/*------------------------------------------------------------------------- * * testlo64.c * test using large objects with libpq using 64-bit APIs * * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION * src/test/examples/testlo64.c * *------------------------------------------------------------------------- */ #include #include #include #include #include #include #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, "%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; }