[Firebird-odbc-devel] Error in parsing transaction settings ?!

[Marco H. <mh...@de...>]

Hello all,

 

due to I had some problem with transaction setting I ran through the code by
debugger  and found the following function which maybe did not work like it
should. It is used to parse a “set transaction” command and check if some
tables are required to be used in a special reservation mode.

 

According to the sql syntax declaration

Syntax SET TRANSACTION [NAME transaction]

[READ WRITE | READ ONLY]

[WAIT | NO WAIT]

[[ISOLATION LEVEL] {SNAPSHOT [TABLE STABILITY]

| READ COMMITTED [[NO] RECORD_VERSION]}]

[RESERVING <reserving_clause>

| USING dbhandle [, dbhandle …]];

<reserving_clause> = table [, table …]

[FOR [SHARED | PROTECTED] {READ | WRITE}] [, <reserving_clause>]

 

it is possible to define several tables in a comma separated list for a
special reserving mode. The function below does not respect this possibility
in my opinion. Only the comma for separation of different “FOR” clauses is
respected.

Furthermore there seems to be a problem in setting the “lockMode” for the
table. Within the last “if“ section for all tables found during the parsing,
the “lockMode” of the last “FOR” clause is set. So the possibility of having
different “lockMode” for each “FOR” clause is not respected.

 

 

 

void IscConnection::parseReservingTable( char *& string, char *& tpbBuffer,
short transFlags )

{

      char *saveLockMode[256];

      int countTable = 0;

      char lockMode = 0;

      char *& ptOut = string;

      char *beg = tpbBuffer + 2;

      char *end;

 

      while ( true )

    {

            saveLockMode[countTable++] = beg - 2;

            char &lengthTableName = *(beg - 1);

            end = beg;

 

            while ( !IS_END_TOKEN( *ptOut ) )

                  *end++ = *ptOut++;

 

            lengthTableName = end - beg;

 

            SKIP_WHITE ( ptOut );

      //          SYNTAX_ERROR ("relation name");

 

            char &lockLevel = *end++;

 

            IS_MATCH_EXT( "FOR" );

            lockLevel = (transFlags & TRA_con) ? isc_tpb_protected :
isc_tpb_shared;

            lockMode = isc_tpb_lock_read;

 

            if ( IS_MATCH_EXT( "PROTECTED" ) )

                  lockLevel = isc_tpb_protected;

            else if ( IS_MATCH_EXT( "EXCLUSIVE" ) )

                  lockLevel = isc_tpb_exclusive;

            else if ( IS_MATCH_EXT( "SHARED" ) )

                  lockLevel = isc_tpb_shared;

 

            if ( IS_MATCH_EXT( "WRITE" ) )

            {

                  if ( transFlags & TRA_ro )

                        throw SQLEXCEPTION( SYNTAX_ERROR, "write lock
requested for a read_only transaction" );

 

                  lockMode = isc_tpb_lock_write;

            }

            else 

                  IS_MATCH_EXT( "READ" );

 

            if ( !( IS_MATCH_EXT( "," ) ) )

                  break;

 

            beg = end + 2;

      }

 

      tpbBuffer = end;

 

      if ( countTable )

      {

            //

            // get the lock level and mode and apply them to all the

            // relations in the list

            //

            do

                  *saveLockMode[--countTable] = lockMode;

            while ( countTable );

      }

}

 

 

Can some authorized person check fix this, please?

Thanks for help!

 

Regards,

 

Marco Held

 

phone: +49 271 77202 27

e-mail:   <mailto:mh...@de...> mh...@de...

 

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