device-manager: Add a new module to keep track of the names and descriptions of various sinks.

This will be used as the basis for a queryable system for past and present devices, initially for use in KDE.
Currently all this module does is save lists of sinks/sources and their descriptions, so it needs to
gain a protocol extension to make this queryable.

As things stand it will save the device descriptions of all sinks and restore them if they differ from whats on record.

src/Makefile.am

@@ -992,7 +992,8 @@ modlibexec_LTLIBRARIES += \
 		module-sine-source.la \
 		module-detect.la \
 		module-volume-restore.la \
-		module-device-restore.la \
+    module-device-manager.la \
+    module-device-restore.la \
 		module-stream-restore.la \
 		module-card-restore.la \
 		module-default-device-restore.la \
@@ -1233,7 +1234,8 @@ SYMDEF_FILES = \
 		modules/jack/module-jack-sink-symdef.h \
 		modules/jack/module-jack-source-symdef.h \
 		modules/module-volume-restore-symdef.h \
-		modules/module-device-restore-symdef.h \
+    modules/module-device-manager-symdef.h \
+    modules/module-device-restore-symdef.h \
 		modules/module-stream-restore-symdef.h \
 		modules/module-card-restore-symdef.h \
 		modules/module-default-device-restore-symdef.h \
@@ -1541,6 +1543,12 @@ module_cork_music_on_phone_la_LDFLAGS = $(MODULE_LDFLAGS)
 module_cork_music_on_phone_la_LIBADD = $(AM_LIBADD) libpulsecore-@PA_MAJORMINORMICRO@.la libpulsecommon-@PA_MAJORMINORMICRO@.la libpulse.la
 module_cork_music_on_phone_la_CFLAGS = $(AM_CFLAGS)
 
+# Device description restore module
+module_device_manager_la_SOURCES = modules/module-device-manager.c
+module_device_manager_la_LDFLAGS = $(MODULE_LDFLAGS)
+module_device_manager_la_LIBADD = $(AM_LIBADD) libpulsecore-@PA_MAJORMINORMICRO@.la libpulsecommon-@PA_MAJORMINORMICRO@.la libpulse.la
+module_device_manager_la_CFLAGS = $(AM_CFLAGS)
+
 # Device volume/muted restore module
 module_device_restore_la_SOURCES = modules/module-device-restore.c
 module_device_restore_la_LDFLAGS = $(MODULE_LDFLAGS)

