stasis: Improve topic/subscription names and statistics.

Topic names now follow: <subsystem>:<functionality>[/<object>]

This ensures that they are all unique, and also provides better
insight in to what each topic is for.

Subscriber ids now also use the main topic name they are
subscribed to and an incrementing integer as their identifier to
make it easier to understand what the subscription is primarily
responsible for.

Both the CLI commands for listing topic and subscription statistics
now sort to make it a bit easier to see what is going on.

Subscriptions will now show all topics that they are receiving messages
from, not just the main topic they were subscribed to.

ASTERISK-28335

Change-Id: I484e971a38c3640f2bd156282e532eed84bf220d

main/stasis.c

@@ -349,6 +349,8 @@ struct stasis_topic_statistics {
 	int messages_dispatched;
 	/*! \brief The ids of the subscribers to this topic */
 	struct ao2_container *subscribers;
+	/*! \brief Pointer to the topic (NOT refcounted, and must NOT be accessed) */
+	struct stasis_topic *topic;
 	/*! \brief Name of the topic */
 	char name[0];
 };
@@ -366,6 +368,9 @@ struct stasis_topic {
 	struct stasis_topic_statistics *statistics;
 #endif
 
+	/*! Unique incrementing integer for subscriber ids */
+	int subscriber_id;
+
 	/*! Name of the topic */
 	char name[0];
 };
@@ -412,11 +417,11 @@ static void topic_statistics_destroy(void *obj)
 	ao2_cleanup(statistics->subscribers);
 }
 
-static struct stasis_topic_statistics *stasis_topic_statistics_create(const char *name)
+static struct stasis_topic_statistics *stasis_topic_statistics_create(struct stasis_topic *topic)
 {
 	struct stasis_topic_statistics *statistics;
 
-	statistics = ao2_alloc(sizeof(*statistics) + strlen(name) + 1, topic_statistics_destroy);
+	statistics = ao2_alloc(sizeof(*statistics) + strlen(topic->name) + 1, topic_statistics_destroy);
 	if (!statistics) {
 		return NULL;
 	}
@@ -427,7 +432,9 @@ static struct stasis_topic_statistics *stasis_topic_statistics_create(const char
 		return NULL;
 	}
 
-	strcpy(statistics->name, name); /* SAFE */
+	/* This is strictly used for the pointer address when showing the topic */
+	statistics->topic = topic;
+	strcpy(statistics->name, topic->name); /* SAFE */
 	ao2_link(topic_statistics, statistics);
 
 	return statistics;
@@ -448,7 +455,7 @@ struct stasis_topic *stasis_topic_create(const char *name)
 	res |= AST_VECTOR_INIT(&topic->subscribers, INITIAL_SUBSCRIBERS_MAX);
 	res |= AST_VECTOR_INIT(&topic->upstream_topics, 0);
 #ifdef AST_DEVMODE
-	topic->statistics = stasis_topic_statistics_create(name);
+	topic->statistics = stasis_topic_statistics_create(topic);
 	if (!topic->name || !topic->statistics || res)
 #else
 	if (!topic->name || res)
@@ -477,8 +484,8 @@ struct stasis_subscription_statistics {
 	const char *file;
 	/*! \brief The function where the subscription originates */
 	const char *func;
-	/*! \brief Name of the topic we subscribed to */
-	char *topic;
+	/*! \brief Names of the topics we are subscribed to */
+	struct ao2_container *topics;
 	/*! \brief The message type that currently took the longest to process */
 	struct stasis_message_type *highest_time_message_type;
 	/*! \brief Highest time spent invoking a message */
@@ -495,6 +502,8 @@ struct stasis_subscription_statistics {
 	int uses_threadpool;
 	/*! \brief The line number where the subscription originates */
 	int lineno;
+	/*! \brief Pointer to the subscription (NOT refcounted, and must NOT be accessed) */
+	struct stasis_subscription *sub;
 	/*! \brief Unique ID of the subscription */
 	char uniqueid[0];
 };
@@ -503,7 +512,7 @@ struct stasis_subscription_statistics {
 /*! \internal */
 struct stasis_subscription {
 	/*! Unique ID for this subscription */
-	char uniqueid[AST_UUID_STR_LEN];
+	char *uniqueid;
 	/*! Topic subscribed to. */
 	struct stasis_topic *topic;
 	/*! Mailbox for processing incoming messages. */
@@ -546,6 +555,7 @@ static void subscription_dtor(void *obj)
 	 * be bad. */
 	ast_assert(stasis_subscription_is_done(sub));
 
