474068 - Update WebSocket Extension for permessage-deflate draft-22

+ Copying inflated byte buffers
+ Simplifying Accumulator of buffer/chunks
+ Removing references to frame compression extensions

jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/extensions/compress/ByteAccumulator.java

@@ -27,7 +27,7 @@
 
 public class ByteAccumulator
 {
-    private final List<Chunk> chunks = new ArrayList<>();
+    private final List<byte[]> chunks = new ArrayList<>();
     private final int maxSize;
     private int length = 0;
 
@@ -36,13 +36,17 @@ public ByteAccumulator(int maxOverallBufferSize)
         this.maxSize = maxOverallBufferSize;
     }
 
-    public void addChunk(byte buf[], int offset, int length)
+    public void copyChunk(byte buf[], int offset, int length)
     {
         if (this.length + length > maxSize)
         {
             throw new MessageTooLargeException("Frame is too large");
         }
-        chunks.add(new Chunk(buf, offset, length));
+
+        byte copy[] = new byte[length - offset];
+        System.arraycopy(buf,offset,copy,0,length);
+
+        chunks.add(copy);
         this.length += length;
     }
 
@@ -54,26 +58,16 @@ public int getLength()
     public void transferTo(ByteBuffer buffer)
     {
         if (buffer.remaining() < length)
-            throw new IllegalArgumentException();
-        int position = buffer.position();
-        for (Chunk chunk : chunks)
         {
-            buffer.put(chunk.buffer, chunk.offset, chunk.length);
+            throw new IllegalArgumentException(String.format("Not enough space in ByteBuffer remaining [%d] for accumulated buffers length [%d]",
+                    buffer.remaining(),length));
         }
-        BufferUtil.flipToFlush(buffer, position);
-    }
 
-    private static class Chunk
-    {
-        private final byte[] buffer;
-        private final int offset;
-        private final int length;
-
-        private Chunk(byte[] buffer, int offset, int length)
+        int position = buffer.position();
+        for (byte[] chunk : chunks)
         {
-            this.buffer = buffer;
-            this.offset = offset;
-            this.length = length;
+            buffer.put(chunk,0,chunk.length);
         }
+        BufferUtil.flipToFlush(buffer,position);
     }
 }

jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/extensions/compress/CompressExtension.java

@@ -149,7 +149,7 @@ protected void decompress(ByteAccumulator accumulator, ByteBuffer buf)
         {
             return;
         }
-        byte[] output = new byte[1024];
+        byte[] output = new byte[1024]; // TODO: make configurable size
 
         if (inflater.needsInput() && !supplyInput(inflater, buf))
         {
@@ -163,22 +163,7 @@ protected void decompress(ByteAccumulator accumulator, ByteBuffer buf)
             if (read == 0)
             {
                 LOG.debug("Decompress: read 0 {}",toDetail(inflater));
-                if (inflater.finished() || inflater.needsDictionary())
-                {
-                    if (LOG.isDebugEnabled())
-                    {
-                        LOG.debug("Decompress: finished? {}",toDetail(inflater));
-                    }
-                    // We are finished ?
-                    break;
-                }
-                else if (inflater.needsInput())
-                {
-                    if (!supplyInput(inflater, buf))
-                    {
-                        break;
-                    }
-                }
+                break;
             }
             else
             {
@@ -187,7 +172,8 @@ else if (inflater.needsInput())
                 {
                     LOG.debug("Decompressed {} bytes: {}",read,toDetail(inflater));
                 }
-                accumulator.addChunk(output,0,read);
+
+                accumulator.copyChunk(output,0,read);
             }
         }
 

jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/extensions/compress/package-info.java

@@ -17,7 +17,7 @@
 //
 
 /**
- * Jetty WebSocket Common : Frame & Message Compression Extension Implementations
+ * Jetty WebSocket Common : Message Compression Extension Implementations
  */
 package org.eclipse.jetty.websocket.common.extensions.compress;