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Improve error detection and recovery in lo_import()/lo_export().

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Problems noted while experimenting with new control-C code for psql.
This commit is contained in:
Tom Lane 2006-06-14 01:28:55 +00:00
parent 067e40cc6d
commit ace93353ea
1 changed files with 56 additions and 29 deletions
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85
src/interfaces/libpq/fe-lobj.c
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@ -8,7 +8,7 @@
* *
* *
* IDENTIFICATION * IDENTIFICATION
* $PostgreSQL: pgsql/src/interfaces/libpq/fe-lobj.c,v 1.56 2006/03/05 15:59:09 momjian Exp $ * $PostgreSQL: pgsql/src/interfaces/libpq/fe-lobj.c,v 1.57 2006/06/14 01:28:55 tgl Exp $
* *
*------------------------------------------------------------------------- *-------------------------------------------------------------------------
*/ */
@ -58,6 +58,12 @@ lo_open(PGconn *conn, Oid lobjId, int mode)
PQArgBlock argv[2]; PQArgBlock argv[2];
PGresult *res; PGresult *res;
if (conn->lobjfuncs == NULL)
{
if (lo_initialize(conn) < 0)
return -1;
}
argv[0].isint = 1; argv[0].isint = 1;
argv[0].len = 4; argv[0].len = 4;
argv[0].u.integer = lobjId; argv[0].u.integer = lobjId;
@ -66,12 +72,6 @@ lo_open(PGconn *conn, Oid lobjId, int mode)
argv[1].len = 4; argv[1].len = 4;
argv[1].u.integer = mode; argv[1].u.integer = mode;
if (conn->lobjfuncs == NULL)
{
if (lo_initialize(conn) < 0)
return -1;
}
res = PQfn(conn, conn->lobjfuncs->fn_lo_open, &fd, &result_len, 1, argv, 2); res = PQfn(conn, conn->lobjfuncs->fn_lo_open, &fd, &result_len, 1, argv, 2);
if (PQresultStatus(res) == PGRES_COMMAND_OK) if (PQresultStatus(res) == PGRES_COMMAND_OK)
{ {
@ -438,6 +438,7 @@ lo_import(PGconn *conn, const char *filename)
char buf[LO_BUFSIZE]; char buf[LO_BUFSIZE];
Oid lobjOid; Oid lobjOid;
int lobj; int lobj;
char sebuf[256];
/* /*
* open the file to be read in * open the file to be read in
@ -445,8 +446,6 @@ lo_import(PGconn *conn, const char *filename)
fd = open(filename, O_RDONLY | PG_BINARY, 0666); fd = open(filename, O_RDONLY | PG_BINARY, 0666);
if (fd < 0) if (fd < 0)
{ /* error */ { /* error */
char sebuf[256];
printfPQExpBuffer(&conn->errorMessage, printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("could not open file \"%s\": %s\n"), libpq_gettext("could not open file \"%s\": %s\n"),
filename, pqStrerror(errno, sebuf, sizeof(sebuf))); filename, pqStrerror(errno, sebuf, sizeof(sebuf)));
@ -454,7 +453,7 @@ lo_import(PGconn *conn, const char *filename)
} }
/* /*
* create an inversion "object" * create an inversion object
*/ */
lobjOid = lo_creat(conn, INV_READ | INV_WRITE); lobjOid = lo_creat(conn, INV_READ | INV_WRITE);
if (lobjOid == InvalidOid) if (lobjOid == InvalidOid)
@ -477,24 +476,46 @@ lo_import(PGconn *conn, const char *filename)
} }
/* /*
* read in from the Unix file and write to the inversion file * read in from the file and write to the large object
*/ */
while ((nbytes = read(fd, buf, LO_BUFSIZE)) > 0) while ((nbytes = read(fd, buf, LO_BUFSIZE)) > 0)
{ {
tmp = lo_write(conn, lobj, buf, nbytes); tmp = lo_write(conn, lobj, buf, nbytes);
if (tmp < nbytes) if (tmp != nbytes)
{ {
printfPQExpBuffer(&conn->errorMessage, /*
libpq_gettext("error while reading file \"%s\"\n"), * If the lo_write failed, we are probably in an aborted
filename); * transaction and so lo_close will fail. Try it anyway for
(void) close(fd); * cleanliness, but don't let it determine the returned error
* message.
