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Diffstat (limited to 'src/com/android/messaging/datamodel/media/MediaResourceManager.java')
| -rw-r--r-- | src/com/android/messaging/datamodel/media/MediaResourceManager.java | 325 |
1 files changed, 0 insertions, 325 deletions
diff --git a/src/com/android/messaging/datamodel/media/MediaResourceManager.java b/src/com/android/messaging/datamodel/media/MediaResourceManager.java deleted file mode 100644 index 13f7291..0000000 --- a/src/com/android/messaging/datamodel/media/MediaResourceManager.java +++ /dev/null @@ -1,325 +0,0 @@ -/* - * Copyright (C) 2015 The Android Open Source Project - * - * Licensed under the Apache License, Version 2.0 (the "License"); - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - */ -package com.android.messaging.datamodel.media; - -import android.os.AsyncTask; - -import com.android.messaging.Factory; -import com.android.messaging.util.Assert; -import com.android.messaging.util.Assert.RunsOnAnyThread; -import com.android.messaging.util.LogUtil; -import com.google.common.annotations.VisibleForTesting; - -import java.util.ArrayList; -import java.util.List; -import java.util.concurrent.Executor; -import java.util.concurrent.Executors; -import java.util.concurrent.ThreadFactory; - -/** - * <p>Loads and maintains a set of in-memory LRU caches for different types of media resources. - * Right now we don't utilize any disk cache as all media urls are expected to be resolved to - * local content.<p/> - * - * <p>The MediaResourceManager takes media loading requests through one of two ways:</p> - * - * <ol> - * <li>{@link #requestMediaResourceAsync(MediaRequest)} that takes a MediaRequest, which may be a - * regular request if the caller doesn't want to listen for events (fire-and-forget), - * or an async request wrapper if event callback is needed.</li> - * <li>{@link #requestMediaResourceSync(MediaRequest)} which takes a MediaRequest and synchronously - * returns the loaded result, or null if failed.</li> - * </ol> - * - * <p>For each media loading task, MediaResourceManager starts an AsyncTask that runs on a - * dedicated thread, which calls MediaRequest.loadMediaBlocking() to perform the actual media - * loading work. As the media resources are loaded, MediaResourceManager notifies the callers - * (which must implement the MediaResourceLoadListener interface) via onMediaResourceLoaded() - * callback. Meanwhile, MediaResourceManager also pushes the loaded resource onto its dedicated - * cache.</p> - * - * <p>The media resource caches ({@link MediaCache}) are maintained as a set of LRU caches. They are - * created on demand by the incoming MediaRequest's getCacheId() method. The implementations of - * MediaRequest (such as {@link ImageRequest}) get to determine the desired cache id. For Bugle, - * the list of available caches are in {@link BugleMediaCacheManager}</p> - * - * <p>Optionally, media loading can support on-demand media encoding and decoding. - * All {@link MediaRequest}'s can opt to chain additional {@link MediaRequest}'s to be executed - * after the completion of the main media loading task, by adding new tasks to the chained - * task list in {@link MediaRequest#loadMediaBlocking(List)}. One possible type of chained task is - * media encoding task. Loaded media will be encoded on a dedicated single threaded executor - * *after* the UI is notified of the loaded media. In this case, the encoded media resource will - * be eventually pushed to the cache, which will later be decoded before posting to the UI thread - * on cache hit.</p> - * - * <p><b>To add support for a new type of media resource,</b></p> - * - * <ol> - * <li>Create a new subclass of {@link RefCountedMediaResource} for the new resource type (example: - * {@link ImageResource} class).</li> - * - * <li>Implement the {@link MediaRequest} interface (example: {@link ImageRequest}). Perform the - * media loading work in loadMediaBlocking() and return a cache id in getCacheId().