LengthFieldBasedFrameDecoder

[Trustin Lee (이희승)]

Hi Hez,

Thanks for closing this thread with a good answer and sorry that I'm late.

Do you find the Javadoc of LengthFieldBasedFrameDecoder difficult to
understand?  I thought your use case is explained already there.  Let
me know what you think so that we can improve the documentation.

Cheers

— Trustin Lee, http://gleamynode.net/



On Sun, Sep 20, 2009 at 9:12 PM, hezjing <hezjing at gmail.com> wrote:
> Hi Mike
> Hmmm ... do you mean the example of the frame like the following?
> <-- HEADER 20 bytes --><-- PAYLOAD 14 bytes -->
> +-------+---------+----+-----------------------+
> |       | Length  |    | Payload               |
> |       | 0x000C  |    |                       |
> +-------+---------+----+-----------------------+
> Total frame size is 34 bytes.
> <-- HEADER 20 bytes --><-- PAYLOAD 100 bytes -->
> +-------+--------+-----+------------------------+
> |       | Length |     | Payload                |
> |       | 0x0064 |     |                        |
> +-------+--------+-----+------------------------+
> Total frame size is 120 bytes.
>
>
> On Sun, Sep 20, 2009 at 1:41 AM, Mike McGrady <mmcgrady at topiatechnology.com>
> wrote:
>>
>> Could you include an example write with this?  The two together, I
>> suspect, will be most helpful to many people, including me.
>> Mike
>> On Sep 19, 2009, at 8:11 AM, hezjing wrote:
>>
>> Hi
>> To close this thread, my solution is to extends FrameDecoder like the
>> following code:
>> @ChannelPipelineCoverage("all")
>> public class MyFrameDecoder extends FrameDecoder {
>>     @Override
>>     protected Object decode(ChannelHandlerContext ctx, Channel channel,
>> ChannelBuffer buf) throws Exception {
>>         // the length field is at 3rd and 4th octet
>>         if (buf.readableBytes() < 4) {
>>             return null;
>>         }
>>         // The length field is in the buffer.
>>         buf.markReaderIndex();
>>         ...
>>         // Read the length field (the payload size)
>>         int length = buf.readUnsignedShort();
>>         // The actual frame size is header (20) + payload size
>>         length += 20;
>>         buf.resetReaderIndex();
>>         if (buf.readableBytes() < length) {
>>             return null;
>>         }
>>         ChannelBuffer frame = buf.readBytes(length);
>>         return frame;
>>     }
>> }
>>
>> Thank you!
>>
>> On Thu, Sep 10, 2009 at 9:23 PM, hezjing <hezjing at gmail.com> wrote:
>>>
>>> Hi
>>> I have a message containing a fixed length header of 20 bytes, followed
>>> by a payload of variable length.
>>> The header contains a 2 bytes length field, indicating the length of the
>>> payload (excluding the header).
>>> For example if the message has 10 bytes payload, then the entire frame
>>> length is 30 bytes (20 bytes header + 10 bytes of payload),
>>> and the length field is 10.
>>> May I know what is the parameter to create LengthFieldBasedFrameDecoder?
>>>
>>> Thank you!
>>>
>>> --
>>>
>>> Hez
>>
>>
>>
>> --
>>
>> Hez
>> _______________________________________________
>> netty-users mailing list
>> netty-users at lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/netty-users
>>
>> Mike McGrady
>> Principal Investigator AF081-028 AFRL SBIR
>> Senior Engineer
>> Topia Technology, Inc.
>> 1.253.720.3365
>> mmcgrady at topiatechnology.com
>>
>>
>>
>>
>>
>>
>>
>>
>>
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>
>
>
> --
>
> Hez
>
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