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

[Nikolay S. <nik...@re...>]

Hello, Marco!

1) Can you open this issue in a tracker? Test case would be welcome there.

2) Is it possible for you to prepare "unified context diff" (diff -u) 
format patch against current HEAD?

I will review/apply it afterwards.

Thanks!

Nikolay Samofatov

On 15.02.2010 11:22, Marco Held wrote:
>
> 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: mh...@de... <mailto:mh...@de...>
>
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