</li> - * - * <li>For the UI component that requests the media resource, let it implement - * {@link MediaResourceLoadListener} interface to listen for resource load callback. Let the - * UI component call MediaResourceManager.requestMediaResourceAsync() to request a media source. - * (example: {@link com.android.messaging.ui.ContactIconView}</li> - * </ol> - */ -public class MediaResourceManager { - private static final String TAG = LogUtil.BUGLE_TAG; - - public static MediaResourceManager get() { - return Factory.get().getMediaResourceManager(); - } - - /** - * Listener for asynchronous callback from media loading events. - */ - public interface MediaResourceLoadListener<T extends RefCountedMediaResource> { - void onMediaResourceLoaded(MediaRequest<T> request, T resource, boolean cached); - void onMediaResourceLoadError(MediaRequest<T> request, Exception exception); - } - - // We use a fixed thread pool for handling media loading tasks. Using a cached thread pool - // allows for unlimited thread creation which can lead to OOMs so we limit the threads here. - private static final Executor MEDIA_LOADING_EXECUTOR = Executors.newFixedThreadPool(10); - - // A dedicated single thread executor for performing background task after loading the resource - // on the media loading executor. This includes work such as encoding loaded media to be cached. - // These tasks are run on a single worker thread with low priority so as not to contend with the - // media loading tasks. - private static final Executor MEDIA_BACKGROUND_EXECUTOR = Executors.newSingleThreadExecutor( - new ThreadFactory() { - @Override - public Thread newThread(final Runnable runnable) { - final Thread encodingThread = new Thread(runnable); - encodingThread.setPriority(Thread.MIN_PRIORITY); - return encodingThread; - } - }); - - /** - * Requests a media resource asynchronously. Upon completion of the media loading task, - * the listener will be notified of success/failure iff it's still bound. A refcount on the - * resource is held and guaranteed for the caller for the duration of the - * {@link MediaResourceLoadListener#onMediaResourceLoaded( - * MediaRequest, RefCountedMediaResource, boolean)} callback. - * @param mediaRequest the media request. May be either an - * {@link AsyncMediaRequestWrapper} for listening for event callbacks, or a regular media - * request for fire-and-forget type of behavior. - */ - public <T extends RefCountedMediaResource> void requestMediaResourceAsync( - final MediaRequest<T> mediaRequest) { - scheduleAsyncMediaRequest(mediaRequest, MEDIA_LOADING_EXECUTOR); - } - - /** - * Requests a media resource synchronously. - * @return the loaded resource with a refcount reserved for the caller. The caller must call - * release() on the resource once it's done using it (like with Cursors). - */ - public <T extends RefCountedMediaResource> T requestMediaResourceSync( - final MediaRequest<T> mediaRequest) { - Assert.isNotMainThread(); - // Block and load media. - MediaLoadingResult<T> loadResult = null; - try { - loadResult = processMediaRequestInternal(mediaRequest); - // The loaded resource should have at least one refcount by now reserved for the caller. - Assert.isTrue(loadResult.loadedResource.getRefCount() > 0); - return loadResult.loadedResource; - } catch (final Exception e) { - LogUtil.e(LogUtil.BUGLE_TAG, "Synchronous media loading failed, key=" + - mediaRequest.getKey(), e); - return null; - } finally { - if (loadResult != null) { - // Schedule the background requests chained to the main request. - loadResult.scheduleChainedRequests(); - } - } - } - - @SuppressWarnings("unchecked") - private <T extends RefCountedMediaResource> MediaLoadingResult<T> processMediaRequestInternal( - final MediaRequest<T> mediaRequest) - throws Exception { - final List<MediaRequest<T>> chainedRequests = new ArrayList<>(); - T loadedResource = null; - // Try fetching from cache first. - final T cachedResource = loadMediaFromCache(mediaRequest); - if (cachedResource != null) { - if (cachedResource.isEncoded()) { - // The resource is encoded, issue a decoding request. - final MediaRequest<T> decodeRequest = (MediaRequest<T>) cachedResource - .getMediaDecodingRequest(mediaRequest); - Assert.notNull(decodeRequest); - cachedResource.release(); - loadedResource = loadMediaFromRequest(decodeRequest, chainedRequests); - } else { - // The resource is ready-to-use. - loadedResource = cachedResource; - } - } else { - // Actually load the media after cache miss. - loadedResource = loadMediaFromRequest(mediaRequest, chainedRequests); - } - return new MediaLoadingResult<>(loadedResource, cachedResource != null /* fromCache */, - chainedRequests); - } - - private <T extends RefCountedMediaResource> T loadMediaFromCache( - final MediaRequest<T> mediaRequest) { - if (mediaRequest.getRequestType() != MediaRequest.REQUEST_LOAD_MEDIA) { - // Only look up in the cache if we are loading media. - return null; - } - final MediaCache<T> mediaCache = mediaRequest.getMediaCache(); - if (mediaCache != null) { - final T mediaResource = mediaCache.fetchResourceFromCache(mediaRequest.getKey()); - if (mediaResource != null) { - return mediaResource; - } - } - return null; - } - - private <T extends RefCountedMediaResource> T loadMediaFromRequest( - final MediaRequest<T> mediaRequest, final