diff options
Diffstat (limited to 'mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/upstream/cache/CacheUtil.java')
| -rw-r--r-- | mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/upstream/cache/CacheUtil.java | 434 |
1 files changed, 434 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/upstream/cache/CacheUtil.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/upstream/cache/CacheUtil.java new file mode 100644 index 0000000000..01fef2b605 --- /dev/null +++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/upstream/cache/CacheUtil.java @@ -0,0 +1,434 @@ +/* + * Copyright (C) 2017 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 org.mozilla.thirdparty.com.google.android.exoplayer2.upstream.cache; + +import android.net.Uri; +import android.util.Pair; +import androidx.annotation.Nullable; +import androidx.annotation.WorkerThread; +import org.mozilla.thirdparty.com.google.android.exoplayer2.C; +import org.mozilla.thirdparty.com.google.android.exoplayer2.upstream.DataSource; +import org.mozilla.thirdparty.com.google.android.exoplayer2.upstream.DataSourceException; +import org.mozilla.thirdparty.com.google.android.exoplayer2.upstream.DataSpec; +import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Assertions; +import org.mozilla.thirdparty.com.google.android.exoplayer2.util.PriorityTaskManager; +import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Util; +import java.io.EOFException; +import java.io.IOException; +import java.util.NavigableSet; +import java.util.concurrent.atomic.AtomicBoolean; + +/** + * Caching related utility methods. + */ +public final class CacheUtil { + + /** Receives progress updates during cache operations. */ + public interface ProgressListener { + + /** + * Called when progress is made during a cache operation. + * + * @param requestLength The length of the content being cached in bytes, or {@link + * C#LENGTH_UNSET} if unknown. + * @param bytesCached The number of bytes that are cached. + * @param newBytesCached The number of bytes that have been newly cached since the last progress + * update. + */ + void onProgress(long requestLength, long bytesCached, long newBytesCached); + } + + /** Default buffer size to be used while caching. */ + public static final int DEFAULT_BUFFER_SIZE_BYTES = 128 * 1024; + + /** Default {@link CacheKeyFactory}. */ + public static final CacheKeyFactory DEFAULT_CACHE_KEY_FACTORY = + (dataSpec) -> dataSpec.key != null ? dataSpec.key : generateKey(dataSpec.uri); + + /** + * Generates a cache key out of the given {@link Uri}. + * + * @param uri Uri of a content which the requested key is for. + */ + public static String generateKey(Uri uri) { + return uri.toString(); + } + + /** + * Queries the cache to obtain the request length and the number of bytes already cached for a + * given {@link DataSpec}. + * + * @param dataSpec Defines the data to be checked. + * @param cache A {@link Cache} which has the data. + * @param cacheKeyFactory An optional factory for cache keys. + * @return A pair containing the request length and the number of bytes that are already cached. + */ + public static Pair<Long, Long> getCached( + DataSpec dataSpec, Cache cache, @Nullable CacheKeyFactory cacheKeyFactory) { + String key = buildCacheKey(dataSpec, cacheKeyFactory); + long position = dataSpec.absoluteStreamPosition; + long requestLength = getRequestLength(dataSpec, cache, key); + long bytesAlreadyCached = 0; + long bytesLeft = requestLength; + while (bytesLeft != 0) { + long blockLength = + cache.getCachedLength( + key, position, bytesLeft != C.LENGTH_UNSET ? bytesLeft : Long.MAX_VALUE); + if (blockLength > 0) { + bytesAlreadyCached += blockLength; + } else { + blockLength = -blockLength; + if (blockLength == Long.MAX_VALUE) { + break; + } + } + position += blockLength; + bytesLeft -= bytesLeft == C.LENGTH_UNSET ? 