dbwrap: Pass "value" to dbwrap_do_locked() callback

I want to reduce dbwrap_record_get_value(). It makes the caller believe it can
make a copy of the TDB_DATA returned and that the value remains constant. It's
not, as you can always do a dbwrap_record_store().

This patch removes one requirement for getting the value out of a
db_record via dbwrap_record_get_value(). You can still make a copy, but from an
API perspective to me it's more obvious that "value" as a parameter to the
callback has a limited lifetime.

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

4 files changed, 14 insertions, 4 deletions

diff --git a/lib/dbwrap/dbwrap.c b/lib/dbwrap/dbwrap.c
index 3d8d2ae78d7..cc58397eb6e 100644
--- a/lib/dbwrap/dbwrap.c
+++ b/lib/dbwrap/dbwrap.c
@@ -307,7 +307,10 @@ struct dbwrap_store_state {
 	NTSTATUS status;
 };
 
-static void dbwrap_store_fn(struct db_record *rec, void *private_data)
+static void dbwrap_store_fn(
+	struct db_record *rec,
+	TDB_DATA value,
+	void *private_data)
 {
 	struct dbwrap_store_state *state = private_data;
 	state->status = dbwrap_record_store(rec, state->data, state->flags);
@@ -331,7 +334,10 @@ struct dbwrap_delete_state {
 	NTSTATUS status;
 };
 
-static void dbwrap_delete_fn(struct db_record *rec, void *private_data)
+static void dbwrap_delete_fn(
+	struct db_record *rec,
+	TDB_DATA value,
+	void *private_data)
 {
 	struct dbwrap_delete_state *state = private_data;
 	state->status = dbwrap_record_delete(rec);
@@ -514,6 +520,7 @@ NTSTATUS dbwrap_parse_record_recv(struct tevent_req *req)
 
 NTSTATUS dbwrap_do_locked(struct db_context *db, TDB_DATA key,
 			  void (*fn)(struct db_record *rec,
+				     TDB_DATA value,
 				     void *private_data),
 			  void *private_data)
 {
@@ -542,7 +549,7 @@ NTSTATUS dbwrap_do_locked(struct db_context *db, TDB_DATA key,
 		return NT_STATUS_NO_MEMORY;
 	}
 
-	fn(rec, private_data);
+	fn(rec, rec->value, private_data);
 
 	TALLOC_FREE(rec);
 
diff --git a/lib/dbwrap/dbwrap.h b/lib/dbwrap/dbwrap.h
index 591eac5c63a..b5a7fb315c7 100644
--- a/lib/dbwrap/dbwrap.h
+++ b/lib/dbwrap/dbwrap.h
@@ -81,6 +81,7 @@ struct db_context *dbwrap_record_get_db(struct db_record *rec);
 
 NTSTATUS dbwrap_do_locked(struct db_context *db, TDB_DATA key,
 			  void (*fn)(struct db_record *rec,
+				     TDB_DATA value,
 				     void *private_data),
 			  void *private_data);
 
diff --git a/lib/dbwrap/dbwrap_private.h b/lib/dbwrap/dbwrap_private.h
index b548168b9a9..a493b261dcb 100644
--- a/lib/dbwrap/dbwrap_private.h
+++ b/lib/dbwrap/dbwrap_private.h
@@ -70,6 +70,7 @@ struct db_context {
 	NTSTATUS (*parse_record_recv)(struct tevent_req *req);
 	NTSTATUS (*do_locked)(struct db_context *db, TDB_DATA key,
 			      void (*fn)(struct db_record *rec,
+					 TDB_DATA value,
 					 void *private_data),
 			      void *private_data);
 	int (*exists)(struct db_context *db,TDB_DATA key);
diff --git a/lib/dbwrap/dbwrap_tdb.c b/lib/dbwrap/dbwrap_tdb.c
index ed20f885278..b7bba40705a 100644
--- a/lib/dbwrap/dbwrap_tdb.c
+++ b/lib/dbwrap/dbwrap_tdb.c
@@ -184,6 +184,7 @@ static struct db_record *db_tdb_try_fetch_locked(
 
 static NTSTATUS db_tdb_do_locked(struct db_context *db, TDB_DATA key,
 				 void (*fn)(struct db_record *rec,
+					    TDB_DATA value,
 					    void *private_data),
 				 void *private_data)
 {
@@ -218,7 +219,7 @@ static NTSTATUS db_tdb_do_locked(struct db_context *db, TDB_DATA key,
 		.private_data = ctx
 	};
 
-	fn(&rec, private_data);
+	fn(&rec, rec.value, private_data);
 
 	tdb_chainunlock(ctx->wtdb->tdb, key);