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Migrate png decoder

pull/1681/head
James Jackson-South 5 years ago
parent
dcd9890c9d
commit
4b7b1df088
2 changed files with 30 additions and 29 deletions
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  1. 6
      src/ImageSharp/Formats/Png/PngChunk.cs
  2. 53
      src/ImageSharp/Formats/Png/PngDecoderCore.cs

6
src/ImageSharp/Formats/Png/PngChunk.cs
View File

@ -1,7 +1,7 @@
// Copyright (c) Six Labors.
// Licensed under the Apache License, Version 2.0.
using SixLabors.ImageSharp.Memory;
using System.Buffers;
namespace SixLabors.ImageSharp.Formats.Png
{
@ -10,7 +10,7 @@ namespace SixLabors.ImageSharp.Formats.Png
/// </summary>
internal readonly struct PngChunk
{
public PngChunk(int length, PngChunkType type, IManagedByteBuffer data = null)
public PngChunk(int length, PngChunkType type, IMemoryOwner<byte> data = null)
{
this.Length = length;
this.Type = type;
@ -35,7 +35,7 @@ namespace SixLabors.ImageSharp.Formats.Png
/// Gets the data bytes appropriate to the chunk type, if any.
/// This field can be of zero length or null.
/// </summary>
public IManagedByteBuffer Data { get; }
public IMemoryOwner<byte> Data { get; }
/// <summary>
/// Gets a value indicating whether the given chunk is critical to decoding

