2 files changed, 31 insertions, 0 deletions
diff --git a/source3/lib/dbwrap/dbwrap.c b/source3/lib/dbwrap/dbwrap.c
index c2d28b3a0e..9ec7a3e59a 100644
--- a/source3/lib/dbwrap/dbwrap.c
+++ b/source3/lib/dbwrap/dbwrap.c
@@ -44,6 +44,24 @@ int dbwrap_fallback_fetch(struct db_context *db, TALLOC_CTX *mem_ctx,
 }
 
 /*
+ * Fall back using fetch if no genuine exists operation is provided
+ */
+
+static int dbwrap_fallback_exists(struct db_context *db, TDB_DATA key)
+{
+	TDB_DATA val;
+	if ( db->fetch(db, talloc_tos(), key, &val) != 0 ) {
+		return 0;
+	}
+	if (val.dptr == NULL ) {
+		return 0;
+	} else {
+		TALLOC_FREE(val.dptr);
+		return 1;
+	}
+}
+
+/*
  * Fall back using fetch if no genuine parse operation is provided
  */
 
@@ -79,6 +97,17 @@ TDB_DATA dbwrap_fetch(struct db_context *db, TALLOC_CTX *mem_ctx,
 	return result;
 }
 
+bool dbwrap_exists(struct db_context *db, TDB_DATA key)
+{
+	int result;
+	if (db->exists != NULL) {
+		result = db->exists(db, key);
+	} else {
+		result = dbwrap_fallback_exists(db,key);
+	}
+	return (result == 1);
+}
+
 NTSTATUS dbwrap_store(struct db_context *db, TDB_DATA key,
 		      TDB_DATA data, int flags)
 {
diff --git a/source3/lib/dbwrap/dbwrap.h b/source3/lib/dbwrap/dbwrap.h
index 2ba96b2482..9ff47c4285 100644
--- a/source3/lib/dbwrap/dbwrap.h
+++ b/source3/lib/dbwrap/dbwrap.h
@@ -52,6 +52,7 @@ struct db_context {
 			    int (*parser)(TDB_DATA key, TDB_DATA data,
 					  void *private_data),
 			    void *private_data);
+	int (*exists)(struct db_context *db,TDB_DATA key);
 	void *private_data;
 	bool persistent;
 };
@@ -63,6 +64,7 @@ NTSTATUS dbwrap_store(struct db_context *db, TDB_DATA key,
 		      TDB_DATA data, int flags);
 TDB_DATA dbwrap_fetch(struct db_context *db, TALLOC_CTX *mem_ctx,
 		      TDB_DATA key);
+bool dbwrap_exists(struct db_context *db, TDB_DATA key);
 NTSTATUS dbwrap_traverse(struct db_context *db,
 			 int (*f)(struct db_record*, void*),
 			 void *private_data,