/* Modified PQexec & friends from POSTGRES */ /* * It was necessary to receive the actual error message from the backend * In libpq, upon receiving an 'E' + errmsg pair from the backend, * PQexec prints the errmsg on stderr and returns just a single 'R' * The message would then end up in a window which started alberi. * Also, read_remark has been modified to insert a notice message in * textpane1, instead of printing it on the stderr. * * (KJK) */ /* ---------------------------------------------------------------- * FILE * fe-pqexec.c * * DESCRIPTION * support for executing POSTGRES commands and functions * from a frontend application. * * SUPPORT ROUTINES * read_initstr, read_remark, EstablishComm, process_portal, * StringPointerSet * * INTERFACE ROUTINES * PQdb - Return the current database being accessed. * PQsetdb - Make the specified database the current database. * PQreset - Reset the communication port with the backend. * PQfinish - Close communication ports with the backend. * PQFlushI - Used for flushing out "poll" queries by the monitor. * * >> PQfn - Send a function call to the POSTGRES backend. * >> PQexec - Send a query to the POSTGRES backend * * NOTES * These routines are NOT compiled into the postgres backend, * rather they end up in libpq.a. * * IDENTIFICATION * $Header: /private/postgres/src/lib/libpq/RCS/fe-pqexec.c,v 1.27 1992/08/07 00:38:18 mao Exp $ * ---------------------------------------------------------------- */ #include "tmp/c.h" #include "tmp/simplelists.h" #include "tmp/libpq-fe.h" #include "tmp/fastpath.h" #ifdef POSTGRES_4_1 #include "fmgr.h" #else #include "utils/fmgr.h" #endif #include "utils/exception.h" #define DefaultHost "localhost" #define DefaultPort "4321" #define DefaultTty "/dev/null" #define DefaultOption "" #define DefaultVacuum "~/bin/vacuumd" extern char *PQhost; extern char *PQport; extern char *PQtty; extern char *PQoption; extern char PQdatabase[]; extern int PQportset; extern int PQxactid; char * alberi_PQexec(query) char *query; { char id[2]; char errormsg[error_msg_length]; char command[command_length]; static char PQcommand[command_length+1]; void alberi_EstablishComm(), alberi_read_remark_notice(); char *alberi_process_portal(); static char buff[1024]; /* If the communication is not established, establish it. */ if (!PQportset) alberi_EstablishComm(); /* Send a query to backend. */ pq_putnchar("Q", 1); pq_putint(PQxactid, 4); pq_putstr(query); pqdebug("The query sent to the backend: %s", query); pq_flush(); /* forever (or at least until we get something besides a notice) */ for (;;) { /* Process return values from the backend. * The code in this function is the implementation of * the communication protocol. */ id[0] = '?'; /* Get the identifier. */ pq_getnchar(id,0,1); alberi_read_remark_notice(id); pqdebug("The Identifier is: %c", (char *)id[0]); /* Read in the transaction id. */ PQxactid = pq_getint(4); pqdebug("The Transaction Id is: %d", (char *)PQxactid); switch (id[0]) { case 'I': return("I"); case 'E': /* An error, return 0. */ pq_getstr(errormsg, error_msg_length); pqdebug("%s error encountered.", errormsg); /* (KJK) */ buff[0] = 'R'; /* set up the answer string "R errmsg" */ buff[1] = '\0'; strcat( buff, errormsg ); return buff; /* and return it back */ case 'N': /* print notice and go back to processing return values */ /* * If we get an EOF (i.e. backend quickdies) return an R to the fe */ if (pq_getstr(errormsg, error_msg_length) == EOF) { buff[0] = 'R'; /* (KJK) -- same here */ buff[1] = '\0'; strcat( buff, errormsg ); return buff; } pqdebug("%s notice encountered.", errormsg); buff[0] = 'R'; buff[1] = '\0'; strcat( buff, errormsg ); return buff; case 'A': { char relname[16]; extern int PQAsyncNotifyWaiting; int pid; PQAsyncNotifyWaiting = 0; /* Asynchronized portal. */ /* No tuple transfer at this stage. */ pqdebug("%s portal encountered.", "Asynchronized"); /* Processed the same way as synchronized