*/
(void) lo_close(conn, lobj); (void) lo_close(conn, lobj);
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("error while writing large object %u\n"),
lobjOid);
(void) close(fd);
return InvalidOid; return InvalidOid;
} }
} }
if (nbytes < 0)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("could not read from file \"%s\": %s\n"),
filename, pqStrerror(errno, sebuf, sizeof(sebuf)));
lobjOid = InvalidOid;
}
(void) close(fd); (void) close(fd);
(void) lo_close(conn, lobj);
if (lo_close(conn, lobj) != 0)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("error while writing large object %u\n"),
lobjOid);
return InvalidOid;
}
return lobjOid; return lobjOid;
} }
@ -502,16 +523,18 @@ lo_import(PGconn *conn, const char *filename)
/* /*
* lo_export - * lo_export -
* exports an (inversion) large object. * exports an (inversion) large object.
* returns -1 upon failure, 1 otherwise * returns -1 upon failure, 1 if OK
*/ */
int int
lo_export(PGconn *conn, Oid lobjId, const char *filename) lo_export(PGconn *conn, Oid lobjId, const char *filename)
{ {
int result = 1;
int fd; int fd;
int nbytes, int nbytes,
tmp; tmp;
char buf[LO_BUFSIZE]; char buf[LO_BUFSIZE];
int lobj; int lobj;
char sebuf[256];
/* /*
* open the large object. * open the large object.
@ -530,8 +553,6 @@ lo_export(PGconn *conn, Oid lobjId, const char *filename)
fd = open(filename, O_CREAT | O_WRONLY | O_TRUNC | PG_BINARY, 0666); fd = open(filename, O_CREAT | O_WRONLY | O_TRUNC | PG_BINARY, 0666);
if (fd < 0) if (fd < 0)
{ /* error */ { /* error */
char sebuf[256];
printfPQExpBuffer(&conn->errorMessage, printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("could not open file \"%s\": %s\n"), libpq_gettext("could not open file \"%s\": %s\n"),
filename, pqStrerror(errno, sebuf, sizeof(sebuf))); filename, pqStrerror(errno, sebuf, sizeof(sebuf)));
@ -540,33 +561,39 @@ lo_export(PGconn *conn, Oid lobjId, const char *filename)
} }
/* /*
* read in from the inversion file and write to the Unix file * read in from the large object and write to the file
*/ */
while ((nbytes = lo_read(conn, lobj, buf, LO_BUFSIZE)) > 0) while ((nbytes = lo_read(conn, lobj, buf, LO_BUFSIZE)) > 0)
{ {
tmp = write(fd, buf, nbytes); tmp = write(fd, buf, nbytes);
if (tmp < nbytes) if (tmp != nbytes)
{ {
printfPQExpBuffer(&conn->errorMessage, printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("error while writing to file \"%s\"\n"), libpq_gettext("error while writing to file \"%s\": %s\n"),
filename); filename, pqStrerror(errno, sebuf, sizeof(sebuf)));
(void) lo_close(conn, lobj); (void) lo_close(conn, lobj);
(void) close(fd); (void) close(fd);
return -1; return -1;
} }
} }
(void) lo_close(conn, lobj); if (lo_close(conn, lobj) != 0 || nbytes < 0)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("error while reading large object %u\n"),
lobjId);
result = -1;
}
if (close(fd)) if (close(fd))
{ {
printfPQExpBuffer(&conn->errorMessage, printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("error while writing to file \"%s\"\n"), libpq_gettext("error while writing to file \"%s\": %s\n"),
filename); filename, pqStrerror(errno, sebuf, sizeof(sebuf)));
return -1; result = -1;
} }
return 1; return result;
} }