+	ast_free(sub->uniqueid);
 	ao2_cleanup(sub->topic);
 	sub->topic = NULL;
 	ast_taskprocessor_unreference(sub->mailbox);
@@ -628,26 +638,37 @@ void stasis_subscription_cb_noop(void *data, struct stasis_subscription *sub, st
 }
 
 #ifdef AST_DEVMODE
-static struct stasis_subscription_statistics *stasis_subscription_statistics_create(const char *uniqueid,
-	const char *topic, int needs_mailbox, int use_thread_pool, const char *file, int lineno,
+static void subscription_statistics_destroy(void *obj)
+{
+	struct stasis_subscription_statistics *statistics = obj;
+
+	ao2_cleanup(statistics->topics);
+}
+
+static struct stasis_subscription_statistics *stasis_subscription_statistics_create(struct stasis_subscription *sub,
+	int needs_mailbox, int use_thread_pool, const char *file, int lineno,
 	const char *func)
 {
 	struct stasis_subscription_statistics *statistics;
-	size_t uniqueid_len = strlen(uniqueid) + 1;
 
-	statistics = ao2_alloc(sizeof(*statistics) + uniqueid_len + strlen(topic) + 1, NULL);
+	statistics = ao2_alloc(sizeof(*statistics) + strlen(sub->uniqueid) + 1, subscription_statistics_destroy);
 	if (!statistics) {
 		return NULL;
 	}
 
+	statistics->topics = ast_str_container_alloc(1);
+	if (!statistics->topics) {
+		ao2_ref(statistics, -1);
+		return NULL;
+	}
+
 	statistics->file = file;
 	statistics->lineno = lineno;
 	statistics->func = func;
 	statistics->uses_mailbox = needs_mailbox;
 	statistics->uses_threadpool = use_thread_pool;
-	strcpy(statistics->uniqueid, uniqueid); /* SAFE */
-	statistics->topic = statistics->uniqueid + uniqueid_len;
-	strcpy(statistics->topic, topic); /* SAFE */
+	strcpy(statistics->uniqueid, sub->uniqueid); /* SAFE */
+	statistics->sub = sub;
 	ao2_link(subscription_statistics, statistics);
 
 	return statistics;
@@ -665,6 +686,7 @@ struct stasis_subscription *internal_stasis_subscribe(
 	const char *func)
 {
 	struct stasis_subscription *sub;
+	int ret;
 
 	if (!topic) {
 		return NULL;
@@ -675,12 +697,17 @@ struct stasis_subscription *internal_stasis_subscribe(
 	if (!sub) {
 		return NULL;
 	}
-	ast_uuid_generate_str(sub->uniqueid, sizeof(sub->uniqueid));
 
 #ifdef AST_DEVMODE
-	sub->statistics = stasis_subscription_statistics_create(sub->uniqueid, topic->name, needs_mailbox,
-		use_thread_pool, file, lineno, func);
-	if (!sub->statistics) {
+	ret = ast_asprintf(&sub->uniqueid, "%s:%s-%d", file, stasis_topic_name(topic), ast_atomic_fetchadd_int(&topic->subscriber_id, +1));
+	sub->statistics = stasis_subscription_statistics_create(sub, needs_mailbox, use_thread_pool, file, lineno, func);
+	if (ret < 0 || !sub->statistics) {
+		ao2_ref(sub, -1);
+		return NULL;
+	}
+#else
+	ret = ast_asprintf(&sub->uniqueid, "%s-%d", stasis_topic_name(topic), ast_atomic_fetchadd_int(&topic->subscriber_id, +1));
+	if (ret < 0) {
 		ao2_ref(sub, -1);
 		return NULL;
 	}
@@ -1012,6 +1039,7 @@ static int topic_add_subscription(struct stasis_topic *topic, struct stasis_subs
 
