Merge pull request #130 from jcorporation/protocol

Implement new protocol command to toggle features

NEWS

@@ -1,7 +1,7 @@
 libmpdclient 2.23 (not yet released)
 * support MPD protocol 0.24.0
   - allow window for listplaylist and listplaylistinfo
-  - command "playlistlength", "stickertypes", "stickernamestypes", "searchplaylist"
+  - command "playlistlength", "protocol", "stickertypes", "stickernamestypes", "searchplaylist"
   - tag "ShowMovement"
   - new sticker find api
   - new subcommand "tagtypes available"

include/mpd/capabilities.h

@@ -13,6 +13,7 @@
 #include "recv.h"
 #include "compiler.h"
 #include "tag.h"
+#include "feature.h"
 
 #include <stdbool.h>
 
@@ -217,6 +218,136 @@ mpd_send_all_tag_types(struct mpd_connection *connection);
 bool
 mpd_run_all_tag_types(struct mpd_connection *connection);
 
+/**
+ * Requests a list of enabled protocol features.
+ * Use mpd_recv_protocol_feature_pair() to obtain the list of
+ * "protocol feature" pairs.
+ *
+ * @param connection the connection to MPD
+ * @return true on success, false on error
+ *
+ * @since libmpdclient 2.23, MPD 0.24
+ */
+bool
+mpd_send_list_protocol_features(struct mpd_connection *connection);
+
+/**
+ * Requests a list of available protocol features.
+ * Use mpd_recv_protocol_feature_pair() to obtain the list of
+ * "protocol feature" pairs.
+ *
+ * @param connection the connection to MPD
+ * @return true on success, false on error
+ *
+ * @since libmpdclient 2.23, MPD 0.24
+ */
+bool
+mpd_send_list_protocol_features_available(struct mpd_connection *connection);
+
+/**
+ * Receives the next protocol feature name.  Call this in a loop after
+ * mpd_send_list_protocol().
+ *
+ * Free the return value with mpd_return_pair().
+ *
+ * @param connection a #mpd_connection
+ * @returns a "protocol feature" pair, or NULL on error or if the end of the
+ * response is reached
+ *
+ * @since libmpdclient 2.23, MPD 0.24
+ */
+mpd_malloc
+static inline struct mpd_pair *
+mpd_recv_protocol_feature_pair(struct mpd_connection *connection)
+{
+	return mpd_recv_pair_named(connection, "feature");
+}
+
+/**
+ * Disables one or more features from the list of protocol features.
+ *
+ * @param connection the connection to MPD
+ * @param features an array of protocol features to disable
+ * @param n the number of protocol features in the array
+ * @return true on success, false on error
+ *
+ * @since libmpdclient 2.23, MPD 0.24
+ */
+bool
+mpd_send_disable_protocol_features(struct mpd_connection *connection,
+				   const enum mpd_protocol_feature *features, unsigned n);
+
+/**
+ * Shortcut for mpd_send_disable_protocol_features() and mpd_response_finish().
+ *
+ * @since libmpdclient 2.23, MPD 0.24
+ */
+bool
+mpd_run_disable_protocol_features(struct mpd_connection *connection,
+				  const enum mpd_protocol_feature *features, unsigned n);
+
+/**
+ * Re-enable one or more features from the list of protocol features
+ * for this client.
+ *
+ * @param connection the connection to MPD
+ * @param features an array of protocol features to enable
+ * @param n the number of protocol features in the array
+ * @return true on success, false on error
+ *
+ * @since libmpdclient 2.23, MPD 0.24
+ */
+bool
+mpd_send_enable_protocol_features(struct mpd_connection *connection,
+				  const enum mpd_protocol_feature *features, unsigned n);
+
+/**
+ * Shortcut for mpd_send_enable_protocol_features() and mpd_response_finish().
+ *
+ * @since libmpdclient 2.23, MPD 0.24
+ */
+bool
+mpd_run_enable_protocol_features(struct mpd_connection *connection,
+				 const enum mpd_protocol_feature *features, unsigned n);
+
+/**
+ * Clear the list of enabled protocol features for this client.
+ *
+ * @param connection the connection to MPD
+ * @return true on success, false on error
+ *
+ * @since libmpdclient 2.23, MPD 0.24
+ */
+bool
+mpd_send_clear_protocol_features(struct mpd_connection *connection);
+
+/**
+ * Shortcut for mpd_send_clear_protocol_features() and mpd_response_finish().
+ *
+ * @since libmpdclient 2.23, MPD 0.24
+ */
+bool
+mpd_run_clear_protocol_features(struct mpd_connection *connection);
+
+/**
+ * Enable all available features for this client.
+ *
+ * @param connection the connection to MPD
+ * @return true on success, false on error
+ *
+ * @since libmpdclient 2.23, MPD 0.24
+ */
+bool
+mpd_send_all_protocol_features(struct mpd_connection *connection);
+
+/**
+ * Shortcut for mpd_send_all_protocol_features() and mpd_response_finish().
+ *
+ * @since libmpdclient 2.23, MPD 0.24
+ */
+bool
+mpd_run_all_protocol_features(struct mpd_connection *connection);
+
 #ifdef __cplusplus
 }
 #endif

