ag2s20150909
3 years ago
parent
0d895548df
commit
dd32d433bc
@ -0,0 +1,902 @@ |
||||
package io.legado.app.help; |
||||
|
||||
import static com.google.android.exoplayer2.util.Assertions.checkNotNull; |
||||
import static com.google.android.exoplayer2.util.Util.castNonNull; |
||||
import static java.lang.Math.min; |
||||
|
||||
import android.net.Uri; |
||||
|
||||
import androidx.annotation.IntDef; |
||||
import androidx.annotation.Nullable; |
||||
|
||||
import com.google.android.exoplayer2.C; |
||||
import com.google.android.exoplayer2.PlaybackException; |
||||
import com.google.android.exoplayer2.ext.okhttp.OkHttpDataSource; |
||||
import com.google.android.exoplayer2.upstream.DataSink; |
||||
import com.google.android.exoplayer2.upstream.DataSource; |
||||
import com.google.android.exoplayer2.upstream.DataSourceException; |
||||
import com.google.android.exoplayer2.upstream.DataSpec; |
||||
import com.google.android.exoplayer2.upstream.DummyDataSource; |
||||
import com.google.android.exoplayer2.upstream.FileDataSource; |
||||
import com.google.android.exoplayer2.upstream.PriorityDataSource; |
||||
import com.google.android.exoplayer2.upstream.TeeDataSource; |
||||
import com.google.android.exoplayer2.upstream.TransferListener; |
||||
import com.google.android.exoplayer2.upstream.cache.Cache; |
||||
import com.google.android.exoplayer2.upstream.cache.Cache.CacheException; |
||||
import com.google.android.exoplayer2.upstream.cache.CacheDataSink; |
||||
import com.google.android.exoplayer2.upstream.cache.CacheKeyFactory; |
||||
import com.google.android.exoplayer2.upstream.cache.CacheSpan; |
||||
import com.google.android.exoplayer2.upstream.cache.ContentMetadata; |
||||
import com.google.android.exoplayer2.upstream.cache.ContentMetadataMutations; |
||||
import com.google.android.exoplayer2.util.Assertions; |
||||
import com.google.android.exoplayer2.util.PriorityTaskManager; |
||||
|
||||
import java.io.IOException; |
||||
import java.io.InterruptedIOException; |
||||
import java.lang.annotation.Documented; |
||||
import java.lang.annotation.Retention; |
||||
import java.lang.annotation.RetentionPolicy; |
||||
import java.util.Collections; |
||||
import java.util.List; |
||||
import java.util.Map; |
||||
|
||||
/** |
||||
* A {@link DataSource} that reads and writes a {@link Cache}. Requests are fulfilled from the cache |
||||
* when possible. When data is not cached it is requested from an upstream {@link DataSource} and |
||||
* written into the cache. |
||||
*/ |
||||
public final class OkhttpCacheDataSource implements DataSource { |
||||
|
||||
/** |
||||
* {@link DataSource.Factory} for {@link OkhttpCacheDataSource} instances. |
||||
*/ |
||||
public static final class Factory implements DataSource.Factory { |
||||
|
||||
private Cache cache; |
||||
private DataSource.Factory cacheReadDataSourceFactory; |
||||
@Nullable |
||||
private DataSink.Factory cacheWriteDataSinkFactory; |
||||
private CacheKeyFactory cacheKeyFactory; |
||||
private boolean cacheIsReadOnly; |
||||
@Nullable |
||||
private OkHttpDataSource.Factory upstreamDataSourceFactory; |
||||
@Nullable |
||||
private PriorityTaskManager upstreamPriorityTaskManager; |
||||
private int upstreamPriority; |
||||
@OkhttpCacheDataSource.Flags |
||||
private int flags; |
||||
@Nullable |
||||
private OkhttpCacheDataSource.EventListener eventListener; |
||||
|
||||
public Factory() { |
||||
cacheReadDataSourceFactory = new FileDataSource.Factory(); |
||||
cacheKeyFactory = CacheKeyFactory.DEFAULT; |
||||
} |
||||
|
||||
/** |
||||
* Sets the cache that will be used. |
||||
* |
||||
* <p>Must be called before the factory is used. |
||||
* |
||||
