Newer version of Bruce's pginterface library...
This commit is contained in:
Marc G. Fournier
parent
ee9b8016c7
commit
715c6b6d25
|
|
@ -0,0 +1,24 @@
|
|||
#
|
||||
# Makefile
|
||||
#
|
||||
#
|
||||
PGINTERFACE = pginterface.o halt.o
|
||||
TARGET = pginsert pgwordcount pgnulltest
|
||||
CFLAGS = -g -Wall -I/u/postgres95/include
|
||||
LDFLAGS = -L/u/postgres95/lib -lpq
|
||||
|
||||
all : $(TARGET)
|
||||
|
||||
$(TARGET): $(PGINTERFACE) $*.c
|
||||
cc -o $* $(CFLAGS) $*.c $(PGINTERFACE) $(LDFLAGS)
|
||||
|
||||
$(PGINTERFACE): pginterface.c halt.c
|
||||
cc -c $(CFLAGS) pginterface.c halt.c
|
||||
|
||||
clean:
|
||||
rm -f *.o $(TARGET) log core
|
||||
|
||||
install:
|
||||
make clean
|
||||
make CFLAGS=-O
|
||||
install -s -o bin -g bin $(TARGET) /usr/local/bin
|
||||
|
|
@ -0,0 +1,42 @@
|
|||
|
||||
|
||||
Pginterface 1.0
|
||||
|
||||
Attached is a copy of the Postgres support routines I wrote to allow me
|
||||
to more cleanly interface to the libpg library, more like a 4gl SQL
|
||||
interface.
|
||||
|
||||
It has several features that may be useful for others:
|
||||
|
||||
I have simplified the C code that calls libpq by wrapping all the
|
||||
functionality of libpq in calls to connectdb(), doquery(), fetch(),
|
||||
fetchisnull() and disconnectdb(). Each call returns a structure or
|
||||
value, so if you need to do more work with the result, you can. Also, I
|
||||
have a global variable that allows you to disable the error checking I
|
||||
have added to the doquery() routine.
|
||||
|
||||
I have added a function called fetch(), which allows you to pass
|
||||
pointers as parameters, and on return the variables are filled with the
|
||||
data from the binary cursor you opened. These binary cursors are not
|
||||
useful if you are running the query engine on a system with a different
|
||||
architecture than the database server. If you pass a NULL pointer, the
|
||||
column is skipped, and you can use libpq to handle it as you wish.
|
||||
|
||||
I have used sigprocmask() to block the reception of certain signals
|
||||
while the program is executing SQL queries. This prevents a user
|
||||
pressing Control-C from stopping all the back ends. It blocks SIGHUP,
|
||||
SIGINT, and SIGTERM, but does not block SIGQUIT or obviously kill -9.
|
||||
If your platform does not support sigprocmask(), you can remove those
|
||||
function calls. ( Am I correct that abnormal termination can cause
|
||||
shared memory resynchronization?)
|
||||
|
||||
There is a demo program called pginsert that demonstrates how the
|
||||
library can be used.
|
||||
|
||||
You can create a library of pginterface.c and halt.c, and just include
|
||||
pginterface.h in your source code.
|
||||
|
||||
I am willing to maintain this if people find problems or want additional
|
||||
functionality.
|
||||
|
||||
Bruce Momjian (root@candle.pha.pa.us)
|
||||
|
|
@ -0,0 +1,58 @@
|
|||
/*
|
||||
**
|
||||
** halt.c
|
||||
**
|
||||
** This is used to print out error messages and exit
|
||||
*/
|
||||
|
||||
#include <varargs.h>
|
||||
#include <signal.h>
|
||||
#include <stdio.h>
|
||||
#include <stdlib.h>
|
||||
#include <string.h>
|
||||
#include <errno.h>
|
||||
|
||||
|
||||
/*-------------------------------------------------------------------------
|
||||
**
|
||||
** halt - print error message, and call clean up routine or exit
|
||||
**
|
||||
**------------------------------------------------------------------------*/
|
||||
|
||||
/*VARARGS*/
|
||||
void halt(va_alist)
|
||||
va_dcl
|
||||
{
|
||||
va_list arg_ptr;
|
||||
char *format, *pstr;
|
||||
void (*sig_func)();
|
||||
|
||||
va_start(arg_ptr);
|
||||
format = va_arg(arg_ptr,char *);
|
||||
