private SendBuffer acquire(ChannelBuffer src) { final int size = src.readableBytes(); if (size == 0) { return EMPTY_BUFFER; } if (src instanceof CompositeChannelBuffer && ((CompositeChannelBuffer) src).useGathering()) { return new GatheringSendBuffer(src.toByteBuffers()); } if (src.isDirect()) { return new UnpooledSendBuffer(src.toByteBuffer()); } if (src.readableBytes() > DEFAULT_PREALLOCATION_SIZE) { return new UnpooledSendBuffer(src.toByteBuffer()); } Preallocation current = this.current; ByteBuffer buffer = current.buffer; int remaining = buffer.remaining(); PooledSendBuffer dst; if (size < remaining) { int nextPos = buffer.position() + size; ByteBuffer slice = buffer.duplicate(); buffer.position(align(nextPos)); slice.limit(nextPos); current.refCnt++; dst = new PooledSendBuffer(current, slice); } else if (size > remaining) { this.current = current = getPreallocation(); buffer = current.buffer; ByteBuffer slice = buffer.duplicate(); buffer.position(align(size)); slice.limit(size); current.refCnt++; dst = new PooledSendBuffer(current, slice); } else { // size == remaining current.refCnt++; this.current = getPreallocation0(); dst = new PooledSendBuffer(current, current.buffer); } ByteBuffer dstbuf = dst.buffer; dstbuf.mark(); src.getBytes(src.readerIndex(), dstbuf); dstbuf.reset(); return dst; }