterEngine(DeflaterPending pending) + { + this.pending = pending; + this.huffman = new DeflaterHuffman(pending); + this.adler = new Adler32(); + + this.window = new byte[2 * WSIZE]; + this.head = new short[HASH_SIZE]; + this.previousIndex = new short[WSIZE]; + + // We start at index 1, to avoid an implementation deficiency, that + // we cannot build a repeat pattern at index 0. + this.blockStart = this.strstart = 1; + } + + /// + /// Get current value of Adler checksum + /// + public int Adler => unchecked((int)this.adler.Value); + + /// + /// Total data processed + /// + public long TotalIn => this.totalIn; + + /// + /// Get or sets the + /// + public DeflateStrategy Strategy { get; set; } + + /// + /// Deflate drives actual compression of data + /// + /// True to flush input buffers + /// Finish deflation with the current input. + /// Returns true if progress has been made. + public bool Deflate(bool flush, bool finish) + { + bool progress; + do + { + this.FillWindow(); + bool canFlush = flush && (this.inputOff == this.inputEnd); + + switch (this.compressionFunction) + { + case DEFLATE_STORED: + progress = this.DeflateStored(canFlush, finish); + break; + case DEFLATE_FAST: + progress = this.DeflateFast(canFlush, finish); + break; + case DEFLATE_SLOW: + progress = this.DeflateSlow(canFlush, finish); + break; + default: + throw new InvalidOperationException("unknown compressionFunction"); + } + } + while (this.pending.IsFlushed && progress); // repeat while we have no pending output and progress was made + return progress; + } + + /// + /// Sets input data to be deflated. Should only be called when NeedsInput() + /// returns true + /// + /// The buffer containing input data. + /// The offset of the first byte of data. + /// The number of bytes of data to use as input. + public void SetInput(byte[] buffer, int offset, int count) + { + if (buffer == null) + { + throw new ArgumentNullException(nameof(buffer)); + } + + if (offset < 0) + { + throw new ArgumentOutOfRangeException(nameof(offset)); + } + + if (count < 0) + { + throw new ArgumentOutOfRangeException(nameof(count)); + } + + if (this.inputOff < this.inputEnd) + { + throw new InvalidOperationException("Old input was not completely processed"); + } + + int end = offset + count; + + // We want to throw an ArrayIndexOutOfBoundsException early. The + // check is very tricky: it also handles integer wrap around. + if ((offset > end) || (end > buffer.Length)) + { + throw new ArgumentOutOfRangeException(nameof(count)); + } + + this.inputBuf = buffer; + this.inputOff = offset; + this.inputEnd = end; + } + + /// + /// Determines if more input is needed. + /// + /// Return true if input is needed via SetInput + public bool NeedsInput() + { + return this.inputEnd == this.inputOff; + } + + /// + /// Set compression dictionary + /// + /// The buffer containing the dictionary data + /// The offset in the buffer for the first byte of data + /// The length of the dictionary data. + public void SetDictionary(byte[] buffer, int offset, int length) + { + this.adler.Update(buffer, offset, length); + if (length < MIN_MATCH) + { + return; + } + + if (length > MAX_DIST) + { + offset += length - MAX_DIST; + length = MAX_DIST; + } + + Array.Copy(buffer, offset, this.window, this.strstart, length); + + this.UpdateHash(); + --length; + while (--length > 0) + { + this.InsertString(); + this.strstart++; + } + + this.strstart += 2; + this.blockStart = this.strstart; + } + + /// + /// Reset internal state + /// + public void Reset() + { + this.huffman.Reset(); + this.adler.Reset(); + this.blockStart = this.strstart = 1; + this.lookahead = 0; + this.totalIn = 0; + this.prevAvailable = false; + this.matchLen = MIN_MATCH - 1; + + for (int i = 0; i < HASH_SIZE; i++) + { + this.head[i] = 0; + } + + for (int i = 0; i < WSIZE; i++) + { + this.previousIndex[i] = 0; + } + } + + /// + /// Reset Adler checksum + /// + public void ResetAdler() + { + this.adler.Reset(); + } + + /// + /// Set the deflate level (0-9) + /// + /// The value to set the level to. + public void SetLevel(int level) + { + if ((level < 0) || (level > 9)) + { + throw new ArgumentOutOfRangeException(nameof(level)); + } + + this.goodLength = GOOD_LENGTH[level]; + this.maxLazy = MAX_LAZY[level]; + this.niceLength = NICE_LENGTH[level]; + this.maxChain = MAX_CHAIN[level]; + + if (COMPR_FUNC[level] != this.compressionFunction) + { + switch (this.compressionFunction) + { + case DEFLATE_STORED: + if (this.strstart > this.blockStart) + { + this.huffman.FlushStoredBlock(this.window, this.blockStart, this.strstart - this.blockStart, false); + this.blockStart = this.strstart; + } + + this.UpdateHash(); + break; + + case DEFLATE_FAST: + if (this.strstart > this.blockStart) + { + this.huffman.FlushBlock(this.window, this.blockStart, this.strstart - this.blockStart, + false); + this.blockStart = this.strstart; + } + + break; + + case DEFLATE_SLOW: + if (this.prevAvailable) + { + this.huffman.TallyLit(this.window[this.strstart - 1] & 0xff); + } + + if (this.strstart > this.blockStart) + { + this.huffman.FlushBlock(this.window, this.blockStart, this.strstart - this.blockStart, false); + this.blockStart = this.strstart; + } + + this.prevAvailable = false; + this.matchLen = MIN_MATCH - 1; + break; + } + + this.compressionFunction = COMPR_FUNC[level]; + } + } + + /// + /// Fill the window + /// + public void FillWindow() + { + // If the window is almost full and there is insufficient lookahead, + // move the upper half to the lower one to make room in the upper half. + if (this.strstart >= WSIZE + MAX_DIST) + { + this.SlideWindow(); + } + + // If there is not enough lookahead, but still some input left, + // read in the input + while (this.lookahead < MIN_LOOKAHEAD && this.inputOff < this.inputEnd) + { + int more = (2 * WSIZE) - this.lookahead - this.strstart; + + if (more > this.inputEnd - this.inputOff) + { + more = this.inputEnd - this.inputOff; + } + + Array.Copy(this.inputBuf, this.inputOff, this.window, this.strstart + this.lookahead, more); + this.adler.Update(this.inputBuf, this.inputOff, more); + + this.inputOff += more; + this.totalIn += more; + this.lookahead += more; + } + + if (this.lookahead >= MIN_MATCH) + { + this.UpdateHash(); + } + } + + private void UpdateHash() + { + this.insertHashIndex = (this.window[this.strstart] << HASH_SHIFT) ^ this.window[this.strstart + 1]; + } + + /// + /// Inserts the current string in the head hash and returns the previous + /// value for this hash. + /// + /// The previous hash value + private int InsertString() + { + short match; + int hash = ((this.insertHashIndex << HASH_SHIFT) ^ this.window[this.strstart + (MIN_MATCH - 1)]) & HASH_MASK; + + this.previousIndex[this.strstart & WMASK] = match = this.head[hash]; + this.head[hash] = unchecked((short)this.strstart); + this.insertHashIndex = hash; + return match & 0xffff; + } + + private void SlideWindow() + { + Array.Copy(this.window, WSIZE, this.window, 0, WSIZE); + this.matchStart -= WSIZE; + this.strstart -= WSIZE; + this.blockStart -= WSIZE; + + // Slide the hash table (could be avoided with 32 bit values + // at the expense of memory usage). + for (int i = 0; i < HASH_SIZE; ++i) + { + int m = this.head[i] & 0xffff; + this.head[i] = (short)(m >= WSIZE ? (m - WSIZE) : 0); + } + + // Slide the prev table. + for (int i = 0; i < WSIZE; i++) + { + int m = this.previousIndex[i] & 0xffff; + this.previousIndex[i] = (short)(m >= WSIZE ? (m - WSIZE) : 0); + } + } + + /// + /// Find the best (longest) string in the window matching the + /// string starting at strstart. + /// + /// Preconditions: + /// + /// strstart + MAX_MATCH <= window.length. + /// + /// The current match. + /// True if a match greater than the minimum length is found + private bool FindLongestMatch(int curMatch) + { + int chainLength = this.maxChain; + int length = this.niceLength; + short[] previous = this.previousIndex; + int scan = this.strstart; + int bestEnd = this.strstart + this.matchLen; + int bestLength = Math.Max(this.matchLen, MIN_MATCH - 1); + + int limit = Math.Max(this.strstart - MAX_DIST, 0); + + int strend = this.strstart + MAX_MATCH - 1; + byte scanEnd1 = this.window[bestEnd - 1]; + byte scanEnd = this.window[bestEnd]; + + // Do not waste too much time if we already have a good match: + if (bestLength >= this.goodLength) + { + chainLength >>= 2; + } + + // Do not look for matches beyond the end of the input. This is necessary + // to make deflate deterministic. + if (length > this.lookahead) + { + length = this.lookahead; + } + + do + { + if (this.window[curMatch + bestLength] != scanEnd || + this.window[curMatch + bestLength - 1] != scanEnd1 || + this.window[curMatch] != this.window[scan] || + this.window[curMatch + 1] != this.window[scan + 1]) + { + continue; + } + + int match = curMatch + 2; + scan += 2; + + // We check for insufficient lookahead only every 8th comparison; + // the 256th check will be made at strstart + 258. + while ( + this.window[++scan] == this.window[++match] && + this.window[++scan] == this.window[++match] && + this.window[++scan] == this.window[++match] && + this.window[++scan] == this.window[++match] && + this.window[++scan] == this.window[++match] && + this.window[++scan] == this.window[++match] && + this.window[++scan] == this.window[++match] && + this.window[++scan] == this.window[++match] && + (scan < strend)) + { + // Do nothing + } + + if (scan > bestEnd) + { + this.matchStart = curMatch; + bestEnd = scan; + bestLength = scan - this.strstart; + + if (bestLength >= length) + { + break; + } + + scanEnd1 = this.window[bestEnd - 1]; + scanEnd = this.window[bestEnd]; + } + + scan = this.strstart; + } while ((curMatch = previous[curMatch & WMASK] & 0xffff) > limit && --chainLength != 0); + + this.matchLen = Math.Min(bestLength, this.lookahead); + return this.matchLen >= MIN_MATCH; + } + + private bool DeflateStored(bool flush, bool finish) + { + if (!flush && (this.lookahead == 0)) + { + return false; + } + + this.strstart += this.lookahead; + this.lookahead = 0; + + int storedLength = this.strstart - this.blockStart; + + if ((storedLength >= MAX_BLOCK_SIZE) || // Block is full + (this.blockStart < WSIZE && storedLength >= MAX_DIST) || // Block may move out of window + flush) + { + bool lastBlock = finish; + if (storedLength > MAX_BLOCK_SIZE) + { + storedLength = MAX_BLOCK_SIZE; + lastBlock = false; + } + + this.huffman.FlushStoredBlock(this.window, this.blockStart, storedLength, lastBlock); + this.blockStart += storedLength; + return !lastBlock; + } + + return true; + } + + private bool DeflateFast(bool flush, bool finish) + { + if (this.lookahead < MIN_LOOKAHEAD && !flush) + { + return false; + } + + while (this.lookahead >= MIN_LOOKAHEAD || flush) + { + if (this.lookahead == 0) + { + // We are flushing everything + this.huffman.FlushBlock(this.window, this.blockStart, this.strstart - this.blockStart, finish); + this.blockStart = this.strstart; + return false; + } + + if (this.strstart > (2 * WSIZE) - MIN_LOOKAHEAD) + { + /* slide window, as FindLongestMatch needs this. + * This should only happen when flushing and the window + * is almost full. + */ + this.SlideWindow(); + } + + int hashHead; + if (this.lookahead >= MIN_MATCH && + (hashHead = this.InsertString()) != 0 && + this.Strategy != DeflateStrategy.HuffmanOnly && + this.strstart - hashHead <= MAX_DIST && + this.FindLongestMatch(hashHead)) + { + // longestMatch sets matchStart and matchLen + bool full = this.huffman.TallyDist(this.strstart - this.matchStart, this.matchLen); + + this.lookahead -= this.matchLen; + if (this.matchLen <= this.maxLazy && this.lookahead >= MIN_MATCH) + { + while (--this.matchLen > 0) + { + ++this.strstart; + this.InsertString(); + } + + ++this.strstart; + } + else + { + this.strstart += this.matchLen; + if (this.lookahead >= MIN_MATCH - 1) + { + this.UpdateHash(); + } + } + + this.matchLen = MIN_MATCH - 1; + if (!full) + { + continue; + } + } + else + { + // No match found + this.huffman.TallyLit(this.window[this.strstart] & 0xff); + ++this.strstart; + --this.lookahead; + } + + if (this.huffman.IsFull()) + { + bool lastBlock = finish && (this.lookahead == 0); + this.huffman.FlushBlock(this.window, this.blockStart, this.strstart - this.blockStart, lastBlock); + this.blockStart = this.strstart; + return !lastBlock; + } + } + + return true; + } + + private bool DeflateSlow(bool flush, bool finish) + { + if (this.lookahead < MIN_LOOKAHEAD && !flush) + { + return false; + } + + while (this.lookahead >= MIN_LOOKAHEAD || flush) + { + if (this.lookahead == 0) + { + if (this.prevAvailable) + { + this.huffman.TallyLit(this.window[this.strstart - 1] & 0xff); + } + + this.prevAvailable = false; + + // We are flushing everything + this.huffman.FlushBlock(this.window, this.blockStart, this.strstart - this.blockStart, + finish); + this.blockStart = this.strstart; + return false; + } + + if (this.strstart >= (2 * WSIZE) - MIN_LOOKAHEAD) + { + // slide window, as FindLongestMatch needs this. + // This should only happen when flushing and the window + // is almost full. + this.SlideWindow(); + } + + int prevMatch = this.matchStart; + int prevLen = this.matchLen; + if (this.lookahead >= MIN_MATCH) + { + + int hashHead = this.InsertString(); + + if (this.Strategy != DeflateStrategy.HuffmanOnly && + hashHead != 0 && + this.strstart - hashHead <= MAX_DIST && + this.FindLongestMatch(hashHead)) + { + + // longestMatch sets matchStart and matchLen + + // Discard match if too small and too far away + if (this.matchLen <= 5 && (this.Strategy == DeflateStrategy.Filtered || (this.matchLen == MIN_MATCH && this.strstart - this.matchStart > TooFar))) + { + this.matchLen = MIN_MATCH - 1; + } + } + } + + // previous match was better + if ((prevLen >= MIN_MATCH) && (this.matchLen <= prevLen)) + { + this.huffman.TallyDist(this.strstart - 1 - prevMatch, prevLen); + prevLen -= 2; + do + { + this.strstart++; + this.lookahead--; + if (this.lookahead >= MIN_MATCH) + { + this.InsertString(); + } + } while (--prevLen > 0); + + this.strstart++; + this.lookahead--; + this.prevAvailable = false; + this.matchLen = MIN_MATCH - 1; + } + else + { + if (this.prevAvailable) + { + this.huffman.TallyLit(this.window[this.strstart - 1] & 0xff); + } + + this.prevAvailable = true; + this.strstart++; + this.lookahead--; + } + + if (this.huffman.IsFull()) + { + int len = this.strstart - this.blockStart; + if (this.prevAvailable) + { + len--; + } + + bool lastBlock = finish && (this.lookahead == 0) && !this.prevAvailable; + this.huffman.FlushBlock(this.window, this.blockStart, len, lastBlock); + this.blockStart += len; + return !lastBlock; + } + } + + return true; + } + + private int matchStart; + + // Length of best match + private int matchLen; + + // Set if previous match exists + private bool prevAvailable; + + private int blockStart; + + /// + /// Points to the current character in the window. + /// + private int strstart; + + /// + /// lookahead is the number of characters starting at strstart in + /// window that are valid. + /// So window[strstart] until window[strstart+lookahead-1] are valid + /// characters. + /// + private int lookahead; + + /// + /// This array contains the part of the uncompressed stream that + /// is of relevance. The current character