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Postgres FD Implementation
Commit 41b8c2c8 authored by Marc G. Fournier's avatar Marc G. Fournier
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As proposed, 

    following is the patch to libpq's large object interface that
    removes the requirement to  include  fmgr.h  into  fe-lobj.c.
    The  large object interface now ask's the backend to tell the
    OID's of all the required functions in pg_proc.

From: wieck@sapserv.debis.de (Jan Wieck)
parent 2bdded35
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Showing with 237 additions and 12 deletions
src/interfaces/libpq/fe-connect.c
View file @ 41b8c2c8
......@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-connect.c,v 1.17 1996/11/10 03:06:36 momjian Exp $
* $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-connect.c,v 1.18 1996/11/11 12:16:54 scrappy Exp $
*
*-------------------------------------------------------------------------
*/
......@@ -192,6 +192,7 @@ PQconnectdb(const char *conninfo)
conn->Pfdebug = NULL;
conn->port = NULL;
conn->notifyList = DLNewList();
conn->lobjfuncs = NULL;
conn->pghost = strdup(conninfo_getval("host"));
conn->pgport = strdup(conninfo_getval("port"));
......@@ -299,6 +300,7 @@ PQsetdb(const char *pghost, const char* pgport, const char* pgoptions, const cha
conn->Pfdebug = NULL;
conn->port = NULL;
conn->notifyList = DLNewList();
conn->lobjfuncs = NULL;
if (!pghost || pghost[0] == '\0') {
if (!(tmp = getenv("PGHOST"))) {
......@@ -519,6 +521,7 @@ freePGconn(PGconn *conn)
if (conn->dbName) free(conn->dbName);
if (conn->pguser) free(conn->pguser);
if (conn->notifyList) DLFreeList(conn->notifyList);
if (conn->lobjfuncs) free(conn->lobjfuncs);
free(conn);
}
......
src/interfaces/libpq/fe-lobj.c
View file @ 41b8c2c8
......@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-lobj.c,v 1.3 1996/11/08 06:02:28 momjian Exp $
* $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-lobj.c,v 1.4 1996/11/11 12:16:56 scrappy Exp $
*
*-------------------------------------------------------------------------
*/
......@@ -18,7 +18,6 @@
#include <sys/types.h>
#include "postgres.h"
#include "libpq-fe.h"
#include "fmgr.h"
#include "libpq/libpq-fs.h"
#ifndef MAXPATHLEN
......@@ -27,6 +26,8 @@
#define LO_BUFSIZE 1024
static int lo_initialize(PGconn *conn);
/*
* lo_open
* opens an existing large object
......@@ -49,8 +50,14 @@ lo_open(PGconn* conn, Oid lobjId, int mode)
argv[1].isint = 1;
argv[1].len = 4;
argv[1].u.integer = mode;
if(conn->lobjfuncs == (PGlobjfuncs *)NULL) {
if(lo_initialize(conn) < 0) {
return -1;
}
}
res = PQfn(conn, F_LO_OPEN,&fd,&result_len,1,argv,2);
res = PQfn(conn, conn->lobjfuncs->fn_lo_open,&fd,&result_len,1,argv,2);
if (PQresultStatus(res) == PGRES_COMMAND_OK) {
PQclear(res);
......@@ -78,10 +85,17 @@ lo_close(PGconn *conn, int fd)
int retval;
int result_len;
if(conn->lobjfuncs == (PGlobjfuncs *)NULL) {
if(lo_initialize(conn) < 0) {
return -1;
}
}
argv[0].isint = 1;
argv[0].len = 4;
argv[0].u.integer = fd;
res = PQfn(conn, F_LO_CLOSE,&retval,&result_len,1,argv,1);
res = PQfn(conn, conn->lobjfuncs->fn_lo_close,
&retval,&result_len,1,argv,1);
if (PQresultStatus(res) == PGRES_COMMAND_OK) {
PQclear(res);
return retval;
......@@ -104,6 +118,12 @@ lo_read(PGconn *conn, int fd, char *buf, int len)
PGresult *res;
int result_len;
