res_parking: Add parking_devicestate.c left out from previous commit

(issue ASTERISK-21645)
Reported by: Matt Jordan
Review: https://reviewboard.asterisk.org/r/2545/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@390920 65c4cc65-6c06-0410-ace0-fbb531ad65f3

res/parking/parking_devicestate.c

+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2013, Digium, Inc.
+ *
+ * Jonathan Rose <jrose@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 Call Parking Device State Management
+ *
+ * \author Jonathan Rose <jrose@digium.com>
+ */
+
+#include "asterisk.h"
+#include "asterisk/logger.h"
+#include "res_parking.h"
+#include "asterisk/devicestate.h"
+
+struct parking_lot_extension_inuse_search {
+	char *context;
+	int exten;
+};
+
+static int retrieve_parked_user_targeted(void *obj, void *arg, int flags)
+{
+	int *target = arg;
+	struct parked_user *user = obj;
+	if (user->parking_space == *target) {
+		return CMP_MATCH;
+	}
+
+	return 0;
+}
+
+static int parking_lot_search_context_extension_inuse(void *obj, void *arg, int flags)
+{
+	struct parking_lot *lot = obj;
+	struct parking_lot_extension_inuse_search *search = arg;
+	RAII_VAR(struct parked_user *, user, NULL, ao2_cleanup);
+
+	if (strcmp(lot->cfg->parking_con, search->context)) {
+		return 0;
+	}
+
+	if ((search->exten < lot->cfg->parking_start) || (search->exten > lot->cfg->parking_stop)) {
+		return 0;
+	}
+
+	user = ao2_callback(lot->parked_users, 0, retrieve_parked_user_targeted, &search->exten);
+	if (!user) {
+		return 0;
+	}
+
+	ao2_lock(user);
+	if (user->resolution != PARK_UNSET) {
+		/* The parked user isn't in an answerable state. */
+		ao2_unlock(user);
+		return 0;
+	}
+	ao2_unlock(user);
+
+	return CMP_MATCH;
+}
+
+static enum ast_device_state metermaidstate(const char *data)
+{
+	struct ao2_container *global_lots = get_parking_lot_container();
+	RAII_VAR(struct parking_lot *, lot, NULL, ao2_cleanup);
+	char *context;
+	char *exten;
+	struct parking_lot_extension_inuse_search search = {};
+
+	context = ast_strdupa(data);
+
+	exten = strsep(&context, "@");
+
+	if (ast_strlen_zero(context) || ast_strlen_zero(exten)) {
+		return AST_DEVICE_INVALID;
+	}
+
+	search.context = context;
+	if (sscanf(exten, "%d", &search.exten) != 1) {
+		return AST_DEVICE_INVALID;
+	}
+
+	ast_debug(4, "Checking state of exten %d in context %s\n", search.exten, context);
+
+	lot = ao2_callback(global_lots, 0, parking_lot_search_context_extension_inuse, &data);
+	if (!lot) {
+		return AST_DEVICE_NOT_INUSE;
+	}
+
+	return AST_DEVICE_INUSE;
+}
+
+void parking_notify_metermaids(int exten, const char *context, enum ast_device_state state)
+{
+	ast_debug(4, "Notification of state change to metermaids %d@%s\n to state '%s'\n",
+		exten, context, ast_devstate2str(state));
+
+	ast_devstate_changed(state, AST_DEVSTATE_CACHABLE, "park:%d@%s", exten, context);
+}
+
+void unload_parking_devstate(void)
+{
+	ast_devstate_prov_del("Park");
+}
+
+int load_parking_devstate(void)
+{
+	return ast_devstate_prov_add("Park", metermaidstate);
+}