is indexed by strstart. + /// + private byte[] window; + + private int maxChain; + + private int maxLazy; + + private int niceLength; + + private int goodLength; + + /// + /// The current compression function. + /// + private int compressionFunction; + + /// + /// The input data for compression. + /// + private byte[] inputBuf; + + /// + /// The total bytes of input read. + /// + private long totalIn; + + /// + /// The offset into inputBuf, where input data starts. + /// + private int inputOff; + + /// + /// The end offset of the input data. + /// + private int inputEnd; + + private DeflaterPending pending; + + private DeflaterHuffman huffman; + + /// + /// The adler checksum + /// + private Adler32 adler; + } +} diff --git a/src/ImageProcessor/Formats/Png/Zlib/DeflaterHuffman.cs b/src/ImageProcessor/Formats/Png/Zlib/DeflaterHuffman.cs new file mode 100644 index 000000000..8ea1369c1 --- /dev/null +++ b/src/ImageProcessor/Formats/Png/Zlib/DeflaterHuffman.cs @@ -0,0 +1,958 @@ +namespace ImageProcessor.Formats +{ + using System; + + /// + /// This is the DeflaterHuffman class. + /// + /// This class is not thread safe. This is inherent in the API, due + /// to the split of Deflate and SetInput. + /// + /// author of the original java version : Jochen Hoenicke + /// + public class DeflaterHuffman + { + const int BUFSIZE = 1 << (DeflaterConstants.DEFAULT_MEM_LEVEL + 6); + const int LITERAL_NUM = 286; + + // Number of distance codes + const int DIST_NUM = 30; + // Number of codes used to transfer bit lengths + const int BITLEN_NUM = 19; + + // repeat previous bit length 3-6 times (2 bits of repeat count) + const int REP_3_6 = 16; + // repeat a zero length 3-10 times (3 bits of repeat count) + const int REP_3_10 = 17; + // repeat a zero length 11-138 times (7 bits of repeat count) + const int REP_11_138 = 18; + + const int EOF_SYMBOL = 256; + + // The lengths of the bit length codes are sent in order of decreasing + // probability, to avoid transmitting the lengths for unused bit length codes. + static readonly int[] BL_ORDER = { 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 }; + + static readonly byte[] bit4Reverse = + { + 0, + 8, + 4, + 12, + 2, + 10, + 6, + 14, + 1, + 9, + 5, + 13, + 3, + 11, + 7, + 15 + }; + + static short[] staticLCodes; + static byte[] staticLLength; + static short[] staticDCodes; + static byte[] staticDLength; + + class Tree + { + #region Instance Fields + public short[] freqs; + + public byte[] length; + + public int minNumCodes; + + public int numCodes; + + short[] codes; + int[] bl_counts; + int maxLength; + DeflaterHuffman dh; + #endregion + + #region Constructors + public Tree(DeflaterHuffman dh, int elems, int minCodes, int maxLength) + { + this.dh = dh; + this.minNumCodes = minCodes; + this.maxLength = maxLength; + freqs = new short[elems]; + bl_counts = new int[maxLength]; + } + + #endregion + + /// + /// Resets the internal state of the tree + /// + public void Reset() + { + for (int i = 0; i < freqs.Length; i++) + { + freqs[i] = 0; + } + codes = null; + length = null; + } + + public void WriteSymbol(int code) + { + // if (DeflaterConstants.DEBUGGING) { + // freqs[code]--; + // // Console.Write("writeSymbol("+freqs.length+","+code+"): "); + // } + dh.pending.WriteBits(codes[code] & 0xffff, length[code]); + } + + /// + /// Check that all frequencies are zero + /// + /// + /// At least one frequency is non-zero + /// + public void CheckEmpty() + { + bool empty = true; + for (int i = 0; i < freqs.Length; i++) + { + if (freqs[i] != 0) + { + //Console.WriteLine("freqs[" + i + "] == " + freqs[i]); + empty = false; + } + } + + if (!empty) + { + throw new InvalidOperationException("!Empty"); + } + } + + /// + /// Set static codes and length + /// + /// new codes + /// length for new codes + public void SetStaticCodes(short[] staticCodes, byte[] staticLengths) + { + codes = staticCodes; + length = staticLengths; + } + + /// + /// Build dynamic codes and lengths + /// + public void BuildCodes() + { + int numSymbols = freqs.Length; + int[] nextCode = new int[maxLength]; + int code = 0; + + codes = new short[freqs.Length]; + + // if (DeflaterConstants.DEBUGGING) { + // //Console.WriteLine("buildCodes: "+freqs.Length); + // } + + for (int bits = 0; bits < maxLength; bits++) + { + nextCode[bits] = code; + code += bl_counts[bits] << (15 - bits); + + // if (DeflaterConstants.DEBUGGING) { + // //Console.WriteLine("bits: " + ( bits + 1) + " count: " + bl_counts[bits] + // +" nextCode: "+code); + // } + } + +#if DebugDeflation + if ( DeflaterConstants.DEBUGGING && (code != 65536) ) + { + throw new ImageFormatException("Inconsistent bl_counts!"); + } +#endif + for (int i = 0; i < numCodes; i++) + { + int bits = length[i]; + if (bits > 0) + { + + // if (DeflaterConstants.DEBUGGING) { + // //Console.WriteLine("codes["+i+"] = rev(" + nextCode[bits-1]+"), + // +bits); + // } + + codes[i] = BitReverse(nextCode[bits - 1]); + nextCode[bits - 1] += 1 << (16 - bits); + } + } + } + + public void BuildTree() + { + int numSymbols = freqs.Length; + + /* heap is a priority queue, sorted by frequency, least frequent + * nodes first. The heap is a binary tree, with the property, that + * the parent node is smaller than both child nodes. This assures + * that the smallest node is the first parent. + * + * The binary tree is encoded in an array: 0 is root node and + * the nodes 2*n+1, 2*n+2 are the child nodes of node n. + */ + int[] heap = new int[numSymbols]; + int heapLen = 0; + int maxCode = 0; + for (int n = 0; n < numSymbols; n++) + { + int freq = freqs[n]; + if (freq != 0) + { + // Insert n into heap + int pos = heapLen++; + int ppos; + while (pos > 0 && freqs[heap[ppos = (pos - 1) / 2]] > freq) + { + heap[pos] = heap[ppos]; + pos = ppos; + } + heap[pos] = n; + + maxCode = n; + } + } + + /* We could encode a single literal with 0 bits but then we + * don't see the literals. Therefore we force at least two + * literals to avoid this case. We don't care about order in + * this case, both literals get a 1 bit code. + */ + while (heapLen < 2) + { + int node = maxCode < 2 ? ++maxCode : 0; + heap[heapLen++] = node; + } + + numCodes = Math.Max(maxCode + 1, minNumCodes); + + int numLeafs = heapLen; + int[] childs = new int[4 * heapLen - 2]; + int[] values = new int[2 * heapLen - 1]; + int numNodes = numLeafs; + for (int i = 0; i < heapLen; i++) + { + int node = heap[i]; + childs[2 * i] = node; + childs[2 * i + 1] = -1; + values[i] = freqs[node] << 8; + heap[i] = i; + } + + /* Construct the Huffman tree by repeatedly combining the least two + * frequent nodes. + */ + do + { + int first = heap[0]; + int last = heap[--heapLen]; + + // Propagate the hole to the leafs of the heap + int ppos = 0; + int path = 1; + + while (path < heapLen) + { + if (path + 1 < heapLen && values[heap[path]] > values[heap[path + 1]]) + { + path++; + } + + heap[ppos] = heap[path]; + ppos = path; + path = path * 2 + 1; + } + + /* Now propagate the last element down along path. Normally + * it shouldn't go too deep. + */ + int lastVal = values[last]; + while ((path = ppos) > 0 && values[heap[ppos = (path - 1) / 2]] > lastVal) + { + heap[path] = heap[ppos]; + } + heap[path] = last; + + + int second = heap[0]; + + // Create a new node father of first and second + last = numNodes++; + childs[2 * last] = first; + childs[2 * last + 1] = second; + int mindepth = Math.Min(values[first] & 0xff, values[second] & 0xff); + values[last] = lastVal = values[first] + values[second] - mindepth + 1; + + // Again, propagate the hole to the leafs + ppos = 0; + path = 1; + + while (path < heapLen) + { + if (path + 1 < heapLen && values[heap[path]] > values[heap[path + 1]]) + { + path++; + } + + heap[ppos] = heap[path]; + ppos = path; + path = ppos * 2 + 1; + } + + // Now propagate the new element down along path + while ((path = ppos) > 0 && values[heap[ppos = (path - 1) / 2]] > lastVal) + { + heap[path] = heap[ppos]; + } + heap[path] = last; + } while (heapLen > 1); + + if (heap[0] != (childs.Length / 2) - 1) + { + throw new ImageFormatException("Heap invariant violated"); + } + + BuildLength(childs); + } + + /// + /// Get encoded length + /// + /// Encoded length, the sum of frequencies * lengths + public int GetEncodedLength() + { + int len = 0; + for (int i = 0; i < freqs.Length; i++) + { + len += freqs[i] * length[i]; + } + return len; + } + + /// + /// Scan a literal or distance tree to determine the frequencies of the codes + /// in the bit length tree. + /// + public void CalcBLFreq(Tree blTree) + { + int max_count; /* max repeat count */ + int min_count; /* min repeat count */ + int count; /* repeat count of the current code */ + int curlen = -1; /* length of current code */ + + int i = 0; + while (i < numCodes) + { + count = 1; + int nextlen = length[i]; + if (nextlen == 0) + { + max_count = 138; + min_count = 3; + } + else + { + max_count = 6; + min_count = 3; + if (curlen != nextlen) + { + blTree.freqs[nextlen]++; + count = 0; + } + } + curlen = nextlen; + i++; + + while (i < numCodes && curlen == length[i]) + { + i++; + if (++count >= max_count) + { + break; + } + } + + if (count < min_count) + { + blTree.freqs[curlen] += (short)count; + } + else if (curlen != 0) + { + blTree.freqs[REP_3_6]++; + } + else if (count <= 10) + { + blTree.freqs[REP_3_10]++; + } + else + { + blTree.freqs[REP_11_138]++; + } + } + } + + /// + /// Write tree values + /// + /// Tree to write + public void WriteTree(Tree blTree) + { + int max_count; // max repeat count + int min_count; // min repeat count + int count; // repeat count of the current code + int curlen = -1; // length of current code + + int i = 0; + while (i < numCodes) + { + count = 1; + int nextlen = length[i]; + if (nextlen == 0) + { + max_count = 138; + min_count = 3; + } + else + { + max_count = 6; + min_count = 3; + if (curlen != nextlen) + { + blTree.WriteSymbol(nextlen); + count = 0; + } + } + curlen = nextlen; + i++; + + while (i < numCodes && curlen == length[i]) + { + i++; + if (++count >= max_count) + { + break; + } + } + + if (count < min_count) + { + while (count-- > 0) + { + blTree.WriteSymbol(curlen); + } + } + else if (curlen != 0) + { + blTree.WriteSymbol(REP_3_6); + dh.pending.WriteBits(count - 3, 2); + } + else if (count <= 10) + { + blTree.WriteSymbol(REP_3_10); + dh.pending.WriteBits(count - 3, 3); + } + else + { + blTree.WriteSymbol(REP_11_138); + dh.pending.WriteBits(count - 11, 7); + } + } + } + + void BuildLength(int[] childs) + { + this.length = new byte[freqs.Length]; + int numNodes = childs.Length / 2; + int numLeafs = (numNodes + 1) / 2; + int overflow = 0; + + for (int i = 0; i < maxLength; i++) + { + bl_counts[i] = 0; + } + + // First calculate optimal bit lengths + int[] lengths = new int[numNodes]; + lengths[numNodes - 1] = 0; + + for (int i = numNodes - 1; i >= 0; i--) + { + if (childs[2 * i + 1] != -1) + { + int bitLength = lengths[i] + 1; + if (bitLength > maxLength) + { + bitLength = maxLength; + overflow++; + } + lengths[childs[2 * i]] = lengths[childs[2 * i + 1]] = bitLength; + } + else + { + // A leaf node + int bitLength = lengths[i]; + bl_counts[bitLength - 1]++; + this.length[childs[2 * i]] = (byte)lengths[i]; + } + } + + // if (DeflaterConstants.DEBUGGING) { + // //Console.WriteLine("Tree "+freqs.Length+" lengths:"); + // for (int i=0; i < numLeafs; i++) { + // //Console.WriteLine("Node "+childs[2*i]+" freq: "+freqs[childs[2*i]] + // + " len: "+length[childs[2*i]]); + // } + // } + + if (overflow == 0) + { + return; + } + + int incrBitLen = maxLength - 1; + do + { + // Find the first bit length which could increase: + while (bl_counts[--incrBitLen] == 0) + ; + + // Move this node one down and remove a corresponding + // number of overflow nodes. + do + { + bl_counts[incrBitLen]--; + bl_counts[++incrBitLen]++; + overflow -= 1 << (maxLength - 1 - incrBitLen); + } while (overflow > 0 && incrBitLen < maxLength - 1); + } while (overflow > 0); + + /* We may have overshot above. Move some nodes from maxLength to + * maxLength-1 in that case. + */ + bl_counts[maxLength - 1] += overflow; + bl_counts[maxLength - 2] -= overflow; + + /* Now recompute all bit lengths, scanning in increasing + * frequency. It is simpler to reconstruct all lengths instead of + * fixing only the wrong ones. This idea is taken from 'ar' + * written by Haruhiko Okumura. + * + * The nodes were inserted with decreasing frequency into the childs + * array. + */ + int nodePtr = 2 * numLeafs; + for (int bits = maxLength; bits != 0; bits--) + { + int n = bl_counts[bits - 1]; + while (n > 0) + { + int childPtr = 2 * childs[nodePtr++]; + if (childs[childPtr + 1] == -1) + { + // We found another leaf + length[childs[childPtr]] = (byte)bits; + n--; + } + } + } + // if (DeflaterConstants.DEBUGGING) { + // //Console.WriteLine("*** After overflow elimination. ***"); + // for (int i=0; i < numLeafs; i++) { + // //Console.WriteLine("Node "+childs[2*i]+" freq: "+freqs[childs[2*i]] + // + " len: "+length[childs[2*i]]); + // } + // } + } + + } + + #region Instance Fields + /// + /// Pending buffer to use + /// + public DeflaterPending pending; + + Tree literalTree; + Tree distTree; + Tree blTree; + + // Buffer for distances + short[] d_buf; + byte[] l_buf; + int last_lit; + int extra_bits; + #endregion + + static DeflaterHuffman() + { + // See RFC 1951 3.2.6 + // Literal codes + staticLCodes = new short[LITERAL_NUM]; + staticLLength = new byte[LITERAL_NUM]; + + int i = 0; + while (i < 144) + { + staticLCodes[i] = BitReverse((0x030 + i) << 8); + staticLLength[i++] = 8; + } + + while (i < 256) + { + staticLCodes[i] = BitReverse((0x190 - 144 + i) << 7); + staticLLength[i++] = 9; + } + + while (i < 280) + { + staticLCodes[i] = BitReverse((0x000 - 256 + i) << 9); + staticLLength[i++] = 7; + } + + while (i < LITERAL_NUM) + { + staticLCodes[i] = BitReverse((0x0c0 - 280 + i) << 8); + staticLLength[i++] = 8; + } + + // Distance codes + staticDCodes = new short[DIST_NUM]; + staticDLength = new byte[DIST_NUM]; + for (i = 0; i < DIST_NUM; i++) + { + staticDCodes[i] = BitReverse(i << 11); + staticDLength[i] = 5; + } + } + + /// + /// Construct instance with pending buffer + /// + /// Pending buffer to use + public DeflaterHuffman(DeflaterPending pending) + { + this.pending = pending; + + literalTree = new Tree(this, LITERAL_NUM, 257, 15); + distTree = new Tree(this, DIST_NUM, 1, 15); + blTree = new Tree(this, BITLEN_NUM, 4, 7); + + d_buf = new short[BUFSIZE]; + l_buf = new byte[BUFSIZE]; + } + + /// + /// Reset internal state + /// + public void Reset() + { + last_lit = 0; + extra_bits = 0; + literalTree.Reset(); + distTree.Reset(); + blTree.Reset(); + } + + /// + /// Write all trees to pending buffer + /// + /// The number/rank of treecodes to send. + public void SendAllTrees(int blTreeCodes) + { + blTree.BuildCodes(); + literalTree.BuildCodes(); + distTree.BuildCodes(); + pending.WriteBits(literalTree.numCodes - 257, 5); + pending.WriteBits(distTree.numCodes - 1, 5); + pending.WriteBits(blTreeCodes - 4, 4); + for (int rank = 0; rank < blTreeCodes; rank++) + { + pending.WriteBits(blTree.length[BL_ORDER[rank]], 3); + } + literalTree.WriteTree(blTree); + distTree.WriteTree(blTree); + +#if DebugDeflation + if (DeflaterConstants.DEBUGGING) { + blTree.CheckEmpty(); + } +#endif + } + + /// + /// Compress current buffer writing data to pending buffer + /// + public void CompressBlock() + { + for (int i = 0; i < last_lit; i++) + { + int litlen = l_buf[i] & 0xff; + int dist = d_buf[i]; + if (dist-- != 0) + { + // if (DeflaterConstants.DEBUGGING) { + // Console.Write("["+(dist+1)+","+(litlen+3)+"]: "); + // } + + int lc = Lcode(litlen); + literalTree.WriteSymbol(lc); + + int bits = (lc - 261) / 4; + if (bits > 0 && bits <= 5) + { + pending.WriteBits(litlen & ((1 << bits) - 1), bits); + } + + int dc = Dcode(dist); + distTree.WriteSymbol(dc); + + bits = dc / 2 - 1; + if (bits > 0) + { + pending.WriteBits(dist & ((1 << bits) - 1), bits); + } + } + else + { + // if (DeflaterConstants.DEBUGGING) { + // if (litlen > 32 && litlen < 127) { + // Console.Write("("+(char)litlen+"): "); + // } else { + // Console.Write("{"+litlen+"}: "); + // } + // } + literalTree.WriteSymbol(litlen); + } + } + +#if DebugDeflation + if (DeflaterConstants.DEBUGGING) { + Console.Write("EOF: "); + } +#endif + literalTree.WriteSymbol(EOF_SYMBOL); + +#if DebugDeflation + if (DeflaterConstants.DEBUGGING) { + literalTree.CheckEmpty(); + distTree.CheckEmpty(); + } +#endif + } + + /// + /// Flush block to output with no compression + /// + /// Data to write + /// Index of first byte to write + /// Count of bytes to write + /// True if this is the last block + public void FlushStoredBlock(byte[] stored, int storedOffset, int storedLength, bool lastBlock) + { +#if DebugDeflation + // if (DeflaterConstants.DEBUGGING) { + // //Console.WriteLine("Flushing stored block "+ storedLength); + // } +#endif + pending.WriteBits((DeflaterConstants.STORED_BLOCK << 1) + (lastBlock ? 