pulseaudio/src/pulsecore/message-handler.c

/***
  This file is part of PulseAudio.

  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, see <http://www.gnu.org/licenses/>.
***/

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

#include <stdlib.h>
#include <stdio.h>

#include <pulse/xmalloc.h>

#include <pulsecore/core.h>
#include <pulsecore/core-util.h>
#include <pulsecore/log.h>
#include <pulsecore/macro.h>

#include "message-handler.h"

/* Message handler functions */

/* Register message handler for the specified object. object_path must be a unique name starting with "/". */
void pa_message_handler_register(pa_core *c, const char *object_path, const char *description, pa_message_handler_cb_t cb, void *userdata) {
    struct pa_message_handler *handler;

    pa_assert(c);
    pa_assert(object_path);
    pa_assert(cb);
    pa_assert(userdata);

    /* Ensure that the object path is not empty and starts with "/". */
    pa_assert(object_path[0] == '/');

    handler = pa_xnew0(struct pa_message_handler, 1);
    handler->userdata = userdata;
    handler->callback = cb;
    handler->object_path = pa_xstrdup(object_path);
    handler->description = pa_xstrdup(description);

    pa_assert_se(pa_hashmap_put(c->message_handlers, handler->object_path, handler) == 0);
}

/* Unregister a message handler */
void pa_message_handler_unregister(pa_core *c, const char *object_path) {
    struct pa_message_handler *handler;

    pa_assert(c);
    pa_assert(object_path);

    pa_assert_se(handler = pa_hashmap_remove(c->message_handlers, object_path));

    pa_xfree(handler->object_path);
    pa_xfree(handler->description);
    pa_xfree(handler);
}

/* Send a message to an object identified by object_path */
int pa_message_handler_send_message(pa_core *c, const char *object_path, const char *message, const char *message_parameters, char **response) {
    struct pa_message_handler *handler;

    pa_assert(c);
    pa_assert(object_path);
    pa_assert(message);
    pa_assert(response);

    *response = NULL;

    if (!(handler = pa_hashmap_get(c->message_handlers, object_path)))
        return -PA_ERR_NOENTITY;

    /* The handler is expected to return an error code and may also
       return an error string in response */
    return handler->callback(handler->object_path, message, message_parameters, response, handler->userdata);
}

/* Set handler description */
int pa_message_handler_set_description(pa_core *c, const char *object_path, const char *description) {
    struct pa_message_handler *handler;

    pa_assert(c);
    pa_assert(object_path);

    if (!(handler = pa_hashmap_get(c->message_handlers, object_path)))
        return -PA_ERR_NOENTITY;

    pa_xfree(handler->description);
    handler->description = pa_xstrdup(description);

    return PA_OK;
}