ArrayPool

src/ImageSharp46/Formats/Jpg/Components/Block.cs

@@ -3,6 +3,7 @@
 // Licensed under the Apache License, Version 2.0.
 // </copyright>
 
+using System;
 using System.Buffers;
 
 namespace ImageSharp.Formats
@@ -10,8 +11,10 @@ namespace ImageSharp.Formats
     /// <summary>
     /// Represents an 8x8 block of coefficients to transform and encode.
     /// </summary>
-    internal struct Block
+    internal struct Block : IDisposable
     {
+        private static ArrayPool<int> IntArrayPool => ArrayPool<int>.Shared; /*= ArrayPool<int>.Create(BlockSize, 50);*/
+
         /// <summary>
         /// Gets the size of the block.
         /// </summary>
@@ -32,7 +35,25 @@ namespace ImageSharp.Formats
 
         public void Init()
         {
-            this.Data = new int[BlockSize];
+            //this.Data = new int[BlockSize];
+            this.Data = IntArrayPool.Rent(BlockSize);
+        }
+
+        public static Block Create()
+        {
+            var block = new Block();
+            block.Init();
+            return block;
+        }
+
+        public static Block[] CreateArray(int size)
+        {
+            Block[] result = new Block[size];
+            for (int i = 0; i < result.Length; i++)
+            {
+                result[i].Init();
+            }
+            return result;
         }
 
         public bool IsInitialized => this.Data != null;
@@ -49,5 +70,23 @@ namespace ImageSharp.Formats
             get { return this.Data[index]; }
             set { this.Data[index] = value; }
         }
+
+        // TODO: Refactor Block.Dispose() callers to always use 'using' or 'finally' statement!
+        public void Dispose()
+        {
+            if (Data != null)
+            {
+                IntArrayPool.Return(Data, true);
+                Data = null;
+            }
+        }
+
+        public static void DisposeAll(Block[] blocks)
+        {
+            for (int i = 0; i < blocks.Length; i++)
+            {
+                blocks[i].Dispose();
+            }
+        }
     }
 }

src/ImageSharp46/Formats/Jpg/Components/IDCT.cs

@@ -41,10 +41,8 @@ namespace ImageSharp.Formats
         /// ASSP, Vol. ASSP- 32, pp. 803-816, Aug. 1984.
         /// </summary>
         /// <param name="src">The source block of coefficients</param>
-        public static void Transform(ref Block block)
+        public static void Transform(ref Block src)
         {
-            
-            var src = block.Data;
             // Horizontal 1-D IDCT.
             for (int y = 0; y < 8; y++)
             {

src/ImageSharp46/Formats/Jpg/JpegDecoder.cs

@@ -83,8 +83,10 @@ namespace ImageSharp.Formats
             Guard.NotNull(image, "image");
             Guard.NotNull(stream, "stream");
 
-            JpegDecoderCore decoder = new JpegDecoderCore();
-            decoder.Decode(image, stream, false);
+            using (JpegDecoderCore decoder = new JpegDecoderCore())
+            {
+                decoder.Decode(image, stream, false);
+            }
         }
 
         /// <summary>

src/ImageSharp46/Formats/Jpg/JpegDecoderCore.cs

@@ -12,7 +12,7 @@ namespace ImageSharp.Formats
     /// <summary>
     /// Performs the jpeg decoding operation.
     /// </summary>
-    internal class JpegDecoderCore
+    internal class JpegDecoderCore : IDisposable
     {
         /// <summary>
         /// The maximum (inclusive) number of bits in a Huffman code.
@@ -201,7 +201,7 @@ namespace ImageSharp.Formats
             //this.huffmanTrees = new Huffman[MaxTc + 1, MaxTh + 1];
             this.huffmanTrees = new Huffman[(MaxTc + 1)*(MaxTh + 1)];
 
-            this.quantizationTables = new Block[MaxTq + 1];
+            this.quantizationTables = Block.CreateArray(MaxTq + 1);
             this.temp = new byte[2 * Block.BlockSize];
             this.componentArray = new Component[MaxComponents];
             this.progCoeffs = new Block[MaxComponents][];
@@ -219,11 +219,11 @@ namespace ImageSharp.Formats
                 }
             }
 
-            for (int i = 0; i < this.quantizationTables.Length; i++)
-            {
-                //this.quantizationTables[i] = new Block();
-                this.quantizationTables[i].Init();
-            }
+            //for (int i = 0; i < this.quantizationTables.Length; i++)
+            //{
+            //    //this.quantizationTables[i] = new Block();
+            //    this.quantizationTables[i].Init();
+            //}
 
