modules: add new API module to monitor files

modules/meson.build

@@ -166,6 +166,17 @@ shared_library(
   dependencies : [wp_dep, pipewire_dep, mathlib],
 )
 
+shared_library(
+  'wireplumber-module-file-monitor-api',
+  [
+    'module-file-monitor-api.c',
+  ],
+  c_args : [common_c_args, '-DG_LOG_DOMAIN="m-file-monitor-api"'],
+  install : true,
+  install_dir : wireplumber_module_dir,
+  dependencies : [wp_dep, pipewire_dep],
+)
+
 if wpipc_dep.found()
   shared_library(
     'wireplumber-module-ipc',

modules/module-file-monitor-api.c

@@ -0,0 +1,212 @@
+/* WirePlumber
+ *
+ * Copyright © 2021 Collabora Ltd.
+ *    @author Julian Bouzas <julian.bouzas@collabora.com>
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <stdio.h>
+
+#include <wp/wp.h>
+
+struct _WpFileMonitorApi
+{
+  WpPlugin parent;
+
+  GHashTable *monitors;
+};
+
+enum {
+  ACTION_ADD_WATCH,
+  ACTION_REMOVE_WATCH,
+  SIGNAL_CHANGED,
+  N_SIGNALS
+};
+
+static guint signals[N_SIGNALS] = {0};
+
+G_DECLARE_FINAL_TYPE (WpFileMonitorApi, wp_file_monitor_api, WP,
+    FILE_MONITOR_API, WpPlugin)
+G_DEFINE_TYPE (WpFileMonitorApi, wp_file_monitor_api, WP_TYPE_PLUGIN)
+
+static void
+wp_file_monitor_api_init (WpFileMonitorApi * self)
+{
+  self->monitors = g_hash_table_new_full (g_str_hash, g_str_equal, g_free,
+      g_object_unref);
+}
+
+static void
+wp_file_monitor_api_finalize (GObject * object)
+{
+  WpFileMonitorApi * self = WP_FILE_MONITOR_API (object);
+
+  g_clear_pointer (&self->monitors, g_hash_table_unref);
+
+  G_OBJECT_CLASS (wp_file_monitor_api_parent_class)->finalize (object);
+}
+
+static void
+on_file_monitor_changed (GFileMonitor *monitor, GFile *file, GFile *other,
+    GFileMonitorEvent evtype, gpointer data)
+{
+  WpFileMonitorApi * self = WP_FILE_MONITOR_API (data);
+
+  g_autofree char *fpath = g_file_get_path (file);
+  g_autofree char *opath = NULL;
+  const gchar *evtype_str = NULL;
+
+  if (other)
+      opath = g_file_get_path (other);
+
+  switch(evtype) {
+    case G_FILE_MONITOR_EVENT_CHANGED:
+      evtype_str = "changed";
+      break;
+    case G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT:
+      evtype_str = "changes-done-hint";
+      break;
+    case G_FILE_MONITOR_EVENT_DELETED:
+      evtype_str = "deleted";
+      break;
+    case G_FILE_MONITOR_EVENT_CREATED:
+      evtype_str = "created";
+      break;
+    case G_FILE_MONITOR_EVENT_ATTRIBUTE_CHANGED:
+      evtype_str = "attribute-changed";
+      break;
+    case G_FILE_MONITOR_EVENT_PRE_UNMOUNT:
+      evtype_str = "pre-unmount";
+      break;
+    case G_FILE_MONITOR_EVENT_UNMOUNTED:
+      evtype_str = "unmounted";
+      break;
+    case G_FILE_MONITOR_EVENT_MOVED:
+      evtype_str = "moved";
+      break;
+    case G_FILE_MONITOR_EVENT_RENAMED:
+      evtype_str = "renamed";
+      break;
+    case G_FILE_MONITOR_EVENT_MOVED_IN:
+      evtype_str = "moved-in";
+      break;
+    case G_FILE_MONITOR_EVENT_MOVED_OUT:
+      evtype_str = "moved-out";
+      break;
+    default:
+      wp_warning_object (self, "Unknown event type %d", evtype);
+      break;
+  }
+
+  g_signal_emit (self, signals[SIGNAL_CHANGED], 0, fpath, opath, evtype_str);
+}
+
+static gboolean
+wp_file_monitor_api_add_watch (WpFileMonitorApi * self, const gchar *path,
+    const gchar *flags_str)
+{
+  g_autoptr (GError) e = NULL;
