Refactor WvCdmEventListener and some cleanups

Bug: 19771437

It is a merge of below CLs from Widevine CDM repo:

Clean up CdmSession and PolicyEngine testing injection
https://widevine-internal-review.googlesource.com/#/c/13700

Refactor WvCdmEventListener handling
https://widevine-internal-review.googlesource.com/#/c/13702

Change-Id: I356b90000c056113d394926862b859aab380d305

libwvdrmengine/cdm/core/include/cdm_engine.h

@@ -32,11 +32,13 @@ class CdmEngine {
   // Session related methods
   virtual CdmResponseType OpenSession(const CdmKeySystem& key_system,
                                       const CdmClientPropertySet* property_set,
+                                      WvCdmEventListener* event_listener,
                                       CdmSessionId* session_id);
   virtual CdmResponseType CloseSession(const CdmSessionId& session_id);
 
   virtual CdmResponseType OpenKeySetSession(
-      const CdmKeySetId& key_set_id, const CdmClientPropertySet* property_set);
+      const CdmKeySetId& key_set_id, const CdmClientPropertySet* property_set,
+      WvCdmEventListener* event_listener);
   virtual CdmResponseType CloseKeySetSession(const CdmKeySetId& key_set_id);
 
   // License related methods
@@ -138,25 +140,17 @@ class CdmEngine {
   virtual bool IsKeyLoaded(const KeyId& key_id);
   virtual bool FindSessionForKey(const KeyId& key_id, CdmSessionId* sessionId);
 
-  // Event listener related methods.
-
-  // We assume that the WvCdmEventListener is asynchronous -- i.e. an event
-  // should be dispatched to another thread which actually does the work. In
-  // particular, if a synchronous listener calls OpenSession or CloseSession,
-  // the thread will dead lock.
-  // Returns false if listener already attached.
-  virtual bool AttachEventListener(const CdmSessionId& session_id,
-                                   WvCdmEventListener* listener);
-  // Returns true if listener was detached.
-  virtual bool DetachEventListener(const CdmSessionId& session_id,
-                                   WvCdmEventListener* listener);
-
   // Used for notifying the Max-Res Engine of resolution changes
   virtual void NotifyResolution(const CdmSessionId& session_id, uint32_t width,
                                 uint32_t height);
 
   // Timer expiration method. This method is not re-entrant -- there can be
   // only one timer.
+  // This method triggers appropriate event callbacks from |event_listener_|,
+  // which is assumed to be asynchronous -- i.e. an event should be dispatched
+  // to another thread which does the actual work. In particular, if a
+  // synchronous listener calls OpenSession or CloseSession, the thread will
+  // dead lock.
   virtual void OnTimerEvent();
 
  private:

libwvdrmengine/cdm/core/include/cdm_session.h

@@ -21,7 +21,8 @@ class WvCdmEventListener;
 
 class CdmSession {
  public:
-  explicit CdmSession(const CdmClientPropertySet* cdm_client_property_set);
+  CdmSession(const CdmClientPropertySet* cdm_client_property_set,
+             WvCdmEventListener* event_listener);
   virtual ~CdmSession();
 
   virtual CdmResponseType Init();
@@ -74,10 +75,6 @@ class CdmSession {
 
   virtual bool IsKeyLoaded(const KeyId& key_id);
 
-  // See comments for CdmEngine::AttachEventListener/DetachEventListener.
-  virtual bool AttachEventListener(WvCdmEventListener* listener);
-  virtual bool DetachEventListener(WvCdmEventListener* listener);
-
   // Used for notifying the Policy Engine of resolution changes
   virtual void NotifyResolution(uint32_t width, uint32_t height);
 
@@ -112,10 +109,7 @@ class CdmSession {
   bool DeleteLicense();
 
  private:
-  // Internal constructor
-  void Create(CdmLicense* license_parser, CryptoSession* crypto_session,
-              PolicyEngine* policy_engine, DeviceFiles* file_handle,
-              const CdmClientPropertySet* cdm_client_property_set);
+  friend class CdmSessionTest;
 
   // Generate unique ID for each new session.
   CdmSessionId GenerateSessionId();
@@ -123,9 +117,17 @@ class CdmSession {
 
   CdmResponseType StoreLicense();
   bool StoreLicense(DeviceFiles::LicenseState state);
+
+  // These setters are for testing only. Takes ownership of the pointers.
+  void set_license_parser(CdmLicense* license_parser);
+  void set_crypto_session(CryptoSession* crypto_session);
+  void set_policy_engine(PolicyEngine* policy_engine);
+  void set_file_handle(DeviceFiles* file_handle);
+
   // instance variables
   bool initialized_;
   CdmSessionId session_id_;
+  WvCdmEventListener* event_listener_;
   scoped_ptr<CdmLicense> license_parser_;
   scoped_ptr<CryptoSession> crypto_session_;
   scoped_ptr<PolicyEngine> policy_engine_;
@@ -156,18 +158,6 @@ class CdmSession {
   // license type release and offline related information
   CdmKeySetId key_set_id_;
 
-  std::set<WvCdmEventListener*> listeners_;
-
-  // For testing only
-  // Takes ownership of license_parser, crypto_session, policy_engine
-  // and device_files
-  CdmSession(CdmLicense* license_parser, CryptoSession* crypto_session,
-             PolicyEngine* policy_engine, DeviceFiles* file_handle,
-             const CdmClientPropertySet* cdm_client_property_set);
-#if defined(UNIT_TEST)
-  friend class CdmSessionTest;
-#endif
-
   CORE_DISALLOW_COPY_AND_ASSIGN(CdmSession);
 };
 

libwvdrmengine/cdm/core/include/policy_engine.h

@@ -7,6 +7,7 @@
 
 #include "license_protocol.pb.h"
 #include "max_res_engine.h"
+#include "scoped_ptr.h"
 #include "wv_cdm_types.h"
 
 namespace wvcdm {
@@ -15,7 +16,6 @@ using video_widevine_server::sdk::LicenseIdentification;
 
 class Clock;
 class CryptoSession;
-class PolicyEngineTest;
 
 // This acts as an oracle that basically says "Yes(true) you may still decrypt
 // or no(false) you may not decrypt this data anymore."
@@ -78,6 +78,8 @@ class PolicyEngine {
   bool IsLicenseForFuture() { return license_state_ == kLicenseStatePending; }
 
  private:
+  friend class PolicyEngineTest;
+
   typedef enum {
     kLicenseStateInitial,
     kLicenseStatePending,  // if license is issued for sometime in the future
@@ -87,8 +89,6 @@ class PolicyEngine {
     kLicenseStateExpired
   } LicenseState;
 
-  void Init(Clock* clock);
-
   int64_t GetLicenseDurationRemaining(int64_t current_time);
   int64_t GetPlaybackDurationRemaining(int64_t current_time);
 
@@ -98,6 +98,9 @@ class PolicyEngine {
 
   void UpdateRenewalRequest(int64_t current_time);
 
+  // These setters are for testing only. Takes ownership of the pointers.
+  void set_clock(Clock* clock);
+
   LicenseState license_state_;
   bool can_decrypt_;
 
@@ -124,11 +127,7 @@ class PolicyEngine {
   int64_t policy_max_duration_seconds_;
 
   MaxResEngine max_res_engine_;
-  Clock* clock_;
-
-  // For testing
-  friend class PolicyEngineTest;
-  PolicyEngine(CryptoSession* crypto_session, Clock* clock);
+  scoped_ptr<Clock> clock_;
 
   CORE_DISALLOW_COPY_AND_ASSIGN(PolicyEngine);
 };

libwvdrmengine/cdm/core/include/wv_cdm_event_listener.h

@@ -8,9 +8,6 @@
 namespace wvcdm {
 
 // Listener for events from the Content Decryption Module.
-// The caller of the CDM API must provide an implementation for OnEvent
-// and signal its intent by using the Attach/DetachEventListener methods
-// in the WvContentDecryptionModule class.
 class WvCdmEventListener {
  public:
   WvCdmEventListener() {}