1 : 0), 3); + pending.AlignToByte(); + pending.WriteShort(storedLength); + pending.WriteShort(~storedLength); + pending.WriteBlock(stored, storedOffset, storedLength); + Reset(); + } + + /// + /// Flush block to output with compression + /// + /// Data to flush + /// Index of first byte to flush + /// Count of bytes to flush + /// True if this is the last block + public void FlushBlock(byte[] stored, int storedOffset, int storedLength, bool lastBlock) + { + literalTree.freqs[EOF_SYMBOL]++; + + // Build trees + literalTree.BuildTree(); + distTree.BuildTree(); + + // Calculate bitlen frequency + literalTree.CalcBLFreq(blTree); + distTree.CalcBLFreq(blTree); + + // Build bitlen tree + blTree.BuildTree(); + + int blTreeCodes = 4; + for (int i = 18; i > blTreeCodes; i--) + { + if (blTree.length[BL_ORDER[i]] > 0) + { + blTreeCodes = i + 1; + } + } + int opt_len = 14 + blTreeCodes * 3 + blTree.GetEncodedLength() + + literalTree.GetEncodedLength() + distTree.GetEncodedLength() + + extra_bits; + + int static_len = extra_bits; + for (int i = 0; i < LITERAL_NUM; i++) + { + static_len += literalTree.freqs[i] * staticLLength[i]; + } + for (int i = 0; i < DIST_NUM; i++) + { + static_len += distTree.freqs[i] * staticDLength[i]; + } + if (opt_len >= static_len) + { + // Force static trees + opt_len = static_len; + } + + if (storedOffset >= 0 && storedLength + 4 < opt_len >> 3) + { + // Store Block + + // if (DeflaterConstants.DEBUGGING) { + // //Console.WriteLine("Storing, since " + storedLength + " < " + opt_len + // + " <= " + static_len); + // } + FlushStoredBlock(stored, storedOffset, storedLength, lastBlock); + } + else if (opt_len == static_len) + { + // Encode with static tree + pending.WriteBits((DeflaterConstants.STATIC_TREES << 1) + (lastBlock ? 1 : 0), 3); + literalTree.SetStaticCodes(staticLCodes, staticLLength); + distTree.SetStaticCodes(staticDCodes, staticDLength); + CompressBlock(); + Reset(); + } + else + { + // Encode with dynamic tree + pending.WriteBits((DeflaterConstants.DYN_TREES << 1) + (lastBlock ? 1 : 0), 3); + SendAllTrees(blTreeCodes); + CompressBlock(); + Reset(); + } + } + + /// + /// Get value indicating if internal buffer is full + /// + /// true if buffer is full + public bool IsFull() + { + return last_lit >= BUFSIZE; + } + + /// + /// Add literal to buffer + /// + /// Literal value to add to buffer. + /// Value indicating internal buffer is full + public bool TallyLit(int literal) + { + // if (DeflaterConstants.DEBUGGING) { + // if (lit > 32 && lit < 127) { + // //Console.WriteLine("("+(char)lit+")"); + // } else { + // //Console.WriteLine("{"+lit+"}"); + // } + // } + d_buf[last_lit] = 0; + l_buf[last_lit++] = (byte)literal; + literalTree.freqs[literal]++; + return IsFull(); + } + + /// + /// Add distance code and length to literal and distance trees + /// + /// Distance code + /// Length + /// Value indicating if internal buffer is full + public bool TallyDist(int distance, int length) + { + // if (DeflaterConstants.DEBUGGING) { + // //Console.WriteLine("[" + distance + "," + length + "]"); + // } + + d_buf[last_lit] = (short)distance; + l_buf[last_lit++] = (byte)(length - 3); + + int lc = Lcode(length - 3); + literalTree.freqs[lc]++; + if (lc >= 265 && lc < 285) + { + extra_bits += (lc - 261) / 4; + } + + int dc = Dcode(distance - 1); + distTree.freqs[dc]++; + if (dc >= 4) + { + extra_bits += dc / 2 - 1; + } + return IsFull(); + } + + + /// + /// Reverse the bits of a 16 bit value. + /// + /// Value to reverse bits + /// Value with bits reversed + public static short BitReverse(int toReverse) + { + return (short)(bit4Reverse[toReverse & 0xF] << 12 | + bit4Reverse[(toReverse >> 4) & 0xF] << 8 | + bit4Reverse[(toReverse >> 8) & 0xF] << 4 | + bit4Reverse[toReverse >> 12]); + } + + static int Lcode(int length) + { + if (length == 255) + { + return 285; + } + + int code = 257; + while (length >= 8) + { + code += 4; + length >>= 1; + } + return code + length; + } + + static int Dcode(int distance) + { + int code = 0; + while (distance >= 4) + { + code += 2; + distance >>= 1; + } + return code + distance; + } + } +} diff --git a/src/ImageProcessor/Formats/Png/Zlib/DeflaterOutputStream.cs b/src/ImageProcessor/Formats/Png/Zlib/DeflaterOutputStream.cs new file mode 100644 index 000000000..2f4d9eefd --- /dev/null +++ b/src/ImageProcessor/Formats/Png/Zlib/DeflaterOutputStream.cs @@ -0,0 +1,577 @@ +namespace ImageProcessor.Formats +{ + using System; + using System.IO; + + /// + /// A special stream deflating or compressing the bytes that are + /// written to it. It uses a Deflater to perform actual deflating.
+ /// Authors of the original java version : Tom Tromey, Jochen Hoenicke + /// + public class DeflaterOutputStream : Stream + { + #region Constructors + /// + /// Creates a new DeflaterOutputStream with a default Deflater and default buffer size. + /// + /// + /// the output stream where deflated output should be written. + /// + public DeflaterOutputStream(Stream baseOutputStream) + : this(baseOutputStream, new Deflater(), 512) + { + } + + /// + /// Creates a new DeflaterOutputStream with the given Deflater and + /// default buffer size. + /// + /// + /// the output stream where deflated output should be written. + /// + /// + /// the underlying deflater. + /// + public DeflaterOutputStream(Stream baseOutputStream, Deflater deflater) + : this(baseOutputStream, deflater, 512) + { + } + + /// + /// Creates a new DeflaterOutputStream with the given Deflater and + /// buffer size. + /// + /// + /// The output stream where deflated output is written. + /// + /// + /// The underlying deflater to use + /// + /// + /// The buffer size in bytes to use when deflating (minimum value 512) + /// + /// + /// bufsize is less than or equal to zero. + /// + /// + /// baseOutputStream does not support writing + /// + /// + /// deflater instance is null + /// + public DeflaterOutputStream(Stream baseOutputStream, Deflater deflater, int bufferSize) + { + if (baseOutputStream == null) + { + throw new ArgumentNullException("baseOutputStream"); + } + + if (baseOutputStream.CanWrite == false) + { + throw new ArgumentException("Must support writing", "baseOutputStream"); + } + + if (deflater == null) + { + throw new ArgumentNullException("deflater"); + } + + if (bufferSize < 512) + { + throw new ArgumentOutOfRangeException("bufferSize"); + } + + baseOutputStream_ = baseOutputStream; + buffer_ = new byte[bufferSize]; + deflater_ = deflater; + } + #endregion + + #region Public API + /// + /// Finishes the stream by calling finish() on the deflater. + /// + /// + /// Not all input is deflated + /// + public virtual void Finish() + { + deflater_.Finish(); + while (!deflater_.IsFinished) + { + int len = deflater_.Deflate(buffer_, 0, buffer_.Length); + if (len <= 0) + { + break; + } + + if (keys != null) + { + EncryptBlock(buffer_, 0, len); + } + + baseOutputStream_.Write(buffer_, 0, len); + } + + if (!deflater_.IsFinished) + { + throw new ImageFormatException("Can't deflate all input?"); + } + + baseOutputStream_.Flush(); + + if (keys != null) + { + keys = null; + } + } + + /// + /// Get/set flag indicating ownership of the underlying stream. + /// When the flag is true will close the underlying stream also. + /// + public bool IsStreamOwner + { + get { return isStreamOwner_; } + set { isStreamOwner_ = value; } + } + + /// + /// Allows client to determine if an entry can be patched after its added + /// + public bool CanPatchEntries + { + get + { + return baseOutputStream_.CanSeek; + } + } + + #endregion + + #region Encryption + + string password; + + uint[] keys; + + /// + /// Get/set the password used for encryption. + /// + /// When set to null or if the password is empty no encryption is performed + public string Password + { + get + { + return password; + } + set + { + if ((value != null) && (value.Length == 0)) + { + password = null; + } + else + { + password = value; + } + } + } + + /// + /// Encrypt a block of data + /// + /// + /// Data to encrypt. NOTE the original contents of the buffer are lost + /// + /// + /// Offset of first byte in buffer to encrypt + /// + /// + /// Number of bytes in buffer to encrypt + /// + protected void EncryptBlock(byte[] buffer, int offset, int length) + { + for (int i = offset; i < offset + length; ++i) + { + byte oldbyte = buffer[i]; + buffer[i] ^= EncryptByte(); + UpdateKeys(oldbyte); + } + } + + /// + /// Initializes encryption keys based on given . + /// + /// The password. + protected void InitializePassword(string password) + { + keys = new uint[] { + 0x12345678, + 0x23456789, + 0x34567890 + }; + + byte[] rawPassword = ZipConstants.ConvertToArray(password); + + for (int i = 0; i < rawPassword.Length; ++i) + { + UpdateKeys((byte)rawPassword[i]); + } + } + +#if !NET_1_1 && !NETCF_2_0 && !NOCRYPTO + /// + /// Initializes encryption keys based on given password. + /// + protected void InitializeAESPassword(ZipEntry entry, string rawPassword, + out byte[] salt, out byte[] pwdVerifier) { + salt = new byte[entry.AESSaltLen]; + // Salt needs to be cryptographically random, and unique per file + if (_aesRnd == null) + _aesRnd = new RNGCryptoServiceProvider(); + _aesRnd.GetBytes(salt); + int blockSize = entry.AESKeySize / 8; // bits to bytes + + cryptoTransform_ = new ZipAESTransform(rawPassword, salt, blockSize, true); + pwdVerifier = ((ZipAESTransform)cryptoTransform_).PwdVerifier; + } +#endif + +#if NETCF_1_0 || NOCRYPTO + + /// + /// Encrypt a single byte + /// + /// + /// The encrypted value + /// + protected byte EncryptByte() + { + uint temp = ((keys[2] & 0xFFFF) | 2); + return (byte)((temp * (temp ^ 1)) >> 8); + } + + /// + /// Update encryption keys + /// + protected void UpdateKeys(byte ch) + { + keys[0] = Crc32.ComputeCrc32(keys[0], ch); + keys[1] = keys[1] + (byte)keys[0]; + keys[1] = keys[1] * 134775813 + 1; + keys[2] = Crc32.ComputeCrc32(keys[2], (byte)(keys[1] >> 24)); + } +#endif + + #endregion + + #region Deflation Support + /// + /// Deflates everything in the input buffers. This will call + /// def.deflate() until all bytes from the input buffers + /// are processed. + /// + protected void Deflate() + { + while (!deflater_.IsNeedingInput) + { + int deflateCount = deflater_.Deflate(buffer_, 0, buffer_.Length); + + if (deflateCount <= 0) + { + break; + } +#if NETCF_1_0 || NOCRYPTO + if (keys != null) +#else + if (cryptoTransform_ != null) +#endif + { + EncryptBlock(buffer_, 0, deflateCount); + } + + baseOutputStream_.Write(buffer_, 0, deflateCount); + } + + if (!deflater_.IsNeedingInput) + { + throw new ImageFormatException("DeflaterOutputStream can't deflate all input?"); + } + } + #endregion + + #region Stream Overrides + /// + /// Gets value indicating stream can be read from + /// + public override bool CanRead + { + get + { + return false; + } + } + + /// + /// Gets a value indicating if seeking is supported for this stream + /// This property always returns false + /// + public override bool CanSeek + { + get + { + return false; + } + } + + /// + /// Get value indicating if this stream supports writing + /// + public override bool CanWrite + { + get + { + return baseOutputStream_.CanWrite; + } + } + + /// + /// Get current length of stream + /// + public override long Length + { + get + { + return baseOutputStream_.Length; + } + } + + /// + /// Gets the current position within the stream. + /// + /// Any attempt to set position + public override long Position + { + get + { + return baseOutputStream_.Position; + } + set + { + throw new NotSupportedException("Position property not supported"); + } + } + + /// + /// Sets the current position of this stream to the given value. Not supported by this class! + /// + /// The offset relative to the to seek. + /// The to seek from. + /// The new position in the stream. + /// Any access + public override long Seek(long offset, SeekOrigin origin) + { + throw new NotSupportedException("DeflaterOutputStream Seek not supported"); + } + + /// + /// Sets the length of this stream to the given value. Not supported by this class! + /// + /// The new stream length. + /// Any access + public override void SetLength(long value) + { + throw new NotSupportedException("DeflaterOutputStream SetLength not supported"); + } + + /// + /// Read a byte from stream advancing position by one + /// + /// The byte read cast to an int. THe value is -1 if at the end of the stream. + /// Any access + public override int ReadByte() + { + throw new NotSupportedException("DeflaterOutputStream ReadByte not supported"); + } + + /// + /// Read a block of bytes from stream + /// + /// The buffer to store read data in. + /// The offset to start storing at. + /// The maximum number of bytes to read. + /// The actual number of bytes read. Zero if end of stream is detected. + /// Any access + public override int Read(byte[] buffer, int offset, int count) + { + throw new NotSupportedException("DeflaterOutputStream Read not supported"); + } +#if !PCL + /// + /// Asynchronous reads are not supported a NotSupportedException is always thrown + /// + /// The buffer to read into. + /// The offset to start storing data at. + /// The number of bytes to read + /// The async callback to use. + /// The state to use. + /// Returns an + /// Any access + public override IAsyncResult BeginRead(byte[] buffer, int offset, int count, AsyncCallback callback, object state) + { + throw new NotSupportedException("DeflaterOutputStream BeginRead not currently supported"); + } + + /// + /// Asynchronous writes arent supported, a NotSupportedException is always thrown + /// + /// The