[pulseaudio-discuss] [PATCH v4 5/7] pactl: Implement list message-handlers
Georg Chini
georg at chini.tk
Sun Jan 28 17:40:27 UTC 2018
For better readability, "pactl list message-handlers" is introduced which
prints a formatted output of "pactl send-message /core list-handlers".
The patch also adds the functions pa_message_param_split_list() and
pa_message_param_read_string() for easy parsing of the message response
string. Because the function needs to modify the parameter string,
the message handler and the pa_context_string_callback function now
receive a char* instead of a const char* as parameter argument.
---
man/pactl.1.xml.in | 2 +-
shell-completion/bash/pulseaudio | 2 +-
shell-completion/zsh/_pulseaudio | 1 +
src/Makefile.am | 1 +
src/map-file | 2 +
src/pulse/introspect.c | 11 +++-
src/pulse/introspect.h | 2 +-
src/pulse/message-params.c | 110 +++++++++++++++++++++++++++++++++++++++
src/pulse/message-params.h | 40 ++++++++++++++
src/pulsecore/core.c | 2 +-
src/pulsecore/message-handler.c | 9 +++-
src/pulsecore/message-handler.h | 2 +-
src/utils/pactl.c | 68 ++++++++++++++++++++++--
13 files changed, 241 insertions(+), 11 deletions(-)
create mode 100644 src/pulse/message-params.c
create mode 100644 src/pulse/message-params.h
diff --git a/man/pactl.1.xml.in b/man/pactl.1.xml.in
index 4052fae3..66c0bda9 100644
--- a/man/pactl.1.xml.in
+++ b/man/pactl.1.xml.in
@@ -76,7 +76,7 @@ License along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
<option>
<p><opt>list</opt> [<arg>short</arg>] [<arg>TYPE</arg>]</p>
<optdesc><p>Dump all currently loaded modules, available sinks, sources, streams, etc. <arg>TYPE</arg> must be one of:
- modules, sinks, sources, sink-inputs, source-outputs, clients, samples, cards. If not specified, all info is listed. If
+ modules, sinks, sources, sink-inputs, source-outputs, clients, samples, cards, message-handlers. If not specified, all info is listed. If
short is given, output is in a tabular format, for easy parsing by scripts.</p></optdesc>
</option>
diff --git a/shell-completion/bash/pulseaudio b/shell-completion/bash/pulseaudio
index 797ec067..24d2aa1c 100644
--- a/shell-completion/bash/pulseaudio
+++ b/shell-completion/bash/pulseaudio
@@ -113,7 +113,7 @@ _pactl() {
local comps
local flags='-h --help --version -s --server= --client-name='
local list_types='short sinks sources sink-inputs source-outputs cards
- modules samples clients'
+ modules samples clients message-handlers'
local commands=(stat info list exit upload-sample play-sample remove-sample
load-module unload-module move-sink-input move-source-output
suspend-sink suspend-source set-card-profile set-sink-port
diff --git a/shell-completion/zsh/_pulseaudio b/shell-completion/zsh/_pulseaudio
index a2817ebb..c24d0387 100644
--- a/shell-completion/zsh/_pulseaudio
+++ b/shell-completion/zsh/_pulseaudio
@@ -285,6 +285,7 @@ _pactl_completion() {
'clients: list connected clients'
'samples: list samples'
'cards: list available cards'
+ 'message-handlers: list available message-handlers'
)
if ((CURRENT == 2)); then
diff --git a/src/Makefile.am b/src/Makefile.am
index 882ed964..d4e34482 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -893,6 +893,7 @@ libpulse_la_SOURCES = \
pulse/timeval.c pulse/timeval.h \
pulse/utf8.c pulse/utf8.h \
pulse/util.c pulse/util.h \
+ pulse/message-params.c pulse/message-params.h \
pulse/volume.c pulse/volume.h \
pulse/xmalloc.c pulse/xmalloc.h
diff --git a/src/map-file b/src/map-file
index 4d747f19..385731dc 100644
--- a/src/map-file
+++ b/src/map-file
@@ -225,6 +225,8 @@ pa_mainloop_quit;
pa_mainloop_run;
pa_mainloop_set_poll_func;
pa_mainloop_wakeup;
+pa_message_param_read_string;
+pa_message_param_split_list;
pa_msleep;
pa_operation_cancel;
pa_operation_get_state;
diff --git a/src/pulse/introspect.c b/src/pulse/introspect.c
index 76bfee41..23901eb3 100644
--- a/src/pulse/introspect.c