* @param cache The cache that will be used. |
||||
* @return This factory. |
||||
*/ |
||||
public Factory setCache(Cache cache) { |
||||
this.cache = cache; |
||||
return this; |
||||
} |
||||
|
||||
/** |
||||
* Returns the cache that will be used, or {@code null} if {@link #setCache} has yet to be |
||||
* called. |
||||
*/ |
||||
@Nullable |
||||
public Cache getCache() { |
||||
return cache; |
||||
} |
||||
|
||||
/** |
||||
* Sets the {@link DataSource.Factory} for {@link DataSource DataSources} for reading from the |
||||
* cache. |
||||
* |
||||
* <p>The default is a {@link FileDataSource.Factory} in its default configuration. |
||||
* |
||||
* @param cacheReadDataSourceFactory The {@link DataSource.Factory} for reading from the cache. |
||||
* @return This factory. |
||||
*/ |
||||
public Factory setCacheReadDataSourceFactory(DataSource.Factory cacheReadDataSourceFactory) { |
||||
this.cacheReadDataSourceFactory = cacheReadDataSourceFactory; |
||||
return this; |
||||
} |
||||
|
||||
/** |
||||
* Sets the {@link DataSink.Factory} for generating {@link DataSink DataSinks} for writing data |
||||
* to the cache. Passing {@code null} causes the cache to be read-only. |
||||
* |
||||
* <p>The default is a {@link CacheDataSink.Factory} in its default configuration. |
||||
* |
||||
* @param cacheWriteDataSinkFactory The {@link DataSink.Factory} for generating {@link DataSink |
||||
* DataSinks} for writing data to the cache, or {@code null} to disable writing. |
||||
* @return This factory. |
||||
*/ |
||||
public Factory setCacheWriteDataSinkFactory( |
||||
@Nullable DataSink.Factory cacheWriteDataSinkFactory) { |
||||
this.cacheWriteDataSinkFactory = cacheWriteDataSinkFactory; |
||||
this.cacheIsReadOnly = cacheWriteDataSinkFactory == null; |
||||
return this; |
||||
} |
||||
|
||||
/** |
||||
* Sets the {@link CacheKeyFactory}. |
||||
* |
||||
* <p>The default is {@link CacheKeyFactory#DEFAULT}. |
||||
* |
||||
* @param cacheKeyFactory The {@link CacheKeyFactory}. |
||||
* @return This factory. |
||||
*/ |
||||
public Factory setCacheKeyFactory(CacheKeyFactory cacheKeyFactory) { |
||||
this.cacheKeyFactory = cacheKeyFactory; |
||||
return this; |
||||
} |
||||
|
||||
/** |
||||
* Returns the {@link CacheKeyFactory} that will be used. |
||||
*/ |
||||
public CacheKeyFactory getCacheKeyFactory() { |
||||
return cacheKeyFactory; |
||||
} |
||||
|
||||
/** |
||||
* Sets the {@link DataSource.Factory} for upstream {@link DataSource DataSources}, which are |
||||
* used to read data in the case of a cache miss. |
||||
* |
||||
* <p>The default is {@code null}, and so this method must be called before the factory is used |
||||
* in order for data to be read from upstream in the case of a cache miss. |
||||
* |
||||
* @param upstreamDataSourceFactory The upstream {@link DataSource} for reading data not in the |
||||
* cache, or {@code null} to cause failure in the case of a cache miss. |
||||
* @return This factory. |
||||
*/ |
||||
public Factory setUpstreamDataSourceFactory( |
||||
@Nullable OkHttpDataSource.Factory upstreamDataSourceFactory) { |
||||
this.upstreamDataSourceFactory = upstreamDataSourceFactory; |
||||
return this; |
||||
} |
||||
|
||||
public Factory setUserAgent(String userAgent) { |
||||
if (this.upstreamDataSourceFactory != null) { |
||||
this.upstreamDataSourceFactory.setUserAgent(userAgent); |
||||
} |
||||
return this; |
||||
} |
||||
|
||||
/** |
||||
* Sets an optional {@link PriorityTaskManager} to use when requesting data from upstream. |
||||
* |
||||
* <p>If set, reads from the upstream {@link DataSource} will only be allowed to proceed if |
||||
