db/upnp: move generic code to lib/upnp/

src/lib/upnp/Discovery.hxx

@@ -0,0 +1,152 @@
+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef _UPNPPDISC_H_X_INCLUDED_
+#define _UPNPPDISC_H_X_INCLUDED_
+
+#include "Device.hxx"
+#include "WorkQueue.hxx"
+#include "thread/Mutex.hxx"
+#include "util/Error.hxx"
+
+#include <upnp/upnp.h>
+
+#include <list>
+#include <vector>
+#include <string>
+
+class LibUPnP;
+class ContentDirectoryService;
+
+/**
+ * Manage UPnP discovery and maintain a directory of active devices. Singleton.
+ *
+ * We are only interested in MediaServers with a ContentDirectory service
+ * for now, but this could be made more general, by removing the filtering.
+ */
+class UPnPDeviceDirectory {
+	/**
+	 * Each appropriate discovery event (executing in a libupnp thread
+	 * context) queues the following task object for processing by the
+	 * discovery thread.
+	 */
+	struct DiscoveredTask {
+		std::string url;
+		std::string deviceId;
+		unsigned expires; // Seconds valid
+
+		DiscoveredTask(const Upnp_Discovery *disco)
+			:url(disco->Location),
+			  deviceId(disco->DeviceId),
+			  expires(disco->Expires) {}
+	};
+
+	/**
+	 * Descriptor for one device having a Content Directory
+	 * service found on the network.
+	 */
+	class ContentDirectoryDescriptor {
+	public:
+		std::string id;
+
+		UPnPDevice device;
+
+		/**
+		 * The MonotonicClockS() time stamp when this device
+		 * expires.
+		 */
+		unsigned expires;
+
+		ContentDirectoryDescriptor() = default;
+
+		ContentDirectoryDescriptor(std::string &&_id,
+					   unsigned last, int exp)
+			:id(std::move(_id)), expires(last + exp + 20) {}
+
+		bool Parse(const std::string &url, const char *description,
+			   Error &_error) {
+			return device.Parse(url, description, _error);
+		}
+	};
+
+	LibUPnP *const lib;
+
+	Mutex mutex;
+	std::list<ContentDirectoryDescriptor> directories;
+	WorkQueue<DiscoveredTask *> discoveredQueue;
+
+	/**
+	 * The UPnP device search timeout, which should actually be
+	 * called delay because it's the base of a random delay that
+	 * the devices apply to avoid responding all at the same time.
+	 */
+	int m_searchTimeout;
+
+	/**
+	 * The MonotonicClockS() time stamp of the last search.
+	 */
+	unsigned m_lastSearch;
+
+public:
+	UPnPDeviceDirectory(LibUPnP *_lib);
+	~UPnPDeviceDirectory();
+
+	UPnPDeviceDirectory(const UPnPDeviceDirectory &) = delete;
+	UPnPDeviceDirectory& operator=(const UPnPDeviceDirectory &) = delete;
+
+	bool Start(Error &error);
+
+	/** Retrieve the directory services currently seen on the network */
+	bool getDirServices(std::vector<ContentDirectoryService> &, Error &);
+
+	/**
+	 * Get server by friendly name.
+	 */
+	bool getServer(const char *friendlyName,
+		       ContentDirectoryService &server,
+		       Error &error);
+
+private:
+	bool search(Error &error);
+
+	/**
+	 * Look at the devices and get rid of those which have not
+	 * been seen for too long. We do this when listing the top
+	 * directory.
+	 */
+	bool expireDevices(Error &error);
+
+	void LockAdd(ContentDirectoryDescriptor &&d);
+	void LockRemove(const std::string &id);
+
+	/**
+	 * Worker routine for the discovery queue. Get messages about
+	 * devices appearing and disappearing, and update the
+	 * directory pool accordingly.
+	 */
+	static void *discoExplorer(void *);
+	void discoExplorer();
+
+	int OnAlive(Upnp_Discovery *disco);
+	int OnByeBye(Upnp_Discovery *disco);
+	int cluCallBack(Upnp_EventType et, void *evp);
+};
+
+
+#endif /* _UPNPPDISC_H_X_INCLUDED_ */