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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:15:05 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:15:05 +0000
commit46651ce6fe013220ed397add242004d764fc0153 (patch)
tree6e5299f990f88e60174a1d3ae6e48eedd2688b2b /src/test/examples/testlo.c
parentInitial commit. (diff)
downloadpostgresql-14-upstream.tar.xz
postgresql-14-upstream.zip
Adding upstream version 14.5.upstream/14.5upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/test/examples/testlo.c')
-rw-r--r--src/test/examples/testlo.c270
1 files changed, 270 insertions, 0 deletions
diff --git a/src/test/examples/testlo.c b/src/test/examples/testlo.c
new file mode 100644
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--- /dev/null
+++ b/src/test/examples/testlo.c
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+/*-------------------------------------------------------------------------
+ *
+ * testlo.c
+ * test using large objects with libpq
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ * src/test/examples/testlo.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "libpq-fe.h"
+#include "libpq/libpq-fs.h"
+
+#define BUFSIZE 1024
+
+/*
+ * importFile -
+ * import file "in_filename" into database as large object "lobjOid"
+ *
+ */
+static Oid
+importFile(PGconn *conn, char *filename)
+{
+ Oid lobjId;
+ int lobj_fd;
+ char buf[BUFSIZE];
+ int nbytes,
+ tmp;
+ int fd;
+
+ /*
+ * open the file to be read in
+ */
+ fd = open(filename, O_RDONLY, 0666);
+ if (fd < 0)
+ { /* error */
+ fprintf(stderr, "cannot open unix file\"%s\"\n", filename);
+ }
+
+ /*
+ * create the large object
+ */
+ lobjId = lo_creat(conn, INV_READ | INV_WRITE);
+ if (lobjId == 0)
+ fprintf(stderr, "cannot create large object");
+
+ lobj_fd = lo_open(conn, lobjId, INV_WRITE);
+
+ /*
+ * read in from the Unix file and write to the inversion file
+ */
+ while ((nbytes = read(fd, buf, BUFSIZE)) > 0)
+ {
+ tmp = lo_write(conn, lobj_fd, buf, nbytes);
+ if (tmp < nbytes)
+ fprintf(stderr, "error while reading \"%s\"", filename);
+ }
+
+ close(fd);
+ lo_close(conn, lobj_fd);
+
+ return lobjId;
+}
+
+static void
+pickout(PGconn *conn, Oid lobjId, int start, int len)
+{
+ int lobj_fd;
+ char *buf;
+ int nbytes;
+ int nread;
+
+ lobj_fd = lo_open(conn, lobjId, INV_READ);
+ if (lobj_fd < 0)
+ fprintf(stderr, "cannot open large object %u", lobjId);
+
+ lo_lseek(conn, lobj_fd, start, SEEK_SET);
+ buf = malloc(len + 1);
+
+ nread = 0;
+ while (len - nread > 0)
+ {
+ nbytes = lo_read(conn, lobj_fd, buf, len - nread);
+ buf[nbytes] = '\0';
+ fprintf(stderr, ">>> %s", buf);
+ nread += nbytes;
+ if (nbytes <= 0)
+ break; /* no more data? */
+ }
+ free(buf);
+ fprintf(stderr, "\n");
+ lo_close(conn, lobj_fd);
+}
+
+static void
+overwrite(PGconn *conn, Oid lobjId, int start, int len)
+{
+ int lobj_fd;
+ char *buf;
+ int nbytes;
+ int nwritten;
+ int i;
+
+ lobj_fd = lo_open(conn, lobjId, INV_WRITE);
+ if (lobj_fd < 0)
+ fprintf(stderr, "cannot open large object %u", lobjId);
+
+ lo_lseek(conn, lobj_fd, start, SEEK_SET);
+ buf = malloc(len + 1);
+