if (strncmp(format,"PERROR", 6) != 0)
|
||||
vfprintf(stderr,format,arg_ptr);
|
||||
else
|
||||
{
|
||||
for (pstr=format+6; *pstr == ' ' || *pstr == ':'; pstr++)
|
||||
;
|
||||
vfprintf(stderr,pstr,arg_ptr);
|
||||
perror("");
|
||||
}
|
||||
va_end(arg_ptr);
|
||||
fflush(stderr);
|
||||
|
||||
/* call one clean up function if defined */
|
||||
if ( (sig_func = signal(SIGTERM, SIG_DFL)) != SIG_DFL &&
|
||||
sig_func != SIG_IGN)
|
||||
(*sig_func)(0);
|
||||
else if ( (sig_func = signal(SIGHUP, SIG_DFL)) != SIG_DFL &&
|
||||
sig_func != SIG_IGN)
|
||||
(*sig_func)(0);
|
||||
else if ( (sig_func = signal(SIGINT, SIG_DFL)) != SIG_DFL &&
|
||||
sig_func != SIG_IGN)
|
||||
(*sig_func)(0);
|
||||
else if ( (sig_func = signal(SIGQUIT, SIG_DFL)) != SIG_DFL &&
|
||||
sig_func != SIG_IGN)
|
||||
(*sig_func)(0);
|
||||
exit(1);
|
||||
}
|
||||
|
|
@ -0,0 +1,7 @@
|
|||
/*
|
||||
** halt.h
|
||||
**
|
||||
*/
|
||||
|
||||
void halt();
|
||||
|
||||
|
|
@ -0,0 +1,98 @@
|
|||
/*
|
||||
* insert.c
|
||||
*
|
||||
*/
|
||||
|
||||
#include <stdio.h>
|
||||
#include <signal.h>
|
||||
#include <time.h>
|
||||
#include <libpq-fe.h>
|
||||
#include "halt.h"
|
||||
#include "pginterface.h"
|
||||
|
||||
int main(int argc, char **argv)
|
||||
{
|
||||
char query[4000];
|
||||
int row =1;
|
||||
int aint;
|
||||
float afloat;
|
||||
double adouble;
|
||||
char achar[11], achar16[17], abpchar[11], avarchar[51], atext[51];
|
||||
time_t aabstime;
|
||||
|
||||
if (argc != 2)
|
||||
halt("Usage: %s database\n",argv[0]);
|
||||
|
||||
connectdb(argv[1],NULL,NULL,NULL,NULL);
|
||||
|
||||
on_error_continue();
|
||||
doquery("DROP TABLE testfetch");
|
||||
on_error_stop();
|
||||
|
||||
doquery("\
|
||||
CREATE TABLE testfetch( \
|
||||
aint int4, \
|
||||
afloat float4, \
|
||||
adouble float8, \
|
||||
achar char, \
|
||||
achar16 char16, \
|
||||
abpchar char(10), \
|
||||
avarchar varchar(50), \
|
||||
atext text, \
|
||||
aabstime abstime) \
|
||||
");
|
||||
|
||||
while(1)
|
||||
{
|
||||
sprintf(query,"INSERT INTO testfetch VALUES ( \
|
||||
%d, \
|
||||
2322.12, \
|
||||
'923121.0323'::float8, \
|
||||
'A', \
|
||||
'Betty', \
|
||||
'Charley', \
|
||||
'Doug', \
|
||||
'Ernie', \
|
||||
'now' )", row);
|
||||
doquery(query);
|
||||
|
||||
doquery("BEGIN WORK");
|
||||
doquery("DECLARE c_testfetch BINARY CURSOR FOR \
|
||||
SELECT * FROM testfetch");
|
||||
|
||||
doquery("FETCH ALL IN c_testfetch");
|
||||
|
||||
while (fetch(
|
||||
&aint,
|
||||
&afloat,
|
||||
&adouble,
|
||||
achar,
|
||||
achar16,
|
||||
abpchar,
|
||||
avarchar,
|
||||
atext,
|
||||
&aabstime) != END_OF_TUPLES)
|
||||
printf("int %d\nfloat %f\ndouble %f\nchar %s\nchar16 %s\n\
|
||||
bpchar %s\nvarchar %s\ntext %s\nabstime %s",
|
||||
aint,
|
||||
afloat,
|
||||
adouble,
|
||||
achar,
|
||||
achar16,
|
||||
abpchar,
|
||||
avarchar,
|
||||
atext,
|
||||
ctime(&aabstime));
|
||||
|
||||
|
||||
doquery("CLOSE c_testfetch");
|
||||
doquery("COMMIT WORK");
|
||||
printf("--- %-d rows inserted so far\n",row);
|
||||
|
||||
row++;
|
||||
}
|
||||
|
||||
disconnectdb();
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
|
@ -0,0 +1,212 @@
|
|||
/*
|
||||
* pginterface.c
|
||||
*
|
||||
*/
|
||||
|
||||
#include <stdio.h>
|
||||
#include <signal.h>
|
||||
#include <string.h>
|
||||
#include <stdarg.h>
|
||||
|
||||
#include <libpq-fe.h>
|
||||
#include "halt.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++;
|
||||
}
|
||||
|
||||
/*
|
||||
**
|
||||
** fetchisnull - returns tuple number (starts at 0), or the value END_OF_TUPLES
|
||||
** NULL pointers are skipped
|
||||
** Returns true or false into null indicator variables
|
||||
*/
|
||||
int fetchisnull(void *param, ...)
