ARI: Add subscription support

This patch adds an /applications API to ARI, allowing explicit management of
Stasis applications.

 * GET /applications - list current applications
 * GET /applications/{applicationName} - get details of a specific application
 * POST /applications/{applicationName}/subscription - explicitly subscribe to
   a channel, bridge or endpoint
 * DELETE /applications/{applicationName}/subscription - explicitly unsubscribe
   from a channel, bridge or endpoint

Subscriptions work by a reference counting mechanism: if you subscript to an
event source X number of times, you must unsubscribe X number of times to stop
receiveing events for that event source.

Review: https://reviewboard.asterisk.org/r/2862

(issue ASTERISK-22451)
Reported by: Matt Jordan
........

Merged revisions 400522 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@400523 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 173 insertions, 0 deletions

diff --git a/res/ari/resource_applications.c b/res/ari/resource_applications.c
new file mode 100644
index 000000000..c422ad17f
--- /dev/null
+++ b/res/ari/resource_applications.c
@@ -0,0 +1,173 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2013, Digium, Inc.
+ *
+ * David M. Lee, II <dlee@digium.com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*! \file
+ *
+ * \brief /api-docs/applications.{format} implementation - Stasis application
+ * resources
+ *
+ * \author David M. Lee, II <dlee@digium.com>
+ */
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+#include "asterisk/stasis_app.h"
+#include "resource_applications.h"
+
+static int append_json(void *obj, void *arg, int flags)
+{
+	const char *app = obj;
+	struct ast_json *array = arg;
+
+	ast_json_array_append(array, stasis_app_to_json(app));
+
+	return 0;
+}
+
+void ast_ari_get_applications(struct ast_variable *headers,
+	struct ast_get_applications_args *args,
+	struct ast_ari_response *response)
+{
+	RAII_VAR(struct ao2_container *, apps, NULL, ao2_cleanup);
+	RAII_VAR(struct ast_json *, json, NULL, ast_json_unref);
+	size_t count;
+
+	apps = stasis_app_get_all();
+	json = ast_json_array_create();
+	if (!apps || !json) {
+		ast_ari_response_error(response, 500, "Internal Server Error",
+			"Allocation failed");
+		return;
+	}
+
+	ao2_lock(apps);
+	count = ao2_container_count(apps);
+	ao2_callback(apps, OBJ_NOLOCK | OBJ_NODATA, append_json, json);
+	ao2_lock(apps);
+
+	if (count != ast_json_array_size(json)) {
+		ast_ari_response_error(response, 500, "Internal Server Error",
+			"Allocation failed");
+		return;
+	}
+
+
+	ast_ari_response_ok(response, json);
+}
+
+void ast_ari_get_application(struct ast_variable *headers,
+	struct ast_get_application_args *args,
+	struct ast_ari_response *response)
+{
+	RAII_VAR(struct ast_json *, json, NULL, ast_json_unref);
+
+	json = stasis_app_to_json(args->application_name);
+
+	if (!json) {
+		ast_ari_response_error(response, 404, "Not Found",
+			"Application not found");
+		return;
+	}
+
+	ast_ari_response_ok(response, json);
+}
+
+void ast_ari_application_subscribe(struct ast_variable *headers,
+	struct ast_application_subscribe_args *args,
+	struct ast_ari_response *response)
+{
+	RAII_VAR(struct ast_json *, json, NULL, ast_json_unref);
+	enum stasis_app_subscribe_res res;
+
+	if (args->event_source_count <= 0) {
+		ast_ari_response_error(response, 400, "Bad Request",
+			"Missing parameter eventSource");
+		return;
+	}
+
+	if (ast_strlen_zero(args->application_name)) {
+		ast_ari_response_error(response, 400, "Bad Request",
+			"Missing parameter applicationName");
+		return;
+	}
+
+	res = stasis_app_subscribe(args->application_name, args->event_source,
+		args->event_source_count, &json);
+
+	switch (res) {
+	case STASIS_ASR_OK:
+		ast_ari_response_ok(response, json);
+		break;
+	case STASIS_ASR_APP_NOT_FOUND:
+		ast_ari_response_error(response, 404, "Not Found",
+			"Application not found");
+		break;
+	case STASIS_ASR_EVENT_SOURCE_NOT_FOUND:
+		ast_ari_response_error(response, 422, "Unprocessable Entity",
+			"Event source does not exist");
+		break;
+	case STASIS_ASR_EVENT_SOURCE_BAD_SCHEME:
+		ast_ari_response_error(response, 400, "Bad Request",
+			"Invalid event source URI scheme");
+		break;
+	case STASIS_ASR_INTERNAL_ERROR:
+		ast_ari_response_error(response, 500, "Internal Server Error",
+			"Error processing request");
+		break;
+	}
+}
+
+void ast_ari_application_unsubscribe(struct ast_variable *headers,
+	struct ast_application_unsubscribe_args *args,
+	struct ast_ari_response *response)
+{
+	RAII_VAR(struct ast_json *, json, NULL, ast_json_unref);
+	enum stasis_app_subscribe_res res;
+
+	if (args->event_source_count == 0) {
+		ast_ari_response_error(response, 400, "Bad Request",
+			"Missing parameter eventSource");
+		return;
+	}
+
+	res = stasis_app_unsubscribe(args->application_name, args->event_source,
+		args->event_source_count, &json);
+
+	switch (res) {
+	case STASIS_ASR_OK:
+		ast_ari_response_ok(response, json);
+		break;
+	case STASIS_ASR_APP_NOT_FOUND:
+		ast_ari_response_error(response, 404, "Not Found",
+			"Application not found");
+		break;
+	case STASIS_ASR_EVENT_SOURCE_NOT_FOUND:
+		ast_ari_response_error(response, 422, "Unprocessable Entity",
+			"Event source was not subscribed to");
+		break;
+	case STASIS_ASR_EVENT_SOURCE_BAD_SCHEME:
+		ast_ari_response_error(response, 400, "Bad Request",
+			"Invalid event source URI scheme");
+		break;
+	case STASIS_ASR_INTERNAL_ERROR:
+		ast_ari_response_error(response, 500, "Internal Server Error",
+			"Error processing request");
+	}
+}