src/modules/module-device-manager.c

@@ -0,0 +1,352 @@
+/***
+  This file is part of PulseAudio.
+
+  Copyright 2006-2008 Lennart Poettering
+  Copyright 2009 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 2.1 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 <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+
+#include <pulse/xmalloc.h>
+#include <pulse/volume.h>
+#include <pulse/timeval.h>
+#include <pulse/util.h>
+#include <pulse/rtclock.h>
+
+#include <pulsecore/core-error.h>
+#include <pulsecore/module.h>
+#include <pulsecore/core-util.h>
+#include <pulsecore/modargs.h>
+#include <pulsecore/log.h>
+#include <pulsecore/core-subscribe.h>
+#include <pulsecore/sink-input.h>
+#include <pulsecore/source-output.h>
+#include <pulsecore/namereg.h>
+#include <pulsecore/database.h>
+
+#include "module-device-manager-symdef.h"
+
+PA_MODULE_AUTHOR("Colin Guthrie");
+PA_MODULE_DESCRIPTION("Keep track of devices (and their descriptions) both past and present");
+PA_MODULE_VERSION(PACKAGE_VERSION);
+PA_MODULE_LOAD_ONCE(TRUE);
+PA_MODULE_USAGE("This module does not take any arguments");
+
+#define SAVE_INTERVAL (10 * PA_USEC_PER_SEC)
+
+static const char* const valid_modargs[] = {
+    NULL
+};
+
+struct userdata {
+    pa_core *core;
+    pa_module *module;
+    pa_subscription *subscription;
+    pa_hook_slot
+        *sink_new_hook_slot,
+        *source_new_hook_slot;
+    pa_time_event *save_time_event;
+    pa_database *database;
+};
+
+#define ENTRY_VERSION 1
+
+struct entry {
+    uint8_t version;
+    char description[PA_NAME_MAX];
+} PA_GCC_PACKED;
+
+static void save_time_callback(pa_mainloop_api*a, pa_time_event* e, const struct timeval *t, void *userdata) {
+    struct userdata *u = userdata;
+
+    pa_assert(a);
+    pa_assert(e);
+    pa_assert(u);
+
+    pa_assert(e == u->save_time_event);
+    u->core->mainloop->time_free(u->save_time_event);
+    u->save_time_event = NULL;
+
+    pa_database_sync(u->database);
+    pa_log_info("Synced.");
+}
+
+static struct entry* read_entry(struct userdata *u, const char *name) {
+    pa_datum key, data;
+    struct entry *e;
+
+    pa_assert(u);
+    pa_assert(name);
+
+    key.data = (char*) name;
+    key.size = strlen(name);
+
+    pa_zero(data);
+
+    if (!pa_database_get(u->database, &key, &data))
+        goto fail;
+
+    if (data.size != sizeof(struct entry)) {
+        pa_log_debug("Database contains entry for device %s of wrong size %lu != %lu. Probably due to upgrade, ignoring.", name, (unsigned long) data.size, (unsigned long) sizeof(struct entry));
+        goto fail;
+    }
+
+    e = (struct entry*) data.data;
+
+    if (e->version != ENTRY_VERSION) {
+        pa_log_debug("Version of database entry for device %s doesn't match our version. Probably due to upgrade, ignoring.", name);
+        goto fail;
+    }
+
+    if (!memchr(e->description, 0, sizeof(e->description))) {
+        pa_log_warn("Database contains entry for device %s with missing NUL byte in description", name);
+        goto fail;
+    }
+
+    return e;
+
+fail:
+
+    pa_datum_free(&data);
+    return NULL;
+}
+
+static void trigger_save(struct userdata *u) {
+    if (u->save_time_event)
+        return;
+
+    u->save_time_event = pa_core_rttime_new(u->core, pa_rtclock_now() + SAVE_INTERVAL, save_time_callback, u);
+}
+
+static pa_bool_t entries_equal(const struct entry *a, const struct entry *b) {
+    if (strncmp(a->description, b->description, sizeof(a->description)))
+        return FALSE;
+
+    return TRUE;
+}
+
+static void subscribe_callback(pa_core *c, pa_subscription_event_type_t t, uint32_t idx, void *userdata) {
+    struct userdata *u = userdata;
+    struct entry entry, *old;
+    char *name;
+    pa_datum key, data;
+
+    pa_assert(c);
+    pa_assert(u);
+
+    if (t != (PA_SUBSCRIPTION_EVENT_SINK|PA_SUBSCRIPTION_EVENT_NEW) &&
+        t != (PA_SUBSCRIPTION_EVENT_SINK|PA_SUBSCRIPTION_EVENT_CHANGE) &&
+        t != (PA_SUBSCRIPTION_EVENT_SOURCE|PA_SUBSCRIPTION_EVENT_NEW) &&
+        t != (PA_SUBSCRIPTION_EVENT_SOURCE|PA_SUBSCRIPTION_EVENT_CHANGE))
+        return;
+
+    pa_zero(entry);
+    entry.version = ENTRY_VERSION;
+
+    if ((t & PA_SUBSCRIPTION_EVENT_FACILITY_MASK) == PA_SUBSCRIPTION_EVENT_SINK) {
+        pa_sink *sink;
+
+        if (!(sink = pa_idxset_get_by_index(c->sinks, idx)))
+            return;
+
+        name = pa_sprintf_malloc("sink:%s", sink->name);
+
+        if ((old = read_entry(u, name)))
+            entry = *old;
+
+        pa_strlcpy(entry.description, pa_strnull(pa_proplist_gets(sink->proplist, PA_PROP_DEVICE_DESCRIPTION)), sizeof(entry.description));
+
+    } else {
+        pa_source *source;
+