|
||||
{
|
||||
va_list ap;
|
||||
int arg, num_args;
|
||||
|
||||
if (tuple == 0)
|
||||
halt("pginterface:fetchisnull(): You must call fetch() first.\n");
|
||||
|
||||
num_args = PQnfields(res);
|
||||
|
||||
if (tuple-1 >= PQntuples(res))
|
||||
return END_OF_TUPLES;
|
||||
va_start(ap, param);
|
||||
for (arg = 0; arg < num_args; arg++)
|
||||
{
|
||||
if (param != NULL)
|
||||
{
|
||||
if (PQgetisnull(res,tuple-1,arg) != 0)
|
||||
*(int *)param = 1;
|
||||
else
|
||||
*(int *)param = 0;
|
||||
}
|
||||
param = va_arg(ap, char *);
|
||||
}
|
||||
va_end(ap);
|
||||
return tuple-1;
|
||||
}
|
||||
|
||||
/*
|
||||
**
|
||||
** 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);
|
||||
}
|
||||
|
|
@ -0,0 +1,14 @@
|
|||
/*
|
||||
* pglib.h
|
||||
*
|
||||
*/
|
||||
|
||||
PGresult *doquery(char *query);
|
||||
PGconn *connectdb();
|
||||
void disconnectdb();
|
||||
int fetch(void *param, ...);
|
||||
int fetchisnull(void *param, ...);
|
||||
void on_error_continue();
|
||||
void on_error_stop();
|
||||
|
||||
#define END_OF_TUPLES (-1)
|
||||
|
|
@ -0,0 +1,140 @@
|
|||
/*
|
||||
* insert.c
|
||||
*
|
||||
*/
|
||||
|
||||
/*#define TEST_NON_NULLS*/
|
||||
|
||||
#include <stdio.h>
|
||||
#include <signal.h>
|
||||
#include <time.h>
|
||||
#include <libpq-fe.h>
|
||||
#include "halt.h"
|
||||
#include "pginterface.h"
|
||||
|
||||
int main(int argc, char **argv)
|
||||
{
|
||||
char query[4000];
|
||||
int row =1;
|
||||
int aint;
|
||||
float afloat;
|
||||
double adouble;
|
||||
char achar[11], achar16[17], abpchar[11], avarchar[51], atext[51];
|
||||
time_t aabstime;
|
||||
int aint_null,
|
||||
afloat_null,
|
||||
adouble_null,
|
||||
achar_null,
|
||||
achar16_null,
|
||||
abpchar_null,
|
||||
avarchar_null,
|
||||
atext_null,
|
||||
aabstime_null;
|
||||
|
||||
if (argc != 2)
|
||||
halt("Usage: %s database\n",argv[0]);
|
||||
|
||||
connectdb(argv[1],NULL,NULL,NULL,NULL);
|
||||
|
||||
on_error_continue();
|
||||
doquery("DROP TABLE testfetch");
|
||||
on_error_stop();
|
||||
|
||||
doquery("\
|
||||
CREATE TABLE testfetch( \
|
||||
aint int4, \
|
||||
afloat float4, \
|
||||
adouble float8, \
|
||||
achar char, \
|
||||
achar16 char16, \
|
||||
abpchar char(10), \
|
||||
avarchar varchar(50), \
|
||||
atext text, \
|
||||
aabstime abstime) \
|
||||
");
|
||||
|
||||
#ifdef TEST_NON_NULLS
|
||||
sprintf(query,"INSERT INTO testfetch VALUES ( \
|
||||
0, \
|
||||
0, \
|
||||
0, \
|
||||
'', \
|
||||
'', \
|
||||
'', \
|
||||
'', \
|
||||
'', \
|
||||
'');");
|
||||
#else
|
||||
sprintf(query,"INSERT INTO testfetch VALUES ( \
|
||||
NULL, \
|
||||
NULL, \
|
||||
NULL, \
|
||||
NULL, \
|
||||
NULL, \
|
||||
NULL, \
|
||||
NULL, \
|
||||
NULL, \
|
||||
NULL);");
|
||||
#endif
|
||||
doquery(query);
|
||||
|
||||
doquery("BEGIN WORK");
|
||||
doquery("DECLARE c_testfetch BINARY CURSOR FOR \
|
||||
SELECT * FROM testfetch");
|
||||
|
||||