if(conn->lobjfuncs == (PGlobjfuncs *)NULL) {
if(lo_initialize(conn) < 0) {
return -1;
}
}
argv[0].isint = 1;
argv[0].len = 4;
argv[0].u.integer = fd;
......@@ -112,7 +132,8 @@ lo_read(PGconn *conn, int fd, char *buf, int len)
argv[1].len = 4;
argv[1].u.integer = len;
res = PQfn(conn, F_LOREAD,(int*)buf,&result_len,0,argv,2);
res = PQfn(conn, conn->lobjfuncs->fn_lo_read,
(int*)buf,&result_len,0,argv,2);
if (PQresultStatus(res) == PGRES_COMMAND_OK) {
PQclear(res);
return result_len;
......@@ -133,6 +154,12 @@ lo_write(PGconn *conn, int fd, char *buf, int len)
int result_len;
int retval;
if(conn->lobjfuncs == (PGlobjfuncs *)NULL) {
if(lo_initialize(conn) < 0) {
return -1;
}
}
if (len <= 0)
return 0;
......@@ -144,7 +171,8 @@ lo_write(PGconn *conn, int fd, char *buf, int len)
argv[1].len = len;
argv[1].u.ptr = (int*)buf;
res = PQfn(conn, F_LOWRITE,&retval,&result_len,1,argv,2);
res = PQfn(conn, conn->lobjfuncs->fn_lo_write,
&retval,&result_len,1,argv,2);
if (PQresultStatus(res) == PGRES_COMMAND_OK) {
PQclear(res);
return retval;
......@@ -167,6 +195,12 @@ lo_lseek(PGconn *conn, int fd, int offset, int whence)
int retval;
int result_len;
if(conn->lobjfuncs == (PGlobjfuncs *)NULL) {
if(lo_initialize(conn) < 0) {
return -1;
}
}
argv[0].isint = 1;
argv[0].len = 4;
argv[0].u.integer = fd;
......@@ -179,7 +213,8 @@ lo_lseek(PGconn *conn, int fd, int offset, int whence)
argv[2].len = 4;
argv[2].u.integer = whence;
res = PQfn(conn, F_LO_LSEEK,&retval,&result_len,1,argv,3);
res = PQfn(conn, conn->lobjfuncs->fn_lo_lseek,
&retval,&result_len,1,argv,3);
if (PQresultStatus(res) == PGRES_COMMAND_OK) {
PQclear(res);
return retval;
......@@ -204,10 +239,17 @@ lo_creat(PGconn *conn, int mode)
int retval;
int result_len;
if(conn->lobjfuncs == (PGlobjfuncs *)NULL) {
if(lo_initialize(conn) < 0) {
return -1;
}
}
argv[0].isint = 1;
argv[0].len = 4;
argv[0].u.integer = mode;
res = PQfn(conn, F_LO_CREAT,&retval,&result_len,1,argv,1);
res = PQfn(conn, conn->lobjfuncs->fn_lo_creat,
&retval,&result_len,1,argv,1);
if (PQresultStatus(res) == PGRES_COMMAND_OK) {
PQclear(res);
return (Oid)retval;
......@@ -230,11 +272,18 @@ lo_tell(PGconn *conn, int fd)
PGresult *res;
int result_len;
if(conn->lobjfuncs == (PGlobjfuncs *)NULL) {
if(lo_initialize(conn) < 0) {
return -1;
}
}
argv[0].isint = 1;
argv[0].len = 4;
argv[0].u.integer = fd;
res = PQfn(conn, F_LO_TELL,&retval,&result_len,1,argv,1);
res = PQfn(conn, conn->lobjfuncs->fn_lo_tell,
&retval,&result_len,1,argv,1);
if (PQresultStatus(res) == PGRES_COMMAND_OK) {
PQclear(res);
return retval;
......@@ -256,11 +305,18 @@ lo_unlink(PGconn *conn, Oid lobjId)
int result_len;
int retval;
if(conn->lobjfuncs == (PGlobjfuncs *)NULL) {
if(lo_initialize(conn) < 0) {
return -1;
}
}
argv[0].isint = 1;
argv[0].len = 4;
argv[0].u.integer = lobjId;
res = PQfn(conn, F_LO_UNLINK,&retval,&result_len,1,argv,1);
res = PQfn(conn, conn->lobjfuncs->fn_lo_unlink,
&retval,&result_len,1,argv,1);
if (PQresultStatus(res) == PGRES_COMMAND_OK) {
PQclear(res);
return retval;
......@@ -380,3 +436,157 @@ lo_export(PGconn *conn, Oid lobjId, char *filename)
return 1;
}
/* ----------------
* lo_initialize
*
* Initialize the large object interface for an existing connection.
* We ask the backend about the functions OID's in pg_proc for all
* functions that are required for large object operations.
