summaryrefslogtreecommitdiffstats
path: root/src/modules/module-always-sink.c
blob: fd644a2fa546fdcbf25bc4344ccb8fed1a1ea178 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
/* $Id$ */

/***
    This file is part of PulseAudio.

    Copyright 2008 Colin Guthrie

    PulseAudio 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 License,
    or (at your option) any later version.

    PulseAudio 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
    General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with PulseAudio; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
    USA.
***/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <pulse/xmalloc.h>

#include <pulsecore/core.h>
#include <pulsecore/sink-input.h>
#include <pulsecore/modargs.h>
#include <pulsecore/log.h>
#include <pulsecore/namereg.h>
#include <pulsecore/core-util.h>

#include "module-always-sink-symdef.h"

PA_MODULE_AUTHOR("Colin Guthrie");
PA_MODULE_DESCRIPTION("Always keeps at least one sink loaded even if it's a null one");
PA_MODULE_VERSION(PACKAGE_VERSION);
PA_MODULE_LOAD_ONCE(TRUE);
PA_MODULE_USAGE(
        "sink_name=<name of sink>");

#define DEFAULT_SINK_NAME "auto_null"

static const char* const valid_modargs[] = {
    "sink_name",
    NULL,
};

struct userdata {
    pa_hook_slot *put_slot, *unlink_slot;
    pa_module* null_module;
    pa_bool_t ignore;
    char *sink_name;
};

static void load_null_sink_if_needed(pa_core *c, pa_sink *sink, struct userdata* u) {
    pa_sink *target;
    uint32_t idx;
    char *t;

    pa_assert(c);
    pa_assert(u);
    pa_assert(!u->null_module);

    /* Loop through all sinks and check to see if we have *any*
     * sinks. Ignore the sink passed in (if it's not null) */
    for (target = pa_idxset_first(c->sinks, &idx); target; target = pa_idxset_next(c->sinks, &idx))
        if (!sink || target != sink)
            break;

    if (target)
        return;

    pa_log_debug("Autoloading null-sink as no other sinks detected.");

    u->ignore = TRUE;

    t = pa_sprintf_malloc("sink_name=%s", u->sink_name);
    u->null_module = pa_module_load(c, "module-null-sink", t);
    pa_xfree(t);

    u->ignore = FALSE;

    if (!u->null_module)
        pa_log_warn("Unable to load module-null-sink");
}

static pa_hook_result_t put_hook_callback(pa_core *c, pa_sink *sink, void* userdata) {
    struct userdata *u = userdata;

    pa_assert(c);
    pa_assert(sink);
    pa_assert(u);

    /* This is us detecting ourselves on load... just ignore this. */
    if (u->ignore)
        return PA_HOOK_OK;

    /* Auto-loaded null-sink not active, so ignoring newly detected sink. */
    if (!u->null_module)
        return PA_HOOK_OK;

    /* This is us detecting ourselves on load in a different way... just ignore this too. */
    if (sink->module == u->null_module)
        return PA_HOOK_OK;

    pa_log_info("A new sink has been discovered. Unloading null-sink.");

    pa_module_unload_request(u->null_module);
    u->null_module = NULL;

    return PA_HOOK_OK;
}

static pa_hook_result_t unlink_hook_callback(pa_core *c, pa_sink *sink, void* userdata) {
    struct userdata *u = userdata;

    pa_assert(c);
    pa_assert(sink);
    pa_assert(u);

    /* First check to see if it's our own null-sink that's been removed... */
    if (u->null_module && sink->module == u->null_module) {
        pa_log_debug("Autoloaded null-sink removed");
        u->null_module = NULL;
        return PA_HOOK_OK;
    }

    load_null_sink_if_needed(c, sink, u);

    return PA_HOOK_OK;
}

int pa__init(pa_module*m) {
    pa_modargs *ma = NULL;
    struct userdata *u;

    pa_assert(m);

    if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
        pa_log("Failed to parse module arguments");
        return -1;
    }

    m->userdata = u = pa_xnew(struct userdata, 1);
    u->sink_name = pa_xstrdup(pa_modargs_get_value(ma, "sink_name", DEFAULT_SINK_NAME));
    u->put_slot = pa_hook_connect(&m->core->hooks[PA_CORE_HOOK_SINK_PUT], PA_HOOK_LATE, (pa_hook_cb_t) put_hook_callback, u);
    u->unlink_slot = pa_hook_connect(&m->core->hooks[PA_CORE_HOOK_SINK_UNLINK], PA_HOOK_EARLY, (pa_hook_cb_t) unlink_hook_callback, u);
    u->null_module = NULL;
    u->ignore = FALSE;

    pa_modargs_free(ma);

    load_null_sink_if_needed(m->core, NULL, u);

    return 0;
}

void pa__done(pa_module*m) {
    struct userdata *u;

    pa_assert(m);

    if (!(u = m->userdata))
        return;

    if (u->put_slot)
        pa_hook_slot_free(u->put_slot);
    if (u->unlink_slot)
        pa_hook_slot_free(u->unlink_slot);
    if (u->null_module)
        pa_module_unload_request(u->null_module);

    pa_xfree(u->sink_name);
    pa_xfree(u);
}