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Diffstat (limited to 'src/interfaces/libpq/fe-lobj.c')
| -rw-r--r-- | src/interfaces/libpq/fe-lobj.c | 381 |
1 files changed, 381 insertions, 0 deletions
diff --git a/src/interfaces/libpq/fe-lobj.c b/src/interfaces/libpq/fe-lobj.c new file mode 100644 index 00000000000..c0c60d4a781 --- /dev/null +++ b/src/interfaces/libpq/fe-lobj.c @@ -0,0 +1,381 @@ +/*------------------------------------------------------------------------- + * + * fe-lobj.c-- + * Front-end large object interface + * + * Copyright (c) 1994, Regents of the University of California + * + * + * IDENTIFICATION + * $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-lobj.c,v 1.1.1.1 1996/07/09 06:22:17 scrappy Exp $ + * + *------------------------------------------------------------------------- + */ +#include <stdio.h> +#include <fcntl.h> +#include <sys/stat.h> +#include <sys/types.h> +#include "postgres.h" +#include "libpq-fe.h" +#include "obj/fmgr.h" +#include "libpq/libpq-fs.h" + +#ifndef MAXPATHLEN +#define MAXPATHLEN 1024 +#endif + +#define LO_BUFSIZE 1024 + +/* + * lo_open + * opens an existing large object + * + * returns the file descriptor for use in later lo_* calls + * return -1 upon failure. + */ +int +lo_open(PGconn* conn, Oid lobjId, int mode) +{ + int fd; + int result_len; + PQArgBlock argv[2]; + PGresult *res; + + argv[0].isint = 1; + argv[0].len = 4; + argv[0].u.integer = lobjId; + + argv[1].isint = 1; + argv[1].len = 4; + argv[1].u.integer = mode; + + res = PQfn(conn, F_LO_OPEN,&fd,&result_len,1,argv,2); + if (PQresultStatus(res) == PGRES_COMMAND_OK) { + PQclear(res); + + /* have to do this to reset offset in shared fd cache */ + /* but only if fd is valid */ + if (fd >= 0 && lo_lseek(conn, fd, 0L, SEEK_SET) < 0) + return -1; + return fd; + } else + return -1; +} + +/* + * lo_close + * closes an existing large object + * + * returns 0 upon success + * returns -1 upon failure. + */ +int +lo_close(PGconn *conn, int fd) +{ + PQArgBlock argv[1]; + PGresult *res; + int retval; + int result_len; + + 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); + if (PQresultStatus(res) == PGRES_COMMAND_OK) { + PQclear(res); + return retval; + } else + return -1; +} + +/* + * lo_read + * read len bytes of the large object into buf + * + * returns the length of bytes read. + * the CALLER must have allocated enough space to hold the result returned + */ + +int +lo_read(PGconn *conn, int fd, char *buf, int len) +{ + PQArgBlock argv[2]; + PGresult *res; + int result_len; + + argv[0].isint = 1; + argv[0].len = 4; + argv[0].u.integer = fd; + + argv[1].isint = 1; + argv[1].len = 4; + argv[1].u.integer = len; + + res = PQfn(conn, F_LOREAD,(int*)buf,&result_len,0,argv,2); + if (PQresultStatus(res) == PGRES_COMMAND_OK) { + PQclear(res); + return result_len; + } else + return -1; +} + +/* + * lo_write + * write len bytes of buf into the large object fd + * + */ +int +lo_write(PGconn *conn, int fd, char *buf, int len) +{ + PQArgBlock argv[2]; + PGresult *res; + int result_len; + int retval; + + if (len <= 0) + return 0; + + argv[0].isint = 1; + argv[0].len = 4; + argv[0].u.integer = fd; + + argv[1].isint = 0; + argv[1].len = len; + argv[1].u.ptr = (int*)buf; + + res = PQfn(conn, F_LOWRITE,&retval,&result_len,1,argv,2); + if (PQresultStatus(res) == PGRES_COMMAND_OK) { + PQclear(res); + return retval; + } else + return -1; +} + +/* + * lo_lseek + * change the current read or write location on a large object + * currently, only L_SET is a legal value for whence + * + */ + +int +lo_lseek(PGconn *conn, int fd, int offset, int whence) +{ + PQArgBlock argv[3]; + PGresult *res; + int retval; + int result_len; + + argv[0].isint = 1; + argv[0].len = 4; + argv[0].u.integer = fd; + + argv[1].isint = 1; + argv[1].len = 4; + argv[1].u.integer = offset; + + argv[2].isint = 1; + argv[2].len = 4; + argv[2].u.integer = whence; + + res = PQfn(conn, F_LO_LSEEK,&retval,&result_len,1,argv,3); + if (PQresultStatus(res) == PGRES_COMMAND_OK) { + PQclear(res); + return retval; + } else + return -1; +} + +/* + * lo_creat + * create a new large object + * the mode is a bitmask describing different attributes of the new object + * + * returns the oid of the large object created or + * InvalidOid upon failure + */ + +Oid +lo_creat(PGconn *conn, int mode) +{ + PQArgBlock argv[1]; + PGresult *res; + int retval; + int result_len; + + 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); + if (PQresultStatus(res) == PGRES_COMMAND_OK) { + PQclear(res); + return (Oid)retval; + } else + return InvalidOid; +} + + +/* + * lo_tell + * returns the current seek location of the large object + * + */ + +int +lo_tell(PGconn *conn, int fd) +{ + int retval; + PQArgBlock argv[1]; + PGresult *res; + int result_len; + + 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); + if (PQresultStatus(res) == PGRES_COMMAND_OK) { + PQclear(res); + return retval; + } else + return -1; +} + +/* + * lo_unlink + * delete a file + * + */ + +int +lo_unlink(PGconn *conn, Oid lobjId) +{ + PQArgBlock argv[1]; + PGresult *res; + int result_len; + int retval; + + 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); + if (PQresultStatus(res) == PGRES_COMMAND_OK) { + PQclear(res); + return retval; + } else + return -1; +} + +/* + * lo_import - + * imports a file as an (inversion) large object. + * returns the oid of that object upon success, + * returns InvalidOid upon failure + * + */ + +Oid +lo_import(PGconn *conn, char* filename) +{ + int fd; + int nbytes, tmp; + char buf[LO_BUFSIZE]; + Oid lobjOid; + int lobj; + + /* + * open the file to be read in + */ + fd = open(filename, O_RDONLY, 0666); + if (fd < 0) { /* error */ + sprintf(conn->errorMessage, + "lo_import: can't open unix file\"%s\"\n", filename); + return InvalidOid; + } + + /* + * create an inversion "object" + */ + lobjOid = lo_creat(conn, INV_READ|INV_WRITE); + if (lobjOid == InvalidOid) { + sprintf(conn->errorMessage, + "lo_import: can't create inv object for \"%s\"", filename); + return InvalidOid; + } + + lobj = lo_open(conn, lobjOid, INV_WRITE); + if (lobj == -1) { + sprintf(conn->errorMessage, + "lo_import: could not open inv object oid %d",lobjOid); + return InvalidOid; + } + /* + * read in from the Unix file and write to the inversion file + */ + while ((nbytes = read(fd, buf, LO_BUFSIZE)) > 0) { + tmp = lo_write(conn,lobj, buf, nbytes); + if (tmp < nbytes) { + sprintf(conn->errorMessage, + "lo_import: error while reading \"%s\"",filename); + return InvalidOid; + } + } + + (void) close(fd); + (void) lo_close(conn, lobj); + + return lobjOid; +} + +/* + * lo_export - + * exports an (inversion) large object. + * returns -1 upon failure, 1 otherwise + */ +int +lo_export(PGconn *conn, Oid lobjId, char *filename) +{ + int fd; + int nbytes, tmp; + char buf[LO_BUFSIZE]; + int lobj; + + /* + * create an inversion "object" + */ + lobj = lo_open(conn, lobjId, INV_READ); + if (lobj == -1) { + sprintf(conn->errorMessage, + "lo_export: can't open inv object %d",lobjId); + return -1; + } + + /* + * open the file to be written to + */ + fd = open(filename, O_CREAT|O_WRONLY, 0666); + if (fd < 0) { /* error */ + sprintf(conn->errorMessage, + "lo_export: can't open unix file\"%s\"",filename); + return 0; + } + + /* + * read in from the Unix file and write to the inversion file + */ + while ((nbytes = lo_read(conn, lobj, buf, LO_BUFSIZE)) > 0) { + tmp = write(fd, buf, nbytes); + if (tmp < nbytes) { + sprintf(conn->errorMessage, + "lo_export: error while writing \"%s\"", + filename); + return -1; + } + } + + (void) lo_close(conn,lobj); + (void) close(fd); + + return 1; +} |