* there are no higher priority tasks registered to the {@link PriorityTaskManager}. If there |
||||
* exists a higher priority task then {@link PriorityTaskManager.PriorityTooLowException} will |
||||
* be thrown instead. |
||||
* |
||||
* <p>Note that requests to {@link OkhttpCacheDataSource} instances are intended to be used as parts |
||||
* of (possibly larger) tasks that are registered with the {@link PriorityTaskManager}, and |
||||
* hence {@link OkhttpCacheDataSource} does <em>not</em> register a task by itself. This must be done |
||||
* by the surrounding code that uses the {@link OkhttpCacheDataSource} instances. |
||||
* |
||||
* <p>The default is {@code null}. |
||||
* |
||||
* @param upstreamPriorityTaskManager The upstream {@link PriorityTaskManager}. |
||||
* @return This factory. |
||||
*/ |
||||
public Factory setUpstreamPriorityTaskManager( |
||||
@Nullable PriorityTaskManager upstreamPriorityTaskManager) { |
||||
this.upstreamPriorityTaskManager = upstreamPriorityTaskManager; |
||||
return this; |
||||
} |
||||
|
||||
/** |
||||
* Returns the {@link PriorityTaskManager} that will bs used when requesting data from upstream, |
||||
* or {@code null} if there is none. |
||||
*/ |
||||
@Nullable |
||||
public PriorityTaskManager getUpstreamPriorityTaskManager() { |
||||
return upstreamPriorityTaskManager; |
||||
} |
||||
|
||||
/** |
||||
* Sets the priority to use when requesting data from upstream. The priority is only used if a |
||||
* {@link PriorityTaskManager} is set by calling {@link #setUpstreamPriorityTaskManager}. |
||||
* |
||||
* <p>The default is {@link C#PRIORITY_PLAYBACK}. |
||||
* |
||||
* @param upstreamPriority The priority to use when requesting data from upstream. |
||||
* @return This factory. |
||||
*/ |
||||
public Factory setUpstreamPriority(int upstreamPriority) { |
||||
this.upstreamPriority = upstreamPriority; |
||||
return this; |
||||
} |
||||
|
||||
/** |
||||
* Sets the {@link OkhttpCacheDataSource.Flags}. |
||||
* |
||||
* <p>The default is {@code 0}. |
||||
* |
||||
* @param flags The {@link OkhttpCacheDataSource.Flags}. |
||||
* @return This factory. |
||||
*/ |
||||
public Factory setFlags(@OkhttpCacheDataSource.Flags int flags) { |
||||
this.flags = flags; |
||||
return this; |
||||
} |
||||
|
||||
/** |
||||
* Sets the {link EventListener} to which events are delivered. |
||||
* |
||||
* <p>The default is {@code null}. |
||||
* |
||||
* @param eventListener The {@link EventListener}. |
||||
* @return This factory. |
||||
*/ |
||||
public Factory setEventListener(@Nullable EventListener eventListener) { |
||||
this.eventListener = eventListener; |
||||
return this; |
||||
} |
||||
|
||||
@Override |
||||
public OkhttpCacheDataSource createDataSource() { |
||||
return createDataSourceInternal( |
||||
upstreamDataSourceFactory != null ? upstreamDataSourceFactory.createDataSource() : null, |
||||
flags, |
||||
upstreamPriority); |
||||
} |
||||
|
||||
/** |
||||
* Returns an instance suitable for downloading content. The created instance is equivalent to |
||||
* one that would be created by {@link #createDataSource()}, except: |
||||
* |
||||
* <ul> |
||||
* <li>The {@link #FLAG_BLOCK_ON_CACHE} is always set. |
||||
* <li>The task priority is overridden to be {@link C#PRIORITY_DOWNLOAD}. |
||||
* </ul> |
||||
* |
||||
* @return An instance suitable for downloading content. |
||||
*/ |
||||
public OkhttpCacheDataSource createDataSourceForDownloading() { |
||||
return createDataSourceInternal( |
||||
upstreamDataSourceFactory != null ? upstreamDataSourceFactory.createDataSource() : null, |
||||
flags | FLAG_BLOCK_ON_CACHE, |
||||
C.PRIORITY_DOWNLOAD); |
||||
} |
||||
|
||||
/** |
||||