53
src/ImageSharp/Formats/Png/PngDecoderCore.cs
View File

@ -2,6 +2,7 @@
// Licensed under the Apache License, Version 2.0.
using System;
using System.Buffers;
using System.Buffers.Binary;
using System.Collections.Generic;
using System.IO;
@ -84,12 +85,12 @@ namespace SixLabors.ImageSharp.Formats.Png
/// <summary>
/// Previous scanline processed.
/// </summary>
private IManagedByteBuffer previousScanline;
private IMemoryOwner<byte> previousScanline;
/// <summary>
/// The current scanline that is being processed.
/// </summary>
private IManagedByteBuffer scanline;
private IMemoryOwner<byte> scanline;
/// <summary>
/// The index of the current scanline being processed.
@ -149,7 +150,7 @@ namespace SixLabors.ImageSharp.Formats.Png
switch (chunk.Type)
{
case PngChunkType.Header:
this.ReadHeaderChunk(pngMetadata, chunk.Data.Array);
this.ReadHeaderChunk(pngMetadata, chunk.Data.GetSpan());
break;
case PngChunkType.Physical:
this.ReadPhysicalChunk(metadata, chunk.Data.GetSpan());
@ -168,29 +169,29 @@ namespace SixLabors.ImageSharp.Formats.Png
break;
case PngChunkType.Palette:
var pal = new byte[chunk.Length];
Buffer.BlockCopy(chunk.Data.Array, 0, pal, 0, chunk.Length);
chunk.Data.GetSpan().CopyTo(pal);
this.palette = pal;
break;
case PngChunkType.Transparency:
var alpha = new byte[chunk.Length];
Buffer.BlockCopy(chunk.Data.Array, 0, alpha, 0, chunk.Length);
chunk.Data.GetSpan().CopyTo(alpha);
this.paletteAlpha = alpha;
this.AssignTransparentMarkers(alpha, pngMetadata);
break;
case PngChunkType.Text:
this.ReadTextChunk(pngMetadata, chunk.Data.Array.AsSpan(0, chunk.Length));
this.ReadTextChunk(pngMetadata, chunk.Data.GetSpan());
break;
case PngChunkType.CompressedText:
this.ReadCompressedTextChunk(pngMetadata, chunk.Data.Array.AsSpan(0, chunk.Length));
this.ReadCompressedTextChunk(pngMetadata, chunk.Data.GetSpan());
break;
case PngChunkType.InternationalText:
this.ReadInternationalTextChunk(pngMetadata, chunk.Data.Array.AsSpan(0, chunk.Length));
this.ReadInternationalTextChunk(pngMetadata, chunk.Data.GetSpan());
break;
case PngChunkType.Exif:
if (!this.ignoreMetadata)
{
var exifData = new byte[chunk.Length];
Buffer.BlockCopy(chunk.Data.Array, 0, exifData, 0, chunk.Length);
chunk.Data.GetSpan().CopyTo(exifData);
metadata.ExifProfile = new ExifProfile(exifData);
}
@ -239,7 +240,7 @@ namespace SixLabors.ImageSharp.Formats.Png
switch (chunk.Type)
{
case PngChunkType.Header:
this.ReadHeaderChunk(pngMetadata, chunk.Data.Array);
this.ReadHeaderChunk(pngMetadata, chunk.Data.GetSpan());
break;
case PngChunkType.Physical:
this.ReadPhysicalChunk(metadata, chunk.Data.GetSpan());
@ -251,19 +252,19 @@ namespace SixLabors.ImageSharp.Formats.Png
this.SkipChunkDataAndCrc(chunk);
break;
case PngChunkType.Text:
this.ReadTextChunk(pngMetadata, chunk.Data.Array.AsSpan(0, chunk.Length));
this.ReadTextChunk(pngMetadata, chunk.Data.GetSpan());
break;
case PngChunkType.CompressedText:
this.ReadCompressedTextChunk(pngMetadata, chunk.Data.Array.AsSpan(0, chunk.Length));
this.ReadCompressedTextChunk(pngMetadata, chunk.Data.GetSpan());
break;
case PngChunkType.InternationalText:
this.ReadInternationalTextChunk(pngMetadata, chunk.Data.Array.AsSpan(0, chunk.Length));
this.ReadInternationalTextChunk(pngMetadata, chunk.Data.GetSpan());
break;
case PngChunkType.Exif:
if (!this.ignoreMetadata)
{
var exifData = new byte[chunk.Length];
Buffer.BlockCopy(chunk.Data.Array, 0, exifData, 0, chunk.Length);
chunk.Data.GetSpan().CopyTo(exifData);
metadata.ExifProfile = new ExifProfile(exifData);
}
@ -312,7 +313,7 @@ namespace SixLabors.ImageSharp.Formats.Png
/// <param name="bits">The number of bits per value.</param>
/// <param name="buffer">The new array.</param>
/// <returns>The resulting <see cref="ReadOnlySpan{Byte}"/> array.</returns>
private bool TryScaleUpTo8BitArray(ReadOnlySpan<byte> source, int bytesPerScanline, int bits, out IManagedByteBuffer buffer)
