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/*
* pginterface.c
*
*/
#include <stdio.h>
#include <signal.h>
#include <string.h>
#include <stdarg.h>
#include "halt.h"
#include <libpq-fe.h>
#include "pginterface.h"
static void sig_disconnect();
static void set_signals();
#define NUL '\0'
/* GLOBAL VARIABLES */
static PGconn* conn;
static PGresult* res = NULL;
#define ON_ERROR_STOP 0
#define ON_ERROR_CONTINUE 1
static int on_error_state = ON_ERROR_STOP;
/* LOCAL VARIABLES */
static sigset_t block_sigs, unblock_sigs;
static int tuple;
/*
**
** connectdb - returns PGconn structure
**
*/
PGconn *connectdb( char *dbName,
char *pghost,
char *pgport,
char *pgoptions,
char *pgtty)
{
/* make a connection to the database */
conn = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName);
if (PQstatus(conn) == CONNECTION_BAD)
halt("Connection to database '%s' failed.\n%s\n", dbName,
PQerrorMessage(conn));
set_signals();
return conn;
}
/*
**
** disconnectdb
**
*/
void disconnectdb()
{
PQfinish(conn);
}
/*
**
** doquery - returns PGresult structure
**
*/
PGresult *doquery(char *query)
{
if (res != NULL)
PQclear(res);
sigprocmask(SIG_SETMASK,&block_sigs,NULL);
res = PQexec(conn, query);
sigprocmask(SIG_SETMASK,&unblock_sigs,NULL);
if (on_error_state == ON_ERROR_STOP &&
(res == NULL ||
PQresultStatus(res) == PGRES_BAD_RESPONSE ||
PQresultStatus(res) == PGRES_NONFATAL_ERROR ||
PQresultStatus(res) == PGRES_FATAL_ERROR))
{
if (res != NULL)
fprintf(stderr,"query error: %s\n",PQcmdStatus(res));
else fprintf(stderr,"connection error: %s\n",PQerrorMessage(conn));
PQfinish(conn);
halt("failed request: %s\n", query);
}
tuple = 0;
return res;
}
/*
**
** fetch - returns tuple number (starts at 0), or the value END_OF_TUPLES
** NULL pointers are skipped
**
*/
int fetch(void *param, ...)
{
va_list ap;
int arg, num_args;
num_args = PQnfields(res);
if (tuple >= PQntuples(res))
return END_OF_TUPLES;
va_start(ap, param);
for (arg = 0; arg < num_args; arg++)
{
if (param != NULL)
{
if (PQfsize(res, arg) == -1)
{
memcpy(param,PQgetvalue(res,tuple,arg),PQgetlength(res,tuple,arg));
((char *)param)[PQgetlength(res,tuple,arg)] = NUL;
}
else
memcpy(param,PQgetvalue(res,tuple,arg),PQfsize(res,arg));
}
param = va_arg(ap, char *);
}
va_end(ap);
return tuple++;
}
/*
**
** on_error_stop
**
*/
void on_error_stop()
{
on_error_state = ON_ERROR_STOP;
}
/*
**
** on_error_continue
**
*/
void on_error_continue()
{
on_error_state = ON_ERROR_CONTINUE;
}
/*
**
** sig_disconnect
**
*/
static void sig_disconnect()
{
fprintf(stderr,"exiting...\n");
PQfinish(conn);
exit(1);
}
/*
**
** set_signals
**
*/
static void set_signals()
{
sigemptyset(&block_sigs);
sigemptyset(&unblock_sigs);
sigaddset(&block_sigs,SIGTERM);
sigaddset(&block_sigs,SIGHUP);
sigaddset(&block_sigs,SIGINT);
/* sigaddset(&block_sigs,SIGQUIT); no block */
sigprocmask(SIG_SETMASK,&unblock_sigs,NULL);
signal(SIGTERM,sig_disconnect);
signal(SIGHUP,sig_disconnect);
signal(SIGINT,sig_disconnect);
signal(SIGQUIT,sig_disconnect);
}
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