buffer to write. + /// The offset to begin writing at. + /// The number of bytes to write. + /// The to use. + /// The state object. + /// Returns an IAsyncResult. + /// Any access + public override IAsyncResult BeginWrite(byte[] buffer, int offset, int count, AsyncCallback callback, object state) + { + throw new NotSupportedException("BeginWrite is not supported"); + } +#endif + /// + /// Flushes the stream by calling Flush on the deflater and then + /// on the underlying stream. This ensures that all bytes are flushed. + /// + public override void Flush() + { + deflater_.Flush(); + Deflate(); + baseOutputStream_.Flush(); + } + + /// + /// Calls and closes the underlying + /// stream when is true. + /// +#if !PCL + public override void Close() + { + if (!isClosed_) + { + isClosed_ = true; + + try { + Finish(); +#if NETCF_1_0 || NOCRYPTO + keys =null; +#else + if ( cryptoTransform_ != null ) { + GetAuthCodeIfAES(); + cryptoTransform_.Dispose(); + cryptoTransform_ = null; + } +#endif + } + finally { + if( isStreamOwner_ ) { + baseOutputStream_.Close(); + } + } + } + } +#else + protected override void Dispose(bool disposing) + { + base.Dispose(disposing); + if (disposing && !isClosed_) + { + isClosed_ = true; + + try + { + Finish(); + keys = null; + } + finally + { + if (isStreamOwner_) + { + baseOutputStream_.Dispose(); + } + } + } + } +#endif + + private void GetAuthCodeIfAES() + { +#if !NET_1_1 && !NETCF_2_0 && !NOCRYPTO + if (cryptoTransform_ is ZipAESTransform) { + AESAuthCode = ((ZipAESTransform)cryptoTransform_).GetAuthCode(); + } +#endif + } + + /// + /// Writes a single byte to the compressed output stream. + /// + /// + /// The byte value. + /// + public override void WriteByte(byte value) + { + byte[] b = new byte[1]; + b[0] = value; + Write(b, 0, 1); + } + + /// + /// Writes bytes from an array to the compressed stream. + /// + /// + /// The byte array + /// + /// + /// The offset into the byte array where to start. + /// + /// + /// The number of bytes to write. + /// + public override void Write(byte[] buffer, int offset, int count) + { + deflater_.SetInput(buffer, offset, count); + Deflate(); + } + #endregion + + #region Instance Fields + /// + /// This buffer is used temporarily to retrieve the bytes from the + /// deflater and write them to the underlying output stream. + /// + byte[] buffer_; + + /// + /// The deflater which is used to deflate the stream. + /// + protected Deflater deflater_; + + /// + /// Base stream the deflater depends on. + /// + protected Stream baseOutputStream_; + + bool isClosed_; + + bool isStreamOwner_ = true; + #endregion + + #region Static Fields + +#if !NET_1_1 && !NETCF_2_0 && !NOCRYPTO + // Static to help ensure that multiple files within a zip will get different random salt + private static RNGCryptoServiceProvider _aesRnd; +#endif + #endregion + } +} diff --git a/src/ImageProcessor/Formats/Png/Zlib/DeflaterPending.cs b/src/ImageProcessor/Formats/Png/Zlib/DeflaterPending.cs new file mode 100644 index 000000000..70df58382 --- /dev/null +++ b/src/ImageProcessor/Formats/Png/Zlib/DeflaterPending.cs @@ -0,0 +1,19 @@ +namespace ImageProcessor.Formats +{ + /// + /// This class stores the pending output of the Deflater. + /// + /// author of the original java version : Jochen Hoenicke + /// + public class DeflaterPending : PendingBuffer + { + /// + /// Initializes a new instance of the class. + /// Construct instance with default buffer size + /// + public DeflaterPending() + : base(DeflaterConstants.PENDING_BUF_SIZE) + { + } + } +} diff --git a/src/ImageProcessor/Formats/Png/Zlib/GeneralBitFlags.cs b/src/ImageProcessor/Formats/Png/Zlib/GeneralBitFlags.cs new file mode 100644 index 000000000..1325b8662 --- /dev/null +++ b/src/ImageProcessor/Formats/Png/Zlib/GeneralBitFlags.cs @@ -0,0 +1,92 @@ +namespace ImageProcessor.Formats +{ + using System; + + /// + /// Defines the contents of the general bit flags field for an archive entry. + /// + [Flags] + public enum GeneralBitFlags + { + /// + /// Bit 0 if set indicates that the file is encrypted + /// + Encrypted = 0x0001, + + /// + /// Bits 1 and 2 - Two bits defining the compression method (only for Method 6 Imploding and 8,9 Deflating) + /// + Method = 0x0006, + + /// + /// Bit 3 if set indicates a trailing data desciptor is appended to the entry data + /// + Descriptor = 0x0008, + + /// + /// Bit 4 is reserved for use with method 8 for enhanced deflation + /// + ReservedPKware4 = 0x0010, + + /// + /// Bit 5 if set indicates the file contains Pkzip compressed patched data. + /// Requires version 2.7 or greater. + /// + Patched = 0x0020, + + /// + /// Bit 6 if set indicates strong encryption has been used for this entry. + /// + StrongEncryption = 0x0040, + + /// + /// Bit 7 is currently unused + /// + Unused7 = 0x0080, + + /// + /// Bit 8 is currently unused + /// + Unused8 = 0x0100, + + /// + /// Bit 9 is currently unused + /// + Unused9 = 0x0200, + + /// + /// Bit 10 is currently unused + /// + Unused10 = 0x0400, + + /// + /// Bit 11 if set indicates the filename and + /// comment fields for this file must be encoded using UTF-8. + /// + UnicodeText = 0x0800, + + /// + /// Bit 12 is documented as being reserved by PKware for enhanced compression. + /// + EnhancedCompress = 0x1000, + + /// + /// Bit 13 if set indicates that values in the local header are masked to hide + /// their actual values, and the central directory is encrypted. + /// + /// + /// Used when encrypting the central directory contents. + /// + HeaderMasked = 0x2000, + + /// + /// Bit 14 is documented as being reserved for use by PKware + /// + ReservedPkware14 = 0x4000, + + /// + /// Bit 15 is documented as being reserved for use by PKware + /// + ReservedPkware15 = 0x8000 + } +} diff --git a/src/ImageProcessor/Formats/Png/Zlib/IChecksum.cs b/src/ImageProcessor/Formats/Png/Zlib/IChecksum.cs new file mode 100644 index 000000000..5da32dd32 --- /dev/null +++ b/src/ImageProcessor/Formats/Png/Zlib/IChecksum.cs @@ -0,0 +1,60 @@ +// +// Copyright © James South and contributors. +// Licensed under the Apache License, Version 2.0. +// + +namespace ImageProcessor.Formats +{ + /// + /// Interface to compute a data checksum used by checked input/output streams. + /// A data checksum can be updated by one byte or with a byte array. After each + /// update the value of the current checksum can be returned by calling + /// getValue. The complete checksum object can also be reset + /// so it can be used again with new data. + /// + public interface IChecksum + { + /// + /// Returns the data checksum computed so far. + /// + long Value + { + get; + } + + /// + /// Resets the data checksum as if no update was ever called. + /// + void Reset(); + + /// + /// Adds one byte to the data checksum. + /// + /// + /// the data value to add. The high byte of the int is ignored. + /// + void Update(int value); + + /// + /// Updates the data checksum with the bytes taken from the array. + /// + /// + /// buffer an array of bytes + /// + void Update(byte[] buffer); + + /// + /// Adds the byte array to the data checksum. + /// + /// + /// The buffer which contains the data + /// + /// + /// The offset in the buffer where the data starts + /// + /// + /// the number of data bytes to add. + /// + void Update(byte[] buffer, int offset, int count); + } +} diff --git a/src/ImageProcessor/Formats/Png/Zlib/Inflater.cs b/src/ImageProcessor/Formats/Png/Zlib/Inflater.cs new file mode 100644 index 000000000..c23a15311 --- /dev/null +++ b/src/ImageProcessor/Formats/Png/Zlib/Inflater.cs @@ -0,0 +1,872 @@ +namespace ImageProcessor.Formats { + using System; + + /// + /// Inflater is used to decompress data that has been compressed according + /// to the "deflate" standard described in rfc1951. + /// + /// By default Zlib (rfc1950) headers and footers are expected in the input. + /// You can use constructor public Inflater(bool noHeader) passing true + /// if there is no Zlib header information + /// + /// The usage is as following. First you have to set some input with + /// SetInput(), then Inflate() it. If inflate doesn't + /// inflate any bytes there may be three reasons: + ///
    + ///
  • IsNeedingInput() returns true because the input buffer is empty. + /// You have to provide more input with SetInput(). + /// NOTE: IsNeedingInput() also returns true when, the stream is finished. + ///
    • + ///
  • IsNeedingDictionary() returns true, you have to provide a preset + /// dictionary with SetDictionary().
    • + ///
  • IsFinished returns true, the inflater has finished.
    • + ///
+ /// Once the first output byte is produced, a dictionary will not be + /// needed at a later stage. + /// + /// author of the original java version : John Leuner, Jochen Hoenicke + /// + public class Inflater + { + #region Constants/Readonly + /// + /// Copy lengths for literal codes 257..285 + /// + static readonly int[] CPLENS = { + 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, + 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258 + }; + + /// + /// Extra bits for literal codes 257..285 + /// + static readonly int[] CPLEXT = { + 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, + 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0 + }; + + /// + /// Copy offsets for distance codes 0..29 + /// + static readonly int[] CPDIST = { + 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, + 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, + 8193, 12289, 16385, 24577 + }; + + /// + /// Extra bits for distance codes + /// + static readonly int[] CPDEXT = { + 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, + 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, + 12, 12, 13, 13 + }; + + /// + /// These are the possible states for an inflater + /// + const int DECODE_HEADER = 0; + const int DECODE_DICT = 1; + const int DECODE_BLOCKS = 2; + const int DECODE_STORED_LEN1 = 3; + const int DECODE_STORED_LEN2 = 4; + const int DECODE_STORED = 5; + const int DECODE_DYN_HEADER = 6; + const int DECODE_HUFFMAN = 7; + const int DECODE_HUFFMAN_LENBITS = 8; + const int DECODE_HUFFMAN_DIST = 9; + const int DECODE_HUFFMAN_DISTBITS = 10; + const int DECODE_CHKSUM = 11; + const int FINISHED = 12; + #endregion + + #region Instance Fields + /// + /// This variable contains the current state. + /// + int mode; + + /// + /// The adler checksum of the dictionary or of the decompressed + /// stream, as it is written in the header resp. footer of the + /// compressed stream. + /// Only valid if mode is DECODE_DICT or DECODE_CHKSUM. + /// + int readAdler; + + /// + /// The number of bits needed to complete the current state. This + /// is valid, if mode is DECODE_DICT, DECODE_CHKSUM, + /// DECODE_HUFFMAN_LENBITS or DECODE_HUFFMAN_DISTBITS. + /// + int neededBits; + int repLength; + int repDist; + int uncomprLen; + + /// + /// True, if the last block flag was set in the last block of the + /// inflated stream. This means that the stream ends after the + /// current block. + /// + bool isLastBlock; + + /// + /// The total number of inflated bytes. + /// + long totalOut; + + /// + /// The total number of bytes set with setInput(). This is not the + /// value returned by the TotalIn property, since this also includes the + /// unprocessed input. + /// + long totalIn; + + /// + /// This variable stores the noHeader flag that was given to the constructor. + /// True means, that the inflated stream doesn't contain a Zlib header or + /// footer. + /// + bool noHeader; + + StreamManipulator input; + OutputWindow outputWindow; + InflaterDynHeader dynHeader; + InflaterHuffmanTree litlenTree, distTree; + Adler32 adler; + #endregion + + #region Constructors + /// + /// Creates a new inflater or RFC1951 decompressor + /// RFC1950/Zlib headers and footers will be expected in the input data + /// + public Inflater() : this(false) + { + } + + /// + /// Creates a new inflater. + /// + /// + /// True if no RFC1950/Zlib header and footer fields are expected in the input data + /// + /// This is used for GZIPed/Zipped input. + /// + /// For compatibility with + /// Sun JDK you should provide one byte of input more than needed in + /// this case. + /// + public Inflater(bool noHeader) + { + this.noHeader = noHeader; + this.adler = new Adler32(); + input = new StreamManipulator(); + outputWindow = new OutputWindow(); + mode = noHeader ? DECODE_BLOCKS : DECODE_HEADER; + } + #endregion + + /// + /// Resets the inflater so that a new stream can be decompressed. All + /// pending input and output will be discarded. + /// + public void Reset() + { + mode = noHeader ? DECODE_BLOCKS : DECODE_HEADER; + totalIn = 0; + totalOut = 0; + input.Reset(); + outputWindow.Reset(); + dynHeader = null; + litlenTree = null; + distTree = null; + isLastBlock = false; + adler.Reset(); + } + + /// + /// Decodes a zlib/RFC1950 header. + /// + /// + /// False if more input is needed. + /// + /// + /// The header is invalid. + /// + private bool DecodeHeader() + { + int header = input.PeekBits(16); + if (header < 0) + { + return false; + } + input.DropBits(16); + + // The header is written in "wrong" byte order + header = ((header << 8) | (header >> 8)) & 0xffff; + if (header % 31 != 0) + { + throw new ImageFormatException("Header checksum illegal"); + } + + if ((header & 0x0f00) != (Deflater.DEFLATED << 8)) + { + throw new ImageFormatException("Compression Method unknown"); + } + + /* Maximum size of the backwards window in bits. + * We currently ignore this, but we could use it to make the + * inflater window more space efficient. On the other hand the + * full window (15 bits) is needed most times, anyway. + int max_wbits = ((header & 0x7000) >> 12) + 8; + */ + + if ((header & 0x0020) == 0) + { // Dictionary flag? + mode = DECODE_BLOCKS; + } + else + { + mode = DECODE_DICT; + neededBits = 32; + } + return true; + } + + /// + /// Decodes the dictionary checksum after the deflate header. + /// + /// + /// False if more input is needed. + /// + private bool DecodeDict() + { + while (neededBits > 0) + { + int dictByte = input.PeekBits(8); + if (dictByte < 0) + { + return false; + } + input.DropBits(8); + readAdler = (readAdler << 8) | dictByte; + neededBits -= 8; + } + return false; + } + + /// + /// Decodes the huffman encoded symbols in the input stream. + /// + /// + /// false if more input is needed, true if output window is + /// full or the current block ends. + /// + /// + /// if deflated stream is invalid. + /// + private bool DecodeHuffman() + { + int free = outputWindow.GetFreeSpace(); + while (free >= 258) + { + int symbol; + switch (mode) + { + case DECODE_HUFFMAN: + // This is the inner loop so it is optimized a bit + while (((symbol = litlenTree.GetSymbol(input)) & ~0xff) == 0) + { + outputWindow.Write(symbol); + if (--free < 258) + { + return true; + } + } + + if (symbol < 257) + { + if (symbol < 0) + { + return false; + } + else + { + // symbol == 256: end of block + distTree = null; + litlenTree = null; + mode = DECODE_BLOCKS; + return true; + } + } + + try + { + repLength = CPLENS[symbol - 257]; + neededBits = CPLEXT[symbol - 257]; + } + catch (Exception) + { + throw new ImageFormatException("Illegal rep length code"); + } + goto case DECODE_HUFFMAN_LENBITS; // fall through + + case