Support OSS

1 files changed, 483 insertions, 15 deletions

diff --git a/backends/oss/oss-backend.c b/backends/oss/oss-backend.c
index 22d3547..6e058f8 100644
--- a/backends/oss/oss-backend.c
+++ b/backends/oss/oss-backend.c
@@ -15,43 +15,95 @@
  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
 #include <glib.h>
 #include <glib-object.h>
+#include <glib/gstdio.h>
+#include <glib/gprintf.h>
+#include <glib/gi18n.h>
+#include <gio/gio.h>
 
 #include <libmatemixer/matemixer-backend.h>
 #include <libmatemixer/matemixer-backend-module.h>
 #include <libmatemixer/matemixer-enums.h>
+#include <libmatemixer/matemixer-stream.h>
 
 #include "oss-backend.h"
+#include "oss-common.h"
+#include "oss-device.h"
 
 #define BACKEND_NAME      "OSS"
-#define BACKEND_PRIORITY  90
+#define BACKEND_PRIORITY  9
+
+#define PATH_SNDSTAT      "/dev/sndstat"
+
+struct _OssBackendPrivate
+{
+    GFile           *sndstat;
+    GFile           *dev;
+    GFileMonitor    *dev_monitor;
+    GHashTable      *devices;
+    GHashTable      *streams;
+    MateMixerStream *default_input;
+    MateMixerStream *default_output;
+    MateMixerState   state;
+};
 
 enum {
     PROP_0,
     PROP_STATE,
     PROP_DEFAULT_INPUT,
-    PROP_DEFAULT_OUTPUT,
-    N_PROPERTIES
+    PROP_DEFAULT_OUTPUT
 };
 
 static void mate_mixer_backend_interface_init (MateMixerBackendInterface *iface);
 
 static void oss_backend_class_init     (OssBackendClass *klass);
 static void oss_backend_class_finalize (OssBackendClass *klass);
+
 static void oss_backend_get_property   (GObject         *object,
                                         guint            param_id,
                                         GValue          *value,
                                         GParamSpec      *pspec);
+
 static void oss_backend_init           (OssBackend      *oss);
+static void oss_backend_dispose        (GObject         *object);
+static void oss_backend_finalize       (GObject         *object);
 
 G_DEFINE_DYNAMIC_TYPE_EXTENDED (OssBackend, oss_backend,
                                 G_TYPE_OBJECT, 0,
                                 G_IMPLEMENT_INTERFACE_DYNAMIC (MATE_MIXER_TYPE_BACKEND,
                                                                mate_mixer_backend_interface_init))
 
-static gboolean       backend_open      (MateMixerBackend *backend);
-static MateMixerState backend_get_state (MateMixerBackend *backend);
+static gboolean oss_backend_open         (MateMixerBackend  *backend);
+static void     oss_backend_close        (MateMixerBackend  *backend);
+static GList *  oss_backend_list_devices (MateMixerBackend  *backend);
+static GList *  oss_backend_list_streams (MateMixerBackend  *backend);
+
+static void     change_state                    (OssBackend        *oss,
+                                                 MateMixerState     state);
+
+static void     on_dev_monitor_changed          (GFileMonitor      *monitor,
+                                                 GFile             *file,
+                                                 GFile             *other_file,
+                                                 GFileMonitorEvent  event_type,
+                                                 OssBackend        *oss);
+
+static gboolean read_device                     (OssBackend        *oss,
+                                                 const gchar        *path);
+
+static gchar *  read_device_description         (OssBackend        *oss,
+                                                 const gchar       *path,
+                                                 gint               fd);
+static gchar *  read_device_sndstat_description (const gchar       *path,
+                                                 GFileInputStream  *input);
+
+static void     add_device                      (OssBackend        *oss,
+                                                 OssDevice         *device);
+static void     remove_device                   (OssBackend        *oss,
+                                                 OssDevice         *device);
 
 static MateMixerBackendInfo info;
 
@@ -66,8 +118,7 @@ backend_module_init (GTypeModule *module)
     info.backend_type = MATE_MIXER_BACKEND_OSS;
 }
 
