path: root/backends/oss4/oss4-backend.c

/*
 * Copyright (C) 2014 Michal Ratajsky <michal.ratajsky@gmail.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the licence, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * 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 "oss4-backend.h"
#include "oss4-common.h"
#include "oss4-device.h"

#define BACKEND_NAME      "OSS4"
#define BACKEND_PRIORITY  8

#define PATH_SNDSTAT      "/dev/sndstat"

struct _Oss4BackendPrivate
{
    gint fd;
    gchar           *sndstat;
    GHashTable      *devices;
    GHashTable      *streams;
    MateMixerStream *default_input;
    MateMixerStream *default_output;
    MateMixerState   state;
};

enum {
    PROP_0,
    PROP_STATE,
    PROP_DEFAULT_INPUT,
    PROP_DEFAULT_OUTPUT
};

static void mate_mixer_backend_interface_init (MateMixerBackendInterface *iface);

static void oss4_backend_class_init     (Oss4BackendClass *klass);
static void oss4_backend_class_finalize (Oss4BackendClass *klass);

static void oss4_backend_get_property   (GObject         *object,
                                         guint            param_id,
                                         GValue          *value,
                                         GParamSpec      *pspec);

static void oss4_backend_init           (Oss4Backend     *oss);
static void oss4_backend_dispose        (GObject         *object);
static void oss4_backend_finalize       (GObject         *object);

G_DEFINE_DYNAMIC_TYPE_EXTENDED (Oss4Backend, oss4_backend,
                                G_TYPE_OBJECT, 0,
                                G_IMPLEMENT_INTERFACE_DYNAMIC (MATE_MIXER_TYPE_BACKEND,
                                                               mate_mixer_backend_interface_init))

static gboolean oss4_backend_open         (MateMixerBackend  *backend);
static void     oss4_backend_close        (MateMixerBackend  *backend);
static GList *  oss4_backend_list_devices (MateMixerBackend  *backend);
static GList *  oss4_backend_list_streams (MateMixerBackend  *backend);

static void     change_state                    (Oss4Backend       *oss,
                                                 MateMixerState     state);

static gboolean read_device (Oss4Backend *oss, gint index);

static gchar *  read_device_sndstat_description (Oss4Backend *oss,
                                                 const gchar *prefix);

static void     add_device      (Oss4Backend *oss, Oss4Device *device);
static void     remove_device   (Oss4Backend *oss, Oss4Device *device);

static MateMixerBackendInfo info;

void
backend_module_init (GTypeModule *module)
{
    oss4_backend_register_type (module);

    info.name         = BACKEND_NAME;
    info.priority     = BACKEND_PRIORITY;
    info.g_type       = OSS4_TYPE_BACKEND;
    info.backend_type = MATE_MIXER_BACKEND_OSS4;
}

const MateMixerBackendInfo *backend_module_get_info (void)
{
    return &info;
}

static void
mate_mixer_backend_interface_init (MateMixerBackendInterface *iface)
{
    iface->open         = oss4_backend_open;
    iface->close        = oss4_backend_close;
    iface->list_devices = oss4_backend_list_devices;
    iface->list_streams = oss4_backend_list_streams;
}

static void
oss4_backend_class_init (Oss4BackendClass *klass)
{
    GObjectClass *object_class;

    object_class = G_OBJECT_CLASS (klass);
    object_class->dispose      = oss4_backend_dispose;
    object_class->finalize     = oss4_backend_finalize;
    object_class->get_property = oss4_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 (Oss4BackendPrivate));
}

/* Called in the code generated by G_DEFINE_DYNAMIC_TYPE_EXTENDED() */
static void
oss4_backend_class_finalize (Oss4BackendClass *klass)
{
}

static void
oss4_backend_get_property (GObject    *object,
                           guint       param_id,
                           GValue     *value,
                           GParamSpec *pspec)
{
    Oss4Backend *oss;

    oss = OSS4_BACKEND (object);

    switch (param_id) {
    case PROP_STATE:
        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, oss->priv->default_output);
        break;
        break;
    default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, param_id, pspec);
        break;
    }
}

static void
oss4_backend_init (Oss4Backend *oss)
{
    oss->priv = G_TYPE_INSTANCE_GET_PRIVATE (oss,
                                             OSS4_TYPE_BACKEND,
                                             Oss4BackendPrivate);

    oss->priv->devices = g_hash_table_new_full (g_direct_hash,
                                                g_direct_equal,
                                                NULL,
                                                g_object_unref);

    oss->priv->streams = g_hash_table_new_full (g_str_hash,
                                                g_str_equal,
                                                g_free,
                                                g_object_unref);
}

static void
oss4_backend_dispose (GObject *object)
{
    oss4_backend_close (MATE_MIXER_BACKEND (object));
}

static void
oss4_backend_finalize (GObject *object)
{
    Oss4Backend *oss;

    oss = OSS4_BACKEND (object);

    g_hash_table_destroy (oss->priv->devices);
    g_hash_table_destroy (oss->priv->streams);
}

static gboolean
oss4_backend_open (MateMixerBackend *backend)
{
    Oss4Backend       *oss;
    gint               fd;
    gint               i;
    gint               ret;
    struct oss_sysinfo info;

    g_return_val_if_fail (OSS4_IS_BACKEND (backend), FALSE);

    oss = OSS4_BACKEND (backend);

    fd = g_open ("/dev/mixer", O_RDONLY, 0);
    if (fd == -1)
        fd = g_open ("/dev/mixer0", O_RDONLY, 0);
    if (fd == -1) {
        change_state (oss, MATE_MIXER_STATE_FAILED);
        return FALSE;
    }