+        pa_assert((t & PA_SUBSCRIPTION_EVENT_FACILITY_MASK) == PA_SUBSCRIPTION_EVENT_SOURCE);
+
+        if (!(source = pa_idxset_get_by_index(c->sources, idx)))
+            return;
+
+        name = pa_sprintf_malloc("source:%s", source->name);
+
+        if ((old = read_entry(u, name)))
+            entry = *old;
+
+        pa_strlcpy(entry.description, pa_strnull(pa_proplist_gets(source->proplist, PA_PROP_DEVICE_DESCRIPTION)), sizeof(entry.description));
+    }
+
+    if (old) {
+
+        if (entries_equal(old, &entry)) {
+            pa_xfree(old);
+            pa_xfree(name);
+            return;
+        }
+
+        pa_xfree(old);
+    }
+
+    key.data = name;
+    key.size = strlen(name);
+
+    data.data = &entry;
+    data.size = sizeof(entry);
+
+    pa_log_info("Storing device description for %s.", name);
+
+    pa_database_set(u->database, &key, &data, TRUE);
+
+    pa_xfree(name);
+
+    trigger_save(u);
+}
+
+static pa_hook_result_t sink_new_hook_callback(pa_core *c, pa_sink_new_data *new_data, struct userdata *u) {
+    char *name;
+    struct entry *e;
+
+    pa_assert(c);
+    pa_assert(new_data);
+    pa_assert(u);
+
+    name = pa_sprintf_malloc("sink:%s", new_data->name);
+
+    if ((e = read_entry(u, name))) {
+        if (strncmp(e->description, pa_proplist_gets(new_data->proplist, PA_PROP_DEVICE_DESCRIPTION), sizeof(e->description)) != 0) {
+            pa_log_info("Restoring description for sink %s.", name);
+            pa_proplist_sets(new_data->proplist, PA_PROP_DEVICE_DESCRIPTION, e->description);
+        }
+
+        pa_xfree(e);
+    }
+
+    pa_xfree(name);
+
+    return PA_HOOK_OK;
+}
+
+static pa_hook_result_t source_new_hook_callback(pa_core *c, pa_source_new_data *new_data, struct userdata *u) {
+    char *name;
+    struct entry *e;
+
+    pa_assert(c);
+    pa_assert(new_data);
+    pa_assert(u);
+
+    name = pa_sprintf_malloc("source:%s", new_data->name);
+
+    if ((e = read_entry(u, name))) {
+
+        if (strncmp(e->description, pa_proplist_gets(new_data->proplist, PA_PROP_DEVICE_DESCRIPTION), sizeof(e->description)) != 0) {
+            pa_log_info("Restoring description for sink %s.", name);
+            pa_proplist_sets(new_data->proplist, PA_PROP_DEVICE_DESCRIPTION, e->description);
+        }
+
+        pa_xfree(e);
+    }
+
+    pa_xfree(name);
+
+    return PA_HOOK_OK;
+}
+
+int pa__init(pa_module*m) {
+    pa_modargs *ma = NULL;
+    struct userdata *u;
+    char *fname;
+    pa_sink *sink;
+    pa_source *source;
+    uint32_t idx;
+
+    pa_assert(m);
+
+    if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
+        pa_log("Failed to parse module arguments");
+        goto fail;
+    }
+
+    m->userdata = u = pa_xnew0(struct userdata, 1);
+    u->core = m->core;
+    u->module = m;
+
+    u->subscription = pa_subscription_new(m->core, PA_SUBSCRIPTION_MASK_SINK|PA_SUBSCRIPTION_MASK_SOURCE, subscribe_callback, u);
+
+    u->sink_new_hook_slot = pa_hook_connect(&m->core->hooks[PA_CORE_HOOK_SINK_NEW], PA_HOOK_EARLY, (pa_hook_cb_t) sink_new_hook_callback, u);
+    u->source_new_hook_slot = pa_hook_connect(&m->core->hooks[PA_CORE_HOOK_SOURCE_NEW], PA_HOOK_EARLY, (pa_hook_cb_t) source_new_hook_callback, u);
+
+    if (!(fname = pa_state_path("device-manager", TRUE)))
+        goto fail;
+
+    if (!(u->database = pa_database_open(fname, TRUE))) {
+        pa_log("Failed to open volume database '%s': %s", fname, pa_cstrerror(errno));
+        pa_xfree(fname);
+        goto fail;
+    }
+
+    pa_log_info("Sucessfully opened database file '%s'.", fname);
+    pa_xfree(fname);
+
+    for (sink = pa_idxset_first(m->core->sinks, &idx); sink; sink = pa_idxset_next(m->core->sinks, &idx))
+        subscribe_callback(m->core, PA_SUBSCRIPTION_EVENT_SINK|PA_SUBSCRIPTION_EVENT_NEW, sink->index, u);
+
+    for (source = pa_idxset_first(m->core->sources, &idx); source; source = pa_idxset_next(m->core->sources, &idx))
+        subscribe_callback(m->core, PA_SUBSCRIPTION_EVENT_SOURCE|PA_SUBSCRIPTION_EVENT_NEW, source->index, u);
+
+    pa_modargs_free(ma);
+    return 0;
+
+fail:
+    pa__done(m);
+
+    if (ma)
+        pa_modargs_free(ma);
+
+    return  -1;
+}
+
+void pa__done(pa_module*m) {
+    struct userdata* u;
+
+    pa_assert(m);
+
+    if (!(u = m->userdata))
+        return;
+
+    if (u->subscription)
+        pa_subscription_free(u->subscription);
+
+    if (u->sink_new_hook_slot)
+        pa_hook_slot_free(u->sink_new_hook_slot);
+    if (u->source_new_hook_slot)
+        pa_hook_slot_free(u->source_new_hook_slot);
+
+    if (u->save_time_event)
+        u->core->mainloop->time_free(u->save_time_event);
+
+    if (u->database)
+        pa_database_close(u->database);
+
+    pa_xfree(u);
+}