Ensure read components can be discarded when COMPOSITE_CUMULATOR is used.

normanmaurer · normanmaurer · commit 0b1c82b25444 · 2016-02-17T19:51:08.000-08:00
Motivation:

ByteToMessageDecoder must ensure that read components of the CompositeByteBuf can be discard by default when discardSomeReadBytes() is called. This may not be the case before as because of the default maxNumComponents that will cause consolidation.

Modifications:

Ensure we not do any consolidation to actually be abel to discard read components

Result:

Less memory usage and allocations.
diff --git a/codec/src/main/java/io/netty/handler/codec/ByteToMessageDecoder.java b/codec/src/main/java/io/netty/handler/codec/ByteToMessageDecoder.java
@@ -121,7 +121,7 @@ public ByteBuf cumulate(ByteBufAllocator alloc, ByteBuf cumulation, ByteBuf in)
                     composite = (CompositeByteBuf) cumulation;
                 } else {
                     int readable = cumulation.readableBytes();
-                    composite = alloc.compositeBuffer();
+                    composite = alloc.compositeBuffer(Integer.MAX_VALUE);
                     composite.addComponent(cumulation).writerIndex(readable);
                 }
                 composite.addComponent(in).writerIndex(composite.writerIndex() + in.readableBytes());

Original file line number	Diff line number	Diff line change
`@@ -121,7 +121,7 @@ public ByteBuf cumulate(ByteBufAllocator alloc, ByteBuf cumulation, ByteBuf in)`
`121`	`121`	`composite = (CompositeByteBuf) cumulation;`
`122`	`122`	`} else {`
`123`	`123`	`int readable = cumulation.readableBytes();`
`124`		`- composite = alloc.compositeBuffer();`
	`124`	`+ composite = alloc.compositeBuffer(Integer.MAX_VALUE);`
`125`	`125`	`composite.addComponent(cumulation).writerIndex(readable);`
`126`	`126`	`}`
`127`	`127`	`composite.addComponent(in).writerIndex(composite.writerIndex() + in.readableBytes());`