Cleanup the contrib/lo module: there is no need anymore to implement

a physically separate type.  Defining 'lo' as a domain over OID works
just fine and is more efficient.  Improve documentation and fix up the
test script.  (Would like to turn test script into a proper regression
test, but right now its output is not constant because of numeric OIDs;
plus it makes Unix-specific assumptions about files it can import.)

1 files changed, 12 insertions, 116 deletions

diff --git a/contrib/lo/lo.c b/contrib/lo/lo.c
index bdc9307bc29..8d6ba169a22 100644
--- a/contrib/lo/lo.c
+++ b/contrib/lo/lo.c
@@ -1,7 +1,7 @@
 /*
- *	PostgreSQL type definitions for managed LargeObjects.
+ *	PostgreSQL definitions for managed Large Objects.
  *
- *	$PostgreSQL: pgsql/contrib/lo/lo.c,v 1.14 2003/11/29 19:51:35 pgsql Exp $
+ *	$PostgreSQL: pgsql/contrib/lo/lo.c,v 1.15 2005/06/23 00:06:37 tgl Exp $
  *
  */
 
@@ -21,117 +21,12 @@
 #define atooid(x)  ((Oid) strtoul((x), NULL, 10))
 
 
-/*
- *	This is the internal storage format for managed large objects
- *
- */
-
-typedef Oid Blob;
-
-/*
- *	Various forward declarations:
- */
-
-Blob	   *lo_in(char *str);	/* Create from String		*/
-char	   *lo_out(Blob * addr);	/* Output oid as String		*/
-Oid			lo_oid(Blob * addr);	/* Return oid as an oid		*/
-Blob	   *lo(Oid oid);		/* Return Blob based on oid */
-Datum		lo_manage(PG_FUNCTION_ARGS);		/* Trigger handler		   */
-
-/*
- * This creates a large object, and sets its OID to the value in the
- * supplied string.
- *
- * If the string is empty, then a new LargeObject is created, and its oid
- * is placed in the resulting lo.
- */
-Blob *
-lo_in(char *str)
-{
-	Blob	   *result;
-	Oid			oid;
-	int			count;
-
-	if (strlen(str) > 0)
-	{
-		count = sscanf(str, "%u", &oid);
-
-		if (count < 1)
-			ereport(ERROR,
-					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-					 errmsg("error in parsing \"%s\"", str)));
-
-		if (oid == InvalidOid)
-			ereport(ERROR,
-					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-					 errmsg("illegal oid: \"%s\"", str)));
-	}
-	else
-	{
-		/*
-		 * There is no Oid passed, so create a new one
-		 */
-		oid = DatumGetObjectId(DirectFunctionCall1(lo_creat,
-								   Int32GetDatum(INV_READ | INV_WRITE)));
-		if (oid == InvalidOid)
-			/* internal error */
-			elog(ERROR, "InvalidOid returned from lo_creat");
-	}
-
-	result = (Blob *) palloc(sizeof(Blob));
-
-	*result = oid;
-
-	return (result);
-}
-
-/*
- * This simply outputs the Oid of the Blob as a string.
- */
-char *
-lo_out(Blob * addr)
-{
-	char	   *result;
-
-	if (addr == NULL)
-		return (NULL);
-
-	result = (char *) palloc(32);
-	snprintf(result, 32, "%u", *addr);
-	return (result);
-}
-
-/*
- * This function converts Blob to oid.
- *
- * eg: select lo_export(raster::oid,'/path/file') from table;
- *
- */
-Oid
-lo_oid(Blob * addr)
-{
-	if (addr == NULL)
-		return InvalidOid;
-	return (Oid) (*addr);
-}
-
-/*
- * This function is used so we can convert oid's to lo's
- *
- * ie:	insert into table values(lo_import('/path/file')::lo);
- *
- */
-Blob *
-lo(Oid oid)
-{
-	Blob	   *result = (Blob *) palloc(sizeof(Blob));
+/* forward declarations */
+Datum		lo_manage(PG_FUNCTION_ARGS);
 
-	*result = oid;
-	return (result);
-}
 
 /*
- * This handles the trigger that protects us from orphaned large objects
+ * This is the trigger that protects us from orphaned large objects
  */
 PG_FUNCTION_INFO_V1(lo_manage);
 
@@ -144,11 +39,10 @@ lo_manage(PG_FUNCTION_ARGS)
 	TupleDesc	tupdesc;		/* Tuple Descriptor				*/
 	HeapTuple	rettuple;		/* Tuple to be returned			*/
 	bool		isdelete;		/* are we deleting?				*/
-	HeapTuple	newtuple = NULL;	/* The new value for tuple		*/
+	HeapTuple	newtuple;		/* The new value for tuple		*/
 	HeapTuple	trigtuple;		/* The original value of tuple	*/
 
-	if (!CALLED_AS_TRIGGER(fcinfo))
-		/* internal error */
+	if (!CALLED_AS_TRIGGER(fcinfo))		/* internal error */
 		elog(ERROR, "not fired by trigger manager");
 
 	/*
@@ -168,9 +62,12 @@ lo_manage(PG_FUNCTION_ARGS)
 	/* Are we deleting the row? */
 	isdelete = TRIGGER_FIRED_BY_DELETE(trigdata->tg_event);
 
-	/* Get the column were interested in */
+	/* Get the column we're interested in */
 	attnum = SPI_fnumber(tupdesc, args[0]);
 
+	if (attnum <= 0)
+		elog(ERROR, "column \"%s\" does not exist", args[0]);
+
 	/*
 	 * Handle updates
 	 *
@@ -182,7 +79,7 @@ lo_manage(PG_FUNCTION_ARGS)
 		char	   *orig = SPI_getvalue(trigtuple, tupdesc, attnum);
 		char	   *newv = SPI_getvalue(newtuple, tupdesc, attnum);
 
-		if (orig != NULL && (newv == NULL || strcmp(orig, newv)))
+		if (orig != NULL && (newv == NULL || strcmp(orig, newv) != 0))
 			DirectFunctionCall1(lo_unlink,
 								ObjectIdGetDatum(atooid(orig)));
 
@@ -196,7 +93,6 @@ lo_manage(PG_FUNCTION_ARGS)
 	 * Handle deleting of rows
 	 *
 	 * Here, we unlink the large object associated with the managed attribute
-	 *
 	 */
 	if (isdelete)
 	{