From: Gregor Beck <gbeck@sernet.de>
Date: Mon, 4 Jul 2011 08:15:44 +0000 (+0200)
Subject: s3:dbwrap: add function dbwrap_exists()
X-Git-Tag: 3.6.0-ctdb-27~48
X-Git-Url: http://git.samba.org/?p=obnox%2Fsamba-ctdb.git;a=commitdiff_plain;h=14531d1bea6a1b1149f91b789ee9a7906b594aaf

s3:dbwrap: add function dbwrap_exists()

Signed-off-by: Michael Adam <obnox@samba.org>
---

diff --git a/source3/include/dbwrap.h b/source3/include/dbwrap.h
index d657ee7f30..e3f2228f50 100644
--- a/source3/include/dbwrap.h
+++ b/source3/include/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;
 };
@@ -91,6 +92,7 @@ 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_delete_bystring(struct db_context *db, const char *key);
 NTSTATUS dbwrap_store_bystring(struct db_context *db, const char *key,
 			       TDB_DATA data, int flags);
diff --git a/source3/lib/dbwrap.c b/source3/lib/dbwrap.c
index 9b3197f402..e1b3f26f4b 100644
--- a/source3/lib/dbwrap.c
+++ b/source3/lib/dbwrap.c
@@ -44,6 +44,24 @@ static int dbwrap_fallback_fetch(struct db_context *db, TALLOC_CTX *mem_ctx,
 	return 0;
 }
 
+/*
+ * 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
  */
@@ -200,6 +218,17 @@ 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_delete_bystring(struct db_context *db, const char *key)
 {
 	return dbwrap_delete(db, string_term_tdb_data(key));