+++ b/src/pulse/introspect.c
@@ -2215,8 +2215,15 @@ static void context_string_callback(pa_pdispatch *pd, uint32_t command, uint32_t
response = "";
if (o->callback) {
- pa_context_string_cb_t cb = (pa_context_string_cb_t) o->callback;
- cb(o->context, success, response, o->userdata);
+ char *response_copy;
+ pa_context_string_cb_t cb;
+
+ response_copy = pa_xstrdup(response);
+
+ cb = (pa_context_string_cb_t) o->callback;
+ cb(o->context, success, response_copy, o->userdata);
+
+ pa_xfree(response_copy);
}
finish:
diff --git a/src/pulse/introspect.h b/src/pulse/introspect.h
index fbe5b668..bcec48da 100644
--- a/src/pulse/introspect.h
+++ b/src/pulse/introspect.h
@@ -449,7 +449,7 @@ pa_operation* pa_context_unload_module(pa_context *c, uint32_t idx, pa_context_s
/** @{ \name Messages */
/** Callback prototype for pa_context_send_message_to_object() */
-typedef void (*pa_context_string_cb_t)(pa_context *c, int success, const char *response, void *userdata);
+typedef void (*pa_context_string_cb_t)(pa_context *c, int success, char *response, void *userdata);
/** Send a message to an object that registered a message handler. For more information
* see https://cgit.freedesktop.org/pulseaudio/pulseaudio/tree/doc/messaging_api.txt. */
diff --git a/src/pulse/message-params.c b/src/pulse/message-params.c
new file mode 100644
index 00000000..324fbb7b
--- /dev/null
+++ b/src/pulse/message-params.c
@@ -0,0 +1,110 @@
+/***
+ 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
+ Lesser 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 <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+
+#include <pulse/xmalloc.h>
+
+#include <pulsecore/macro.h>
+
+#include "message-params.h"
+
+/* Split the specified string into elements. An element is defined as
+ * a sub-string between curly braces. The function is needed to parse
+ * the parameters of messages. Each time it is called returns the position
+ * of the current element in result and the state pointer is advanced to
+ * the next list element.
+ * The variable state points to, should be initialized to NULL before
+ * the first call. The function returns 1 on success, 0 if end of string
+ * is encountered and -1 on parse error. */
+int pa_message_param_split_list(char *c, char **result, void **state) {
+ char *current = *state ? *state : c;
+ uint32_t open_braces;
+
+ pa_assert(result);
+
+ *result = NULL;
+
+ /* Empty or no string */
+ if (!*current || *c == 0)
+ return 0;
+
+ /* Find opening brace */
+ while (*current != 0) {
+
+ if (*current == '{')
+ break;
+
+ /* unexpected closing brace, parse error */
+ if (*current == '}')
+ return -1;
+
+ current++;
+ }
+
+ /* No opening brace found, end of string */
+ if (*current == 0)
+ return 0;
+
+ *result = current + 1;
+ open_braces = 1;
+
+ while (open_braces != 0 && *current != 0) {
+ current++;
+ if (*current == '{')
+ open_braces++;
+ if (*current == '}')
+ open_braces--;
+ }
+
+ /* Parse error, closing brace missing */
+ if (open_braces != 0) {
+ *result = NULL;
+ return -1;
+ }
+
+ /* Replace } with 0 */
+ *current = 0;
+
+ *state = current + 1;
+
+ return 1;
+}
+
+/* Read a string from the parameter list. The state pointer is
+ * advanced to the next element of the list */
+int pa_message_param_read_string(char *c, char **result, void **state) {
+ char *start_pos;
+ int err;
+
+ pa_assert(result);
+
+ *result = NULL;
+
+ if ((err = pa_message_param_split_list(c, &start_pos, state)) > 0)
+ *result = pa_xstrdup(start_pos);
+
+ return err;
+}
diff --git a/src/pulse/message-params.h b/src/pulse/message-params.h
new file mode 100644
index 00000000..45c5850d
--- /dev/null
+++ b/src/pulse/message-params.h
@@ -0,0 +1,40 @@
+#ifndef foomessagehelperhfoo
+#define foomessagehelperhfoo
+
+/***
+ 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
+ Lesser 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/>.