-const MateMixerBackendInfo *
-backend_module_get_info (void)
+const MateMixerBackendInfo *backend_module_get_info (void)
 {
     return &info;
 }
@@ -75,8 +126,10 @@ backend_module_get_info (void)
 static void
 mate_mixer_backend_interface_init (MateMixerBackendInterface *iface)
 {
-    iface->open      = backend_open;
-    iface->get_state = backend_get_state;
+    iface->open         = oss_backend_open;
+    iface->close        = oss_backend_close;
+    iface->list_devices = oss_backend_list_devices;
+    iface->list_streams = oss_backend_list_streams;
 }
 
 static void
@@ -85,11 +138,15 @@ oss_backend_class_init (OssBackendClass *klass)
     GObjectClass *object_class;
 
     object_class = G_OBJECT_CLASS (klass);
+    object_class->dispose      = oss_backend_dispose;
+    object_class->finalize     = oss_backend_finalize;
     object_class->get_property = oss_backend_get_property;
 
     g_object_class_override_property (object_class, PROP_STATE, "state");
     g_object_class_override_property (object_class, PROP_DEFAULT_INPUT, "default-input");
     g_object_class_override_property (object_class, PROP_DEFAULT_OUTPUT, "default-output");
+
+    g_type_class_add_private (object_class, sizeof (OssBackendPrivate));
 }
 
 /* Called in the code generated by G_DEFINE_DYNAMIC_TYPE_EXTENDED() */
@@ -104,13 +161,20 @@ oss_backend_get_property (GObject    *object,
                           GValue     *value,
                           GParamSpec *pspec)
 {
+    OssBackend *oss;
+
+    oss = OSS_BACKEND (object);
+
     switch (param_id) {
     case PROP_STATE:
-        g_value_set_enum (value, MATE_MIXER_STATE_READY);
+        g_value_set_enum (value, oss->priv->state);
         break;
     case PROP_DEFAULT_INPUT:
+        g_value_set_object (value, oss->priv->default_input);
+        break;
     case PROP_DEFAULT_OUTPUT:
-        g_value_set_object (value, NULL);
+        g_value_set_object (value, oss->priv->default_output);
+        break;
         break;
     default:
         G_OBJECT_WARN_INVALID_PROPERTY_ID (object, param_id, pspec);
@@ -121,16 +185,420 @@ oss_backend_get_property (GObject    *object,
 static void
 oss_backend_init (OssBackend *oss)
 {
+    oss->priv = G_TYPE_INSTANCE_GET_PRIVATE (oss,
+                                             OSS_TYPE_BACKEND,
+                                             OssBackendPrivate);
+
+    oss->priv->devices = g_hash_table_new_full (g_str_hash,
+                                                g_str_equal,
+                                                g_free,
+                                                g_object_unref);
+
+    oss->priv->streams = g_hash_table_new_full (g_str_hash,
+                                                g_str_equal,
+                                                g_free,
+                                                g_object_unref);
+}
+
+static void
+oss_backend_dispose (GObject *object)
+{
+    oss_backend_close (MATE_MIXER_BACKEND (object));
+}
+
+static void
+oss_backend_finalize (GObject *object)
+{
+    OssBackend *oss;
+
+    oss = OSS_BACKEND (object);
+
+    g_hash_table_destroy (oss->priv->devices);
+    g_hash_table_destroy (oss->priv->streams);
 }
 