include/mpd/client.h

@@ -31,6 +31,7 @@
 #include "database.h"
 #include "directory.h"
 #include "entity.h"
+#include "feature.h"
 #include "fingerprint.h"
 #include "idle.h"
 #include "list.h"

include/mpd/feature.h

@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: BSD-3-Clause
+// Copyright The Music Player Daemon Project
+
+#ifndef LIBMPDCLIENT_FEATURE_H
+#define LIBMPDCLIENT_FEATURE_H
+
+/**
+ * @since libmpdclient 2.23 added support for #MPD_TAG_SHOWMOVEMENT.
+ */
+enum mpd_protocol_feature
+{
+	/**
+	 * Special value returned by mpd_feature_parse() when an
+	 * unknown name was passed.
+	 */
+	MPD_FEATURE_UNKNOWN = -1,
+
+	MPD_FEATURE_HIDE_PLAYLISTS_IN_ROOT,
+
+	/* IMPORTANT: the ordering of tag types above must be
+	   retained, or else the libmpdclient ABI breaks */
+
+	MPD_FEATURE_COUNT
+};
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * Looks up the name of the specified protocol feature.
+ *
+ * @return the name, or NULL if the tag type is not valid
+ */
+const char *
+mpd_feature_name(enum mpd_protocol_feature feature);
+
+/**
+ * Parses a protocol feature name, and returns its #mpd_protocol_feature value.
+ *
+ * @return a #mpd_protocol_feature value, or MPD_FEATURE_UNKNOWN if the name was
+ * not recognized
+ */
+enum mpd_protocol_feature
+mpd_feature_name_parse(const char *name);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

libmpdclient.ld

@@ -28,6 +28,17 @@ global:
 	mpd_run_clear_tag_types;
 	mpd_send_all_tag_types;
 	mpd_run_all_tag_types;
+	mpd_send_list_protocol_features;
+	mpd_send_list_protocol_features_available;
+	mpd_recv_protocol_feature_pair;
+	mpd_send_disable_protocol_features;
+	mpd_run_disable_protocol_features;
+	mpd_send_enable_protocol_features;
+	mpd_run_enable_protocol_features;
+	mpd_send_clear_protocol_features;
+	mpd_run_clear_protocol_features;
+	mpd_send_all_protocol_features;
+	mpd_run_all_protocol_features;
 
 	/* mpd/connection.h */
 	mpd_connection_new;
@@ -78,6 +89,10 @@ global:
 	mpd_entity_feed;
 	mpd_recv_entity;
 
+	/* mpd/feature.h */
+	mpd_feature_name;
+	mpd_feature_name_parse;
+
 	/* mpd/idle.h */
 	mpd_idle_name;
 	mpd_idle_name_parse;

meson.build

@@ -105,6 +105,7 @@ libmpdclient = library('mpdclient',
   'src/directory.c',
   'src/rdirectory.c',
   'src/error.c',
+  'src/feature.c',
   'src/fd_util.c',
   'src/fingerprint.c',
   'src/output.c',