 #ifdef AST_DEVMODE
 	ast_str_container_add(topic->statistics->subscribers, stasis_subscription_uniqueid(sub));
+	ast_str_container_add(sub->statistics->topics, stasis_topic_name(topic));
 #endif
 
 	ao2_unlock(topic);
@@ -1035,6 +1063,7 @@ static int topic_remove_subscription(struct stasis_topic *topic, struct stasis_s
 #ifdef AST_DEVMODE
 	if (!res) {
 		ast_str_container_remove(topic->statistics->subscribers, stasis_subscription_uniqueid(sub));
+		ast_str_container_remove(sub->statistics->topics, stasis_topic_name(topic));
 	}
 #endif
 
@@ -1498,6 +1527,7 @@ static void send_subscription_unsubscribe(struct stasis_topic *topic,
 struct topic_pool_entry {
 	struct stasis_forward *forward;
 	struct stasis_topic *topic;
+	char name[0];
 };
 
 static void topic_pool_entry_dtor(void *obj)
@@ -1509,10 +1539,19 @@ static void topic_pool_entry_dtor(void *obj)
 	entry->topic = NULL;
 }
 
-static struct topic_pool_entry *topic_pool_entry_alloc(void)
+static struct topic_pool_entry *topic_pool_entry_alloc(const char *topic_name)
 {
-	return ao2_alloc_options(sizeof(struct topic_pool_entry), topic_pool_entry_dtor,
-		AO2_ALLOC_OPT_LOCK_NOLOCK);
+	struct topic_pool_entry *topic_pool_entry;
+
+	topic_pool_entry = ao2_alloc_options(sizeof(*topic_pool_entry) + strlen(topic_name) + 1,
+		topic_pool_entry_dtor, AO2_ALLOC_OPT_LOCK_NOLOCK);
+	if (!topic_pool_entry) {
+		return NULL;
+	}
+
+	strcpy(topic_pool_entry->name, topic_name); /* Safe */
+
+	return topic_pool_entry;
 }
 
 struct stasis_topic_pool {
@@ -1550,7 +1589,7 @@ static int topic_pool_entry_hash(const void *obj, const int flags)
 		break;
 	case OBJ_SEARCH_OBJECT:
 		object = obj;
-		key = stasis_topic_name(object->topic);
+		key = object->name;
 		break;
 	default:
 		/* Hash can only work on something with a full key. */
@@ -1569,10 +1608,10 @@ static int topic_pool_entry_cmp(void *obj, void *arg, int flags)
 
 	switch (flags & OBJ_SEARCH_MASK) {
 	case OBJ_SEARCH_OBJECT:
-		right_key = stasis_topic_name(object_right->topic);
+		right_key = object_right->name;
 		/* Fall through */
 	case OBJ_SEARCH_KEY:
-		cmp = strcasecmp(stasis_topic_name(object_left->topic), right_key);
+		cmp = strcasecmp(object_left->name, right_key);
 		break;
 	case OBJ_SEARCH_PARTIAL_KEY:
 		/* Not supported by container */
@@ -1649,18 +1688,29 @@ struct stasis_topic *stasis_topic_pool_get_topic(struct stasis_topic_pool *pool,
 {
 	RAII_VAR(struct topic_pool_entry *, topic_pool_entry, NULL, ao2_cleanup);
 	SCOPED_AO2LOCK(topic_container_lock, pool->pool_container);
+	char *new_topic_name;
+	int ret;
 
 	topic_pool_entry = ao2_find(pool->pool_container, topic_name, OBJ_SEARCH_KEY | OBJ_NOLOCK);
 	if (topic_pool_entry) {
 		return topic_pool_entry->topic;
 	}
 
-	topic_pool_entry = topic_pool_entry_alloc();
+	topic_pool_entry = topic_pool_entry_alloc(topic_name);
 	if (!topic_pool_entry) {
 		return NULL;
 	}
 
-	topic_pool_entry->topic = stasis_topic_create(topic_name);
+	/* To provide further detail and to ensure that the topic is unique within the scope of the
+	 * system we prefix it with the pooling topic name, which should itself already be unique.
+	 */
+	ret = ast_asprintf(&new_topic_name, "%s/%s", stasis_topic_name(pool->pool_topic), topic_name);
+	if (ret < 0) {
+		return NULL;
+	}
+
+	topic_pool_entry->topic = stasis_topic_create(new_topic_name);
+	ast_free(new_topic_name);
 	if (!topic_pool_entry->topic) {
 		return NULL;
 	}
@@ -2082,12 +2132,15 @@ STASIS_MESSAGE_TYPE_DEFN(ast_multi_user_event_type,
 
