modified the WebStorageClient to keep a cache of the playlists which are

currently being edited

livesupport/modules/storage/src/TestStorageClient.cxx

@@ -22,7 +22,7 @@
  
  
     Author   : $Author: fgerlits $
-    Version  : $Revision: 1.30 $
+    Version  : $Revision: 1.31 $
     Location : $Source: /home/paul/cvs2svn-livesupport/newcvsrepo/livesupport/modules/storage/src/TestStorageClient.cxx,v $
 
 ------------------------------------------------------------------------------*/
@@ -300,17 +300,19 @@ TestStorageClient :: savePlaylist(Ptr<SessionId>::Ref sessionId,
                     editIt = editedPlaylists.find(playlist->getId()->getId());
     
     if ((editIt == editedPlaylists.end()) 
-        || (*playlist->getToken() != *editIt->second->getToken())) {
+            || (*playlist->getToken() != *editIt->second->getToken())) {
         throw XmlRpcException("savePlaylist() called without editPlaylist()");
     }
 
+    Ptr<std::string>::Ref   nullPointer;
+    playlist->setToken(nullPointer);
+
     PlaylistMapType::iterator
                     storeIt = playlistMap.find(playlist->getId()->getId());
 
     if (storeIt == playlistMap.end()) {
         throw XmlRpcException("playlist deleted while it was being edited???");
     }
-
     storeIt->second = playlist;
 
     editedPlaylists.erase(editIt);

livesupport/modules/storage/src/WebStorageClient.cxx

@@ -22,7 +22,7 @@
  
  
     Author   : $Author: fgerlits $
-    Version  : $Revision: 1.26 $
+    Version  : $Revision: 1.27 $
     Location : $Source: /home/paul/cvs2svn-livesupport/newcvsrepo/livesupport/modules/storage/src/WebStorageClient.cxx,v $
 
 ------------------------------------------------------------------------------*/
@@ -693,6 +693,14 @@ WebStorageClient :: getPlaylist(Ptr<SessionId>::Ref sessionId,
                                 Ptr<UniqueId>::Ref  id) const
                                                 throw (Core::XmlRpcException)
 {
+    EditedPlaylistsType::const_iterator
+                    editIt = editedPlaylists.find(id->getId());
+
+    if (editIt != editedPlaylists.end()                     // is being edited
+            && (*editIt->second.first == *sessionId)) {        // by us
+         return editIt->second.second;
+    }
+
     XmlRpcValue     parameters;
     XmlRpcValue     result;
 
@@ -808,11 +816,16 @@ WebStorageClient :: editPlaylist(Ptr<SessionId>::Ref sessionId,
                                  Ptr<UniqueId>::Ref  id)
                                                 throw (Core::XmlRpcException)
 {
-    Ptr<Playlist>::Ref              playlist(new Playlist(id));
+    if (editedPlaylists.find(id->getId()) != editedPlaylists.end()) {
+        throw XmlRpcInvalidArgumentException("playlist is already"
+                                             " being edited");
+    }
+    
     Ptr<const std::string>::Ref     url, token;
 
     editPlaylistGetUrl(sessionId, id, url, token);
 
+    Ptr<Playlist>::Ref              playlist(new Playlist(id));
     try {
         Ptr<xmlpp::DomParser>::Ref  parser(new xmlpp::DomParser());
         parser->parse_file(*url);
@@ -830,6 +843,7 @@ WebStorageClient :: editPlaylist(Ptr<SessionId>::Ref sessionId,
     }
 
     playlist->setToken(token);
+    editedPlaylists[id->getId()] = std::make_pair(sessionId, playlist);
 
     return playlist;
 }
@@ -905,6 +919,16 @@ WebStorageClient :: savePlaylist(Ptr<SessionId>::Ref sessionId,
         throw XmlRpcInvalidArgumentException("playlist has no token field");
     }
     
+    EditedPlaylistsType::iterator
+                    editIt = editedPlaylists.find(playlist->getId()->getId());
+    
+    if ((editIt == editedPlaylists.end()) 
+            || *editIt->second.first != *sessionId) {
+        throw XmlRpcInvalidArgumentException("savePlaylist() called without "
+                                             "editPlaylist()");
+    }
+    editedPlaylists.erase(editIt);
+
     XmlRpcValue     parameters;
     XmlRpcValue     result;
 
@@ -1238,6 +1262,7 @@ WebStorageClient :: createPlaylist(Ptr<SessionId>::Ref sessionId)
     Ptr<Playlist>::Ref          playlist(new Playlist(newId, playlength));
     playlist->setToken(token);
     
+    editedPlaylists[newId->getId()] = std::make_pair(sessionId, playlist);
     savePlaylist(sessionId, playlist);
     
     token.reset();

livesupport/modules/storage/src/WebStorageClient.h

@@ -22,7 +22,7 @@
  
  
     Author   : $Author: fgerlits $
-    Version  : $Revision: 1.18 $
+    Version  : $Revision: 1.19 $
     Location : $Source: /home/paul/cvs2svn-livesupport/newcvsrepo/livesupport/modules/storage/src/WebStorageClient.h,v $
 
 ------------------------------------------------------------------------------*/
@@ -99,7 +99,7 @@ using namespace LiveSupport::Core;
  *  </code></pre>
  *
  *  @author  $Author: fgerlits $
- *  @version $Revision: 1.18 $
+ *  @version $Revision: 1.19 $
  */
 class WebStorageClient :
                     virtual public Configurable,
@@ -131,6 +131,18 @@ class WebStorageClient :
          */
         std::string                 storageServerPath;
 
+        /**
+         *  The type for the list of playlists which are currently being edited
+         */
+        typedef std::map<const UniqueId::IdType, 
+                         std::pair<Ptr<SessionId>::Ref, Ptr<Playlist>::Ref> >
+                                                            EditedPlaylistsType;
+
+        /**
+         *  The list of playlists which are currently being edited
+         */
+        EditedPlaylistsType         editedPlaylists;
+
         /**
          *  Auxilliary method used by editPlaylist() and createPlaylist().
          *  Opens the playlist for editing, and returns its URL.
@@ -215,7 +227,12 @@ class WebStorageClient :
 
         /**
          *  Return a playlist with the specified id to be displayed.
-         *  If the playlist is being edited, its last saved state is returned.
+         *  If the playlist is being edited, and this method is called
+         *  by the same user who is editing the playlist,
+         *  (i.e., the method is called with the same sessionId and playlistId
+         *  that editPlaylist() was), then the working copy of the playlist
+         *  is returned.
+         *  Any other user gets the old (pre-editPlaylist()) copy from storage.
          *
          *  @param sessionId the session ID from the authentication client
          *  @param id the id of the playlist to return.
@@ -235,6 +252,10 @@ class WebStorageClient :
          *  This puts a lock on the playlist, and nobody else can edit it
          *  until we release it using savePlaylist().
          *
+         *  This method creates a working copy of the playlist, which will
+         *  be returned by getPlaylist() if it is called with the same
+         *  sessionId and playlistId, until we call savePlaylist().
+         *
          *  @param sessionId the session ID from the authentication client
          *  @param id the id of the playlist to return.
          *  @return the requested playlist.
@@ -252,6 +273,8 @@ class WebStorageClient :
          *  Can only be called after we obtained a lock on the playlist using
          *  editPlaylist(); this method releases the lock.
          *
+         *  This method destroys the working copy created by editPlaylist().
+         *
          *  @param sessionId the session ID from the authentication client
          *  @param playlist the playlist to save.
          *  @exception XmlRpcException if there is a problem with the XML-RPC

livesupport/modules/storage/src/WebStorageClientTest.cxx

@@ -22,7 +22,7 @@
  
  
     Author   : $Author: fgerlits $
-    Version  : $Revision: 1.28 $
+    Version  : $Revision: 1.29 $
     Location : $Source: /home/paul/cvs2svn-livesupport/newcvsrepo/livesupport/modules/storage/src/WebStorageClientTest.cxx,v $
 
 ------------------------------------------------------------------------------*/
@@ -239,7 +239,7 @@ WebStorageClientTest :: playlistTest(void)
     try {
         playlist = wsc->editPlaylist(sessionId, playlistIdxx);
         CPPUNIT_FAIL("allowed to open playlist for editing twice");
-    } catch (Core::XmlRpcMethodFaultException &e) {
+    } catch (Core::XmlRpcInvalidArgumentException &e) {
     } catch (XmlRpcException &e) {
         std::string eMsg = "editPlaylist() threw unexpected exception:\n";
         CPPUNIT_FAIL(eMsg + e.what());
@@ -265,9 +265,21 @@ WebStorageClientTest :: playlistTest(void)
     try {
         Ptr<Playlist>::Ref  throwAwayPlaylist
                             = wsc->getPlaylist(sessionId, playlistIdxx);
-        // this should be OK, get old copy
+        // we are editing it, get another working copy
+        CPPUNIT_ASSERT(throwAwayPlaylist->getPlaylength()
+                                        ->total_seconds() == 9);
+    } catch (XmlRpcException &e) {
+        CPPUNIT_FAIL(e.what());
+    }
+
+    try {
+        Ptr<SessionId>::Ref newSessionId = authentication->login("root", "q");
+        Ptr<Playlist>::Ref  throwAwayPlaylist
+                            = wsc->getPlaylist(newSessionId, playlistIdxx);
+        // somebody else is editing it, get the old copy
         CPPUNIT_ASSERT(throwAwayPlaylist->getPlaylength()
                                         ->total_seconds() == 0);
+        authentication->logout(newSessionId);
     } catch (XmlRpcException &e) {
         CPPUNIT_FAIL(e.what());
     }