src/capabilities.c

@@ -134,3 +134,109 @@ mpd_run_all_tag_types(struct mpd_connection *connection)
 	return mpd_send_all_tag_types(connection) &&
 		mpd_response_finish(connection);
 }
+
+bool
+mpd_send_list_protocol_features(struct mpd_connection *connection)
+{
+	return mpd_send_command(connection, "protocol", NULL);
+}
+
+bool
+mpd_send_list_protocol_features_available(struct mpd_connection *connection)
+{
+	return mpd_send_command(connection, "protocol", "available", NULL);
+}
+
+static bool
+mpd_send_protocol_features_v(struct mpd_connection *connection,
+			     const char *sub_command,
+			     const enum mpd_protocol_feature *features, unsigned n)
+{
+	assert(connection != NULL);
+	assert(features != NULL);
+	assert(n > 0);
+
+	if (mpd_error_is_defined(&connection->error))
+		return false;
+
+	char buffer[1024] = "protocol ";
+	strcat(buffer, sub_command);
+	size_t length = strlen(buffer);
+
+	for (unsigned i = 0; i < n; ++i) {
+		const char *t = mpd_feature_name(features[i]);
+		assert(t != NULL);
+		size_t t_length = strlen(t);
+
+		if (length + 1 + t_length + 1 > sizeof(buffer)) {
+			mpd_error_code(&connection->error, MPD_ERROR_ARGUMENT);
+			mpd_error_message(&connection->error,
+					  "Protocol feature list is too long");
+			return false;
+		}
+
+		buffer[length++] = ' ';
+		memcpy(buffer + length, t, t_length);
+		length += t_length;
+	}
+
+	buffer[length] = 0;
+
+	return mpd_send_command(connection, buffer, NULL);
+}
+
+bool
+mpd_send_disable_protocol_features(struct mpd_connection *connection,
+			   const enum mpd_protocol_feature *features, unsigned n)
+{
+	return mpd_send_protocol_features_v(connection, "disable", features, n);
+}
+
+bool
+mpd_run_disable_protocol_features(struct mpd_connection *connection,
+				  const enum mpd_protocol_feature *features, unsigned n)
+{
+	return mpd_send_disable_protocol_features(connection, features, n) &&
+		mpd_response_finish(connection);
+}
+
+bool
+mpd_send_enable_protocol_features(struct mpd_connection *connection,
+				  const enum mpd_protocol_feature *features, unsigned n)
+{
+	return mpd_send_protocol_features_v(connection, "enable", features, n);
+}
+
+bool
+mpd_run_enable_protocol_features(struct mpd_connection *connection,
+				 const enum mpd_protocol_feature *features, unsigned n)
+{
+	return mpd_send_enable_protocol_features(connection, features, n) &&
+		mpd_response_finish(connection);
+}
+
+bool
+mpd_send_clear_protocol_features(struct mpd_connection *connection)
+{
+	return mpd_send_command(connection, "protocol", "clear", NULL);
+}
+
+bool
+mpd_run_clear_protocol_features(struct mpd_connection *connection)
+{
+	return mpd_send_clear_protocol_features(connection) &&
+		mpd_response_finish(connection);
+}
+
+bool
+mpd_send_all_protocol_features(struct mpd_connection *connection)
+{
+	return mpd_send_command(connection, "protocol", "all", NULL);
+}
+
+bool
+mpd_run_all_protocol_features(struct mpd_connection *connection)
+{
+	return mpd_send_all_protocol_features(connection) &&
+		mpd_response_finish(connection);
+}

src/feature.c

@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: BSD-3-Clause
+// Copyright The Music Player Daemon Project
+
+#include <mpd/feature.h>
+
+#include <assert.h>
+#include <string.h>
+#include <stdbool.h>
+
+static const char *const mpd_feature_names[MPD_FEATURE_COUNT] =
+{
+	[MPD_FEATURE_HIDE_PLAYLISTS_IN_ROOT] = "hide_playlists_in_root",
+};
+
+const char *
+mpd_feature_name(enum mpd_protocol_feature feature)
+{
+	if ((unsigned)feature >= MPD_FEATURE_COUNT)
+		return NULL;
+
+	return mpd_feature_names[feature];
+}
+
+enum mpd_protocol_feature
+mpd_feature_name_parse(const char *name)
+{
+	assert(name != NULL);
+
+	for (unsigned i = 0; i < MPD_FEATURE_COUNT; ++i)
+		if (strcmp(name, mpd_feature_names[i]) == 0)
+			return (enum mpd_protocol_feature)i;
+
+	return MPD_FEATURE_UNKNOWN;
+}