1 files changed, 302 insertions, 0 deletions
diff --git a/src/test/examples/testlo64.c b/src/test/examples/testlo64.c
new file mode 100644
index 0000000..96a55b9
--- /dev/null
+++ b/src/test/examples/testlo64.c
@@ -0,0 +1,302 @@
+/*-------------------------------------------------------------------------
+ *
+ * testlo64.c
+ *	  test using large objects with libpq using 64-bit APIs
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/test/examples/testlo64.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, pg_int64 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);
+
+	if (lo_lseek64(conn, lobj_fd, start, SEEK_SET) < 0)
+		fprintf(stderr, "error in lo_lseek64: %s", PQerrorMessage(conn));
+
+	if (lo_tell64(conn, lobj_fd) != start)
+		fprintf(stderr, "error in lo_tell64: %s", PQerrorMessage(conn));
+
+	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, pg_int64 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);
+
+	if (lo_lseek64(conn, lobj_fd, start, SEEK_SET) < 0)
+		fprintf(stderr, "error in lo_lseek64: %s", PQerrorMessage(conn));
+
+	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);
+}
+
+static void
+my_truncate(PGconn *conn, Oid lobjId, pg_int64 len)
+{
+	int			lobj_fd;
+
+	lobj_fd = lo_open(conn, lobjId, INV_READ | INV_WRITE);
+	if (lobj_fd < 0)
+		fprintf(stderr, "cannot open large object %u", lobjId);
+
+	if (lo_truncate64(conn, lobj_fd, len) < 0)
+		fprintf(stderr, "error in lo_truncate64: %s", PQerrorMessage(conn));
+
+	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,
+			   *out_filename2;
+	char	   *database;
+	Oid			lobjOid;
+	PGconn	   *conn;
+	PGresult   *res;
+
+	if (argc != 5)
+	{
+		fprintf(stderr, "Usage: %s database_name in_filename out_filename out_filename2\n",
+				argv[0]);
+		exit(1);
+	}
+
+	database = argv[1];
+	in_filename = argv[2];
+	out_filename = argv[3];
+	out_filename2 = argv[4];
+
+	/*
+	 * 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, "Connection to database failed: %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 4294967000-4294968000 of the large object\n");
+		pickout(conn, lobjOid, 4294967000U, 1000);
+
+		printf("overwriting bytes 4294967000-4294968000 of the large object with X's\n");
+		overwrite(conn, lobjOid, 4294967000U, 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));
+
+		printf("truncating to 3294968000 bytes\n");
+		my_truncate(conn, lobjOid, 3294968000U);
+
+		printf("exporting truncated large object to file \"%s\" ...\n", out_filename2);
+		if (lo_export(conn, lobjOid, out_filename2) < 0)
+			fprintf(stderr, "%s\n", PQerrorMessage(conn));
+	}
+
+	res = PQexec(conn, "end");
+	PQclear(res);
+	PQfinish(conn);
+	return 0;
+}