* ----------------
*/
static int lo_initialize(PGconn *conn)
{
PGresult *res;
PGlobjfuncs *lobjfuncs;
int n;
char *fname;
Oid foid;
/* ----------------
* Allocate the structure to hold the functions OID's
* ----------------
*/
lobjfuncs = (PGlobjfuncs *)malloc(sizeof(PGlobjfuncs));
if (lobjfuncs == (PGlobjfuncs *)NULL) {
strcpy(conn->errorMessage,
"FATAL: malloc() failed in lo_initialize()\n");
return -1;
}
memset((char *)lobjfuncs, 0, sizeof(PGlobjfuncs));
/* ----------------
* Execute the query to get all the functions at once
* ----------------
*/
res = PQexec(conn, "select proname, oid from pg_proc \
where proname = 'lo_open' \
or proname = 'lo_close' \
or proname = 'lo_creat' \
or proname = 'lo_unlink' \
or proname = 'lo_lseek' \
or proname = 'lo_tell' \
or proname = 'LOread' \
or proname = 'LOwrite'");
if (res == (PGresult *)NULL) {
free(lobjfuncs);
return -1;
}
if (res->resultStatus != PGRES_TUPLES_OK) {
free(lobjfuncs);
PQclear(res);
strcpy(conn->errorMessage,
"ERROR: SELECT didn't return data in lo_initialize()\n");
return -1;
}
/* ----------------
* Examine the result and put the OID's into the struct
* ----------------
*/
for(n = 0; n < PQntuples(res); n++) {
fname = PQgetvalue(res, n, 0);
foid = (Oid)atoi(PQgetvalue(res, n, 1));
if(!strcmp(fname, "lo_open")) {
lobjfuncs->fn_lo_open = foid;
} else
if(!strcmp(fname, "lo_close")) {
lobjfuncs->fn_lo_close = foid;
} else
if(!strcmp(fname, "lo_creat")) {
lobjfuncs->fn_lo_creat = foid;
} else
if(!strcmp(fname, "lo_unlink")) {
lobjfuncs->fn_lo_unlink = foid;
} else
if(!strcmp(fname, "lo_lseek")) {
lobjfuncs->fn_lo_lseek = foid;
} else
if(!strcmp(fname, "lo_tell")) {
lobjfuncs->fn_lo_tell = foid;
} else
if(!strcmp(fname, "LOread")) {
lobjfuncs->fn_lo_read = foid;
} else
if(!strcmp(fname, "LOwrite")) {
lobjfuncs->fn_lo_write = foid;
}
}
PQclear(res);
/* ----------------
* Finally check that we really got all large object
* interface functions.
* ----------------
*/
if(lobjfuncs->fn_lo_open == 0) {
strcpy(conn->errorMessage,
"ERROR: Cannot determine OID for function lo_open\n");
free(lobjfuncs);
return -1;
}
if(lobjfuncs->fn_lo_close == 0) {
strcpy(conn->errorMessage,
"ERROR: Cannot determine OID for function lo_close\n");
free(lobjfuncs);
return -1;
}
if(lobjfuncs->fn_lo_creat == 0) {
strcpy(conn->errorMessage,
"ERROR: Cannot determine OID for function lo_creat\n");
free(lobjfuncs);
return -1;
}
if(lobjfuncs->fn_lo_unlink == 0) {
strcpy(conn->errorMessage,
"ERROR: Cannot determine OID for function lo_unlink\n");
free(lobjfuncs);
return -1;
}
if(lobjfuncs->fn_lo_lseek == 0) {
strcpy(conn->errorMessage,
"ERROR: Cannot determine OID for function lo_lseek\n");
free(lobjfuncs);
return -1;
}
if(lobjfuncs->fn_lo_tell == 0) {
strcpy(conn->errorMessage,
"ERROR: Cannot determine OID for function lo_tell\n");
free(lobjfuncs);
return -1;
}
if(lobjfuncs->fn_lo_read == 0) {
strcpy(conn->errorMessage,
"ERROR: Cannot determine OID for function LOread\n");
free(lobjfuncs);
return -1;
}
if(lobjfuncs->fn_lo_write == 0) {
strcpy(conn->errorMessage,
"ERROR: Cannot determine OID for function LOwrite\n");
free(lobjfuncs);
return -1;
}
/* ----------------
* Put the structure into the connection control
* ----------------
*/
conn->lobjfuncs = lobjfuncs;
return 0;
}
src/interfaces/libpq/libpq-fe.h
View file @ 41b8c2c8
......@@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: libpq-fe.h,v 1.11 1996/11/10 03:06:38 momjian Exp $
* $Id: libpq-fe.h,v 1.12 1996/11/11 12:16:57 scrappy Exp $
*
*-------------------------------------------------------------------------
*/
......@@ -96,6 +96,17 @@ typedef struct pgNotify {
int be_pid; /* process id of backend */
} PGnotify;
typedef struct pgLobjfuncs {
Oid fn_lo_open; /* OID of backend function lo_open */
Oid fn_lo_close; /* OID of backend function lo_close */
Oid fn_lo_creat; /* OID of backend function lo_creat */
Oid fn_lo_unlink; /* OID of backend function lo_unlink */
Oid fn_lo_lseek; /* OID of backend function lo_lseek */
Oid fn_lo_tell; /* OID of backend function lo_tell */
Oid fn_lo_read; /* OID of backend function LOread */
Oid fn_lo_write; /* OID of backend function LOwrite */
} PGlobjfuncs;
/* PGconn encapsulates a connection to the backend */
typedef struct pg_conn{
char *pghost; /* the machine on which the server is running */
......@@ -113,6 +124,7 @@ typedef struct pg_conn{
int asyncNotifyWaiting;
Dllist* notifyList;
char *pguser; /* Postgres username of user who is connected */
PGlobjfuncs *lobjfuncs; /* Backend function OID's for large object access */
} PGconn;
#define CMDSTATUS_LEN 40
......
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