[pulseaudio-discuss] [PATCH v2 21/21] New module: module-experimental-router

[Tanu Kaskinen]

The experimental router will be used as a tool for exercising new
routing functionality in the core. Another goal is to evolve the
module into a Murphy module - it's expected that the module will gain
features that are only used in the Murphy module. A rename to
module-murphy should happen at some point.

This first version just routes streams to the default sink/source when
the streams are created.
---
 src/Makefile.am                          |   8 ++
 src/modules/module-experimental-router.c | 122 +++++++++++++++++++++++++++++++
 2 files changed, 130 insertions(+)
 create mode 100644 src/modules/module-experimental-router.c

diff --git a/src/Makefile.am b/src/Makefile.am
index 168415e..e09d48a 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1074,6 +1074,7 @@ endif
 modlibexec_LTLIBRARIES += \
 		module-cli.la \
 		module-cli-protocol-tcp.la \
+		module-experimental-router.la \
 		module-simple-protocol-tcp.la \
 		module-null-sink.la \
 		module-null-source.la \
@@ -1357,6 +1358,7 @@ SYMDEF_FILES = \
 		module-cli-symdef.h \
 		module-cli-protocol-tcp-symdef.h \
 		module-cli-protocol-unix-symdef.h \
+		module-experimental-router-symdef.h \
 		module-pipe-sink-symdef.h \
 		module-pipe-source-symdef.h \
 		module-simple-protocol-tcp-symdef.h \
@@ -1915,6 +1917,12 @@ module_intended_roles_la_LDFLAGS = $(MODULE_LDFLAGS)
 module_intended_roles_la_LIBADD = $(MODULE_LIBADD)
 module_intended_roles_la_CFLAGS = $(AM_CFLAGS)
 
+# An experimental router module
+module_experimental_router_la_SOURCES = modules/module-experimental-router.c
+module_experimental_router_la_LDFLAGS = $(MODULE_LDFLAGS)
+module_experimental_router_la_LIBADD = $(MODULE_LIBADD)
+module_experimental_router_la_CFLAGS = $(AM_CFLAGS)
+
 # Suspend-on-idle module
 module_suspend_on_idle_la_SOURCES = modules/module-suspend-on-idle.c
 module_suspend_on_idle_la_LDFLAGS = $(MODULE_LDFLAGS)
diff --git a/src/modules/module-experimental-router.c b/src/modules/module-experimental-router.c
new file mode 100644
index 0000000..fe918bc
--- /dev/null
+++ b/src/modules/module-experimental-router.c
@@ -0,0 +1,122 @@
+/***
+  This file is part of PulseAudio.
+
+  Copyright 2013 Intel Corporation
+
+  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 "module-experimental-router-symdef.h"
+
+#include <pulsecore/i18n.h>
+#include <pulsecore/module.h>
+#include <pulsecore/namereg.h>
+
+PA_MODULE_AUTHOR("Tanu Kaskinen");
+PA_MODULE_DESCRIPTION(_("An experimental router module"));
+PA_MODULE_VERSION(PACKAGE_VERSION);
+PA_MODULE_LOAD_ONCE(true);
+
+struct userdata {
+    pa_hook_slot *node_set_initial_routing_slot;
+};
+
+static pa_hook_result_t node_set_initial_routing_cb(void *hook_data, void *call_data, void *userdata) {
+    pa_core *core = hook_data;
+    pa_node *node = call_data;
+    int r;
+
+    pa_assert(core);
+    pa_assert(node);
+
+    if (node->type != PA_NODE_TYPE_SINK_INPUT && node->type != PA_NODE_TYPE_SOURCE_OUTPUT)
+        goto finish;
+
+    if (node->type == PA_NODE_TYPE_SINK_INPUT) {
+        pa_sink_input *sink_input = node->owner;
+        pa_sink *default_sink;
+
+        pa_assert(sink_input->state == PA_SINK_INPUT_INIT);
+
+        if (sink_input->sink)
+            goto finish;
+
+        default_sink = pa_namereg_get_default_sink(core);
+
+        if (!default_sink)
+            goto fail;
+
+        r = pa_sink_input_set_initial_sink(sink_input, default_sink);
+    } else {
+        pa_source_output *source_output = node->owner;
+        pa_source *default_source;
+
+        pa_assert(source_output->state == PA_SOURCE_OUTPUT_INIT);
+
+        if (source_output->source)
+            goto finish;
+
+        default_source = pa_namereg_get_default_source(core);
+
+        if (!default_source)
+            goto fail;
+
+        r = pa_source_output_set_initial_source(source_output, default_source);
+    }
+
+    if (r < 0)
+        goto fail;
+
+finish:
+    pa_log_debug("Successfully routed node %s.", node->name);
+
+    return PA_HOOK_OK;
+
+fail:
+    pa_log_debug("Failed to route node %s.", node->name);
+
+    return PA_HOOK_OK;
+}
+
+int pa__init(pa_module *module) {
+    struct userdata *u;
+
+    pa_assert(module);
+
+    module->userdata = u = pa_xnew0(struct userdata, 1);
+    u->node_set_initial_routing_slot = pa_hook_connect(&module->core->hooks[PA_CORE_HOOK_NODE_SET_INITIAL_ROUTING],
+                                                       PA_HOOK_NORMAL, node_set_initial_routing_cb, u);
+
+    return 0;
+}
+
+void pa__done(pa_module *module) {
+    struct userdata *u;
+
+    pa_assert(module);
+
+    if (!(u = module->userdata))
+        return;
+
+    if (u->node_set_initial_routing_slot)
+        pa_hook_slot_free(u->node_set_initial_routing_slot);
+
+    pa_xfree(u);
+}
-- 
1.8.3.1