DECODE_HUFFMAN_LENBITS: + if (neededBits > 0) + { + mode = DECODE_HUFFMAN_LENBITS; + int i = input.PeekBits(neededBits); + if (i < 0) + { + return false; + } + input.DropBits(neededBits); + repLength += i; + } + mode = DECODE_HUFFMAN_DIST; + goto case DECODE_HUFFMAN_DIST; // fall through + + case DECODE_HUFFMAN_DIST: + symbol = distTree.GetSymbol(input); + if (symbol < 0) + { + return false; + } + + try + { + repDist = CPDIST[symbol]; + neededBits = CPDEXT[symbol]; + } + catch (Exception) + { + throw new ImageFormatException("Illegal rep dist code"); + } + + goto case DECODE_HUFFMAN_DISTBITS; // fall through + + case DECODE_HUFFMAN_DISTBITS: + if (neededBits > 0) + { + mode = DECODE_HUFFMAN_DISTBITS; + int i = input.PeekBits(neededBits); + if (i < 0) + { + return false; + } + input.DropBits(neededBits); + repDist += i; + } + + outputWindow.Repeat(repLength, repDist); + free -= repLength; + mode = DECODE_HUFFMAN; + break; + + default: + throw new ImageFormatException("Inflater unknown mode"); + } + } + return true; + } + + /// + /// Decodes the adler checksum after the deflate stream. + /// + /// + /// false if more input is needed. + /// + /// + /// If checksum doesn't match. + /// + private bool DecodeChksum() + { + while (neededBits > 0) + { + int chkByte = input.PeekBits(8); + if (chkByte < 0) + { + return false; + } + input.DropBits(8); + readAdler = (readAdler << 8) | chkByte; + neededBits -= 8; + } + + if ((int)adler.Value != readAdler) + { + throw new ImageFormatException("Adler chksum doesn't match: " + (int)adler.Value + " vs. " + readAdler); + } + + mode = FINISHED; + return false; + } + + /// + /// Decodes the deflated stream. + /// + /// + /// false if more input is needed, or if finished. + /// + /// + /// if deflated stream is invalid. + /// + private bool Decode() + { + switch (mode) + { + case DECODE_HEADER: + return DecodeHeader(); + + case DECODE_DICT: + return DecodeDict(); + + case DECODE_CHKSUM: + return DecodeChksum(); + + case DECODE_BLOCKS: + if (isLastBlock) + { + if (noHeader) + { + mode = FINISHED; + return false; + } + else + { + input.SkipToByteBoundary(); + neededBits = 32; + mode = DECODE_CHKSUM; + return true; + } + } + + int type = input.PeekBits(3); + if (type < 0) + { + return false; + } + input.DropBits(3); + + if ((type & 1) != 0) + { + isLastBlock = true; + } + switch (type >> 1) + { + case DeflaterConstants.STORED_BLOCK: + input.SkipToByteBoundary(); + mode = DECODE_STORED_LEN1; + break; + case DeflaterConstants.STATIC_TREES: + litlenTree = InflaterHuffmanTree.defLitLenTree; + distTree = InflaterHuffmanTree.defDistTree; + mode = DECODE_HUFFMAN; + break; + case DeflaterConstants.DYN_TREES: + dynHeader = new InflaterDynHeader(); + mode = DECODE_DYN_HEADER; + break; + default: + throw new ImageFormatException("Unknown block type " + type); + } + return true; + + case DECODE_STORED_LEN1: + { + if ((uncomprLen = input.PeekBits(16)) < 0) + { + return false; + } + input.DropBits(16); + mode = DECODE_STORED_LEN2; + } + goto case DECODE_STORED_LEN2; // fall through + + case DECODE_STORED_LEN2: + { + int nlen = input.PeekBits(16); + if (nlen < 0) + { + return false; + } + input.DropBits(16); + if (nlen != (uncomprLen ^ 0xffff)) + { + throw new ImageFormatException("broken uncompressed block"); + } + mode = DECODE_STORED; + } + goto case DECODE_STORED; // fall through + + case DECODE_STORED: + { + int more = outputWindow.CopyStored(input, uncomprLen); + uncomprLen -= more; + if (uncomprLen == 0) + { + mode = DECODE_BLOCKS; + return true; + } + return !input.IsNeedingInput; + } + + case DECODE_DYN_HEADER: + if (!dynHeader.Decode(input)) + { + return false; + } + + litlenTree = dynHeader.BuildLitLenTree(); + distTree = dynHeader.BuildDistTree(); + mode = DECODE_HUFFMAN; + goto case DECODE_HUFFMAN; // fall through + + case DECODE_HUFFMAN: + case DECODE_HUFFMAN_LENBITS: + case DECODE_HUFFMAN_DIST: + case DECODE_HUFFMAN_DISTBITS: + return DecodeHuffman(); + + case FINISHED: + return false; + + default: + throw new ImageFormatException("Inflater.Decode unknown mode"); + } + } + + /// + /// Sets the preset dictionary. This should only be called, if + /// needsDictionary() returns true and it should set the same + /// dictionary, that was used for deflating. The getAdler() + /// function returns the checksum of the dictionary needed. + /// + /// + /// The dictionary. + /// + public void SetDictionary(byte[] buffer) + { + SetDictionary(buffer, 0, buffer.Length); + } + + /// + /// Sets the preset dictionary. This should only be called, if + /// needsDictionary() returns true and it should set the same + /// dictionary, that was used for deflating. The getAdler() + /// function returns the checksum of the dictionary needed. + /// + /// + /// The dictionary. + /// + /// + /// The index into buffer where the dictionary starts. + /// + /// + /// The number of bytes in the dictionary. + /// + /// + /// No dictionary is needed. + /// + /// + /// The adler checksum for the buffer is invalid + /// + public void SetDictionary(byte[] buffer, int index, int count) + { + if (buffer == null) + { + throw new ArgumentNullException(nameof(buffer)); + } + + if (index < 0) + { + throw new ArgumentOutOfRangeException(nameof(index)); + } + + if (count < 0) + { + throw new ArgumentOutOfRangeException(nameof(count)); + } + + if (!IsNeedingDictionary) + { + throw new InvalidOperationException("Dictionary is not needed"); + } + + adler.Update(buffer, index, count); + + if ((int)adler.Value != readAdler) + { + throw new ImageFormatException("Wrong adler checksum"); + } + adler.Reset(); + outputWindow.CopyDict(buffer, index, count); + mode = DECODE_BLOCKS; + } + + /// + /// Sets the input. This should only be called, if needsInput() + /// returns true. + /// + /// + /// the input. + /// + public void SetInput(byte[] buffer) + { + SetInput(buffer, 0, buffer.Length); + } + + /// + /// Sets the input. This should only be called, if needsInput() + /// returns true. + /// + /// + /// The source of input data + /// + /// + /// The index into buffer where the input starts. + /// + /// + /// The number of bytes of input to use. + /// + /// + /// No input is needed. + /// + /// + /// The index and/or count are wrong. + /// + public void SetInput(byte[] buffer, int index, int count) + { + input.SetInput(buffer, index, count); + totalIn += (long)count; + } + + /// + /// Inflates the compressed stream to the output buffer. If this + /// returns 0, you should check, whether IsNeedingDictionary(), + /// IsNeedingInput() or IsFinished() returns true, to determine why no + /// further output is produced. + /// + /// + /// the output buffer. + /// + /// + /// The number of bytes written to the buffer, 0 if no further + /// output can be produced. + /// + /// + /// if buffer has length 0. + /// + /// + /// if deflated stream is invalid. + /// + public int Inflate(byte[] buffer) + { + if (buffer == null) + { + throw new ArgumentNullException(nameof(buffer)); + } + + return Inflate(buffer, 0, buffer.Length); + } + + /// + /// Inflates the compressed stream to the output buffer. If this + /// returns 0, you should check, whether needsDictionary(), + /// needsInput() or finished() returns true, to determine why no + /// further output is produced. + /// + /// + /// the output buffer. + /// + /// + /// the offset in buffer where storing starts. + /// + /// + /// the maximum number of bytes to output. + /// + /// + /// the number of bytes written to the buffer, 0 if no further output can be produced. + /// + /// + /// if count is less than 0. + /// + /// + /// if the index and / or count are wrong. + /// + /// + /// if deflated stream is invalid. + /// + public int Inflate(byte[] buffer, int offset, int count) + { + if (buffer == null) + { + throw new ArgumentNullException(nameof(buffer)); + } + + if (count < 0) + { +#if NETCF_1_0 + throw new ArgumentOutOfRangeException("count"); +#else + throw new ArgumentOutOfRangeException(nameof(count), "count cannot be negative"); +#endif + } + + if (offset < 0) + { +#if NETCF_1_0 + throw new ArgumentOutOfRangeException("offset"); +#else + throw new ArgumentOutOfRangeException(nameof(offset), "offset cannot be negative"); +#endif + } + + if (offset + count > buffer.Length) + { + throw new ArgumentException("count exceeds buffer bounds"); + } + + // Special case: count may be zero + if (count == 0) + { + if (!IsFinished) + { // -jr- 08-Nov-2003 INFLATE_BUG fix.. + Decode(); + } + return 0; + } + + int bytesCopied = 0; + + do + { + if (mode != DECODE_CHKSUM) + { + /* Don't give away any output, if we are waiting for the + * checksum in the input stream. + * + * With this trick we have always: + * IsNeedingInput() and not IsFinished() + * implies more output can be produced. + */ + int more = outputWindow.CopyOutput(buffer, offset, count); + if (more > 0) + { + adler.Update(buffer, offset, more); + offset += more; + bytesCopied += more; + totalOut += (long)more; + count -= more; + if (count == 0) + { + return bytesCopied; + } + } + } + } while (Decode() || ((outputWindow.GetAvailable() > 0) && (mode != DECODE_CHKSUM))); + return bytesCopied; + } + + /// + /// Returns true, if the input buffer is empty. + /// You should then call setInput(). + /// NOTE: This method also returns true when the stream is finished. + /// + public bool IsNeedingInput + { + get + { + return input.IsNeedingInput; + } + } + + /// + /// Returns true, if a preset dictionary is needed to inflate the input. + /// + public bool IsNeedingDictionary + { + get + { + return mode == DECODE_DICT && neededBits == 0; + } + } + + /// + /// Returns true, if the inflater has finished. This means, that no + /// input is needed and no output can be produced. + /// + public bool IsFinished + { + get + { + return mode == FINISHED && outputWindow.GetAvailable() == 0; + } + } + + /// + /// Gets the adler checksum. This is either the checksum of all + /// uncompressed bytes returned by inflate(), or if needsDictionary() + /// returns true (and thus no output was yet produced) this is the + /// adler checksum of the expected dictionary. + /// + /// + /// the adler checksum. + /// + public int Adler + { + get + { + return IsNeedingDictionary ? readAdler : (int)adler.Value; + } + } + + /// + /// Gets the total number of output bytes returned by Inflate(). + /// + /// + /// the total number of output bytes. + /// + public long TotalOut + { + get + { + return totalOut; + } + } + + /// + /// Gets the total number of processed compressed input bytes. + /// + /// + /// The total number of bytes of processed input bytes. + /// + public long TotalIn + { + get + { + return totalIn - (long)RemainingInput; + } + } + + /// + /// Gets the number of unprocessed input bytes. Useful, if the end of the + /// stream is reached and you want to further process the bytes after + /// the deflate stream. + /// + /// + /// The number of bytes of the input which have not been processed. + /// + public int RemainingInput + { + // TODO: This should be a long? + get + { + return input.AvailableBytes; + } + } + } +} diff --git a/src/ImageProcessor/Formats/Png/Zlib/InflaterDynHeader.cs b/src/ImageProcessor/Formats/Png/Zlib/InflaterDynHeader.cs new file mode 100644 index 000000000..d1811dd3b --- /dev/null +++ b/src/ImageProcessor/Formats/Png/Zlib/InflaterDynHeader.cs @@ -0,0 +1,196 @@ +namespace ImageProcessor.Formats +{ + using System; + + class InflaterDynHeader + { + #region Constants + const int LNUM = 0; + const int DNUM = 1; + const int BLNUM = 2; + const int BLLENS = 3; + const int LENS = 4; + const int REPS = 5; + + static readonly int[] repMin = { 3, 3, 11 }; + static readonly int[] repBits = { 2, 3, 7 }; + + static readonly int[] BL_ORDER = + { 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 }; + + #endregion + + #region Constructors + public InflaterDynHeader() + { + } + #endregion + + public bool Decode(StreamManipulator input) + { + decode_loop: + for (;;) + { + switch (mode) + { + case LNUM: + lnum = input.PeekBits(5); + if (lnum < 0) + { + return false; + } + lnum += 257; + input.DropBits(5); + // System.err.println("LNUM: "+lnum); + mode = DNUM; + goto case DNUM; // fall through + case DNUM: + dnum = input.PeekBits(5); + if (dnum < 0) + { + return false; + } + dnum++; + input.DropBits(5); + // System.err.println("DNUM: "+dnum); + num = lnum + dnum; + litdistLens = new byte[num]; + mode = BLNUM; + goto case BLNUM; // fall through + case BLNUM: + blnum = input.PeekBits(4); + if (blnum < 0) + { + return false; + } + blnum += 4; + input.DropBits(4); + blLens = new byte[19]; + ptr = 0; + // System.err.println("BLNUM: "+blnum); + mode = BLLENS; + goto case BLLENS; // fall through + case BLLENS: + while (ptr < blnum) + { + int len = input.PeekBits(3); + if (len < 0) + { + return false; + } + input.DropBits(3); + // System.err.println("blLens["+BL_ORDER[ptr]+"]: "+len); + blLens[BL_ORDER[ptr]] = (byte)len; + ptr++; + } + blTree = new InflaterHuffmanTree(blLens); + blLens = null; + ptr = 0; + mode = LENS; + goto case LENS; // fall through + case LENS: + { + int symbol; + while (((symbol = blTree.GetSymbol(input)) & ~15) == 0) + { + /* Normal case: symbol in [0..15] */ + + // System.err.println("litdistLens["+ptr+"]: "+symbol); + litdistLens[ptr++] = lastLen = (byte)symbol; + + if (ptr == num) + { + /* Finished */ + return true; + } + } + + /* need more input ? */ + if (symbol < 0) + { + return false; + } + + /* otherwise repeat code */ + if (symbol >= 17) + { + /* repeat zero */ + // System.err.println("repeating zero"); + lastLen = 0; + } + else + { + if (ptr == 0) + { + throw new ImageFormatException(); + } + } + repSymbol = symbol - 16; + } + mode = REPS; + goto case REPS; // fall through + case REPS: + { + int bits = repBits[repSymbol]; + int count = input.PeekBits(bits); + if (count < 0) + { + return false; + } + input.DropBits(bits); + count += repMin[repSymbol]; + // System.err.println("litdistLens repeated: "+count); + + if (ptr + count > num) + { + throw new ImageFormatException(); + } + while (count-- > 0) + { + litdistLens[ptr++] = lastLen; + } + + if (ptr == num) + { + /* Finished */ + return true; + } + } + mode = LENS; + goto decode_loop; + } + } + } + + public InflaterHuffmanTree BuildLitLenTree() + { + byte[] litlenLens = new byte[lnum]; + Array.Copy(litdistLens, 0, litlenLens, 0, lnum); + return new InflaterHuffmanTree(litlenLens); + } + + public InflaterHuffmanTree BuildDistTree() + { + byte[] distLens = new byte[dnum]; + Array.Copy(litdistLens, lnum, distLens, 0, dnum); + return new InflaterHuffmanTree(distLens); + } + + #region Instance Fields + byte[] blLens; + byte[] litdistLens; + + InflaterHuffmanTree blTree; + + /// + /// The current decode mode + /// + int mode; + int lnum, dnum, blnum, num; + int repSymbol; + byte lastLen; + int ptr; + #endregion + + } +} diff --git a/src/ImageProcessor/Formats/Png/Zlib/InflaterHuffmanTree.cs b/src/ImageProcessor/Formats/Png/Zlib/InflaterHuffmanTree.cs new file mode 100644 index 000000000..f6b7332f5 --- /dev/null +++ b/src/ImageProcessor/Formats/Png/Zlib/InflaterHuffmanTree.cs @@ -0,0 +1,225 @@ +namespace ImageProcessor.Formats +{ + using System; + + /// + /// Huffman tree used for inflation + /// + public class InflaterHuffmanTree + { + #region Constants + const