+***/
+
+#include <stddef.h>
+#include <inttypes.h>
+
+#include <pulse/cdecl.h>
+#include <pulse/version.h>
+
+/** \file
+ * Utility functions for reading and writing message parameters */
+
+PA_C_DECL_BEGIN
+
+/** Split message parameter string into list elements */
+int pa_message_param_split_list(char *c, char **result, void **state);
+
+/** Read a string from the parameter list. */
+int pa_message_param_read_string(char *c, char **result, void **state);
+
+PA_C_DECL_END
+
+#endif
diff --git a/src/pulsecore/core.c b/src/pulsecore/core.c
index f1ddc655..94717a4f 100644
--- a/src/pulsecore/core.c
+++ b/src/pulsecore/core.c
@@ -86,7 +86,7 @@ static char *message_handler_list(pa_core *c) {
return pa_strbuf_to_string_free(buf);
}
-static int core_message_handler(const char *object_path, const char *message, const char *message_parameters, char **response, void *userdata) {
+static int core_message_handler(const char *object_path, const char *message, char *message_parameters, char **response, void *userdata) {
pa_core *c;
pa_assert(c = (pa_core *) userdata);
diff --git a/src/pulsecore/message-handler.c b/src/pulsecore/message-handler.c
index db6b06ce..a9187b41 100644
--- a/src/pulsecore/message-handler.c
+++ b/src/pulsecore/message-handler.c
@@ -90,6 +90,8 @@ void pa_message_handler_unregister(pa_core *c, const char *object_path) {
/* 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;
+ int ret;
+ char *parameter_copy;
pa_assert(c);
pa_assert(object_path);
@@ -101,9 +103,14 @@ int pa_message_handler_send_message(pa_core *c, const char *object_path, const c
if (!(handler = pa_hashmap_get(c->message_handlers, object_path)))
return -PA_ERR_NOENTITY;
+ parameter_copy = pa_xstrdup(message_parameters);
+
/* 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);
+ ret = handler->callback(handler->object_path, message, parameter_copy, response, handler->userdata);
+
+ pa_xfree(parameter_copy);
+ return ret;
}
/* Set handler description */
diff --git a/src/pulsecore/message-handler.h b/src/pulsecore/message-handler.h
index be94510f..38b24e1b 100644
--- a/src/pulsecore/message-handler.h
+++ b/src/pulsecore/message-handler.h
@@ -26,7 +26,7 @@
typedef int (*pa_message_handler_cb_t)(
const char *object_path,
const char *message,
- const char *message_parameters,
+ char *message_parameters,
char **response,
void *userdata);
diff --git a/src/utils/pactl.c b/src/utils/pactl.c
index 66c0f251..73ed33e0 100644
--- a/src/utils/pactl.c
+++ b/src/utils/pactl.c
@@ -35,6 +35,7 @@
#include <sndfile.h>
#include <pulse/pulseaudio.h>
+#include <pulse/message-params.h>
#include <pulse/ext-device-restore.h>
#include <pulsecore/i18n.h>
@@ -838,7 +839,7 @@ static void index_callback(pa_context *c, uint32_t idx, void *userdata) {
complete_action();
}
-static void send_message_callback(pa_context *c, int success, const char *response, void *userdata) {
+static void send_message_callback(pa_context *c, int success, char *response, void *userdata) {
if (!success) {
pa_log(_("Send message failed: %s"), pa_strerror(pa_context_errno(c)));