    /* Query the number of mixer devices */
    ret = ioctl (fd, OSS_SYSINFO, &info);
    if (ret == -1) {
        close (fd);
        change_state (oss, MATE_MIXER_STATE_FAILED);
        return FALSE;
    }

    g_debug ("The sound system is %s version %s",
             info.product,
             info.version);

#if !defined(__linux__)
    /* 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 = PATH_SNDSTAT;
#endif

    oss->priv->fd = fd;

    for (i = 0; i < info.nummixers; i++)
        read_device (oss, i);

    change_state (oss, MATE_MIXER_STATE_READY);
    return TRUE;
}

void
oss4_backend_close (MateMixerBackend *backend)
{
    Oss4Backend *oss;

    g_return_if_fail (OSS4_IS_BACKEND (backend));

    oss = OSS4_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);
}

static GList *
oss4_backend_list_devices (MateMixerBackend *backend)
{
    GList *list;

    g_return_val_if_fail (OSS4_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 (OSS4_BACKEND (backend)->priv->devices);
    if (list != NULL) {
        g_list_foreach (list, (GFunc) g_object_ref, NULL);

        return list;
    }
    return NULL;
}

static GList *
oss4_backend_list_streams (MateMixerBackend *backend)
{
    GList *list;

    g_return_val_if_fail (OSS4_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 (OSS4_BACKEND (backend)->priv->streams);
    if (list != NULL) {
        g_list_foreach (list, (GFunc) g_object_ref, NULL);

        return list;
    }
    return NULL;
}

static void
change_state (Oss4Backend *oss, MateMixerState state)
{
    if (oss->priv->state == state)
        return;

    oss->priv->state = state;

    g_object_notify (G_OBJECT (oss), "state");
}

static gboolean
read_device (Oss4Backend *oss, gint index)
{
    Oss4Device          *device;
    gboolean             ret;
    gchar               *description = NULL;
    struct oss_mixerinfo info;

    /* We assume that the name and capabilities of a device do not change */
    device = g_hash_table_lookup (oss->priv->devices, GINT_TO_POINTER (index));
    if (G_UNLIKELY (device != NULL)) {
        g_debug ("Attempt to re-read already know device with index %d", index);
        return TRUE;
    }

    info.dev = index;
    ret = ioctl (oss->priv->fd, SNDCTL_MIXERINFO, &info);
    if (ret == -1) {
        g_debug ("Failed to read mixer info: %s", g_strerror (errno));
        return FALSE;
    }

    if (info.enabled == 0)
        return TRUE;

    /* Use the id as the device name and try to figure out the name of the
     * sound card from the sndstat file if it is available, otherwise use
     * the name from the mixer info */
    if (oss->priv->sndstat != NULL &&
        g_str_has_prefix (info.name, "pcm") == TRUE)
        description = read_device_sndstat_description (oss, info.name);

    if (description == NULL)
        description = g_strdup (info.name);

    device = oss4_device_new (info.id, description, oss->priv->fd, index);

    ret = oss4_device_read (device);
    if (ret == TRUE)
        add_device (oss, device);

    g_object_unref (device);
    g_free (description);

    return ret;
}

static gchar *
read_device_sndstat_description (Oss4Backend *oss, const gchar *prefix)
{
    FILE  *fp;
    gchar  line[256];
    gchar *description = NULL;

    g_debug ("reading prefix %s", prefix);

    fp = fopen (oss->priv->sndstat, "r");
    if (fp == NULL) {
        g_warning ("Failed to read %s: %s", oss->priv->sndstat, g_strerror (errno));
        return FALSE;
    }

    while (fgets (line, sizeof (line), fp) != NULL) {
        gchar *p;

        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;
    }

    fclose (fp);
    return description;
}

static void
add_device (Oss4Backend *oss, Oss4Device *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,
                         GINT_TO_POINTER (oss4_device_get_index (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 = oss4_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 = oss4_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 (Oss4Backend *oss, Oss4Device *device)
{
    MateMixerStream *stream;

    /* Remove the device streams first as they are a part of the device */
    stream = oss4_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 = oss4_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);
    }

    /* Remove the device */
    g_object_ref (device);

    g_hash_table_remove (oss->priv->devices,
                         GINT_TO_POINTER (oss4_device_get_index (device)));

    g_signal_emit_by_name (G_OBJECT (oss),
                           "device-removed",
                           mate_mixer_device_get_name (MATE_MIXER_DEVICE (device)));

    g_object_unref (device);
}