Hi Ming Qin,
can you pls. provide an SVN diff file? I will gladly apply your fix.
Thank you very much!
WBR,
Alexey.
On Mar 7, 2010, at 6:20 , ming qin wrote:
>
> Below is an implementation on method parseWithTerminatingSeq for
> class StringDecoder.java by taking terminator backward validation.
>
>
> Assumptions:
> string being read from channel contains one terminator.
>
> How to test:
> Setting up a small value for DEFAULT_READ_BUFFER_SIZE in
> TCPNIOTransport
> Here is my setting up:
> private static final int DEFAULT_READ_BUFFER_SIZE = 2;
>
>
>
> protected TransformationResult<Buffer, String>
> parseWithTerminatingSeq(
> AttributeStorage storage, Buffer input) {
> final int terminationBytesLength =
> stringTerminateBytes.length;
>
> int checkIndexBackWard = stringTerminateBytes.length-1;
>
> int termIndex = -1;
>
> Integer offsetInt = lengthAttribute.get(storage);
> int offset = 0;
> if (offsetInt != null) {
> offset = offsetInt;
> }
> int comparisonMarker =0;
>
>
>
> for( int i= input.limit()-1 ; i >=0; i--) {
>
>
> if (input.get(i) ==
> stringTerminateBytes[checkIndexBackWard]) {
> checkIndexBackWard--;
> comparisonMarker++;
> if (comparisonMarker == terminationBytesLength) {
> termIndex = input.limit() -
> terminationBytesLength ;
> break;
> }
> }else { break;}
> }
>
>
> //rest part of codes is remained as intact as original ones.
>
>
> }
>
>
>
>
>
>
> Ming Qin
> Cell Phone 858-353-2839
>
> --- On Fri, 3/5/10, ming qin <mingqin1_at_yahoo.com> wrote:
>
> From: ming qin <mingqin1_at_yahoo.com>
> Subject: Surplus checking of terminator byte[] performed by
> StringDecoder.parseWithTerminatingSeq
> To: dev_at_grizzly.dev.java.net
> Date: Friday, March 5, 2010, 10:45 PM
>
>
> Surplus checking of terminator byte[] performed by
> StringDecoder.parseWithTerminatingSeq method
>
>
> Symptom:
>
> if size of byte[] read from channel is bigger than value of
> DefaultMemoryManager’s DEFAULT_MAX_BUFFER_SIZE,
> parseWIthTerminatingSeq will be called more than 1 time to determine
> TransformationRequit’s status as COMPLETE. Unfortunately, <Buffer>
> input is not individual chunked byte[] being read from polling
> iteration based on current SelectionKey’s OP_READ, instead
> <Buffer>input is a composite buff[] which comprises cumulative
> chucks of byte[] occurred from the 1st , 2nd… to the current
> SelectionKey’s OP_READ.
>
> The consequence of this design leads low efficiency ( time
> consuming) to determine ending of intended read-in string.
>
> For example : DEFAULT_MAX_BUFFER_SIZE=2, StringFilter’s
> terminator is =’\r\n”, Inputting Sting is =”ABCD\r\n”
> In an idea testing setting up, parseWithTerminatingSeq will
> be called four times and each time consists of iterations of char
> comparison against fixed terminator chars
>
> The 1st time, <Buffer> input contains “AB” , checking
> terminator for the 1st time .
> The 2nd time, <Buffer> input contains “ABC” checking terminator
> for the 2nd time , but it run from char A to C , instead starting
> from char C.
> The 3rd time, <Buffer> input contains “ABCD\r” checking
> terminator for the 3nd time , but it run from char A to \r , instead
> starting from char D.
> The 4th time, <Buffer> input contains “ABCD\r\n” checking
> terminator for the 4th time , it run from char A to \n , Eventually,
> it works since if it starts from “\n” ( newly added char from
> SelectionKey OP_READ), it will go forever.
>
>
>
> Here is my proposed backward validating of terminator,
>
> Terminator sting =”\r\n”, <Buffer> input is a composite buffer[]
>
> The 1st time, <Buffer> input contains “AB”, checking terminator
> backward for the 1st time .
> Chr B is validated against “\n”, failure -> polling
>
> The 2nd time, <Buffer> input contains “ABC”, checking
> terminator backward for the 1st time .
> Chr C is validated against ‘\n”, failure->polling
>
>
> The 3rd time, <Buffer> input contains “ABCD\r”, checking
> terminator backward for the 1st time .
>
> Char \r is validated against ‘\n” failure-Polling
>
> The 4th time, <Buffer> input contains “ABCD\r\n”, checking
> terminator backward for the 1st time .-> Stopping polling -> next
> Filter.
>
>
> Chr \n is validate against “\n”, success
> Chr \r validated against “\r”, success.
>
>
>
> Ming Qin
> Cell Phone 858-353-2839
>