+  g_autoptr (GFileMonitor) fm = NULL;
+  g_autoptr (GFile) f = NULL;
+  GFileMonitorFlags flags = G_FILE_MONITOR_NONE;
+
+  /* don't do anything if the directory is already being watched */
+  if (g_hash_table_contains (self->monitors, path))
+    return TRUE;
+
+  /* get directory */
+  f = g_file_new_for_path (path);
+  if (!f) {
+    wp_warning_object (self, "Invalid directory '%s'", path);
+    return FALSE;
+  }
+
+  /* parse flags */
+  for (guint i = 0; flags_str && i < strlen (flags_str); i++) {
+    switch (flags_str[i]) {
+      case 'o': flags |= G_FILE_MONITOR_WATCH_MOUNTS; break;
+      case 's': flags |= G_FILE_MONITOR_SEND_MOVED; break;
+      case 'h': flags |= G_FILE_MONITOR_WATCH_HARD_LINKS; break;
+      case 'm': flags |= G_FILE_MONITOR_WATCH_MOVES; break;
+      default:
+        break;
+    }
+  }
+
+  /* create the file monitor for that directory */
+  fm = g_file_monitor_directory (f, flags, NULL, &e);
+  if (e) {
+    wp_warning_object (self, "Failed to add watch for directory '%s': %s", path,
+        e->message);
+    return FALSE;
+  }
+
+  /* handle changed signal and add it to monitors table */
+  g_signal_connect (fm, "changed", G_CALLBACK (on_file_monitor_changed), self);
+  g_hash_table_insert (self->monitors, g_strdup (path), g_steal_pointer (&fm));
+  return TRUE;
+}
+
+static void
+wp_file_monitor_api_remove_watch (WpFileMonitorApi * self, const gchar *path)
+{
+  g_hash_table_remove (self->monitors, path);
+}
+
+static void
+wp_file_monitor_api_enable (WpPlugin * plugin, WpTransition * transition)
+{
+  WpFileMonitorApi * self = WP_FILE_MONITOR_API (plugin);
+
+  wp_object_update_features (WP_OBJECT (self), WP_PLUGIN_FEATURE_ENABLED, 0);
+}
+
+static void
+wp_file_monitor_api_disable (WpPlugin * plugin)
+{
+  WpFileMonitorApi * self = WP_FILE_MONITOR_API (plugin);
+
+  g_hash_table_remove_all (self->monitors);
+}
+
+static void
+wp_file_monitor_api_class_init (WpFileMonitorApiClass * klass)
+{
+  GObjectClass *object_class = (GObjectClass *) klass;
+  WpPluginClass *plugin_class = (WpPluginClass *) klass;
+
+  object_class->finalize = wp_file_monitor_api_finalize;
+
+  plugin_class->enable = wp_file_monitor_api_enable;
+  plugin_class->disable = wp_file_monitor_api_disable;
+
+  signals[ACTION_ADD_WATCH] = g_signal_new_class_handler (
+      "add-watch", G_TYPE_FROM_CLASS (klass),
+      G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
+      (GCallback) wp_file_monitor_api_add_watch,
+      NULL, NULL, NULL,
+      G_TYPE_BOOLEAN, 2, G_TYPE_STRING, G_TYPE_STRING);
+
+  signals[ACTION_REMOVE_WATCH] = g_signal_new_class_handler (
+      "remove-watch", G_TYPE_FROM_CLASS (klass),
+      G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
+      (GCallback) wp_file_monitor_api_remove_watch,
+      NULL, NULL, NULL,
+      G_TYPE_NONE, 1, G_TYPE_STRING);
+
+  signals[SIGNAL_CHANGED] = g_signal_new (
+      "changed", G_TYPE_FROM_CLASS (klass),
+      G_SIGNAL_RUN_LAST, 0, NULL, NULL, NULL,
+      G_TYPE_NONE, 3, G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING);
+}
+
+WP_PLUGIN_EXPORT gboolean
+wireplumber__module_init (WpCore * core, GVariant * args, GError ** error)
+{
+  wp_plugin_register (g_object_new (wp_file_monitor_api_get_type (),
+          "name", "file-monitor-api",
+          "core", core,
+          NULL));
+  return TRUE;
+}