private bool TryScaleUpTo8BitArray(ReadOnlySpan<byte> source, int bytesPerScanline, int bits, out IMemoryOwner<byte> buffer)
{
if (bits >= 8)
{
@ -320,9 +321,9 @@ namespace SixLabors.ImageSharp.Formats.Png
return false;
}
buffer = this.memoryAllocator.AllocateManagedByteBuffer(bytesPerScanline * 8 / bits, AllocationOptions.Clean);
buffer = this.memoryAllocator.Allocate<byte>(bytesPerScanline * 8 / bits, AllocationOptions.Clean);
ref byte sourceRef = ref MemoryMarshal.GetReference(source);
ref byte resultRef = ref buffer.Array[0];
ref byte resultRef = ref buffer.GetReference();
int mask = 0xFF >> (8 - bits);
int resultOffset = 0;
@ -504,7 +505,8 @@ namespace SixLabors.ImageSharp.Formats.Png
{
while (this.currentRow < this.header.Height)
{
int bytesRead = compressedStream.Read(this.scanline.Array, this.currentRowBytesRead, this.bytesPerScanline - this.currentRowBytesRead);
Span<byte> scanlineSpan = this.scanline.GetSpan();
int bytesRead = compressedStream.Read(scanlineSpan, this.currentRowBytesRead, this.bytesPerScanline - this.currentRowBytesRead);
this.currentRowBytesRead += bytesRead;
if (this.currentRowBytesRead < this.bytesPerScanline)
{
@ -512,7 +514,6 @@ namespace SixLabors.ImageSharp.Formats.Png
}
this.currentRowBytesRead = 0;
Span<byte> scanlineSpan = this.scanline.GetSpan();
switch ((FilterType)scanlineSpan[0])
{
@ -576,7 +577,7 @@ namespace SixLabors.ImageSharp.Formats.Png
while (this.currentRow < this.header.Height)
{
int bytesRead = compressedStream.Read(this.scanline.Array, this.currentRowBytesRead, bytesPerInterlaceScanline - this.currentRowBytesRead);
int bytesRead = compressedStream.Read(this.scanline.GetSpan(), this.currentRowBytesRead, bytesPerInterlaceScanline - this.currentRowBytesRead);
this.currentRowBytesRead += bytesRead;
if (this.currentRowBytesRead < bytesPerInterlaceScanline)
{
@ -653,7 +654,7 @@ namespace SixLabors.ImageSharp.Formats.Png
ReadOnlySpan<byte> trimmed = defilteredScanline.Slice(1, defilteredScanline.Length - 1);
// Convert 1, 2, and 4 bit pixel data into the 8 bit equivalent.
ReadOnlySpan<byte> scanlineSpan = this.TryScaleUpTo8BitArray(trimmed, this.bytesPerScanline - 1, this.header.BitDepth, out IManagedByteBuffer buffer)
ReadOnlySpan<byte> scanlineSpan = this.TryScaleUpTo8BitArray(trimmed, this.bytesPerScanline - 1, this.header.BitDepth, out IMemoryOwner<byte> buffer)
? buffer.GetSpan()
: trimmed;
@ -735,7 +736,7 @@ namespace SixLabors.ImageSharp.Formats.Png
ReadOnlySpan<byte> trimmed = defilteredScanline.Slice(1, defilteredScanline.Length - 1);
// Convert 1, 2, and 4 bit pixel data into the 8 bit equivalent.
ReadOnlySpan<byte> scanlineSpan = this.TryScaleUpTo8BitArray(trimmed, this.bytesPerScanline, this.header.BitDepth, out IManagedByteBuffer buffer)
ReadOnlySpan<byte> scanlineSpan = this.TryScaleUpTo8BitArray(trimmed, this.bytesPerScanline, this.header.BitDepth, out IMemoryOwner<byte> buffer)
? buffer.GetSpan()
: trimmed;
@ -1189,12 +1190,12 @@ namespace SixLabors.ImageSharp.Formats.Png
/// </summary>
/// <param name="length">The length of the chunk data to read.</param>
[MethodImpl(InliningOptions.ShortMethod)]
private IManagedByteBuffer ReadChunkData(int length)
private IMemoryOwner<byte> ReadChunkData(int length)
{
// We rent the buffer here to return it afterwards in Decode()
IManagedByteBuffer buffer = this.Configuration.MemoryAllocator.AllocateManagedByteBuffer(length, AllocationOptions.Clean);
IMemoryOwner<byte> buffer = this.Configuration.MemoryAllocator.Allocate<byte>(length, AllocationOptions.Clean);
this.currentStream.Read(buffer.Array, 0, length);
this.currentStream.Read(buffer.GetSpan(), 0, length);
return buffer;
}
@ -1274,7 +1275,7 @@ namespace SixLabors.ImageSharp.Formats.Png
private void SwapBuffers()
{
IManagedByteBuffer temp = this.previousScanline;
IMemoryOwner<byte> temp = this.previousScanline;
this.previousScanline = this.scanline;
this.scanline = temp;
}

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