Code review for 64-bit-large-object patch.

Fix broken-on-bigendian-machines byte-swapping functions, add missed update
of alternate regression expected file, improve error reporting, remove some
unnecessary code, sync testlo64.c with current testlo.c (it seems to have
been cloned from a very old copy of that), assorted cosmetic improvements.

1 files changed, 21 insertions, 39 deletions

diff --git a/src/backend/libpq/be-fsstubs.c b/src/backend/libpq/be-fsstubs.c
index 4bc81ba9f4d..c4ac1a650f5 100644
--- a/src/backend/libpq/be-fsstubs.c
+++ b/src/backend/libpq/be-fsstubs.c
@@ -39,7 +39,6 @@
 #include "postgres.h"
 
 #include <fcntl.h>
-#include <limits.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
@@ -57,7 +56,9 @@
  */
 bool		lo_compat_privileges;
 
-/*#define FSDB 1*/
+/* define this to enable debug logging */
+/* #define FSDB 1 */
+/* chunk size for lo_import/lo_export transfers */
 #define BUFSIZE			8192
 
 /*
@@ -210,7 +211,6 @@ lo_write(int fd, const char *buf, int len)
 	return status;
 }
 
-
 Datum
 lo_lseek(PG_FUNCTION_ARGS)
 {
@@ -226,42 +226,31 @@ lo_lseek(PG_FUNCTION_ARGS)
 
 	status = inv_seek(cookies[fd], offset, whence);
 
-	if (INT_MAX < status)
-	{
+	/* guard against result overflow */
+	if (status != (int32) status)
 		ereport(ERROR,
-				(errcode(ERRCODE_BLOB_OFFSET_OVERFLOW),
-				 errmsg("offset overflow: %d", fd)));
-		PG_RETURN_INT32(-1);
-	}
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("lo_lseek result out of range for large-object descriptor %d",
+						fd)));
 
-	PG_RETURN_INT32(status);
+	PG_RETURN_INT32((int32) status);
 }
 
-
 Datum
 lo_lseek64(PG_FUNCTION_ARGS)
 {
 	int32		fd = PG_GETARG_INT32(0);
 	int64		offset = PG_GETARG_INT64(1);
 	int32		whence = PG_GETARG_INT32(2);
-	MemoryContext currentContext;
-	int64			status;
+	int64		status;
 
 	if (fd < 0 || fd >= cookies_size || cookies[fd] == NULL)
-	{
 		ereport(ERROR,
 				(errcode(ERRCODE_UNDEFINED_OBJECT),
 				 errmsg("invalid large-object descriptor: %d", fd)));
-		PG_RETURN_INT64(-1);
-	}
-
-	Assert(fscxt != NULL);
-	currentContext = MemoryContextSwitchTo(fscxt);
 
 	status = inv_seek(cookies[fd], offset, whence);
 
-	MemoryContextSwitchTo(currentContext);
-
 	PG_RETURN_INT64(status);
 }
 
@@ -301,7 +290,7 @@ Datum
 lo_tell(PG_FUNCTION_ARGS)
 {
 	int32		fd = PG_GETARG_INT32(0);
-	int64		offset = 0;
+	int64		offset;
 
 	if (fd < 0 || fd >= cookies_size || cookies[fd] == NULL)
 		ereport(ERROR,
@@ -310,37 +299,30 @@ lo_tell(PG_FUNCTION_ARGS)
 
 	offset = inv_tell(cookies[fd]);
 
-	if (INT_MAX < offset)
-	{
+	/* guard against result overflow */
+	if (offset != (int32) offset)
 		ereport(ERROR,
-				(errcode(ERRCODE_BLOB_OFFSET_OVERFLOW),
-				 errmsg("offset overflow: %d", fd)));
-		PG_RETURN_INT32(-1);
-	}
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("lo_tell result out of range for large-object descriptor %d",
+						fd)));
 
-	PG_RETURN_INT32(offset);
+	PG_RETURN_INT32((int32) offset);
 }
 
-
 Datum
 lo_tell64(PG_FUNCTION_ARGS)
 {
 	int32		fd = PG_GETARG_INT32(0);
+	int64		offset;
 
 	if (fd < 0 || fd >= cookies_size || cookies[fd] == NULL)
-	{
 		ereport(ERROR,
 				(errcode(ERRCODE_UNDEFINED_OBJECT),
 				 errmsg("invalid large-object descriptor: %d", fd)));
-		PG_RETURN_INT64(-1);
-	}
 
-	/*
-	 * We assume we do not need to switch contexts for inv_tell. That is
-	 * true for now, but is probably more than this module ought to
-	 * assume...
-	 */
-	PG_RETURN_INT64(inv_tell(cookies[fd]));
+	offset = inv_tell(cookies[fd]);
+
+	PG_RETURN_INT64(offset);
 }
 
 Datum