Further thoughts about lo_export/lo_import error handling: if one of

the lower-level large object functions fails, it will have already set
a suitable error message --- probably something from the backend ---
and it is not useful to overwrite that with a generic 'error while
reading large object' message.  So remove redundant messages.
This commit is contained in:
Tom Lane 2006-06-14 17:49:25 +00:00
parent f3164c0200
commit 2193beb761
1 changed files with 20 additions and 28 deletions

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/interfaces/libpq/fe-lobj.c,v 1.57 2006/06/14 01:28:55 tgl Exp $
* $PostgreSQL: pgsql/src/interfaces/libpq/fe-lobj.c,v 1.58 2006/06/14 17:49:25 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -32,7 +32,6 @@
#include <fcntl.h>
#include <sys/stat.h>
#include <errno.h>
#include "libpq-fe.h"
#include "libpq-int.h"
@ -458,9 +457,7 @@ lo_import(PGconn *conn, const char *filename)
lobjOid = lo_creat(conn, INV_READ | INV_WRITE);
if (lobjOid == InvalidOid)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("could not create large object for file \"%s\"\n"),
filename);
/* we assume lo_creat() already set a suitable error message */
(void) close(fd);
return InvalidOid;
}
@ -468,9 +465,7 @@ lo_import(PGconn *conn, const char *filename)
lobj = lo_open(conn, lobjOid, INV_WRITE);
if (lobj == -1)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("could not open large object %u\n"),
lobjOid);
/* we assume lo_open() already set a suitable error message */
(void) close(fd);
return InvalidOid;
}
@ -484,16 +479,11 @@ lo_import(PGconn *conn, const char *filename)
if (tmp != nbytes)
{
/*
* If the lo_write failed, we are probably in an aborted
* transaction and so lo_close will fail. Try it anyway for
* cleanliness, but don't let it determine the returned error
* message.
* If lo_write() failed, we are now in an aborted transaction
* so there's no need for lo_close(); furthermore, if we tried
* it we'd overwrite the useful error result with a useless one.
* So just nail the doors shut and get out of town.
*/
(void) lo_close(conn, lobj);
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("error while writing large object %u\n"),
lobjOid);
(void) close(fd);
return InvalidOid;
}
@ -511,9 +501,7 @@ lo_import(PGconn *conn, const char *filename)
if (lo_close(conn, lobj) != 0)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("error while writing large object %u\n"),
lobjOid);
/* we assume lo_close() already set a suitable error message */
return InvalidOid;
}
@ -542,8 +530,7 @@ lo_export(PGconn *conn, Oid lobjId, const char *filename)
lobj = lo_open(conn, lobjId, INV_READ);
if (lobj == -1)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("could not open large object %u\n"), lobjId);
/* we assume lo_open() already set a suitable error message */
return -1;
}
@ -569,7 +556,7 @@ lo_export(PGconn *conn, Oid lobjId, const char *filename)
if (tmp != nbytes)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("error while writing to file \"%s\": %s\n"),
libpq_gettext("could not write to file \"%s\": %s\n"),
filename, pqStrerror(errno, sebuf, sizeof(sebuf)));
(void) lo_close(conn, lobj);
(void) close(fd);
@ -577,18 +564,23 @@ lo_export(PGconn *conn, Oid lobjId, const char *filename)
}
}
if (lo_close(conn, lobj) != 0 || nbytes < 0)
/*
* If lo_read() failed, we are now in an aborted transaction
* so there's no need for lo_close(); furthermore, if we tried
* it we'd overwrite the useful error result with a useless one.
* So skip lo_close() if we got a failure result.
*/
if (nbytes < 0 ||
lo_close(conn, lobj) != 0)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("error while reading large object %u\n"),
lobjId);
/* assume lo_read() or lo_close() left a suitable error message */
result = -1;
}
if (close(fd))
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("error while writing to file \"%s\": %s\n"),
libpq_gettext("could not write to file \"%s\": %s\n"),
filename, pqStrerror(errno, sebuf, sizeof(sebuf)));
result = -1;
}