1 files changed, 24 insertions, 0 deletions
diff --git a/src/backend/utils/cache/syscache.c b/src/backend/utils/cache/syscache.c
index 78ce0b881a5..c365ec7597a 100644
--- a/src/backend/utils/cache/syscache.c
+++ b/src/backend/utils/cache/syscache.c
@@ -1051,6 +1051,30 @@ SysCacheGetAttr(int cacheId, HeapTuple tup,
 }
 
 /*
+ * GetSysCacheHashValue
+ *
+ * Get the hash value that would be used for a tuple in the specified cache
+ * with the given search keys.
+ *
+ * The reason for exposing this as part of the API is that the hash value is
+ * exposed in cache invalidation operations, so there are places outside the
+ * catcache code that need to be able to compute the hash values.
+ */
+uint32
+GetSysCacheHashValue(int cacheId,
+					 Datum key1,
+					 Datum key2,
+					 Datum key3,
+					 Datum key4)
+{
+	if (cacheId < 0 || cacheId >= SysCacheSize ||
+		!PointerIsValid(SysCache[cacheId]))
+		elog(ERROR, "invalid cache ID: %d", cacheId);
+
+	return GetCatCacheHashValue(SysCache[cacheId], key1, key2, key3, key4);
+}
+
+/*
  * List-search interface
  */
 struct catclist *