 static gboolean
-backend_open (MateMixerBackend *backend)
+oss_backend_open (MateMixerBackend *backend)
 {
+    OssBackend *oss;
+    GError     *error = NULL;
+    gint        i;
+
+    g_return_val_if_fail (OSS_IS_BACKEND (backend), FALSE);
+
+    oss = OSS_BACKEND (backend);
+
+    /* Monitor changes on /dev to catch hot-(un)plugged devices */
+    // XXX works on linux, doesn't on freebsd, what to do on netbsd/openbsd?
+    oss->priv->dev = g_file_new_for_path ("/dev");
+    oss->priv->dev_monitor = g_file_monitor_directory (oss->priv->dev,
+                                                       G_FILE_MONITOR_NONE,
+                                                       NULL,
+                                                       &error);
+    if (oss->priv->dev_monitor != NULL) {
+        g_signal_connect (G_OBJECT (oss->priv->dev_monitor),
+                          "changed",
+                          G_CALLBACK (on_dev_monitor_changed),
+                          oss);
+    } else {
+        g_debug ("Failed to monitor /dev: %s", error->message);
+        g_error_free (error);
+    }
+
+#if !defined(__linux__) && !defined(__NetBSD__) &&  !defined(__OpenBSD__)
+    /* At least on systems based on FreeBSD we will need to read devices names
+     * from the sndstat file, but avoid even trying that on systems where this
+     * is not needed and the file is not present */
+    oss->priv->sndstat = g_file_new_for_path (PATH_SNDSTAT);
+#endif
+
+    for (i = 0; i < 5; i++) {
+        /* According to the OSS documentation the mixer devices are
+         * /dev/mixer0 - /dev/mixer4, of course some systems create them
+         * dynamically but this approach should be good enough */
+        gchar *path = g_strdup_printf ("/dev/mixer%i", i);
+
+        if (read_device (oss, path) == FALSE && i == 0) {
+            /* For the first mixer device check also /dev/mixer, but it
+             * might be a symlink to a real mixer device */
+            if (g_file_test ("/dev/mixer", G_FILE_TEST_IS_SYMLINK) == FALSE)
+                read_device (oss, "/dev/mixer");
+        }
+
+        g_free (path);
+    }
+
+    change_state (oss, MATE_MIXER_STATE_READY);
     return TRUE;
 }
 