0 : blockLength; + } + return Pair.create(requestLength, bytesAlreadyCached); + } + + /** + * Caches the data defined by {@code dataSpec}, skipping already cached data. Caching stops early + * if the end of the input is reached. + * + * <p>This method may be slow and shouldn't normally be called on the main thread. + * + * @param dataSpec Defines the data to be cached. + * @param cache A {@link Cache} to store the data. + * @param cacheKeyFactory An optional factory for cache keys. + * @param upstream A {@link DataSource} for reading data not in the cache. + * @param progressListener A listener to receive progress updates, or {@code null}. + * @param isCanceled An optional flag that will interrupt caching if set to true. + * @throws IOException If an error occurs reading from the source. + * @throws InterruptedException If the thread was interrupted directly or via {@code isCanceled}. + */ + @WorkerThread + public static void cache( + DataSpec dataSpec, + Cache cache, + @Nullable CacheKeyFactory cacheKeyFactory, + DataSource upstream, + @Nullable ProgressListener progressListener, + @Nullable AtomicBoolean isCanceled) + throws IOException, InterruptedException { + cache( + dataSpec, + cache, + cacheKeyFactory, + new CacheDataSource(cache, upstream), + new byte[DEFAULT_BUFFER_SIZE_BYTES], + /* priorityTaskManager= */ null, + /* priority= */ 0, + progressListener, + isCanceled, + /* enableEOFException= */ false); + } + + /** + * Caches the data defined by {@code dataSpec} while skipping already cached data. Caching stops + * early if end of input is reached and {@code enableEOFException} is false. + * + * <p>If a {@link PriorityTaskManager} is given, it's used to pause and resume caching depending + * on {@code priority} and the priority of other tasks registered to the PriorityTaskManager. + * Please note that it's the responsibility of the calling code to call {@link + * PriorityTaskManager#add} to register with the manager before calling this method, and to call + * {@link PriorityTaskManager#remove} afterwards to unregister. + * + * <p>This method may be slow and shouldn't normally be called on the main thread. + * + * @param dataSpec Defines the data to be cached. + * @param cache A {@link Cache} to store the data. + * @param cacheKeyFactory An optional factory for cache keys. + * @param dataSource A {@link CacheDataSource} that works on the {@code cache}. + * @param buffer The buffer to be used while caching. + * @param priorityTaskManager If not null it's used to check whether it is allowed to proceed with + * caching. + * @param priority The priority of this task. Used with {@code priorityTaskManager}. + * @param progressListener A listener to receive progress updates, or {@code null}. + * @param isCanceled An optional flag that will interrupt caching if set to true. + * @param enableEOFException Whether to throw an {@link EOFException} if end of input has been + * reached unexpectedly. + * @throws IOException If an error occurs reading from the source. + * @throws InterruptedException If the thread was interrupted directly or via {@code isCanceled}. + */ + @WorkerThread + public static void cache( + DataSpec dataSpec, + Cache cache, + @Nullable CacheKeyFactory cacheKeyFactory, + CacheDataSource dataSource, + byte[] buffer, + @Nullable PriorityTaskManager priorityTaskManager, + int priority, + @Nullable ProgressListener progressListener, + @Nullable AtomicBoolean isCanceled, + boolean enableEOFException) + throws IOException, InterruptedException { + Assertions.checkNotNull(dataSource); + Assertions.checkNotNull(buffer); + + String key = buildCacheKey(dataSpec, cacheKeyFactory); + long bytesLeft; + ProgressNotifier progressNotifier = null; + if (progressListener != null) { + progressNotifier = new ProgressNotifier(progressListener); + Pair<Long, Long> lengthAndBytesAlreadyCached = getCached(dataSpec, cache, cacheKeyFactory); + progressNotifier.init(lengthAndBytesAlreadyCached.first, lengthAndBytesAlreadyCached.second); + bytesLeft = lengthAndBytesAlreadyCached.first; + } else { + bytesLeft = getRequestLength(dataSpec, cache, key); + } + + long