int MAX_BITLEN = 15; + #endregion + + #region Instance Fields + short[] tree; + #endregion + + /// + /// Literal length tree + /// + public static InflaterHuffmanTree defLitLenTree; + + /// + /// Distance tree + /// + public static InflaterHuffmanTree defDistTree; + + static InflaterHuffmanTree() + { + try + { + byte[] codeLengths = new byte[288]; + int i = 0; + while (i < 144) + { + codeLengths[i++] = 8; + } + while (i < 256) + { + codeLengths[i++] = 9; + } + while (i < 280) + { + codeLengths[i++] = 7; + } + while (i < 288) + { + codeLengths[i++] = 8; + } + defLitLenTree = new InflaterHuffmanTree(codeLengths); + + codeLengths = new byte[32]; + i = 0; + while (i < 32) + { + codeLengths[i++] = 5; + } + defDistTree = new InflaterHuffmanTree(codeLengths); + } + catch (Exception) + { + throw new ImageFormatException("InflaterHuffmanTree: static tree length illegal"); + } + } + + #region Constructors + /// + /// Constructs a Huffman tree from the array of code lengths. + /// + /// + /// the array of code lengths + /// + public InflaterHuffmanTree(byte[] codeLengths) + { + BuildTree(codeLengths); + } + #endregion + + void BuildTree(byte[] codeLengths) + { + int[] blCount = new int[MAX_BITLEN + 1]; + int[] nextCode = new int[MAX_BITLEN + 1]; + + for (int i = 0; i < codeLengths.Length; i++) + { + int bits = codeLengths[i]; + if (bits > 0) + { + blCount[bits]++; + } + } + + int code = 0; + int treeSize = 512; + for (int bits = 1; bits <= MAX_BITLEN; bits++) + { + nextCode[bits] = code; + code += blCount[bits] << (16 - bits); + if (bits >= 10) + { + /* We need an extra table for bit lengths >= 10. */ + int start = nextCode[bits] & 0x1ff80; + int end = code & 0x1ff80; + treeSize += (end - start) >> (16 - bits); + } + } + + /* -jr comment this out! doesnt work for dynamic trees and pkzip 2.04g + if (code != 65536) + { + throw new SharpZipBaseException("Code lengths don't add up properly."); + } + */ + /* Now create and fill the extra tables from longest to shortest + * bit len. This way the sub trees will be aligned. + */ + tree = new short[treeSize]; + int treePtr = 512; + for (int bits = MAX_BITLEN; bits >= 10; bits--) + { + int end = code & 0x1ff80; + code -= blCount[bits] << (16 - bits); + int start = code & 0x1ff80; + for (int i = start; i < end; i += 1 << 7) + { + tree[DeflaterHuffman.BitReverse(i)] = (short)((-treePtr << 4) | bits); + treePtr += 1 << (bits - 9); + } + } + + for (int i = 0; i < codeLengths.Length; i++) + { + int bits = codeLengths[i]; + if (bits == 0) + { + continue; + } + code = nextCode[bits]; + int revcode = DeflaterHuffman.BitReverse(code); + if (bits <= 9) + { + do + { + tree[revcode] = (short)((i << 4) | bits); + revcode += 1 << bits; + } while (revcode < 512); + } + else + { + int subTree = tree[revcode & 511]; + int treeLen = 1 << (subTree & 15); + subTree = -(subTree >> 4); + do + { + tree[subTree | (revcode >> 9)] = (short)((i << 4) | bits); + revcode += 1 << bits; + } while (revcode < treeLen); + } + nextCode[bits] = code + (1 << (16 - bits)); + } + + } + + /// + /// Reads the next symbol from input. The symbol is encoded using the + /// huffman tree. + /// + /// + /// input the input source. + /// + /// + /// the next symbol, or -1 if not enough input is available. + /// + public int GetSymbol(StreamManipulator input) + { + int lookahead, symbol; + if ((lookahead = input.PeekBits(9)) >= 0) + { + if ((symbol = tree[lookahead]) >= 0) + { + input.DropBits(symbol & 15); + return symbol >> 4; + } + int subtree = -(symbol >> 4); + int bitlen = symbol & 15; + if ((lookahead = input.PeekBits(bitlen)) >= 0) + { + symbol = tree[subtree | (lookahead >> 9)]; + input.DropBits(symbol & 15); + return symbol >> 4; + } + else + { + int bits = input.AvailableBits; + lookahead = input.PeekBits(bits); + symbol = tree[subtree | (lookahead >> 9)]; + if ((symbol & 15) <= bits) + { + input.DropBits(symbol & 15); + return symbol >> 4; + } + else + { + return -1; + } + } + } + else + { + int bits = input.AvailableBits; + lookahead = input.PeekBits(bits); + symbol = tree[lookahead]; + if (symbol >= 0 && (symbol & 15) <= bits) + { + input.DropBits(symbol & 15); + return symbol >> 4; + } + else + { + return -1; + } + } + } + } +} diff --git a/src/ImageProcessor/Formats/Png/Zlib/InflaterInputBuffer.cs b/src/ImageProcessor/Formats/Png/Zlib/InflaterInputBuffer.cs new file mode 100644 index 000000000..42fa1753a --- /dev/null +++ b/src/ImageProcessor/Formats/Png/Zlib/InflaterInputBuffer.cs @@ -0,0 +1,326 @@ +namespace ImageProcessor.Formats +{ + using System; + using System.IO; + + //using ICSharpCode.SharpZipLib.Zip; + //using ICSharpCode.SharpZipLib.Zip.Compression; + + /// + /// An input buffer customised for use by + /// + /// + /// The buffer supports decryption of incoming data. + /// + public class InflaterInputBuffer + { + #region Constructors + /// + /// Initialise a new instance of with a default buffer size + /// + /// The stream to buffer. + public InflaterInputBuffer(Stream stream) : this(stream, 4096) + { + } + + /// + /// Initialise a new instance of + /// + /// The stream to buffer. + /// The size to use for the buffer + /// A minimum buffer size of 1KB is permitted. Lower sizes are treated as 1KB. + public InflaterInputBuffer(Stream stream, int bufferSize) + { + inputStream = stream; + if (bufferSize < 1024) + { + bufferSize = 1024; + } + rawData = new byte[bufferSize]; + clearText = rawData; + } + #endregion + + /// + /// Get the length of bytes bytes in the + /// + public int RawLength + { + get + { + return rawLength; + } + } + + /// + /// Get the contents of the raw data buffer. + /// + /// This may contain encrypted data. + public byte[] RawData + { + get + { + return rawData; + } + } + + /// + /// Get the number of useable bytes in + /// + public int ClearTextLength + { + get + { + return clearTextLength; + } + } + + /// + /// Get the contents of the clear text buffer. + /// + public byte[] ClearText + { + get + { + return clearText; + } + } + + /// + /// Get/set the number of bytes available + /// + public int Available + { + get { return available; } + set { available = value; } + } + + /// + /// Call passing the current clear text buffer contents. + /// + /// The inflater to set input for. + public void SetInflaterInput(Inflater inflater) + { + if (available > 0) + { + inflater.SetInput(clearText, clearTextLength - available, available); + available = 0; + } + } + + /// + /// Fill the buffer from the underlying input stream. + /// + public void Fill() + { + rawLength = 0; + int toRead = rawData.Length; + + while (toRead > 0) + { + int count = inputStream.Read(rawData, rawLength, toRead); + if (count <= 0) + { + break; + } + rawLength += count; + toRead -= count; + } + +#if !NETCF_1_0 && !NOCRYPTO + if (cryptoTransform != null) + { + clearTextLength = cryptoTransform.TransformBlock(rawData, 0, rawLength, clearText, 0); + } + else +#endif + { + clearTextLength = rawLength; + } + + available = clearTextLength; + } + + /// + /// Read a buffer directly from the input stream + /// + /// The buffer to fill + /// Returns the number of bytes read. + public int ReadRawBuffer(byte[] buffer) + { + return ReadRawBuffer(buffer, 0, buffer.Length); + } + + /// + /// Read a buffer directly from the input stream + /// + /// The buffer to read into + /// The offset to start reading data into. + /// The number of bytes to read. + /// Returns the number of bytes read. + public int ReadRawBuffer(byte[] outBuffer, int offset, int length) + { + if (length < 0) + { + throw new ArgumentOutOfRangeException("length"); + } + + int currentOffset = offset; + int currentLength = length; + + while (currentLength > 0) + { + if (available <= 0) + { + Fill(); + if (available <= 0) + { + return 0; + } + } + int toCopy = Math.Min(currentLength, available); + System.Array.Copy(rawData, rawLength - (int)available, outBuffer, currentOffset, toCopy); + currentOffset += toCopy; + currentLength -= toCopy; + available -= toCopy; + } + return length; + } + + /// + /// Read clear text data from the input stream. + /// + /// The buffer to add data to. + /// The offset to start adding data at. + /// The number of bytes to read. + /// Returns the number of bytes actually read. + public int ReadClearTextBuffer(byte[] outBuffer, int offset, int length) + { + if (length < 0) + { + throw new ArgumentOutOfRangeException("length"); + } + + int currentOffset = offset; + int currentLength = length; + + while (currentLength > 0) + { + if (available <= 0) + { + Fill(); + if (available <= 0) + { + return 0; + } + } + + int toCopy = Math.Min(currentLength, available); + Array.Copy(clearText, clearTextLength - (int)available, outBuffer, currentOffset, toCopy); + currentOffset += toCopy; + currentLength -= toCopy; + available -= toCopy; + } + return length; + } + + /// + /// Read a from the input stream. + /// + /// Returns the byte read. + public int ReadLeByte() + { + if (available <= 0) + { + Fill(); + if (available <= 0) + { + throw new ImageFormatException("EOF in header"); + } + } + byte result = rawData[rawLength - available]; + available -= 1; + return result; + } + + /// + /// Read an in little endian byte order. + /// + /// The short value read case to an int. + public int ReadLeShort() + { + return ReadLeByte() | (ReadLeByte() << 8); + } + + /// + /// Read an in little endian byte order. + /// + /// The int value read. + public int ReadLeInt() + { + return ReadLeShort() | (ReadLeShort() << 16); + } + + /// + /// Read a in little endian byte order. + /// + /// The long value read. + public long ReadLeLong() + { + return (uint)ReadLeInt() | ((long)ReadLeInt() << 32); + } + +#if !NETCF_1_0 && !NOCRYPTO + /// + /// Get/set the to apply to any data. + /// + /// Set this value to null to have no transform applied. + public ICryptoTransform CryptoTransform + { + set + { + cryptoTransform = value; + if (cryptoTransform != null) + { + if (rawData == clearText) + { + if (internalClearText == null) + { + internalClearText = new byte[rawData.Length]; + } + clearText = internalClearText; + } + clearTextLength = rawLength; + if (available > 0) + { + cryptoTransform.TransformBlock(rawData, rawLength - available, available, clearText, rawLength - available); + } + } + else + { + clearText = rawData; + clearTextLength = rawLength; + } + } + } +#endif + + #region Instance Fields + int rawLength; + byte[] rawData; + + int clearTextLength; + byte[] clearText; +#if !NETCF_1_0 && !NOCRYPTO + byte[] internalClearText; +#endif + + int available; + +#if !NETCF_1_0 && !NOCRYPTO + ICryptoTransform cryptoTransform; +#endif + Stream inputStream; + #endregion + } +} diff --git a/src/ImageProcessor/Formats/Png/Zlib/InflaterInputStream.cs b/src/ImageProcessor/Formats/Png/Zlib/InflaterInputStream.cs new file mode 100644 index 000000000..62cba8bb4 --- /dev/null +++ b/src/ImageProcessor/Formats/Png/Zlib/InflaterInputStream.cs @@ -0,0 +1,407 @@ +namespace ImageProcessor.Formats +{ + using System; + using System.IO; + + //using ICSharpCode.SharpZipLib; + //using ICSharpCode.SharpZipLib.Zip; + //using ICSharpCode.SharpZipLib.Zip.Compression; + + /// + /// This filter stream is used to decompress data compressed using the "deflate" + /// format. The "deflate" format is described in RFC 1951. + /// + /// This stream may form the basis for other decompression filters, such + /// as the GZipInputStream. + /// + /// Author of the original java version : John Leuner. + /// + public class InflaterInputStream : Stream + { + #region Constructors + /// + /// Create an InflaterInputStream with the default decompressor + /// and a default buffer size of 4KB. + /// + /// + /// The InputStream to read bytes from + /// + public InflaterInputStream(Stream baseInputStream) + : this(baseInputStream, new Inflater(), 4096) + { + } + + /// + /// Create an InflaterInputStream with the specified decompressor + /// and a default buffer size of 4KB. + /// + /// + /// The source of input data + /// + /// + /// The decompressor used to decompress data read from baseInputStream + /// + public InflaterInputStream(Stream baseInputStream, Inflater inf) + : this(baseInputStream, inf, 4096) + { + } + + /// + /// Create an InflaterInputStream with the specified decompressor and the specified buffer size. + /// + /// + /// The InputStream to read bytes from + /// + /// + /// The decompressor to use + /// + /// + /// Size of the buffer to use + /// + public InflaterInputStream(Stream baseInputStream, Inflater inflater, int bufferSize) + { + if (baseInputStream == null) + { + throw new ArgumentNullException("baseInputStream"); + } + + if (inflater == null) + { + throw new ArgumentNullException("inflater"); + } + + if (bufferSize <= 0) + { + throw new ArgumentOutOfRangeException("bufferSize"); + } + + this.baseInputStream = baseInputStream; + this.inf = inflater; + + inputBuffer = new InflaterInputBuffer(baseInputStream, bufferSize); + } + + #endregion + + /// + /// Get/set flag indicating ownership of underlying stream. + /// When the flag is true will close the underlying stream also. + /// + /// + /// The default value is true. + /// + public bool IsStreamOwner + { + get { return isStreamOwner; } + set { isStreamOwner = value; } + } + + /// + /// Skip specified number of bytes of uncompressed data + /// + /// + /// Number of bytes to skip + /// + /// + /// The number of bytes skipped, zero if the end of + /// stream has been reached + /// + /// + /// The number of bytes to skip is less than or equal to zero. + /// + public long Skip(long count) + { + if (count <= 0) + { + throw new ArgumentOutOfRangeException("count"); + } + + // v0.80 Skip by seeking if underlying stream supports it... + if (baseInputStream.CanSeek) + { + baseInputStream.Seek(count, SeekOrigin.Current); + return count; + } + else + { + int length = 2048; + if (count < length) + { + length = (int)count; + } + + byte[] tmp = new byte[length]; + int readCount = 1; + long toSkip = count; + + while ((toSkip > 0) && (readCount > 0)) + { + if (toSkip < length) + { + length = (int)toSkip; + } + + readCount = baseInputStream.Read(tmp, 0, length); + toSkip -= readCount; + } + + return count - toSkip; + } + } + + /// + /// Clear any cryptographic state. + /// + protected void StopDecrypting() + { +#if !NETCF_1_0 && !NOCRYPTO + inputBuffer.CryptoTransform = null; +#endif + } + + /// + /// Returns 0 once the end of the stream (EOF) has been reached. + /// Otherwise returns 1. + /// + public virtual int Available + { + get + { + return inf.IsFinished ? 