* Returns an instance suitable for reading cached content as part of removing a download. The |
||||
* created instance is equivalent to one that would be created by {@link #createDataSource()}, |
||||
* except: |
||||
* |
||||
* <ul> |
||||
* <li>The upstream is overridden to be {@code null}, since when removing content we don't |
||||
* want to request anything that's not already cached. |
||||
* <li>The {@link #FLAG_BLOCK_ON_CACHE} is always set. |
||||
* <li>The task priority is overridden to be {@link C#PRIORITY_DOWNLOAD}. |
||||
* </ul> |
||||
* |
||||
* @return An instance suitable for reading cached content as part of removing a download. |
||||
*/ |
||||
public OkhttpCacheDataSource createDataSourceForRemovingDownload() { |
||||
return createDataSourceInternal( |
||||
/* upstreamDataSource= */ null, flags | FLAG_BLOCK_ON_CACHE, C.PRIORITY_DOWNLOAD); |
||||
} |
||||
|
||||
private OkhttpCacheDataSource createDataSourceInternal( |
||||
@Nullable DataSource upstreamDataSource, @Flags int flags, int upstreamPriority) { |
||||
Cache cache = checkNotNull(this.cache); |
||||
@Nullable DataSink cacheWriteDataSink; |
||||
if (cacheIsReadOnly || upstreamDataSource == null) { |
||||
cacheWriteDataSink = null; |
||||
} else if (cacheWriteDataSinkFactory != null) { |
||||
cacheWriteDataSink = cacheWriteDataSinkFactory.createDataSink(); |
||||
} else { |
||||
cacheWriteDataSink = new CacheDataSink.Factory().setCache(cache).createDataSink(); |
||||
} |
||||
return new OkhttpCacheDataSource( |
||||
cache, |
||||
upstreamDataSource, |
||||
cacheReadDataSourceFactory.createDataSource(), |
||||
cacheWriteDataSink, |
||||
cacheKeyFactory, |
||||
flags, |
||||
upstreamPriorityTaskManager, |
||||
upstreamPriority, |
||||
eventListener); |
||||
} |
||||
} |
||||
|
||||
/** |
||||
* Listener of {@link OkhttpCacheDataSource} events. |
||||
*/ |
||||
public interface EventListener { |
||||
|
||||
/** |
||||
* Called when bytes have been read from the cache. |
||||
* |
||||
* @param cacheSizeBytes Current cache size in bytes. |
||||
* @param cachedBytesRead Total bytes read from the cache since this method was last called. |
||||
*/ |
||||
void onCachedBytesRead(long cacheSizeBytes, long cachedBytesRead); |
||||
|
||||
/** |
||||
* Called when the current request ignores cache. |
||||
* |
||||
* @param reason Reason cache is bypassed. |
||||
*/ |
||||
void onCacheIgnored(@CacheIgnoredReason int reason); |
||||
} |
||||
|
||||
/** |
||||
* Flags controlling the OkhttpCacheDataSource's behavior. Possible flag values are {@link |
||||
* #FLAG_BLOCK_ON_CACHE}, {@link #FLAG_IGNORE_CACHE_ON_ERROR} and {@link |
||||
* #FLAG_IGNORE_CACHE_FOR_UNSET_LENGTH_REQUESTS}. |
||||
*/ |
||||
@Documented |
||||
@Retention(RetentionPolicy.SOURCE) |
||||
@IntDef( |
||||
flag = true, |
||||
value = { |
||||
FLAG_BLOCK_ON_CACHE, |
||||
FLAG_IGNORE_CACHE_ON_ERROR, |
||||
FLAG_IGNORE_CACHE_FOR_UNSET_LENGTH_REQUESTS |
||||
}) |
||||
public @interface Flags { |
||||
} |
||||
|
||||
/** |
||||
* A flag indicating whether we will block reads if the cache key is locked. If unset then data is |
||||
* read from upstream if the cache key is locked, regardless of whether the data is cached. |
||||
*/ |
||||
public static final int FLAG_BLOCK_ON_CACHE = 1; |
||||
|
||||
/** |
||||
* A flag indicating whether the cache is bypassed following any cache related error. If set then |
||||
* cache related exceptions may be thrown for one cycle of open, read and close calls. Subsequent |
||||
* cycles of these calls will then bypass the cache. |
||||
*/ |
||||
public static final int FLAG_IGNORE_CACHE_ON_ERROR = 1 << 1; // 2
|
||||
|
||||
/** |
||||