-static MateMixerState
-backend_get_state (MateMixerBackend *backend)
+void
+oss_backend_close (MateMixerBackend *backend)
+{
+    OssBackend *oss;
+
+    g_return_if_fail (OSS_IS_BACKEND (backend));
+
+    oss = OSS_BACKEND (backend);
+
+    g_clear_object (&oss->priv->default_input);
+    g_clear_object (&oss->priv->default_output);
+
+    g_hash_table_remove_all (oss->priv->streams);
+    g_hash_table_remove_all (oss->priv->devices);
+
+    g_clear_object (&oss->priv->dev_monitor);
+    g_clear_object (&oss->priv->dev);
+    g_clear_object (&oss->priv->sndstat);
+}
+
+static GList *
+oss_backend_list_devices (MateMixerBackend *backend)
+{
+    GList *list;
+
+    g_return_val_if_fail (OSS_IS_BACKEND (backend), NULL);
+
+    /* Convert the hash table to a sorted linked list, this list is expected
+     * to be cached in the main library */
+    list = g_hash_table_get_values (OSS_BACKEND (backend)->priv->devices);
+    if (list != NULL) {
+        g_list_foreach (list, (GFunc) g_object_ref, NULL);
+
+        return list;
+    }
+    return NULL;
+}
+
+static GList *
+oss_backend_list_streams (MateMixerBackend *backend)
+{
+    GList *list;
+
+    g_return_val_if_fail (OSS_IS_BACKEND (backend), NULL);
+
+    /* Convert the hash table to a sorted linked list, this list is expected
+     * to be cached in the main library */
+    list = g_hash_table_get_values (OSS_BACKEND (backend)->priv->streams);
+    if (list != NULL) {
+        g_list_foreach (list, (GFunc) g_object_ref, NULL);
+
+        return list;
+    }
+    return NULL;
+}
+
+static void
+change_state (OssBackend *oss, MateMixerState state)
+{
+    if (oss->priv->state == state)
+        return;
+
+    oss->priv->state = state;
+
+    g_object_notify (G_OBJECT (oss), "state");
+}
+
+static void
+on_dev_monitor_changed (GFileMonitor     *monitor,
+                        GFile            *file,
+                        GFile            *other_file,
+                        GFileMonitorEvent event_type,
+                        OssBackend       *oss)
+{
+    gchar *path;
+
+    if (event_type != G_FILE_MONITOR_EVENT_CREATED &&
+        event_type != G_FILE_MONITOR_EVENT_DELETED)
+        return;
+
+    path = g_file_get_path (file);
+
+    /* Only handle creation and deletion of mixer devices */
+    if (g_str_has_prefix (path, "/dev/mixer") == FALSE) {
+        g_free (path);
+        return;
+    }
+    if (strcmp (path, "/dev/mixer") == 0 &&
+        g_file_test (path, G_FILE_TEST_IS_SYMLINK) == TRUE) {
+        g_free (path);
+        return;
+    }
+
+    if (event_type == G_FILE_MONITOR_EVENT_DELETED) {
+        OssDevice *device;
+
+        device = g_hash_table_lookup (oss->priv->devices, path);
+        if (device != NULL)
+            remove_device (oss, device);
+    } else
+        read_device (oss, path);
+
+    g_free (path);
+}
+
+static gboolean
+read_device (OssBackend *oss, const gchar *path)
+{
+    OssDevice   *device;
+    gint         fd;
+    gboolean     ret;
+    const gchar *description;
+
+    /* We assume that the name and capabilities of a device do not change */
+    device = g_hash_table_lookup (oss->priv->devices, path);
+    if (G_UNLIKELY (device != NULL)) {
+        g_debug ("Attempt to re-read already know device %s", path);
+        return TRUE;
+    }
+
+    fd = g_open (path, O_RDWR, 0);
+    if (fd == -1) {
+        if (errno != ENOENT && errno != ENXIO)
+            g_debug ("%s: %s", path, g_strerror (errno));
+        return FALSE;
+    }
+
+    device = oss_device_new (path, fd);
+
+    description = read_device_description (oss, path, fd);
+    if (description != NULL)
+        oss_device_set_description (device, description);
+    else
+        oss_device_set_description (device, _("Unknown device"));
+
+    /* Close the descriptor as the device should dup it if it intends
+     * to keep it */
+    g_close (fd, NULL);
+
+    ret = oss_device_read (device);
+    if (ret == TRUE)
+        add_device (oss, device);
+
+    g_object_unref (device);
+    return ret;
+}
+
+static gchar *
+read_device_description (OssBackend *oss, const gchar *path, gint fd)
+{
+    struct mixer_info info;
+
+    if (ioctl (fd, SOUND_MIXER_INFO, &info) == 0) {
+        /* Prefer device name supplied by the system, but this fails on FreeBSD */
+        return g_strdup (info.name);
+    }
+
+    /* Reading the sndstat file is a bit desperate, but seem to be the only
+     * way to determine the name of the sound card on FreeBSD, it also has an
+     * advantage in being able to find out the default one */
+    if (oss->priv->sndstat != NULL) {
+        GError           *error = NULL;
+        GFileInputStream *input = g_file_read (oss->priv->sndstat, NULL, &error);
+
+        if (input == NULL) {
+            /* The file can only be open by one application, otherwise the call
+             * fails with EBUSY */
+            if (error->code == G_IO_ERROR_BUSY) {
+                g_debug ("Delayed reading %s as it is busy", PATH_SNDSTAT);
+                // XXX use timeout and try again
+            } else {
+                if (error->code == G_IO_ERROR_NOT_FOUND)
+                    g_debug ("Device description is unknown as %s does not exist",