+ for (i = 0; i < len; i++)
+ buf[i] = 'X';
+ buf[i] = '\0';
+
+ nwritten = 0;
+ while (len - nwritten > 0)
+ {
+ nbytes = lo_write(conn, lobj_fd, buf + nwritten, len - nwritten);
+ nwritten += nbytes;
+ if (nbytes <= 0)
+ {
+ fprintf(stderr, "\nWRITE FAILED!\n");
+ break;
+ }
+ }
+ free(buf);
+ fprintf(stderr, "\n");
+ lo_close(conn, lobj_fd);
+}
+
+
+/*
+ * exportFile -
+ * export large object "lobjOid" to file "out_filename"
+ *
+ */
+static void
+exportFile(PGconn *conn, Oid lobjId, char *filename)
+{
+ int lobj_fd;
+ char buf[BUFSIZE];
+ int nbytes,
+ tmp;
+ int fd;
+
+ /*
+ * open the large object
+ */
+ lobj_fd = lo_open(conn, lobjId, INV_READ);
+ if (lobj_fd < 0)
+ fprintf(stderr, "cannot open large object %u", lobjId);
+
+ /*
+ * open the file to be written to
+ */
+ fd = open(filename, O_CREAT | O_WRONLY | O_TRUNC, 0666);
+ if (fd < 0)
+ { /* error */
+ fprintf(stderr, "cannot open unix file\"%s\"",
+ filename);
+ }
+
+ /*
+ * read in from the inversion file and write to the Unix file
+ */
+ while ((nbytes = lo_read(conn, lobj_fd, buf, BUFSIZE)) > 0)
+ {
+ tmp = write(fd, buf, nbytes);
+ if (tmp < nbytes)
+ {
+ fprintf(stderr, "error while writing \"%s\"",
+ filename);
+ }
+ }
+
+ lo_close(conn, lobj_fd);
+ close(fd);
+}
+
+static void
+exit_nicely(PGconn *conn)
+{
+ PQfinish(conn);
+ exit(1);
+}
+
+int
+main(int argc, char **argv)
+{
+ char *in_filename,
+ *out_filename;
+ char *database;
+ Oid lobjOid;
+ PGconn *conn;
+ PGresult *res;
+
+ if (argc != 4)
+ {
+ fprintf(stderr, "Usage: %s database_name in_filename out_filename\n",
+ argv[0]);
+ exit(1);
+ }
+
+ database = argv[1];
+ in_filename = argv[2];
+ out_filename = argv[3];
+
+ /*
+ * set up the connection
+ */
+ conn = PQsetdb(NULL, NULL, NULL, NULL, database);
+
+ /* check to see that the backend connection was successfully made */
+ if (PQstatus(conn) != CONNECTION_OK)
+ {
+ fprintf(stderr, "%s", PQerrorMessage(conn));
+ exit_nicely(conn);
+ }
+
+ /* Set always-secure search path, so malicious users can't take control. */
+ res = PQexec(conn,
+ "SELECT pg_catalog.set_config('search_path', '', false)");
+ if (PQresultStatus(res) != PGRES_TUPLES_OK)
+ {
+ fprintf(stderr, "SET failed: %s", PQerrorMessage(conn));
+ PQclear(res);
+ exit_nicely(conn);
+ }
+ PQclear(res);
+
+ res = PQexec(conn, "begin");
+ PQclear(res);
+ printf("importing file \"%s\" ...\n", in_filename);
+/* lobjOid = importFile(conn, in_filename); */
+ lobjOid = lo_import(conn, in_filename);
+ if (lobjOid == 0)
+ fprintf(stderr, "%s\n", PQerrorMessage(conn));
+ else
+ {
+ printf("\tas large object %u.\n", lobjOid);
+
+ printf("picking out bytes 1000-2000 of the large object\n");
+ pickout(conn, lobjOid, 1000, 1000);
+
+ printf("overwriting bytes 1000-2000 of the large object with X's\n");
+ overwrite(conn, lobjOid, 1000, 1000);
+
+ printf("exporting large object to file \"%s\" ...\n", out_filename);
+/* exportFile(conn, lobjOid, out_filename); */
+ if (lo_export(conn, lobjOid, out_filename) < 0)
+ fprintf(stderr, "%s\n", PQerrorMessage(conn));
+ }
+
+ res = PQexec(conn, "end");
+ PQclear(res);
+ PQfinish(conn);
+ return 0;
+}