             //for (int i = 0; i < this.componentArray.Length; i++)
             //{
@@ -1576,7 +1576,7 @@ namespace ImageSharp.Formats
                     int compIndex = scan[i].Index;
                     if (this.progCoeffs[compIndex] == null)
                     {
-                        this.progCoeffs[compIndex] = new Block[mxx * myy * this.componentArray[compIndex].HorizontalFactor * this.componentArray[compIndex].VerticalFactor];
+                        this.progCoeffs[compIndex] = Block.CreateArray(mxx * myy * this.componentArray[compIndex].HorizontalFactor * this.componentArray[compIndex].VerticalFactor);
 
                         for (int j = 0; j < this.progCoeffs[compIndex].Length; j++)
                         {
@@ -1668,11 +1668,13 @@ namespace ImageSharp.Formats
                             }
                             else
                             {
-                                var b = new Block();
-                                b.Init();
+                                var b = Block.Create();
+                                
                                 ProcessBlockImpl(ah, ref b, scan, i, zigStart, zigEnd, al, dc, compIndex, @by, mxx, hi,
                                     bx, ref this.quantizationTables[qtIndex]
                                     );
+                                
+                                b.Dispose();
                             }
                         }
 
@@ -2252,5 +2254,18 @@ namespace ImageSharp.Formats
         private class EOFException : Exception
         {
         }
+
+        public void Dispose()
+        {
+            Block.DisposeAll(this.quantizationTables);
+
+            foreach (Block[] blocks in progCoeffs)
+            {
+                if (blocks != null)
+                {
+                    Block.DisposeAll(blocks);
+                }
+            }
+        }
     }
 }

src/ImageSharp46/Formats/Jpg/JpegEncoderCore.cs

@@ -579,7 +579,7 @@ namespace ImageSharp.Formats
         /// </summary>
         /// <param name="destination">The destination block array</param>
         /// <param name="source">The source block array.</param>
-        private void Scale16X16To8X8(Block destination, Block[] source)
+        private void Scale16X16To8X8(ref Block destination, Block[] source)
         {
             for (int i = 0; i < 4; i++)
             {
@@ -849,9 +849,9 @@ namespace ImageSharp.Formats
             where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
-            Block b = new Block();
-            Block cb = new Block();
-            Block cr = new Block();
+            Block b = Block.Create();
+            Block cb = Block.Create();
+            Block cr = Block.Create();
             // ReSharper disable once InconsistentNaming
             int prevDCY = 0, prevDCCb = 0, prevDCCr = 0;
 
@@ -865,6 +865,9 @@ namespace ImageSharp.Formats
                     prevDCCr = this.WriteBlock(ref cr, QuantIndex.Chrominance, prevDCCr);
                 }
             }
+            b.Dispose();
+            cb.Dispose();
+            cr.Dispose();
         }
 
         /// <summary>
@@ -878,22 +881,12 @@ namespace ImageSharp.Formats
             where TColor : struct, IPackedPixel<TPacked>
             where TPacked : struct
         {
-            Block b = new Block();
-            Block[] cb = new Block[4];
-            Block[] cr = new Block[4];
+            Block b = Block.Create();
+            Block[] cb = Block.CreateArray(4);
+            Block[] cr = Block.CreateArray(4);
             // ReSharper disable once InconsistentNaming
             int prevDCY = 0, prevDCCb = 0, prevDCCr = 0;
-
-            for (int i = 0; i < 4; i++)
-            {
-                cb[i] = new Block();
-            }
-
-            for (int i = 0; i < 4; i++)
-            {
-                cr[i] = new Block();
-            }
-
+            
             for (int y = 0; y < pixels.Height; y += 16)
             {
                 for (int x = 0; x < pixels.Width; x += 16)
@@ -907,12 +900,16 @@ namespace ImageSharp.Formats
                         prevDCY = this.WriteBlock(ref b, QuantIndex.Luminance, prevDCY);
                     }
 
-                    this.Scale16X16To8X8(b, cb);
+                    this.Scale16X16To8X8(ref b, cb);
                     prevDCCb = this.WriteBlock(ref b, QuantIndex.Chrominance, prevDCCb);
-                    this.Scale16X16To8X8(b, cr);
+                    this.Scale16X16To8X8(ref b, cr);
                     prevDCCr = this.WriteBlock(ref b, QuantIndex.Chrominance, prevDCCr);
                 }
             }
+
+            b.Dispose();
+            Block.DisposeAll(cb);
+            Block.DisposeAll(cr);
         }
 
         /// <summary>

tests/ImageSharp.Tests46/JpegSandbox.cs

@@ -68,6 +68,9 @@ namespace ImageSharp.Tests
         {
             Vector<int> hej = new Vector<int>();
             
+            
+
+            Output.WriteLine(Vector<int>.Count.ToString());
         }
         
     }