portal. */ /* return process_portal(1);*/ pq_getstr(relname,16); pid =pq_getint(4); PQappendNotify(relname,pid); } break; case 'P': /* Synchronized (normal) portal. */ return alberi_process_portal(0); case 'C': /* Query executed successfully. */ pq_getstr (command, command_length); pqdebug ("Query command: %s", command); sprintf (PQcommand, "C%s", command); return PQcommand; case 'B': /* Copy command began successfully - it is sending stuff back... */ return "BCOPY"; case 'D': /* Copy command began successfully - it is waiting to receive... */ return "DCOPY"; default: /* The backend violates the protocol. */ if (id[0] == '?') libpq_raise(&ProtocolError, form((int)"No response from the backend, exiting...\n")); else libpq_raise(&ProtocolError, form((int)"Unexpected response from the backend, exiting...\n")); exit(1); } } } void alberi_EstablishComm() { char *getenv(); if (!PQportset) { read_initstr(); if (pq_connect(PQdatabase, getenv("USER"), PQoption, PQhost, PQtty, (char *) NULL, (short)atoi(PQport) ) == -1 ) { libpq_raise(&ProtocolError, form((int)"Failed to connect to backend (host=%s, port=%s)", PQhost, PQport)); } pq_flush(); PQportset = 1; } } void alberi_read_remark_notice(id) char id[]; { char remarks[remark_length]; char errormsg[error_msg_length]; while (id[0] == 'R') { pq_getstr(remarks, remark_length); if (pq_getnchar(id, 0, 1) == EOF) return; } while(id[0] == 'N') { pq_getstr(errormsg,error_msg_length); print_error( &errormsg[0]+4 ); backend_error( "Postgres backend returned a notice" ); if (pq_getnchar(id, 0, 1) == EOF) return; } } /* ---------------- * process_portal * * Process portal queries. * Return values are the same as PQexec(). * ---------------- */ char * alberi_process_portal(rule_p) int rule_p; { char pname[portal_name_length]; char id[2]; char errormsg[error_msg_length]; char command[command_length]; char PQcommand[portal_name_length+1]; static char retbuf[portal_name_length + 1]; char buff[1024]; /* Read in the portal name. */ pq_getstr(pname, portal_name_length); pqdebug("Portal name = %s", pname); /* * This for loop is necessary so that NOTICES out of portal processing * stuff are handled properly. */ for (;;) { /* Read in the identifier following the portal name. */ pq_getnchar(id, 0, 1); read_remark(id); pqdebug("Identifier is: %c", (char *)id[0]); switch (id[0]) { case 'E': /* An error, return 0. */ pq_getstr(errormsg, error_msg_length); pqdebug("%s error encountered.", errormsg); /* get past gunk at front of errmsg */ buff[0] = 'R'; /* set up the answer string "R errmsg" */ buff[1] = '\0'; strcat( buff, errormsg+4 ); return buff; case 'N': /* print notice and go back to processing return values */ /* * If we get an EOF (i.e. backend quickdies) return an R to the fe */ if (pq_getstr(errormsg, error_msg_length) == EOF) { buff[0] = 'R'; /* (KJK) -- same here */ buff[1] = '\0'; strcat( buff, errormsg ); return buff; } pqdebug("%s notice encountered.", errormsg); buff[0] = 'R'; buff[1] = '\0'; strcat( buff, errormsg+4 ); return buff; break; case 'T': /* Tuples are returned, dump data into a portal buffer. */ if (dump_data(pname, rule_p) == -1) { return("R"); } sprintf(PQcommand, "P%s", pname); strcpy(retbuf, PQcommand); return(retbuf); /* Pending data inquiry - return nothing */ case 'C': /* * Portal query command (e.g., retrieve, close), * no tuple returned. */ PQxactid = pq_getint (4); pqdebug("Transaction Id is: %d", (char *)PQxactid); pq_getstr(command, command_length); pqdebug("Query command: %s", command); /* Process the portal commands. */ if (strcmp(command, "retrieve") == 0) { /* Allocate a portal buffer, if portal table is full, error. */ pbuf_setup(pname); return "Cretrieve"; } else if (strcmp (command, "close") == 0) return "Cclose"; else { sprintf(retbuf, "C%s", command); return retbuf; } default: { char s[45]; PQreset(); sprintf(s, "Unexpected identifier in process_portal: %c", id[0]); libpq_raise(&ProtocolError, form ((int)s)); } } } }