@@ -851,6 +852,58 @@ static void send_message_callback(pa_context *c, int success, const char *respon
complete_action();
}
+static void list_handlers_callback(pa_context *c, int success, char *response, void *userdata) {
+ void *state = NULL;
+ char *param_list;
+ char *start_pos;
+ int err;
+
+ if (!success) {
+ pa_log(_("list-handlers message failed: %s"), pa_strerror(pa_context_errno(c)));
+ quit(1);
+ return;
+ }
+
+ if (pa_message_param_split_list(response, ¶m_list, &state) <= 0) {
+ pa_log(_("list-handlers message response could not be parsed correctly"));
+ quit(1);
+ return;
+ }
+
+ state = NULL;
+ while ((err = pa_message_param_split_list(param_list, &start_pos, &state)) > 0) {
+ void *state2 = NULL;
+ char *path;
+ char *description;
+
+ if (pa_message_param_read_string(start_pos, &path, &state2) <= 0) {
+ err = -1;
+ break;
+ }
+ if (pa_message_param_read_string(start_pos, &description, &state2) <= 0) {
+ pa_xfree(path);
+ err = -1;
+ break;
+ }
+
+ if (short_list_format)
+ printf("%s\n", path);
+ else
+ printf("Message Handler %s\n Description: %s\n", path, description);
+
+ pa_xfree(path);
+ pa_xfree(description);
+ }
+
+ if (err < 0) {
+ pa_log(_("list-handlers message response could not be parsed correctly"));
+ quit(1);
+ return;
+ }
+
+ complete_action();
+}
+
static void volume_relative_adjust(pa_cvolume *cv) {
pa_assert(volume_flags & VOL_RELATIVE);
@@ -1262,6 +1315,8 @@ static void context_state_callback(pa_context *c, void *userdata) {
o = pa_context_get_sample_info_list(c, get_sample_info_callback, NULL);
else if (pa_streq(list_type, "cards"))
o = pa_context_get_card_info_list(c, get_card_info_callback, NULL);
+ else if (pa_streq(list_type, "message-handlers"))
+ o = pa_context_send_message_to_object(c, "/core", "list-handlers", NULL, list_handlers_callback, NULL);
else
pa_assert_not_reached();
} else {
@@ -1312,6 +1367,12 @@ static void context_state_callback(pa_context *c, void *userdata) {
actions++;
}
+ o = pa_context_send_message_to_object(c, "/core", "list-handlers", NULL, list_handlers_callback, NULL);
+ if (o) {
+ pa_operation_unref(o);
+ actions++;
+ }
+
o = NULL;
}
break;
@@ -1698,12 +1759,13 @@ int main(int argc, char *argv[]) {
if (pa_streq(argv[i], "modules") || pa_streq(argv[i], "clients") ||
pa_streq(argv[i], "sinks") || pa_streq(argv[i], "sink-inputs") ||
pa_streq(argv[i], "sources") || pa_streq(argv[i], "source-outputs") ||
- pa_streq(argv[i], "samples") || pa_streq(argv[i], "cards")) {
+ pa_streq(argv[i], "samples") || pa_streq(argv[i], "cards") ||
+ pa_streq(argv[i], "message-handlers")) {
list_type = pa_xstrdup(argv[i]);
} else if (pa_streq(argv[i], "short")) {
short_list_format = true;
} else {
- pa_log(_("Specify nothing, or one of: %s"), "modules, sinks, sources, sink-inputs, source-outputs, clients, samples, cards");
+ pa_log(_("Specify nothing, or one of: %s"), "modules, sinks, sources, sink-inputs, source-outputs, clients, samples, cards, message-handlers");
goto quit;
}
}
--
2.14.1
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