db: Consolidate access to the changes in a db

We were passing them in separately, while we could just retrieve them from the
db instance instead.

lightningd/plugin_hook.c

@@ -156,13 +156,14 @@ static void db_hook_response(const char *buffer, const jsmntok_t *toks,
 	io_break(ph_req);
 }
 
-void plugin_hook_db_sync(struct db *db, const char **changes, const char *final)
+void plugin_hook_db_sync(struct db *db)
 {
 	const struct plugin_hook *hook = &db_write_hook;
 	struct jsonrpc_request *req;
 	struct plugin_hook_request *ph_req;
 	void *ret;
 
+	const char **changes = db_changes(db);
 	if (!hook->plugin)
 		return;
 
@@ -177,8 +178,6 @@ void plugin_hook_db_sync(struct db *db, const char **changes, const char *final)
 	json_array_start(req->stream, "writes");
 	for (size_t i = 0; i < tal_count(changes); i++)
 		json_add_string(req->stream, NULL, changes[i]);
-	if (final)
-		json_add_string(req->stream, NULL, final);
 	json_array_end(req->stream);
 	jsonrpc_request_end(req);
 

lightningd/plugin_hook.h

@@ -108,8 +108,7 @@ bool plugin_hook_unregister(struct plugin *plugin, const char *method);
 /* Unregister all hooks a plugin has registered for */
 void plugin_hook_unregister_all(struct plugin *plugin);
 
-/* Special sync plugin hook for db: changes[] are SQL statements, with optional
+/* Special sync plugin hook for db. */
- * final command appended. */
+void plugin_hook_db_sync(struct db *db);
-void plugin_hook_db_sync(struct db *db, const char **changes, const char *final);
 
 #endif /* LIGHTNING_LIGHTNINGD_PLUGIN_HOOK_H */

wallet/db.c

@@ -764,7 +764,7 @@ static void db_report_changes(struct db *db, const char *final, size_t min)
 	assert(tal_count(db->changes) >= min);
 
 	if (tal_count(db->changes) > min)
-		plugin_hook_db_sync(db, db->changes, final);
+		plugin_hook_db_sync(db);
 	db->changes = tal_free(db->changes);
 }
 
@@ -1399,3 +1399,8 @@ void db_changes_add(struct db_stmt *stmt, const char * expanded)
 
 	tal_arr_expand(&db->changes, tal_strdup(db->changes, expanded));
 }
+
+const char **db_changes(struct db *db)
+{
+	return db->changes;
+}

wallet/db.h

@@ -224,4 +224,9 @@ struct db_stmt *db_prepare_v2_(const char *location, struct db *db,
 #define db_prepare_v2(db,query)						\
 	db_prepare_v2_(__FILE__ ":" stringify(__LINE__), db, query)
 
+/**
+ * Access pending changes that have been added to the current transaction.
+ */
+const char **db_changes(struct db *db);
+
 #endif /* LIGHTNING_WALLET_DB_H */

wallet/test/run-db.c

@@ -47,7 +47,7 @@ static void db_test_fatal(const char *fmt, ...)
 	va_end(ap);
 }
 
-void plugin_hook_db_sync(struct db *db UNNEEDED, const char **changes UNNEEDED, const char *final UNNEEDED)
+void plugin_hook_db_sync(struct db *db UNNEEDED)
 {
 }
 

wallet/test/run-wallet.c

@@ -650,7 +650,7 @@ u8 *wire_sync_read(const tal_t *ctx UNNEEDED, int fd UNNEEDED)
 {
 	return NULL;
 }
-void plugin_hook_db_sync(struct db *db UNNEEDED, const char **changes UNNEEDED, const char *final UNNEEDED)
+void plugin_hook_db_sync(struct db *db UNNEEDED)
 {
 }
 bool fromwire_hsm_get_channel_basepoints_reply(const void *p UNNEEDED,