X-Git-Url: http://git.tuebingen.mpg.de/?a=blobdiff_plain;f=afs.c;h=b15f83852e6919c4f0867065d13776c211416087;hb=0b5c29fae8853bac16b91503df70b0e101dccca4;hp=cea8f2707491f00bab0f457a3463fd4762147a21;hpb=9055c71be97f1095dcdbd83da305b600f204f763;p=paraslash.git

diff --git a/afs.c b/afs.c
index cea8f270..b15f8385 100644
--- a/afs.c
+++ b/afs.c
@@ -525,53 +525,6 @@ static void flush_and_free_pb(struct para_buffer *pb)
 	free(pb->buf);
 }
 
-static int com_select_callback(struct afs_callback_arg *aca)
-{
-	const struct lls_command *cmd = SERVER_CMD_CMD_PTR(SELECT);
-	const char *arg;
-	int ret;
-
-	ret = lls_deserialize_parse_result(aca->query.data, cmd, &aca->lpr);
-	assert(ret >= 0);
-	arg = lls_input(0, aca->lpr);
-	score_clear();
-	if (current_play_mode == PLAY_MODE_MOOD)
-		mood_unload();
-	else
-		playlist_unload();
-	ret = activate_mood_or_playlist(arg, &aca->pbout);
-	if (ret >= 0)
-		goto free_lpr;
-	/* ignore subsequent errors (but log them) */
-	if (current_mop && strcmp(current_mop, arg) != 0) {
-		int ret2;
-		para_printf(&aca->pbout, "switching back to %s\n", current_mop);
-		ret2 = activate_mood_or_playlist(current_mop, &aca->pbout);
-		if (ret2 >= 0)
-			goto free_lpr;
-		para_printf(&aca->pbout, "could not reactivate %s: %s\n",
-			current_mop, para_strerror(-ret2));
-	}
-	activate_mood_or_playlist(NULL, &aca->pbout);
-free_lpr:
-	lls_free_parse_result(aca->lpr, cmd);
-	return ret;
-}
-
-static int com_select(struct command_context *cc, struct lls_parse_result *lpr)
-{
-	const struct lls_command *cmd = SERVER_CMD_CMD_PTR(SELECT);
-	char *errctx;
-	int ret = lls(lls_check_arg_count(lpr, 1, 1, &errctx));
-
-	if (ret < 0) {
-		send_errctx(cc, errctx);
-		return ret;
-	}
-	return send_lls_callback_request(com_select_callback, cmd, lpr, cc);
-}
-EXPORT_SERVER_CMD_HANDLER(select);
-
 static void init_admissible_files(const char *arg)
 {
 	int ret = activate_mood_or_playlist(arg, NULL);
@@ -775,6 +728,43 @@ err:
 	return ret;
 }
 
+/**
+ * Format and send an error message to the command handler.
+ *
+ * To pass an error message from the callback of an afs command to the client,
+ * this function should be called. It formats the message into a buffer which
+ * is passed as a shared memory area to the command handler from where it
+ * propagates to the client.
+ *
+ * The message will be tagged with the ERROR_LOG sideband designator so that
+ * the client writes it to its stderr stream rather than to stdout as with
+ * aca->pbout. In analogy to the default Unix semantics of stderr, the message
+ * is sent without buffering.
+ *
+ * If sending the error message fails, an error is logged on the server side,
+ * but no other action is taken.
+ *
+ * \param aca Used to obtain the fd to send the shmid to.
+ * \param fmt Usual format string.
+ */
+__printf_2_3 void afs_error(const struct afs_callback_arg *aca,
+		const char *fmt,...)
+{
+	va_list argp;
+	char *msg;
+	unsigned n;
+	int ret;
+
+	va_start(argp, fmt);
+	n = xvasprintf(&msg, fmt, argp);
+	va_end(argp);
+	ret = pass_buffer_as_shm(aca->fd, SBD_ERROR_LOG, msg, n + 1);
+	if (ret < 0)
+		PARA_ERROR_LOG("Could not send %s: %s\n", msg,
+			para_strerror(-ret));
+	free(msg);
+}
+
 static int call_callback(int fd, int query_shmid)
 {
 	void *query_shm;
@@ -985,6 +975,53 @@ out:
 	exit(EXIT_FAILURE);
 }
 
+static int com_select_callback(struct afs_callback_arg *aca)
+{
+	const struct lls_command *cmd = SERVER_CMD_CMD_PTR(SELECT);
+	const char *arg;
+	int ret;
+
+	ret = lls_deserialize_parse_result(aca->query.data, cmd, &aca->lpr);
+	assert(ret >= 0);
+	arg = lls_input(0, aca->lpr);
+	score_clear();
+	if (current_play_mode == PLAY_MODE_MOOD)
+		mood_unload();
+	else
+		playlist_unload();
+	ret = activate_mood_or_playlist(arg, &aca->pbout);
+	if (ret >= 0)
+		goto free_lpr;
+	/* ignore subsequent errors (but log them) */
+	if (current_mop && strcmp(current_mop, arg) != 0) {
+		int ret2;
+		afs_error(aca, "switching back to %s\n", current_mop);
+		ret2 = activate_mood_or_playlist(current_mop, &aca->pbout);
+		if (ret2 >= 0)
+			goto free_lpr;
+		afs_error(aca, "could not reactivate %s: %s\n", current_mop,
+			para_strerror(-ret2));
+	}
+	activate_mood_or_playlist(NULL, &aca->pbout);
+free_lpr:
+	lls_free_parse_result(aca->lpr, cmd);
+	return ret;
+}
+
+static int com_select(struct command_context *cc, struct lls_parse_result *lpr)
+{
+	const struct lls_command *cmd = SERVER_CMD_CMD_PTR(SELECT);
+	char *errctx;
+	int ret = lls(lls_check_arg_count(lpr, 1, 1, &errctx));
+
+	if (ret < 0) {
+		send_errctx(cc, errctx);
+		return ret;
+	}
+	return send_lls_callback_request(com_select_callback, cmd, lpr, cc);
+}
+EXPORT_SERVER_CMD_HANDLER(select);
+
 static int com_init_callback(struct afs_callback_arg *aca)
 {
 	uint32_t table_mask = *(uint32_t *)aca->query.data;
@@ -1001,8 +1038,7 @@ static int com_init_callback(struct afs_callback_arg *aca)
 			continue;
 		ret = t->ops->create(database_dir);
 		if (ret < 0) {
-			para_printf(&aca->pbout, "cannot create table %s\n",
-				t->name);
+			afs_error(aca, "cannot create table %s\n", t->name);
 			goto out;
 		}
 		para_printf(&aca->pbout, "successfully created %s table\n",
@@ -1010,7 +1046,7 @@ static int com_init_callback(struct afs_callback_arg *aca)
 	}
 	ret = open_afs_tables();
 	if (ret < 0)
-		para_printf(&aca->pbout, "cannot open afs tables: %s\n",
+		afs_error(aca, "cannot open afs tables: %s\n",
 			para_strerror(-ret));
 out:
 	return ret;