position = dataSpec.absoluteStreamPosition; + boolean lengthUnset = bytesLeft == C.LENGTH_UNSET; + while (bytesLeft != 0) { + throwExceptionIfInterruptedOrCancelled(isCanceled); + long blockLength = + cache.getCachedLength(key, position, lengthUnset ? Long.MAX_VALUE : bytesLeft); + if (blockLength > 0) { + // Skip already cached data. + } else { + // There is a hole in the cache which is at least "-blockLength" long. + blockLength = -blockLength; + long length = blockLength == Long.MAX_VALUE ? C.LENGTH_UNSET : blockLength; + boolean isLastBlock = length == bytesLeft; + long read = + readAndDiscard( + dataSpec, + position, + length, + dataSource, + buffer, + priorityTaskManager, + priority, + progressNotifier, + isLastBlock, + isCanceled); + if (read < blockLength) { + // Reached to the end of the data. + if (enableEOFException && !lengthUnset) { + throw new EOFException(); + } + break; + } + } + position += blockLength; + if (!lengthUnset) { + bytesLeft -= blockLength; + } + } + } + + private static long getRequestLength(DataSpec dataSpec, Cache cache, String key) { + if (dataSpec.length != C.LENGTH_UNSET) { + return dataSpec.length; + } else { + long contentLength = ContentMetadata.getContentLength(cache.getContentMetadata(key)); + return contentLength == C.LENGTH_UNSET + ? C.LENGTH_UNSET + : contentLength - dataSpec.absoluteStreamPosition; + } + } + + /** + * Reads and discards all data specified by the {@code dataSpec}. + * + * @param dataSpec Defines the data to be read. {@code absoluteStreamPosition} and {@code length} + * fields are overwritten by the following parameters. + * @param absoluteStreamPosition The absolute position of the data to be read. + * @param length Length of the data to be read, or {@link C#LENGTH_UNSET} if it is unknown. + * @param dataSource The {@link DataSource} to read the data from. + * @param buffer The buffer to be used while downloading. + * @param priorityTaskManager If not null it's used to check whether it is allowed to proceed with + * caching. + * @param priority The priority of this task. + * @param progressNotifier A notifier through which to report progress updates, or {@code null}. + * @param isLastBlock Whether this read block is the last block of the content. + * @param isCanceled An optional flag that will interrupt caching if set to true. + * @return Number of read bytes, or 0 if no data is available because the end of the opened range + * has been reached. + */ + private static long readAndDiscard( + DataSpec dataSpec, + long absoluteStreamPosition, + long length, + DataSource dataSource, + byte[] buffer, + @Nullable PriorityTaskManager priorityTaskManager, + int priority, + @Nullable ProgressNotifier progressNotifier, + boolean isLastBlock, + @Nullable AtomicBoolean isCanceled) + throws IOException, InterruptedException { + long positionOffset = absoluteStreamPosition - dataSpec.absoluteStreamPosition; + long initialPositionOffset = positionOffset; + long endOffset = length != C.LENGTH_UNSET ? positionOffset + length : C.POSITION_UNSET; + while (true) { + if (priorityTaskManager != null) { + // Wait for any other thread with higher priority to finish its job. + priorityTaskManager.proceed(priority); + } + throwExceptionIfInterruptedOrCancelled(isCanceled); + try { + long resolvedLength = C.LENGTH_UNSET; + boolean isDataSourceOpen = false; + if (endOffset != C.POSITION_UNSET) { + // If a specific length is given, first try to open the data source for that length to + // avoid more data then required to be requested. If the given length exceeds the end of + // input we will get a "position out of range" error. In that case try to open the source + // again with unset length. + try { + resolvedLength = + dataSource.open(dataSpec.subrange(positionOffset, endOffset - positionOffset)); + isDataSourceOpen = true; + } catch (IOException exception) { + if (!isLastBlock || !isCausedByPositionOutOfRange(exception)) { + throw exception; + } + Util.closeQuietly(dataSource); + } + } + if (!isDataSourceOpen) { + resolvedLength = dataSource.open(dataSpec.subrange(positionOffset, C.LENGTH_UNSET)); + } + if (isLastBlock && progressNotifier != null && resolvedLength != C.LENGTH_UNSET) { + progressNotifier.onRequestLengthResolved(positionOffset + resolvedLength); + } + while (positionOffset != endOffset) { + throwExceptionIfInterruptedOrCancelled(isCanceled); + int bytesRead = + dataSource.read( + buffer, + 0, + endOffset != C.POSITION_UNSET + ? (int) Math.min(buffer.length, endOffset - positionOffset) + : buffer.length); + if (bytesRead == C.RESULT_END_OF_INPUT) { + if (progressNotifier != null) { + progressNotifier.onRequestLengthResolved(positionOffset); + } + break; + } + positionOffset += bytesRead; + if (progressNotifier != null) { + progressNotifier.onBytesCached(bytesRead); + } + } + return positionOffset - initialPositionOffset; + } catch (PriorityTaskManager.PriorityTooLowException exception) { + // catch and try again + } finally { + Util.closeQuietly(dataSource); + } + } + } + + /** + * Removes all of the data specified by the {@code dataSpec}. + * + * <p>This methods blocks until the operation is complete. + * + * @param dataSpec Defines the data to be removed. + * @param cache A {@link Cache} to store the data. + * @param cacheKeyFactory An optional factory for cache keys. + */ + @WorkerThread + public static void remove( + DataSpec dataSpec, Cache cache, @Nullable CacheKeyFactory cacheKeyFactory) { + remove(cache, buildCacheKey(dataSpec, cacheKeyFactory)); + } + + /** + * Removes all of the data specified by the {@code key}. + * + * <p>This methods blocks until the operation is complete. + * + * @param cache A {@link Cache} to store the data. + * @param key The key whose data should be removed. + */ + @WorkerThread + public static void remove(Cache cache, String key) { + NavigableSet<CacheSpan> cachedSpans = cache.getCachedSpans(key); + for (CacheSpan cachedSpan : cachedSpans) { + try { + cache.removeSpan(cachedSpan); + } catch (Cache.CacheException e) { + // Do nothing. + } + } + } + + /* package */ static boolean isCausedByPositionOutOfRange(IOException e) { + Throwable cause = e; + while (cause != null) { + if (cause instanceof DataSourceException) { + int reason = ((DataSourceException) cause).reason; + if (reason == DataSourceException.POSITION_OUT_OF_RANGE) { + return true; + } + } + cause = cause.getCause(); + } + return false; + } + + private static String buildCacheKey( + DataSpec dataSpec, @Nullable CacheKeyFactory cacheKeyFactory) { + return (cacheKeyFactory != null ? cacheKeyFactory : DEFAULT_CACHE_KEY_FACTORY) + .buildCacheKey(dataSpec); + } + + private static void throwExceptionIfInterruptedOrCancelled(@Nullable AtomicBoolean isCanceled) + throws InterruptedException { + if (Thread.interrupted() || (isCanceled != null && isCanceled.get())) { + throw new InterruptedException(); + } + } + + private CacheUtil() {} + + private static final class ProgressNotifier { + /** The listener to notify when progress is made. */ + private final ProgressListener listener; + /** The length of the content being cached in bytes, or {@link C#LENGTH_UNSET} if unknown. */ + private long requestLength; + /** The number of bytes that are cached. */ + private long bytesCached; + + public ProgressNotifier(ProgressListener listener) { + this.listener = listener; + } + + public void init(long requestLength, long bytesCached) { + this.requestLength = requestLength; + this.bytesCached = bytesCached; + listener.onProgress(requestLength, bytesCached, /* newBytesCached= */ 0); + } + + public void onRequestLengthResolved(long requestLength) { + if (this.requestLength == C.LENGTH_UNSET && requestLength != C.LENGTH_UNSET) { + this.requestLength = requestLength; + listener.onProgress(requestLength, bytesCached, /* newBytesCached= */ 0); + } + } + + public void onBytesCached(long newBytesCached) { + bytesCached += newBytesCached; + listener.onProgress(requestLength, bytesCached, newBytesCached); + } + } +} |