List<MediaRequest<T>> chainedRequests) - throws Exception { - final T resource = mediaRequest.loadMediaBlocking(chainedRequests); - // mediaRequest.loadMediaBlocking() should never return null without - // throwing an exception. - Assert.notNull(resource); - // It's possible for the media to be evicted right after it's added to - // the cache (possibly because it's by itself too big for the cache). - // It's also possible that, after added to the cache, something else comes - // to the cache and evicts this media resource. To prevent this from - // recycling the underlying resource objects, make sure to add ref before - // adding to cache so that the caller is guaranteed a ref on the resource. - resource.addRef(); - // Don't cache the media request if it is defined as non-cacheable. - if (resource.isCacheable()) { - addResourceToMemoryCache(mediaRequest, resource); - } - return resource; - } - - /** - * Schedule an async media request on the given <code>executor</code>. - * @param mediaRequest the media request to be processed asynchronously. May be either an - * {@link AsyncMediaRequestWrapper} for listening for event callbacks, or a regular media - * request for fire-and-forget type of behavior. - */ - private <T extends RefCountedMediaResource> void scheduleAsyncMediaRequest( - final MediaRequest<T> mediaRequest, final Executor executor) { - final BindableMediaRequest<T> bindableRequest = - (mediaRequest instanceof BindableMediaRequest<?>) ? - (BindableMediaRequest<T>) mediaRequest : null; - if (bindableRequest != null && !bindableRequest.isBound()) { - return; // Request is obsolete - } - // We don't use SafeAsyncTask here since it enforces the shared thread pool executor - // whereas we want a dedicated thread pool executor. - AsyncTask<Void, Void, MediaLoadingResult<T>> mediaLoadingTask = - new AsyncTask<Void, Void, MediaLoadingResult<T>>() { - private Exception mException; - - @Override - protected MediaLoadingResult<T> doInBackground(Void... params) { - // Double check the request is still valid by the time we start processing it - if (bindableRequest != null && !bindableRequest.isBound()) { - return null; // Request is obsolete - } - try { - return processMediaRequestInternal(mediaRequest); - } catch (Exception e) { - mException = e; - return null; - } - } - - @Override - protected void onPostExecute(final MediaLoadingResult<T> result) { - if (result != null) { - Assert.isNull(mException); - Assert.isTrue(result.loadedResource.getRefCount() > 0); - try { - if (bindableRequest != null) { - bindableRequest.onMediaResourceLoaded( - bindableRequest, result.loadedResource, result.fromCache); - } - } finally { - result.loadedResource.release(); - result.scheduleChainedRequests(); - } - } else if (mException != null) { - LogUtil.e(LogUtil.BUGLE_TAG, "Asynchronous media loading failed, key=" + - mediaRequest.getKey(), mException); - if (bindableRequest != null) { - bindableRequest.onMediaResourceLoadError(bindableRequest, mException); - } - } else { - Assert.isTrue(bindableRequest == null || !bindableRequest.isBound()); - if (LogUtil.isLoggable(TAG, LogUtil.VERBOSE)) { - LogUtil.v(TAG, "media request not processed, no longer bound; key=" + - LogUtil.sanitizePII(mediaRequest.getKey()) /* key with phone# */); - } - } - } - }; - mediaLoadingTask.executeOnExecutor(executor, (Void) null); - } - - @VisibleForTesting - @RunsOnAnyThread - <T extends RefCountedMediaResource> void addResourceToMemoryCache( - final MediaRequest<T> mediaRequest, final T mediaResource) { - Assert.isTrue(mediaResource != null); - final MediaCache<T> mediaCache = mediaRequest.getMediaCache(); - if (mediaCache != null) { - mediaCache.addResourceToCache(mediaRequest.getKey(), mediaResource); - if (LogUtil.isLoggable(TAG, LogUtil.VERBOSE)) { - LogUtil.v(TAG, "added media resource to " + mediaCache.getName() + ". key=" + - LogUtil.sanitizePII(mediaRequest.getKey()) /* key can contain phone# */); - } - } - } - - private class MediaLoadingResult<T extends RefCountedMediaResource> { - public final T loadedResource; - public final boolean fromCache; - private final List<MediaRequest<T>> mChainedRequests; - - MediaLoadingResult(final T loadedResource, final boolean fromCache, - final List<MediaRequest<T>> chainedRequests) { - this.loadedResource = loadedResource; - this.fromCache = fromCache; - mChainedRequests = chainedRequests; - } - - /** - * Asynchronously schedule a list of chained requests on the background thread. - */ - public void scheduleChainedRequests() { - for (final MediaRequest<T> mediaRequest : mChainedRequests) { - scheduleAsyncMediaRequest(mediaRequest, MEDIA_BACKGROUND_EXECUTOR); - } - } - } -} |