[Sqlrelay-discussion] oddity with cursors in sqlrelay-0.39

[Guillaume G. <sql...@bl...>]

Hi folks,

I'm working on a project that puts an abstraction layer around sqlrelay. 
And I found something like an inconsistency in the manner the cursors 
are constructed and destructed. All cursors are consumed with the error 
message
"No server-side cursors were available to process the query."


I'm using sqlrelay-0.39 provided by debian

the interesting part of /etc/sqlrelay/sqlrelay.conf
     <instance id="cpta" port="9000" socket="/tmp/.sqlrelay.cpta" 
dbase="postgresql" connections="5" maxconnections="5" maxqueuelength="0" 
growby="1" ttl="60" endofsession="rollback" sessiontimeout="600" 
runasuser="sqlrelay" runasgroup="sqlrelay" cursors="40" 
authtier="listener" handoff="pass">

the snippet of code that exhausts cursors
----------8<--------------------8<--------------------8<----------
#include <iostream>
#include <sqlrelay/sqlrclient.h>

using namespace std;

int main(int argc, char **argv) {

         sqlrconnection      *con=new 
sqlrconnection("localhost",9000,"/tmp/.sqlrelay.cpta","zorro","11digitsprimenumber",1,1);


     for ( int i=0 ; i<100 ; ++i ) {
             sqlrcursor          *cursor1=new sqlrcursor(con);
             sqlrcursor          *cursor2=new sqlrcursor(con);
         if ( cursor1->sendQuery("SELECT 1 AS r1") == 0 ) {
             cout << cursor1->errorMessage() << endl;
             return 1;
         }
         if ( cursor2->sendQuery("SELECT 2 AS r2") == 0 ) {
             cout << cursor2->errorMessage() << endl;
             return 1;
         }
         delete cursor2;
         delete cursor1;
     }

return 0;
}
----------8<--------------------8<--------------------8<----------

I know that in this example sqlrcursor's pointers should be declared and 
initialized outer the for loop. but it is approximatively what the 
abstraction layer does with the following code  :

Connection 
conn("sqlrelay://zoro:11digitsprimenumber@localhost:9000/tmp/.sqlrelay.cpta");
for (...) {
     Begin transaction(conn);
     conn.query(...);
}

Could you tell me if I'm wrong ?
And if I'm wrong, why this strange issue occurs ?

Thanks in advance


Best regards - Guillaume Gimenez


PS: For information this pseudo code
class Begin {
     Connection& conn;
     public:
     Begin(Connection& conn) {
         conn.setAutoCommitOff();
     }
     ~Begin() {
         conn.rollback();
         conn.setAutoCommitOn();
     }
     commit();
     rollback();
     ...
};
class Connection {
     sqlrconnection *sqlrconn;
     public:
     ...
     ResultSet query(const std::string& str);
     ...
}
class ResultSet {
     sqlrcursor *sqlrcur;
     public:
     ...
     next();
     std::string operator[](const std::string& str);
     ...
}