src/config/main.lua.d/30-alsa-monitor.lua

@@ -8,6 +8,11 @@ function alsa_monitor.enable()
     load_module("reserve-device")
   end
 
+  -- The "file-monitor-api" module needs to be loaded for MIDI device monitoring
+  if alsa_monitor.properties["alsa.midi.monitoring"] then
+    load_module("file-monitor-api")
+  end
+
   load_monitor("alsa", {
     properties = alsa_monitor.properties,
     rules = alsa_monitor.rules,

src/config/main.lua.d/50-alsa-config.lua

@@ -10,6 +10,9 @@ alsa_monitor.properties = {
   ["alsa.reserve"] = true,
   --["alsa.reserve.priority"] = -20,
   --["alsa.reserve.application-name"] = "WirePlumber",
+
+  -- Enables monitoring of alsa MIDI devices
+  ["alsa.midi.monitoring"] = true,
 }
 
 alsa_monitor.rules = {

tests/meson.build

@@ -35,6 +35,7 @@ common_test_env = environment({
   'PIPEWIRE_RUNTIME_DIR': '/tmp',
   'XDG_CONFIG_HOME': meson.current_build_dir() / '.config',
   'XDG_STATE_HOME': meson.current_build_dir() / '.local' / '.state',
+  'FILE_MONITOR_DIR': meson.current_build_dir() / '.local' / 'file_monitor',
   'WIREPLUMBER_CONFIG_DIR': '/invalid',
   'WIREPLUMBER_DATA_DIR': '/invalid',
   'WIREPLUMBER_MODULE_DIR': meson.current_build_dir() / '..' / 'modules',

tests/modules/file-monitor.c

@@ -0,0 +1,119 @@
+/* WirePlumber
+ *
+ * Copyright © 2021 Collabora Ltd.
+ *    @author Julian Bouzas <julian.bouzas@collabora.com>
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <fcntl.h>
+#include <sys/inotify.h>
+
+#include "../common/base-test-fixture.h"
+
+typedef struct {
+  WpBaseTestFixture base;
+  WpPlugin *plugin;
+  gchar *path;
+  gchar *file;
+  gchar *evtype;
+} TestFixture;
+
+static void
+test_file_monitor_setup (TestFixture * f, gconstpointer user_data)
+{
+  wp_base_test_fixture_setup (&f->base, WP_BASE_TEST_FLAG_DONT_CONNECT);
+  g_autoptr (GError) error = NULL;
+
+  wp_core_load_component (f->base.core,
+      "libwireplumber-module-file-monitor-api", "module", NULL, &error);
+  g_assert_no_error (error);
+
+  f->plugin = wp_plugin_find (f->base.core, "file-monitor-api");
+  g_assert_nonnull (f->plugin);
+
+  f->path = g_strdup (g_getenv ("FILE_MONITOR_DIR"));
+  g_mkdir_with_parents (f->path, 0700);
+}
+
+static void
+test_file_monitor_teardown (TestFixture * f, gconstpointer user_data)
+{
+  g_clear_pointer (&f->evtype, g_free);
+  g_clear_pointer (&f->file, g_free);
+  g_clear_pointer (&f->path, g_free);
+  g_clear_object (&f->plugin);
+  wp_base_test_fixture_teardown (&f->base);
+}
+
+static void
+on_plugin_activated (WpObject * plugin, GAsyncResult * res, TestFixture * f)
+{
+  g_autoptr (GError) error = NULL;
+  if (!wp_object_activate_finish (plugin, res, &error)) {
+    wp_critical_object (plugin, "%s", error->message);
+    g_main_loop_quit (f->base.loop);
+  }
+}
+
+static void
+on_changed (WpPlugin *plugin, const gchar *file, const gchar *old,
+    const char *evtype, TestFixture * f)
+{
+  g_assert_nonnull (file);
+  g_assert_nonnull (evtype);
+  f->file = g_strdup (file);
+  f->evtype = g_strdup (evtype);
+  g_main_loop_quit (f->base.loop);
+}
+
+static void
+test_file_monitor_basic (TestFixture * f, gconstpointer user_data)
+{
+  gboolean res = FALSE;
+
+  /* activate plugin */
+  g_assert_nonnull (f->plugin);
+  wp_object_activate (WP_OBJECT (f->plugin), WP_PLUGIN_FEATURE_ENABLED,
+      NULL, (GAsyncReadyCallback) on_plugin_activated, f);
+
+  /* delete the 'foo' file if it exists in path */
+  g_autofree gchar *filename = g_build_filename (f->path, "foo", NULL);
+  remove (filename);
+
+  /* handle changed signal */
+  f->file = NULL;
+  f->evtype = NULL;
+  g_signal_connect (f->plugin, "changed", G_CALLBACK (on_changed), f);
+
+  /* add watch */
+  g_signal_emit_by_name (f->plugin, "add-watch", f->path, "m", &res);
+  g_assert_true (res);
+
+  /* create the foo file in path */
+  int fd = open (filename, O_CREAT | O_EXCL, 0700);
+  g_assert_cmpint (fd, >=, 0);
+
+  /* run */
+  g_main_loop_run (f->base.loop);
+  g_assert_cmpstr (f->file, ==, filename);
+  g_assert_cmpstr (f->evtype, ==, "created");
+
+  /* removed watch */
+  g_signal_emit_by_name (f->plugin, "remove-watch", f->path);
+}
+
+gint
+main (gint argc, gchar *argv[])
+{
+  g_test_init (&argc, &argv, NULL);
+  wp_init (WP_INIT_ALL);
+
+  g_test_add ("/modules/file-monitor/basic",
+      TestFixture, NULL,
+      test_file_monitor_setup,
+      test_file_monitor_basic,
+      test_file_monitor_teardown);
+
+  return g_test_run ();
+}

tests/modules/meson.build

@@ -24,6 +24,13 @@ test(
   env: common_env,
 )
 
+test(
+  'test-file-monitor',
+  executable('test-file-monitor', 'file-monitor.c',
+    dependencies: common_deps, c_args: common_args),
+  env: common_env,
+)
+
 test(
   'test-si-node',
   executable('test-si-node', 'si-node.c',