 #ifdef AST_DEVMODE
 
+AO2_STRING_FIELD_SORT_FN(stasis_subscription_statistics, uniqueid);
+
 /*!
  * \internal
  * \brief CLI command implementation for 'stasis statistics show subscriptions'
  */
 static char *statistics_show_subscriptions(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
 {
+	struct ao2_container *sorted_subscriptions;
 	struct ao2_iterator iter;
 	struct stasis_subscription_statistics *statistics;
 	int count = 0;
@@ -2112,9 +2165,22 @@ static char *statistics_show_subscriptions(struct ast_cli_entry *e, int cmd, str
 		return CLI_SHOWUSAGE;
 	}
 
+	sorted_subscriptions = ao2_container_alloc_rbtree(AO2_ALLOC_OPT_LOCK_NOLOCK, 0,
+		stasis_subscription_statistics_sort_fn, NULL);
+	if (!sorted_subscriptions) {
+		ast_cli(a->fd, "Could not create container for sorting subscription statistics\n");
+		return CLI_SUCCESS;
+	}
+
+	if (ao2_container_dup(sorted_subscriptions, subscription_statistics, 0)) {
+		ao2_ref(sorted_subscriptions, -1);
+		ast_cli(a->fd, "Could not sort subscription statistics\n");
+		return CLI_SUCCESS;
+	}
+
 	ast_cli(a->fd, "\n" FMT_HEADERS, "Subscription", "Dropped", "Passed", "Lowest Invoke", "Highest Invoke");
 
-	iter = ao2_iterator_init(subscription_statistics, 0);
+	iter = ao2_iterator_init(sorted_subscriptions, 0);
 	while ((statistics = ao2_iterator_next(&iter))) {
 		ast_cli(a->fd, FMT_FIELDS, statistics->uniqueid, statistics->messages_dropped, statistics->messages_passed,
 			statistics->lowest_time_invoked, statistics->highest_time_invoked);
@@ -2125,6 +2191,8 @@ static char *statistics_show_subscriptions(struct ast_cli_entry *e, int cmd, str
 	}
 	ao2_iterator_destroy(&iter);
 
+	ao2_ref(sorted_subscriptions, -1);
+
 	ast_cli(a->fd, FMT_FIELDS2, "Total", dropped, passed);
 	ast_cli(a->fd, "\n%d subscriptions\n\n", count);
 
@@ -2169,6 +2237,8 @@ static char *subscription_statistics_complete_name(const char *word, int state)
 static char *statistics_show_subscription(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
 {
 	struct stasis_subscription_statistics *statistics;
+	struct ao2_iterator i;
+	char *name;
 
 	switch (cmd) {
 	case CLI_INIT:
@@ -2196,7 +2266,7 @@ static char *statistics_show_subscription(struct ast_cli_entry *e, int cmd, stru
 	}
 
 	ast_cli(a->fd, "Subscription: %s\n", statistics->uniqueid);
-	ast_cli(a->fd, "Topic: %s\n", statistics->topic);
+	ast_cli(a->fd, "Pointer Address: %p\n", statistics->sub);
 	ast_cli(a->fd, "Source filename: %s\n", S_OR(statistics->file, "<unavailable>"));
 	ast_cli(a->fd, "Source line number: %d\n", statistics->lineno);
 	ast_cli(a->fd, "Source function: %s\n", S_OR(statistics->func, "<unavailable>"));
@@ -2213,25 +2283,38 @@ static char *statistics_show_subscription(struct ast_cli_entry *e, int cmd, stru
 	}
 	ao2_unlock(statistics);
 