0 : 1; + } + } + + /// + /// Fills the buffer with more data to decompress. + /// + /// + /// Stream ends early + /// + protected void Fill() + { + // Protect against redundant calls + if (inputBuffer.Available <= 0) + { + inputBuffer.Fill(); + if (inputBuffer.Available <= 0) + { + throw new ImageFormatException("Unexpected EOF"); + } + } + inputBuffer.SetInflaterInput(inf); + } + + #region Stream Overrides + /// + /// Gets a value indicating whether the current stream supports reading + /// + public override bool CanRead + { + get + { + return baseInputStream.CanRead; + } + } + + /// + /// Gets a value of false indicating seeking is not supported for this stream. + /// + public override bool CanSeek + { + get + { + return false; + } + } + + /// + /// Gets a value of false indicating that this stream is not writeable. + /// + public override bool CanWrite + { + get + { + return false; + } + } + + /// + /// A value representing the length of the stream in bytes. + /// + public override long Length + { + get + { + return inputBuffer.RawLength; + } + } + + /// + /// The current position within the stream. + /// Throws a NotSupportedException when attempting to set the position + /// + /// Attempting to set the position + public override long Position + { + get + { + return baseInputStream.Position; + } + set + { + throw new NotSupportedException("InflaterInputStream Position not supported"); + } + } + + /// + /// Flushes the baseInputStream + /// + public override void Flush() + { + baseInputStream.Flush(); + } + + /// + /// Sets the position within the current stream + /// Always throws a NotSupportedException + /// + /// The relative offset to seek to. + /// The defining where to seek from. + /// The new position in the stream. + /// Any access + public override long Seek(long offset, SeekOrigin origin) + { + throw new NotSupportedException("Seek not supported"); + } + + /// + /// Set the length of the current stream + /// Always throws a NotSupportedException + /// + /// The new length value for the stream. + /// Any access + public override void SetLength(long value) + { + throw new NotSupportedException("InflaterInputStream SetLength not supported"); + } + + /// + /// Writes a sequence of bytes to stream and advances the current position + /// This method always throws a NotSupportedException + /// + /// Thew buffer containing data to write. + /// The offset of the first byte to write. + /// The number of bytes to write. + /// Any access + public override void Write(byte[] buffer, int offset, int count) + { + throw new NotSupportedException("InflaterInputStream Write not supported"); + } + + /// + /// Writes one byte to the current stream and advances the current position + /// Always throws a NotSupportedException + /// + /// The byte to write. + /// Any access + public override void WriteByte(byte value) + { + throw new NotSupportedException("InflaterInputStream WriteByte not supported"); + } + + protected override void Dispose(bool disposing) + { + base.Dispose(disposing); + if (disposing && !isClosed) + { + isClosed = true; + if (isStreamOwner) + { + baseInputStream.Dispose(); + } + } + } + + /// + /// Reads decompressed data into the provided buffer byte array + /// + /// + /// The array to read and decompress data into + /// + /// + /// The offset indicating where the data should be placed + /// + /// + /// The number of bytes to decompress + /// + /// The number of bytes read. Zero signals the end of stream + /// + /// Inflater needs a dictionary + /// + public override int Read(byte[] buffer, int offset, int count) + { + if (inf.IsNeedingDictionary) + { + throw new ImageFormatException("Need a dictionary"); + } + + int remainingBytes = count; + while (true) + { + int bytesRead = inf.Inflate(buffer, offset, remainingBytes); + offset += bytesRead; + remainingBytes -= bytesRead; + + if (remainingBytes == 0 || inf.IsFinished) + { + break; + } + + if (inf.IsNeedingInput) + { + Fill(); + } + else if (bytesRead == 0) + { + throw new ImageFormatException("Dont know what to do"); + } + } + return count - remainingBytes; + } + #endregion + + #region Instance Fields + /// + /// Decompressor for this stream + /// + protected Inflater inf; + + /// + /// Input buffer for this stream. + /// + protected InflaterInputBuffer inputBuffer; + + /// + /// Base stream the inflater reads from. + /// + private Stream baseInputStream; + + /// + /// The compressed size + /// + protected long csize; + + /// + /// Flag indicating wether this instance has been closed or not. + /// + bool isClosed; + + /// + /// Flag indicating wether this instance is designated the stream owner. + /// When closing if this flag is true the underlying stream is closed. + /// + bool isStreamOwner = true; + #endregion + } +} + diff --git a/src/ImageProcessor/Formats/Png/Zlib/OutputWindow.cs b/src/ImageProcessor/Formats/Png/Zlib/OutputWindow.cs new file mode 100644 index 000000000..353bebadd --- /dev/null +++ b/src/ImageProcessor/Formats/Png/Zlib/OutputWindow.cs @@ -0,0 +1,217 @@ +namespace ImageProcessor.Formats +{ + using System; + + /// + /// Contains the output from the Inflation process. + /// We need to have a window so that we can refer backwards into the output stream + /// to repeat stuff.
+ /// Author of the original java version : John Leuner + /// + public class OutputWindow + { + #region Constants + const int WindowSize = 1 << 15; + const int WindowMask = WindowSize - 1; + #endregion + + #region Instance Fields + byte[] window = new byte[WindowSize]; //The window is 2^15 bytes + int windowEnd; + int windowFilled; + #endregion + + /// + /// Write a byte to this output window + /// + /// value to write + /// + /// if window is full + /// + public void Write(int value) + { + if (windowFilled++ == WindowSize) + { + throw new InvalidOperationException("Window full"); + } + window[windowEnd++] = (byte)value; + windowEnd &= WindowMask; + } + + + private void SlowRepeat(int repStart, int length, int distance) + { + while (length-- > 0) + { + window[windowEnd++] = window[repStart++]; + windowEnd &= WindowMask; + repStart &= WindowMask; + } + } + + /// + /// Append a byte pattern already in the window itself + /// + /// length of pattern to copy + /// distance from end of window pattern occurs + /// + /// If the repeated data overflows the window + /// + public void Repeat(int length, int distance) + { + if ((windowFilled += length) > WindowSize) + { + throw new InvalidOperationException("Window full"); + } + + int repStart = (windowEnd - distance) & WindowMask; + int border = WindowSize - length; + if ((repStart <= border) && (windowEnd < border)) + { + if (length <= distance) + { + System.Array.Copy(window, repStart, window, windowEnd, length); + windowEnd += length; + } + else + { + // We have to copy manually, since the repeat pattern overlaps. + while (length-- > 0) + { + window[windowEnd++] = window[repStart++]; + } + } + } + else + { + SlowRepeat(repStart, length, distance); + } + } + + /// + /// Copy from input manipulator to internal window + /// + /// source of data + /// length of data to copy + /// the number of bytes copied + public int CopyStored(StreamManipulator input, int length) + { + length = Math.Min(Math.Min(length, WindowSize - windowFilled), input.AvailableBytes); + int copied; + + int tailLen = WindowSize - windowEnd; + if (length > tailLen) + { + copied = input.CopyBytes(window, windowEnd, tailLen); + if (copied == tailLen) + { + copied += input.CopyBytes(window, 0, length - tailLen); + } + } + else + { + copied = input.CopyBytes(window, windowEnd, length); + } + + windowEnd = (windowEnd + copied) & WindowMask; + windowFilled += copied; + return copied; + } + + /// + /// Copy dictionary to window + /// + /// source dictionary + /// offset of start in source dictionary + /// length of dictionary + /// + /// If window isnt empty + /// + public void CopyDict(byte[] dictionary, int offset, int length) + { + if (dictionary == null) + { + throw new ArgumentNullException("dictionary"); + } + + if (windowFilled > 0) + { + throw new InvalidOperationException(); + } + + if (length > WindowSize) + { + offset += length - WindowSize; + length = WindowSize; + } + System.Array.Copy(dictionary, offset, window, 0, length); + windowEnd = length & WindowMask; + } + + /// + /// Get remaining unfilled space in window + /// + /// Number of bytes left in window + public int GetFreeSpace() + { + return WindowSize - windowFilled; + } + + /// + /// Get bytes available for output in window + /// + /// Number of bytes filled + public int GetAvailable() + { + return windowFilled; + } + + /// + /// Copy contents of window to output + /// + /// buffer to copy to + /// offset to start at + /// number of bytes to count + /// The number of bytes copied + /// + /// If a window underflow occurs + /// + public int CopyOutput(byte[] output, int offset, int len) + { + int copyEnd = windowEnd; + if (len > windowFilled) + { + len = windowFilled; + } + else + { + copyEnd = (windowEnd - windowFilled + len) & WindowMask; + } + + int copied = len; + int tailLen = len - copyEnd; + + if (tailLen > 0) + { + System.Array.Copy(window, WindowSize - tailLen, output, offset, tailLen); + offset += tailLen; + len = copyEnd; + } + System.Array.Copy(window, copyEnd - len, output, offset, len); + windowFilled -= copied; + if (windowFilled < 0) + { + throw new InvalidOperationException(); + } + return copied; + } + + /// + /// Reset by clearing window so GetAvailable returns 0 + /// + public void Reset() + { + windowFilled = windowEnd = 0; + } + } +} diff --git a/src/ImageProcessor/Formats/Png/Zlib/PendingBuffer.cs b/src/ImageProcessor/Formats/Png/Zlib/PendingBuffer.cs new file mode 100644 index 000000000..02916ae3d --- /dev/null +++ b/src/ImageProcessor/Formats/Png/Zlib/PendingBuffer.cs @@ -0,0 +1,263 @@ +namespace ImageProcessor.Formats +{ + /// + /// This class is general purpose class for writing data to a buffer. + /// + /// It allows you to write bits as well as bytes + /// Based on DeflaterPending.java + /// + /// author of the original java version : Jochen Hoenicke + /// + public class PendingBuffer + { + #region Instance Fields + /// + /// Internal work buffer + /// + byte[] buffer_; + + int start; + int end; + + uint bits; + int bitCount; + #endregion + + #region Constructors + /// + /// construct instance using default buffer size of 4096 + /// + public PendingBuffer() : this(4096) + { + } + + /// + /// construct instance using specified buffer size + /// + /// + /// size to use for internal buffer + /// + public PendingBuffer(int bufferSize) + { + buffer_ = new byte[bufferSize]; + } + + #endregion + + /// + /// Clear internal state/buffers + /// + public void Reset() + { + start = end = bitCount = 0; + } + + /// + /// Write a byte to buffer + /// + /// + /// The value to write + /// + public void WriteByte(int value) + { +#if DebugDeflation + if (DeflaterConstants.DEBUGGING && (start != 0) ) + { + throw new SharpZipBaseException("Debug check: start != 0"); + } +#endif + buffer_[end++] = unchecked((byte)value); + } + + /// + /// Write a short value to buffer LSB first + /// + /// + /// The value to write. + /// + public void WriteShort(int value) + { +#if DebugDeflation + if (DeflaterConstants.DEBUGGING && (start != 0) ) + { + throw new SharpZipBaseException("Debug check: start != 0"); + } +#endif + buffer_[end++] = unchecked((byte)value); + buffer_[end++] = unchecked((byte)(value >> 8)); + } + + /// + /// write an integer LSB first + /// + /// The value to write. + public void WriteInt(int value) + { +#if DebugDeflation + if (DeflaterConstants.DEBUGGING && (start != 0) ) + { + throw new SharpZipBaseException("Debug check: start != 0"); + } +#endif + buffer_[end++] = unchecked((byte)value); + buffer_[end++] = unchecked((byte)(value >> 8)); + buffer_[end++] = unchecked((byte)(value >> 16)); + buffer_[end++] = unchecked((byte)(value >> 24)); + } + + /// + /// Write a block of data to buffer + /// + /// data to write + /// offset of first byte to write + /// number of bytes to write + public void WriteBlock(byte[] block, int offset, int length) + { +#if DebugDeflation + if (DeflaterConstants.DEBUGGING && (start != 0) ) + { + throw new SharpZipBaseException("Debug check: start != 0"); + } +#endif + System.Array.Copy(block, offset, buffer_, end, length); + end += length; + } + + /// + /// The number of bits written to the buffer + /// + public int BitCount + { + get + { + return bitCount; + } + } + + /// + /// Align internal buffer on a byte boundary + /// + public void AlignToByte() + { +#if DebugDeflation + if (DeflaterConstants.DEBUGGING && (start != 0) ) + { + throw new SharpZipBaseException("Debug check: start != 0"); + } +#endif + if (bitCount > 0) + { + buffer_[end++] = unchecked((byte)bits); + if (bitCount > 8) + { + buffer_[end++] = unchecked((byte)(bits >> 8)); + } + } + bits = 0; + bitCount = 0; + } + + /// + /// Write bits to internal buffer + /// + /// source of bits + /// number of bits to write + public void WriteBits(int b, int count) + { +#if DebugDeflation + if (DeflaterConstants.DEBUGGING && (start != 0) ) + { + throw new SharpZipBaseException("Debug check: start != 0"); + } + + // if (DeflaterConstants.DEBUGGING) { + // //Console.WriteLine("writeBits("+b+","+count+")"); + // } +#endif + bits |= (uint)(b << bitCount); + bitCount += count; + if (bitCount >= 16) + { + buffer_[end++] = unchecked((byte)bits); + buffer_[end++] = unchecked((byte)(bits >> 8)); + bits >>= 16; + bitCount -= 16; + } + } + + /// + /// Write a short value to internal buffer most significant byte first + /// + /// value to write + public void WriteShortMSB(int s) + { +#if DebugDeflation + if (DeflaterConstants.DEBUGGING && (start != 0) ) + { + throw new SharpZipBaseException("Debug check: start != 0"); + } +#endif + buffer_[end++] = unchecked((byte)(s >> 8)); + buffer_[end++] = unchecked((byte)s); + } + + /// + /// Indicates if buffer has been flushed + /// + public bool IsFlushed + { + get + { + return end == 0; + } + } + + /// + /// Flushes the pending buffer into the given output array. If the + /// output array is to small, only a partial flush is done. + /// + /// The output array. + /// The offset into output array. + /// The maximum number of bytes to store. + /// The number of bytes flushed. + public int Flush(byte[] output, int offset, int length) + { + if (bitCount >= 8) + { + buffer_[end++] = unchecked((byte)bits); + bits >>= 8; + bitCount -= 8; + } + + if (length > end - start) + { + length = end - start; + System.Array.Copy(buffer_, start, output, offset, length); + start = 0; + end = 0; + } + else + { + System.Array.Copy(buffer_, start, output, offset, length); + start += length; + } + return length; + } + + /// + /// Convert internal buffer to byte array. + /// Buffer is empty on completion + /// + /// + /// The internal buffer contents converted to a byte array. + /// + public byte[] ToByteArray() + { + byte[] result = new byte[end - start]; + System.Array.Copy(buffer_, start, result, 0, result.Length); + start = 0; + end = 0; + return result; + } + } +} diff --git a/src/ImageProcessor/Formats/Png/Zlib/StreamManipulator.cs b/src/ImageProcessor/Formats/Png/Zlib/StreamManipulator.cs new file mode 100644 index 000000000..1f934558d --- /dev/null +++ b/src/ImageProcessor/Formats/Png/Zlib/StreamManipulator.cs @@ -0,0 +1,279 @@ +namespace ImageProcessor.Formats +{ + using System; + + /// + /// This class allows us to retrieve a specified number of bits from + /// the input buffer, as well as copy big byte blocks. + /// + /// It uses an int buffer to store up to 31 bits for direct + /// manipulation. This guarantees that we can get at least 16 bits, + /// but we only need at most 15, so this is all safe. + /// + /// There are some optimizations in this class, for example, you must + /// never peek more than 8 bits more than needed, and you must first + /// peek bits before you may drop them. This is not a general purpose + /// class but optimized for the behaviour of the