Netty 3.x unbounded DynamicChannelBuffer growth. See http://stackoverflow.com/questions/12134212/trim-dynamicbuffer-to-maintain-size for more information.

gistfile1.txt

    @Override
    public void ensureWritableBytes(int minWritableBytes) {
        if (minWritableBytes <= writableBytes()) {
            return;
        }

        int newCapacity;
        if (capacity() == 0) {
            newCapacity = 1;
        } else {
            newCapacity = capacity();
        }
        int minNewCapacity = writerIndex() + minWritableBytes;
        while (newCapacity < minNewCapacity) {
            newCapacity <<= 1;

            // Check if we exceeded the maximum size of 2gb if this is the case then
            // newCapacity == 0
            //
            // https://github.com/netty/netty/issues/258
            if (newCapacity == 0) {
                throw new IllegalStateException("Maximum size of 2gb exceeded");
            }
        }

        ChannelBuffer newBuffer = factory().getBuffer(order(), newCapacity);
        newBuffer.writeBytes(buffer, 0, writerIndex());
        buffer = newBuffer;
    }