[PATCH 4/4] core: add message handler

[georg@xxxxxxxx (Georg Chini)]

This patch adds a small message handler to the core which enables
clients to list available handlers via the list-handlers message.
Command: pacmd send-message /core list-handlers
pactl can be used with the same parameters.
---
 src/pulsecore/core.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/src/pulsecore/core.c b/src/pulsecore/core.c
index 3145caaf..0e3a078c 100644
--- a/src/pulsecore/core.c
+++ b/src/pulsecore/core.c
@@ -38,6 +38,7 @@
 #include <pulsecore/random.h>
 #include <pulsecore/log.h>
 #include <pulsecore/macro.h>
+#include <pulsecore/strbuf.h>
 
 #include "core.h"
 
@@ -61,6 +62,38 @@ static int core_process_msg(pa_msgobject *o, int code, void *userdata, int64_t o
 
 static void core_free(pa_object *o);
 
+static int core_message_handler(const char *recipient, const char *message, const char *message_parameters, char **response, void *userdata) {
+    pa_core *c;
+    pa_strbuf *buf;
+    void *state = NULL;
+    pa_core_message_handler *handler;
+
+    pa_assert(c = (pa_core *) userdata);
+    pa_assert(message);
+    pa_assert(response);
+    pa_assert(pa_safe_streq(recipient, "/core"));
+
+    buf = pa_strbuf_new();
+
+    if (pa_streq(message, "list-handlers")) {
+        pa_strbuf_puts(buf, "Name\tShort_Name\tDescription");
+
+        while ((handler = pa_hashmap_iterate(c->message_handlers, &state, NULL))) {
+            pa_strbuf_puts(buf, "\n");
+            pa_strbuf_printf(buf, "\"%s\"", handler->recipient);
+            if (handler->short_name)
+                pa_strbuf_printf(buf, "\t\"%s\"", handler->short_name);
+            if (handler->description)
+                pa_strbuf_printf(buf, "\t\"%s\"", handler->description);
+        }
+
+    } else
+        pa_strbuf_puts(buf, "Message not implemented");
+
+    *response = pa_strbuf_to_string_free(buf);
+    return 0;
+}
+
 pa_core* pa_core_new(pa_mainloop_api *m, bool shared, bool enable_memfd, size_t shm_size) {
     pa_core* c;
     pa_mempool *pool;
@@ -105,6 +138,8 @@ pa_core* pa_core_new(pa_mainloop_api *m, bool shared, bool enable_memfd, size_t
     c->shared = pa_hashmap_new(pa_idxset_string_hash_func, pa_idxset_string_compare_func);
     c->message_handlers = pa_hashmap_new(pa_idxset_string_hash_func, pa_idxset_string_compare_func);
 
+    pa_core_register_message_handler(c, "/core", "core", "Core message handler", core_message_handler, (void *) c);
+
     c->default_source = NULL;
     c->default_sink = NULL;
 
@@ -205,6 +240,8 @@ static void core_free(pa_object *o) {
     pa_assert(pa_hashmap_isempty(c->shared));
     pa_hashmap_free(c->shared);
 
+    pa_core_unregister_message_handler(c, "/core");
+
     pa_assert(pa_hashmap_isempty(c->message_handlers));
     pa_hashmap_free(c->message_handlers);
 
-- 
2.11.0