Inflater. + /// + /// authors of the original java version : John Leuner, Jochen Hoenicke + /// + public class StreamManipulator + { + #region Constructors + /// + /// Constructs a default StreamManipulator with all buffers empty + /// + public StreamManipulator() + { + } + #endregion + + /// + /// Get the next sequence of bits but don't increase input pointer. bitCount must be + /// less or equal 16 and if this call succeeds, you must drop + /// at least n - 8 bits in the next call. + /// + /// The number of bits to peek. + /// + /// the value of the bits, or -1 if not enough bits available. */ + /// + public int PeekBits(int bitCount) + { + if (bitsInBuffer_ < bitCount) + { + if (windowStart_ == windowEnd_) + { + return -1; // ok + } + buffer_ |= (uint)((window_[windowStart_++] & 0xff | + (window_[windowStart_++] & 0xff) << 8) << bitsInBuffer_); + bitsInBuffer_ += 16; + } + return (int)(buffer_ & ((1 << bitCount) - 1)); + } + + /// + /// Drops the next n bits from the input. You should have called PeekBits + /// with a bigger or equal n before, to make sure that enough bits are in + /// the bit buffer. + /// + /// The number of bits to drop. + public void DropBits(int bitCount) + { + buffer_ >>= bitCount; + bitsInBuffer_ -= bitCount; + } + + /// + /// Gets the next n bits and increases input pointer. This is equivalent + /// to followed by , except for correct error handling. + /// + /// The number of bits to retrieve. + /// + /// the value of the bits, or -1 if not enough bits available. + /// + public int GetBits(int bitCount) + { + int bits = PeekBits(bitCount); + if (bits >= 0) + { + DropBits(bitCount); + } + return bits; + } + + /// + /// Gets the number of bits available in the bit buffer. This must be + /// only called when a previous PeekBits() returned -1. + /// + /// + /// the number of bits available. + /// + public int AvailableBits + { + get + { + return bitsInBuffer_; + } + } + + /// + /// Gets the number of bytes available. + /// + /// + /// The number of bytes available. + /// + public int AvailableBytes + { + get + { + return windowEnd_ - windowStart_ + (bitsInBuffer_ >> 3); + } + } + + /// + /// Skips to the next byte boundary. + /// + public void SkipToByteBoundary() + { + buffer_ >>= (bitsInBuffer_ & 7); + bitsInBuffer_ &= ~7; + } + + /// + /// Returns true when SetInput can be called + /// + public bool IsNeedingInput + { + get + { + return windowStart_ == windowEnd_; + } + } + + /// + /// Copies bytes from input buffer to output buffer starting + /// at output[offset]. You have to make sure, that the buffer is + /// byte aligned. If not enough bytes are available, copies fewer + /// bytes. + /// + /// + /// The buffer to copy bytes to. + /// + /// + /// The offset in the buffer at which copying starts + /// + /// + /// The length to copy, 0 is allowed. + /// + /// + /// The number of bytes copied, 0 if no bytes were available. + /// + /// + /// Length is less than zero + /// + /// + /// Bit buffer isnt byte aligned + /// + public int CopyBytes(byte[] output, int offset, int length) + { + if (length < 0) + { + throw new ArgumentOutOfRangeException("length"); + } + + if ((bitsInBuffer_ & 7) != 0) + { + // bits_in_buffer may only be 0 or a multiple of 8 + throw new InvalidOperationException("Bit buffer is not byte aligned!"); + } + + int count = 0; + while ((bitsInBuffer_ > 0) && (length > 0)) + { + output[offset++] = (byte)buffer_; + buffer_ >>= 8; + bitsInBuffer_ -= 8; + length--; + count++; + } + + if (length == 0) + { + return count; + } + + int avail = windowEnd_ - windowStart_; + if (length > avail) + { + length = avail; + } + System.Array.Copy(window_, windowStart_, output, offset, length); + windowStart_ += length; + + if (((windowStart_ - windowEnd_) & 1) != 0) + { + // We always want an even number of bytes in input, see peekBits + buffer_ = (uint)(window_[windowStart_++] & 0xff); + bitsInBuffer_ = 8; + } + return count + length; + } + + /// + /// Resets state and empties internal buffers + /// + public void Reset() + { + buffer_ = 0; + windowStart_ = windowEnd_ = bitsInBuffer_ = 0; + } + + /// + /// Add more input for consumption. + /// Only call when IsNeedingInput returns true + /// + /// data to be input + /// offset of first byte of input + /// number of bytes of input to add. + public void SetInput(byte[] buffer, int offset, int count) + { + if (buffer == null) + { + throw new ArgumentNullException("buffer"); + } + + if (offset < 0) + { +#if NETCF_1_0 + throw new ArgumentOutOfRangeException("offset"); +#else + throw new ArgumentOutOfRangeException("offset", "Cannot be negative"); +#endif + } + + if (count < 0) + { +#if NETCF_1_0 + throw new ArgumentOutOfRangeException("count"); +#else + throw new ArgumentOutOfRangeException("count", "Cannot be negative"); +#endif + } + + if (windowStart_ < windowEnd_) + { + throw new InvalidOperationException("Old input was not completely processed"); + } + + int end = offset + count; + + // We want to throw an ArrayIndexOutOfBoundsException early. + // Note the check also handles integer wrap around. + if ((offset > end) || (end > buffer.Length)) + { + throw new ArgumentOutOfRangeException("count"); + } + + if ((count & 1) != 0) + { + // We always want an even number of bytes in input, see PeekBits + buffer_ |= (uint)((buffer[offset++] & 0xff) << bitsInBuffer_); + bitsInBuffer_ += 8; + } + + window_ = buffer; + windowStart_ = offset; + windowEnd_ = end; + } + + #region Instance Fields + private byte[] window_; + private int windowStart_; + private int windowEnd_; + + private uint buffer_; + private int bitsInBuffer_; + #endregion + } +} diff --git a/src/ImageProcessor/Formats/Png/Zlib/ZipConstants.cs b/src/ImageProcessor/Formats/Png/Zlib/ZipConstants.cs new file mode 100644 index 000000000..6dccc6a96 --- /dev/null +++ b/src/ImageProcessor/Formats/Png/Zlib/ZipConstants.cs @@ -0,0 +1,329 @@ +namespace ImageProcessor.Formats +{ + using System.Text; + + /// + /// This class contains constants used for Zip format files + /// + public static class ZipConstants + { + #region Versions + /// + /// The version made by field for entries in the central header when created by this library + /// + /// + /// This is also the Zip version for the library when comparing against the version required to extract + /// for an entry. + public const int VersionMadeBy = 51; // was 45 before AES + + /// + /// The minimum version required to support strong encryption + /// + public const int VersionStrongEncryption = 50; + + /// + /// Version indicating AES encryption + /// + public const int VERSION_AES = 51; + + /// + /// The version required for Zip64 extensions (4.5 or higher) + /// + public const int VersionZip64 = 45; + #endregion + + #region Header Sizes + /// + /// Size of local entry header (excluding variable length fields at end) + /// + public const int LocalHeaderBaseSize = 30; + + /// + /// Size of Zip64 data descriptor + /// + public const int Zip64DataDescriptorSize = 24; + + /// + /// Size of data descriptor + /// + public const int DataDescriptorSize = 16; + + /// + /// Size of central header entry (excluding variable fields) + /// + public const int CentralHeaderBaseSize = 46; + + /// + /// Size of end of central record (excluding variable fields) + /// + public const int EndOfCentralRecordBaseSize = 22; + + /// + /// Size of 'classic' cryptographic header stored before any entry data + /// + public const int CryptoHeaderSize = 12; + #endregion + + #region Header Signatures + + /// + /// Signature for local entry header + /// + public const int LocalHeaderSignature = 'P' | ('K' << 8) | (3 << 16) | (4 << 24); + + /// + /// Signature for spanning entry + /// + public const int SpanningSignature = 'P' | ('K' << 8) | (7 << 16) | (8 << 24); + + /// + /// Signature for temporary spanning entry + /// + public const int SpanningTempSignature = 'P' | ('K' << 8) | ('0' << 16) | ('0' << 24); + + /// + /// Signature for data descriptor + /// + /// + /// This is only used where the length, Crc, or compressed size isnt known when the + /// entry is created and the output stream doesnt support seeking. + /// The local entry cannot be 'patched' with the correct values in this case + /// so the values are recorded after the data prefixed by this header, as well as in the central directory. + /// + public const int DataDescriptorSignature = 'P' | ('K' << 8) | (7 << 16) | (8 << 24); + + /// + /// Signature for central header + /// + public const int CentralHeaderSignature = 'P' | ('K' << 8) | (1 << 16) | (2 << 24); + + /// + /// Signature for Zip64 central file header + /// + public const int Zip64CentralFileHeaderSignature = 'P' | ('K' << 8) | (6 << 16) | (6 << 24); + + /// + /// Signature for Zip64 central directory locator + /// + public const int Zip64CentralDirLocatorSignature = 'P' | ('K' << 8) | (6 << 16) | (7 << 24); + + /// + /// Signature for archive extra data signature (were headers are encrypted). + /// + public const int ArchiveExtraDataSignature = 'P' | ('K' << 8) | (6 << 16) | (7 << 24); + + /// + /// Central header digitial signature + /// + public const int CentralHeaderDigitalSignature = 'P' | ('K' << 8) | (5 << 16) | (5 << 24); + + /// + /// End of central directory record signature + /// + public const int EndOfCentralDirectorySignature = 'P' | ('K' << 8) | (5 << 16) | (6 << 24); + + #endregion + +#if NETCF_1_0 || NETCF_2_0 + // This isnt so great but is better than nothing. + // Trying to work out an appropriate OEM code page would be good. + // 850 is a good default for english speakers particularly in Europe. + static int defaultCodePage = CultureInfo.CurrentCulture.TextInfo.ANSICodePage; +#elif PCL + static Encoding defaultEncoding = Encoding.UTF8; +#else + /// + /// Get OEM codepage from NetFX, which parses the NLP file with culture info table etc etc. + /// But sometimes it yields the special value of 1 which is nicknamed CodePageNoOEM in sources (might also mean CP_OEMCP, but Encoding puts it so). + /// This was observed on Ukranian and Hindu systems. + /// Given this value, throws an . + /// So replace it with some fallback, e.g. 437 which is the default cpcp in a console in a default Windows installation. + /// + static int defaultCodePage = + // these values cause ArgumentException in subsequent calls to Encoding::GetEncoding() + ((Thread.CurrentThread.CurrentCulture.TextInfo.OEMCodePage == 1) || (Thread.CurrentThread.CurrentCulture.TextInfo.OEMCodePage == 2) || (Thread.CurrentThread.CurrentCulture.TextInfo.OEMCodePage == 3) || (Thread.CurrentThread.CurrentCulture.TextInfo.OEMCodePage == 42)) + ? 437 // The default OEM encoding in a console in a default Windows installation, as a fallback. + : Thread.CurrentThread.CurrentCulture.TextInfo.OEMCodePage; +#endif +#if !PCL + /// + /// Default encoding used for string conversion. 0 gives the default system OEM code page. + /// Dont use unicode encodings if you want to be Zip compatible! + /// Using the default code page isnt the full solution neccessarily + /// there are many variable factors, codepage 850 is often a good choice for + /// European users, however be careful about compatability. + /// + public static int DefaultCodePage { + get { + return defaultCodePage; + } + set { + if ((value < 0) || (value > 65535) || + (value == 1) || (value == 2) || (value == 3) || (value == 42)) { + throw new ArgumentOutOfRangeException("value"); + } + + defaultCodePage = value; + } + } +#else + /// + /// PCL don't support CodePage so we used Encoding instead of + /// + public static Encoding DefaultEncoding + { + get + { + return defaultEncoding; + } + set + { + defaultEncoding = value; + } + } +#endif + + /// + /// Convert a portion of a byte array to a string. + /// + /// + /// Data to convert to string + /// + /// + /// Number of bytes to convert starting from index 0 + /// + /// + /// data[0]..data[count - 1] converted to a string + /// + public static string ConvertToString(byte[] data, int count) + { + if (data == null) + { + return string.Empty; + } +#if !PCL + return Encoding.GetEncoding(DefaultCodePage).GetString(data, 0, count); +#else + return DefaultEncoding.GetString(data, 0, count); +#endif + } + + /// + /// Convert a byte array to string + /// + /// + /// Byte array to convert + /// + /// + /// dataconverted to a string + /// + public static string ConvertToString(byte[] data) + { + if (data == null) + { + return string.Empty; + } + return ConvertToString(data, data.Length); + } + + /// + /// Convert a byte array to string + /// + /// The applicable general purpose bits flags + /// + /// Byte array to convert + /// + /// The number of bytes to convert. + /// + /// dataconverted to a string + /// + public static string ConvertToStringExt(int flags, byte[] data, int count) + { + if (data == null) + { + return string.Empty; + } + + if ((flags & (int)GeneralBitFlags.UnicodeText) != 0) + { + return Encoding.UTF8.GetString(data, 0, count); + } + else + { + return ConvertToString(data, count); + } + } + + /// + /// Convert a byte array to string + /// + /// + /// Byte array to convert + /// + /// The applicable general purpose bits flags + /// + /// dataconverted to a string + /// + public static string ConvertToStringExt(int flags, byte[] data) + { + if (data == null) + { + return string.Empty; + } + + if ((flags & (int)GeneralBitFlags.UnicodeText) != 0) + { + return Encoding.UTF8.GetString(data, 0, data.Length); + } + else + { + return ConvertToString(data, data.Length); + } + } + + /// + /// Convert a string to a byte array + /// + /// + /// String to convert to an array + /// + /// Converted array + public static byte[] ConvertToArray(string str) + { + if (str == null) + { + return new byte[0]; + } +#if !PCL + return Encoding.GetEncoding(DefaultCodePage).GetBytes(str); +#else + return DefaultEncoding.GetBytes(str); +#endif + } + + /// + /// Convert a string to a byte array + /// + /// The applicable general purpose bits flags + /// + /// String to convert to an array + /// + /// Converted array + public static byte[] ConvertToArray(int flags, string str) + { + if (str == null) + { + return new byte[0]; + } + + if ((flags & (int)GeneralBitFlags.UnicodeText) != 0) + { + return Encoding.UTF8.GetBytes(str); + } + else + { + return ConvertToArray(str); + } + } + } +} diff --git a/src/ImageProcessor/ImageProcessor.csproj b/src/ImageProcessor/ImageProcessor.csproj index a35f2f0a3..7d32368e7 100644 --- a/src/ImageProcessor/ImageProcessor.csproj +++ b/src/ImageProcessor/ImageProcessor.csproj @@ -17,14 +17,15 @@ v4.5 ..\..\ true - cfa9b76b + + true full false bin\Debug\ - DEBUG;TRACE + TRACE;DEBUG;NOCRYPTO;PCL prompt 4 bin\Debug\ImageProcessor.XML @@ -40,6 +41,9 @@ + + + @@ -57,6 +61,26 @@ + + + + + + + + + + + + + + + + + + + + @@ -211,12 +235,6 @@ - - - ..\..\packages\SharpZipLib.Portable.0.86.0.0002\lib\portable-net45+netcore45+wp8+win8+wpa81+MonoTouch+MonoAndroid\ICSharpCode.SharpZipLib.Portable.dll - True - - @@ -227,18 +245,15 @@ - - - - + + - This project references NuGet package(s) that are missing on this computer. Enable NuGet Package Restore to download them. For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}. + This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them. For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}. -