+                             PATH_SNDSTAT);
+                else
+                    g_debug ("%s: %s", PATH_SNDSTAT, error->message);
+
+                g_clear_object (&oss->priv->sndstat);
+            }
+            g_error_free (error);
+        } else
+            return read_device_sndstat_description (path, input);
+    }
+
+    return NULL;
+}
+
+static gchar *
+read_device_sndstat_description (const gchar *path, GFileInputStream *input)
 {
-    return MATE_MIXER_STATE_READY;
+    gchar            *line;
+    gchar            *prefix;
+    gchar            *description = NULL;
+    GDataInputStream *stream;
+
+    if (G_UNLIKELY (g_str_has_prefix (path, "/dev/mixer")) == FALSE) {
+        g_warn_if_reached ();
+        return NULL;
+    }
+
+    /* We assume that the mixer device number matches the pcm number in the
+     * sndstat file, this is a bit desperate, but it seems to do the
+     * right thing in practice */
+    prefix = g_strdup_printf ("pcm%u: ",
+                              (guint) g_ascii_strtoull (path + sizeof ("/dev/mixer") - 1,
+                                                        NULL,
+                                                        10));
+
+    stream = g_data_input_stream_new (G_INPUT_STREAM (input));
+
+    while (TRUE) {
+        GError *error = NULL;
+        gchar  *p;
+
+        line = g_data_input_stream_read_line (stream, NULL, NULL, &error);
+        if (line == NULL) {
+            if (error != NULL) {
+                g_warning ("%s: %s", path, error->message);
+                g_error_free (error);
+            }
+            break;
+        }
+
+        if (g_str_has_prefix (line, prefix) == FALSE)
+            continue;
+
+        /* Example line:
+         * pcm0: <ATI R6xx (HDMI)> (play) default */
+        p = strchr (line, '<');
+        if (p != NULL && *p && *(++p)) {
+            gchar *end = strchr (p, '>');
+
+            if (end != NULL)
+                description = g_strndup (p, end - p);
+        }
+
+        // XXX we can also read "default" at the end of the line
+        // XXX http://ashish.is.lostca.se/2011/05/23/default-sound-device-in-freebsd/
+        if (g_str_has_suffix (line, "default") ||
+            g_str_has_suffix (line, "default)"))
+            ;
+
+        if (description != NULL)
+            break;
+    }
+
+    g_object_unref (stream);
+    g_free (prefix);
+
+    return description;
+}
+
+static void
+add_device (OssBackend *oss, OssDevice *device)
+{
+    MateMixerStream *stream;
+
+    /* Add device, file path is used as the key rather than the name, because
+     * the name is not known until an OssDevice instance is created */
+    g_hash_table_insert (oss->priv->devices,
+                         g_strdup (oss_device_get_path (device)),
+                         g_object_ref (device));
+
+    g_signal_emit_by_name (G_OBJECT (oss),
+                           "device-added",
+                           mate_mixer_device_get_name (MATE_MIXER_DEVICE (device)));
+
+    /* Add streams if they exist */
+    stream = oss_device_get_input_stream (device);
+    if (stream != NULL) {
+        g_hash_table_insert (oss->priv->streams,
+                             g_strdup (mate_mixer_stream_get_name (stream)),
+                             g_object_ref (stream));
+
+        g_signal_emit_by_name (G_OBJECT (oss),
+                               "stream-added",
+                               mate_mixer_stream_get_name (stream));
+    }
+
+    stream = oss_device_get_output_stream (device);
+    if (stream != NULL) {
+        g_hash_table_insert (oss->priv->streams,
+                             g_strdup (mate_mixer_stream_get_name (stream)),
+                             g_object_ref (stream));
+
+        g_signal_emit_by_name (G_OBJECT (oss),
+                               "stream-added",
+                               mate_mixer_stream_get_name (stream));
+    }
+}
+
+static void
+remove_device (OssBackend *oss, OssDevice *device)
+{
+    MateMixerStream *stream;
+    const gchar     *path;
+
+    /* Remove the device streams first as they are a part of the device */
+    stream = oss_device_get_input_stream (device);
+    if (stream != NULL) {
+        const gchar *name = mate_mixer_stream_get_name (stream);
+
+        g_hash_table_remove (oss->priv->streams, name);
+        g_signal_emit_by_name (G_OBJECT (oss),
+                               "stream-removed",
+                               name);
+    }
+
+    stream = oss_device_get_output_stream (device);
+    if (stream != NULL) {
+        const gchar *name = mate_mixer_stream_get_name (stream);
+
+        g_hash_table_remove (oss->priv->streams, stream);
+        g_signal_emit_by_name (G_OBJECT (oss),
+                               "stream-removed",
+                               name);
+    }
+
+    path = oss_device_get_path (device);
+
+    /* Remove the device */
+    g_object_ref (device);
+
+    g_hash_table_remove (oss->priv->devices, path);
+    g_signal_emit_by_name (G_OBJECT (oss),
+                           "device-removed",
+                           mate_mixer_device_get_name (MATE_MIXER_DEVICE (device)));
+
+    g_object_unref (device);
 }