V18.4.0 CAS plugin

Note that this version does not have Widevine Provisioning 4.0 support.
It is only suitable for device upgrades. A new patch with provisioning
4.0 support will be made later.

plugin/include/widevine_cas_session_map.h

@@ -0,0 +1,54 @@
+// Copyright 2018 Google LLC. All Rights Reserved. This file and proprietary
+// source code may only be used and distributed under the Widevine Master
+// License Agreement.
+
+#ifndef WIDEVINE_CAS_SESSION_MAP_H
+#define WIDEVINE_CAS_SESSION_MAP_H
+
+#include <map>
+#include <memory>
+#include <mutex>
+#include <string>
+#include <utility>
+
+#include "cas_types.h"
+#include "widevine_cas_session.h"
+
+namespace wvcas {
+
+typedef std::map<WvCasSessionId, CasSessionPtr> CasSessionMap;
+
+// WidevineCasSessionMap is a singleton. It used as a shared resource used by
+// both cas and descrambler plugins. Cas sessions are created by the cas plugin,
+// and can be *discovered* by descrambler plugins.
+class WidevineCasSessionMap {
+ public:
+  virtual ~WidevineCasSessionMap() {}
+
+  // Adds a new Widevine cas session to the map.
+  // Returns true if the session is successfully added to the map, false
+  // otherwise.
+  bool AddSession(const WvCasSessionId& cas_session_id, CasSessionPtr session);
+  // Obtain a shared pointer to a cas session. If the session does not exist in
+  // the map, the returned pointer == nullptr.
+  CasSessionPtr GetSession(const WvCasSessionId& cas_session_id) const;
+  // Remove an entry in the map.
+  void RemoveSession(const WvCasSessionId& cas_session_id);
+  // Retrieves all the session ids.
+  std::vector<CasSessionPtr> GetAllSessions() const;
+
+  // Returns a reference to the map.
+  static WidevineCasSessionMap& instance();
+
+  WidevineCasSessionMap(const WidevineCasSessionMap&) = delete;
+  WidevineCasSessionMap& operator=(const WidevineCasSessionMap&) = delete;
+
+ private:
+  WidevineCasSessionMap() {}
+  CasSessionMap map_;
+  mutable std::mutex lock_;
+};
+
+}  // namespace wvcas
+
+#endif  // WIDEVINE_CAS_SESSION_MAP_H