1 files changed, 86 insertions, 0 deletions
diff --git a/src/backend/storage/lmgr/single.c b/src/backend/storage/lmgr/single.c
new file mode 100644
index 00000000000..8d41ea38bb6
--- /dev/null
+++ b/src/backend/storage/lmgr/single.c
@@ -0,0 +1,86 @@
+/*-------------------------------------------------------------------------
+ *
+ * single.c--
+ *    set single locks in the multi-level lock hierarchy
+ *
+ *    Sometimes we don't want to set all levels of the multi-level
+ *	lock hierarchy at once.  This allows us to set and release
+ * 	one level at a time.  It's useful in index scans when
+ *	you can set an intent lock at the beginning and thereafter
+ * 	only set page locks.  Tends to speed things up.
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *    $Header: /cvsroot/pgsql/src/backend/storage/lmgr/Attic/single.c,v 1.1.1.1 1996/07/09 06:21:57 scrappy Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#include <string.h>
+#include "storage/lmgr.h"	/* where the declarations go */
+#include "storage/lock.h"
+#include "storage/multilev.h"
+#include "utils/rel.h"
+
+/*
+ * SingleLockReln -- lock a relation
+ *
+ * Returns: TRUE if the lock can be set, FALSE otherwise.
+ */
+bool
+SingleLockReln(LockInfo linfo, LOCKT lockt, int action)
+{
+    LOCKTAG	tag;
+    
+    /* 
+     * LOCKTAG has two bytes of padding, unfortunately.  The
+     * hash function will return miss if the padding bytes aren't
+     * zero'd.
+     */
+    memset(&tag,0,sizeof(tag));
+    tag.relId = linfo->lRelId.relId;
+    tag.dbId = linfo->lRelId.dbId;
+    BlockIdSet(&(tag.tupleId.ip_blkid), InvalidBlockNumber);
+    tag.tupleId.ip_posid = InvalidOffsetNumber;
+    
+    if (action == UNLOCK)
+	return(LockRelease(MultiTableId, &tag, lockt));
+    else
+	return(LockAcquire(MultiTableId, &tag, lockt));
+}
+
+/*
+ * SingleLockPage -- use multi-level lock table, but lock
+ *	only at the page level.
+ *
+ * Assumes that an INTENT lock has already been set in the
+ * multi-level lock table.
+ *
+ */
+bool
+SingleLockPage(LockInfo linfo,
+	       ItemPointer tidPtr,
+	       LOCKT lockt,
+	       int action)
+{
+    LOCKTAG	tag;
+    
+    /* 
+     * LOCKTAG has two bytes of padding, unfortunately.  The
+     * hash function will return miss if the padding bytes aren't
+     * zero'd.
+     */
+    memset(&tag,0,sizeof(tag));
+    tag.relId = linfo->lRelId.relId;
+    tag.dbId = linfo->lRelId.dbId;
+    BlockIdCopy(&(tag.tupleId.ip_blkid), &(tidPtr->ip_blkid));
+    tag.tupleId.ip_posid = InvalidOffsetNumber;
+    
+    
+    if (action == UNLOCK)
+	return(LockRelease(MultiTableId, &tag, lockt));
+    else
+	return(LockAcquire(MultiTableId, &tag, lockt));
+}
+