doquery("FETCH ALL IN c_testfetch");
|
||||
|
||||
if (fetch(
|
||||
&aint,
|
||||
&afloat,
|
||||
&adouble,
|
||||
achar,
|
||||
achar16,
|
||||
abpchar,
|
||||
avarchar,
|
||||
atext,
|
||||
&aabstime) != END_OF_TUPLES)
|
||||
printf("int %d\nfloat %f\ndouble %f\nchar %s\nchar16 %s\n\
|
||||
bpchar %s\nvarchar %s\ntext %s\nabstime %s\n",
|
||||
aint,
|
||||
afloat,
|
||||
adouble,
|
||||
achar,
|
||||
achar16,
|
||||
abpchar,
|
||||
avarchar,
|
||||
atext,
|
||||
ctime(&aabstime));
|
||||
if (fetchisnull(
|
||||
&aint_null,
|
||||
&afloat_null,
|
||||
&adouble_null,
|
||||
&achar_null,
|
||||
&achar16_null,
|
||||
&abpchar_null,
|
||||
&avarchar_null,
|
||||
&atext_null,
|
||||
&aabstime_null) != END_OF_TUPLES)
|
||||
printf("NULL:\nint %d\nfloat %d\ndouble %d\nchar %d\nchar16 %d\n\
|
||||
bpchar %d\nvarchar %d\ntext %d\nabstime %d\n",
|
||||
aint_null,
|
||||
afloat_null,
|
||||
adouble_null,
|
||||
achar_null,
|
||||
achar16_null,
|
||||
abpchar_null,
|
||||
avarchar_null,
|
||||
atext_null,
|
||||
aabstime_null);
|
||||
|
||||
|
||||
doquery("CLOSE c_testfetch");
|
||||
doquery("COMMIT WORK");
|
||||
printf("--- 1 row inserted\n");
|
||||
|
||||
row++;
|
||||
|
||||
disconnectdb();
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
|
@ -0,0 +1,72 @@
|
|||
/*
|
||||
* wordcount.c
|
||||
*
|
||||
*/
|
||||
|
||||
#include <stdio.h>
|
||||
#include <signal.h>
|
||||
#include <time.h>
|
||||
#include <libpq-fe.h>
|
||||
#include "halt.h"
|
||||
#include "pginterface.h"
|
||||
|
||||
int main(int argc, char **argv)
|
||||
{
|
||||
char query[4000];
|
||||
int row = 0;
|
||||
int count;
|
||||
char line[4000];
|
||||
|
||||
if (argc != 2)
|
||||
halt("Usage: %s database\n",argv[0]);
|
||||
|
||||
connectdb(argv[1],NULL,NULL,NULL,NULL);
|
||||
on_error_continue();
|
||||
doquery("DROP TABLE words");
|
||||
on_error_stop();
|
||||
|
||||
doquery("\
|
||||
CREATE TABLE words( \
|
||||
matches int4, \
|
||||
word text ) \
|
||||
");
|
||||
doquery("\
|
||||
CREATE INDEX i_words_1 ON words USING btree ( \
|
||||
word text_ops )\
|
||||
");
|
||||
|
||||
while(1)
|
||||
{
|
||||
if (scanf("%s",line) != 1)
|
||||
break;
|
||||
doquery("BEGIN WORK");
|
||||
sprintf(query,"\
|
||||
DECLARE c_words BINARY CURSOR FOR \
|
||||
SELECT count(*) \
|
||||
FROM words \
|
||||
WHERE word = '%s'", line);
|
||||
doquery(query);
|
||||
doquery("FETCH ALL IN c_words");
|
||||
|
||||
while (fetch(&count) == END_OF_TUPLES)
|
||||
count = 0;
|
||||
doquery("CLOSE c_words");
|
||||
doquery("COMMIT WORK");
|
||||
|
||||
if (count == 0)
|
||||
sprintf(query,"\
|
||||
INSERT INTO words \
|
||||
VALUES (1, '%s')", line);
|
||||
else
|
||||
sprintf(query,"\
|
||||
UPDATE words \
|
||||
SET matches = matches + 1
|
||||
WHERE word = '%s'", line);
|
||||
doquery(query);
|
||||
row++;
|
||||
}
|
||||
|
||||
disconnectdb();
|
||||
return 0;
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue