Refactor|Audio|Client: Locate music resource files only once per play…

…back request

Revised playFile() so that only one attempt to locate referenced file
is made irrespective of the number playback interfaces tried.

doomsday/apps/client/src/audio/s_mus.cpp

@@ -122,55 +122,51 @@ static String tryFindMusicFile(Record const &definition)
     return "";  // None found.
 }
 
-static dint playFile(String const &virtualOrNativePath, bool looped)
+static dint playFile(String const &virtualOrNativePath, bool looped = false)
 {
     DENG2_ASSERT(::musAvail && App_AudioSystem().musicIsAvailable());
-
-    return App_AudioSystem().forAllInterfaces(AUDIO_IMUSIC, [&virtualOrNativePath, &looped] (void *ifs)
+    try
     {
-        try
+        // Relative paths are relative to the native working directory.
+        String const path  = (NativePath::workPath() / NativePath(virtualOrNativePath).expand()).withSeparators('/');
+        std::unique_ptr<FileHandle> hndl(&App_FileSystem().openFile(path, "rb"));
+
+        auto didPlay = App_AudioSystem().forAllInterfaces(AUDIO_IMUSIC, [&hndl, &looped] (void *ifs)
         {
             auto *iMusic = (audiointerface_music_t *) ifs;
 
-            // Relative paths are relative to the native working directory.
-            String path  = (NativePath::workPath() / NativePath(virtualOrNativePath).expand()).withSeparators('/');
-            std::unique_ptr<FileHandle> hndl(&App_FileSystem().openFile(path, "rb"));
-            dsize const len = hndl->length();
-
             // Does this interface offer buffered playback?
             if(iMusic->Play && iMusic->SongBuffer)
             {
                 // Buffer the data using the driver's own facility.
+                dsize const len = hndl->length();
                 hndl->read((duint8 *) iMusic->SongBuffer(len), len);
-                App_FileSystem().releaseFile(hndl->file());
 
                 return iMusic->Play(looped);
             }
             // Does this interface offer playback from a native file?
             else if(iMusic->PlayFile)
             {
                 // Write the data to disk and play from there.
-                String const fileName = composeBufferFilename();
+                String const bufPath = composeBufferFilename();
 
+                dsize len = hndl->length();
                 duint8 *buf = (duint8 *)M_Malloc(len);
                 hndl->read(buf, len);
-                F_Dump(buf, len, fileName.toUtf8().constData());
+                F_Dump(buf, len, bufPath.toUtf8().constData());
                 M_Free(buf); buf = nullptr;
 
-                App_FileSystem().releaseFile(hndl->file());
-
-                // Music maestro, if you please!
-                return iMusic->PlayFile(fileName.toUtf8().constData(), looped);
-            }
-            else
-            {
-                App_FileSystem().releaseFile(hndl->file());
+                return iMusic->PlayFile(bufPath.toUtf8().constData(), looped);
             }
-        }
-        catch(FS1::NotFoundError const &)
-        {}  // Ignore this error.
-        return 0;  // Continue
-    });
+            return 0;  // Continue.
+        });
+
+        App_FileSystem().releaseFile(hndl->file());
+        return didPlay;
+    }
+    catch(FS1::NotFoundError const &)
+    {}  // Ignore this error.
+    return 0;  // Continue.
 }
 
 /**