+	ast_cli(a->fd, "Number of topics: %d\n", ao2_container_count(statistics->topics));
+
+	ast_cli(a->fd, "Subscribed topics:\n");
+	i = ao2_iterator_init(statistics->topics, 0);
+	while ((name = ao2_iterator_next(&i))) {
+		ast_cli(a->fd, "\t%s\n", name);
+		ao2_ref(name, -1);
+	}
+	ao2_iterator_destroy(&i);
+
 	ao2_ref(statistics, -1);
 
 	return CLI_SUCCESS;
 }
 
+AO2_STRING_FIELD_SORT_FN(stasis_topic_statistics, name);
+
 /*!
  * \internal
  * \brief CLI command implementation for 'stasis statistics show topics'
  */
 static char *statistics_show_topics(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
 {
+	struct ao2_container *sorted_topics;
 	struct ao2_iterator iter;
 	struct stasis_topic_statistics *statistics;
 	int count = 0;
 	int not_dispatched = 0;
 	int dispatched = 0;
-#define FMT_HEADERS		"%-64s %10s %10s %16s %16s\n"
-#define FMT_FIELDS		"%-64s %10d %10d %16ld %16ld\n"
-#define FMT_FIELDS2		"%-64s %10d %10d\n"
+#define FMT_HEADERS		"%-64s %10s %10s %10s %16s %16s\n"
+#define FMT_FIELDS		"%-64s %10d %10d %10d %16ld %16ld\n"
+#define FMT_FIELDS2		"%-64s %10s %10d %10d\n"
 
 	switch (cmd) {
 	case CLI_INIT:
@@ -2248,11 +2331,25 @@ static char *statistics_show_topics(struct ast_cli_entry *e, int cmd, struct ast
 		return CLI_SHOWUSAGE;
 	}
 
-	ast_cli(a->fd, "\n" FMT_HEADERS, "Topic", "Dropped", "Dispatched", "Lowest Dispatch", "Highest Dispatch");
+	sorted_topics = ao2_container_alloc_rbtree(AO2_ALLOC_OPT_LOCK_NOLOCK, 0,
+		stasis_topic_statistics_sort_fn, NULL);
+	if (!sorted_topics) {
+		ast_cli(a->fd, "Could not create container for sorting topic statistics\n");
+		return CLI_SUCCESS;
+	}
 
-	iter = ao2_iterator_init(topic_statistics, 0);
+	if (ao2_container_dup(sorted_topics, topic_statistics, 0)) {
+		ao2_ref(sorted_topics, -1);
+		ast_cli(a->fd, "Could not sort topic statistics\n");
+		return CLI_SUCCESS;
+	}
+
+	ast_cli(a->fd, "\n" FMT_HEADERS, "Topic", "Subscribers", "Dropped", "Dispatched", "Lowest Dispatch", "Highest Dispatch");
+
+	iter = ao2_iterator_init(sorted_topics, 0);
 	while ((statistics = ao2_iterator_next(&iter))) {
-		ast_cli(a->fd, FMT_FIELDS, statistics->name, statistics->messages_not_dispatched, statistics->messages_dispatched,
+		ast_cli(a->fd, FMT_FIELDS, statistics->name, ao2_container_count(statistics->subscribers),
+			statistics->messages_not_dispatched, statistics->messages_dispatched,
 			statistics->lowest_time_dispatched, statistics->highest_time_dispatched);
 		not_dispatched += statistics->messages_not_dispatched;
 		dispatched += statistics->messages_dispatched;
@@ -2261,7 +2358,9 @@ static char *statistics_show_topics(struct ast_cli_entry *e, int cmd, struct ast
 	}
 	ao2_iterator_destroy(&iter);
 
-	ast_cli(a->fd, FMT_FIELDS2, "Total", not_dispatched, dispatched);
+	ao2_ref(sorted_topics, -1);
+
+	ast_cli(a->fd, FMT_FIELDS2, "Total", "", not_dispatched, dispatched);
 	ast_cli(a->fd, "\n%d topics\n\n", count);
 
 #undef FMT_HEADERS
@@ -2334,6 +2433,7 @@ static char *statistics_show_topic(struct ast_cli_entry *e, int cmd, struct ast_
 	}
 
 	ast_cli(a->fd, "Topic: %s\n", statistics->name);
+	ast_cli(a->fd, "Pointer Address: %p\n", statistics->topic);
 	ast_cli(a->fd, "Number of messages published that went to no subscriber: %d\n", statistics->messages_not_dispatched);
 	ast_cli(a->fd, "Number of messages that went to at least one subscriber: %d\n", statistics->messages_dispatched);
 	ast_cli(a->fd, "Lowest amount of time (in milliseconds) spent dispatching message: %ld\n", statistics->lowest_time_dispatched);