* A flag indicating that the cache should be bypassed for requests whose lengths are unset. This |
||||
* flag is provided for legacy reasons only. |
||||
*/ |
||||
public static final int FLAG_IGNORE_CACHE_FOR_UNSET_LENGTH_REQUESTS = 1 << 2; // 4
|
||||
|
||||
/** |
||||
* Reasons the cache may be ignored. One of {@link #CACHE_IGNORED_REASON_ERROR} or {@link |
||||
* #CACHE_IGNORED_REASON_UNSET_LENGTH}. |
||||
*/ |
||||
@Documented |
||||
@Retention(RetentionPolicy.SOURCE) |
||||
@IntDef({CACHE_IGNORED_REASON_ERROR, CACHE_IGNORED_REASON_UNSET_LENGTH}) |
||||
public @interface CacheIgnoredReason { |
||||
} |
||||
|
||||
/** |
||||
* Cache not ignored. |
||||
*/ |
||||
private static final int CACHE_NOT_IGNORED = -1; |
||||
|
||||
/** |
||||
* Cache ignored due to a cache related error. |
||||
*/ |
||||
public static final int CACHE_IGNORED_REASON_ERROR = 0; |
||||
|
||||
/** |
||||
* Cache ignored due to a request with an unset length. |
||||
*/ |
||||
public static final int CACHE_IGNORED_REASON_UNSET_LENGTH = 1; |
||||
|
||||
/** |
||||
* Minimum number of bytes to read before checking cache for availability. |
||||
*/ |
||||
private static final long MIN_READ_BEFORE_CHECKING_CACHE = 100 * 1024; |
||||
|
||||
private final Cache cache; |
||||
private final DataSource cacheReadDataSource; |
||||
@Nullable |
||||
private final DataSource cacheWriteDataSource; |
||||
private final DataSource upstreamDataSource; |
||||
private final CacheKeyFactory cacheKeyFactory; |
||||
@Nullable |
||||
private final EventListener eventListener; |
||||
|
||||
private final boolean blockOnCache; |
||||
private final boolean ignoreCacheOnError; |
||||
private final boolean ignoreCacheForUnsetLengthRequests; |
||||
|
||||
@Nullable |
||||
private Uri actualUri; |
||||
@Nullable |
||||
private DataSpec requestDataSpec; |
||||
@Nullable |
||||
private DataSpec currentDataSpec; |
||||
@Nullable |
||||
private DataSource currentDataSource; |
||||
private long currentDataSourceBytesRead; |
||||
private long readPosition; |
||||
private long bytesRemaining; |
||||
@Nullable |
||||
private CacheSpan currentHoleSpan; |
||||
private boolean seenCacheError; |
||||
private boolean currentRequestIgnoresCache; |
||||
private long totalCachedBytesRead; |
||||
private long checkCachePosition; |
||||
|
||||
/** |
||||
* Constructs an instance with default {@link DataSource} and {@link DataSink} instances for |
||||
* reading and writing the cache. |
||||
* |
||||
* @param cache The cache. |
||||
* @param upstreamDataSource A {@link DataSource} for reading data not in the cache. If null, |
||||
* reading will fail if a cache miss occurs. |
||||
*/ |
||||
public OkhttpCacheDataSource(Cache cache, @Nullable DataSource upstreamDataSource) { |
||||
this(cache, upstreamDataSource, /* flags= */ 0); |
||||
} |
||||
|
||||
/** |
||||
* Constructs an instance with default {@link DataSource} and {@link DataSink} instances for |
||||
* reading and writing the cache. |
||||
* |
||||
* @param cache The cache. |
||||
* @param upstreamDataSource A {@link DataSource} for reading data not in the cache. If null, |
||||
* reading will fail if a cache miss occurs. |
||||
* @param flags A combination of {@link #FLAG_BLOCK_ON_CACHE}, {@link #FLAG_IGNORE_CACHE_ON_ERROR} |
||||
* and {@link #FLAG_IGNORE_CACHE_FOR_UNSET_LENGTH_REQUESTS}, or 0. |
||||
*/ |
||||
public OkhttpCacheDataSource(Cache cache, @Nullable DataSource upstreamDataSource, @Flags int flags) { |
||||
this( |
||||
cache, |
||||
upstreamDataSource, |
||||
new FileDataSource(), |
||||
new CacheDataSink(cache, CacheDataSink.DEFAULT_FRAGMENT_SIZE), |
||||
flags, |
||||
/* eventListener= */ null); |
||||
} |
||||
|
||||
/** |
||||
* Constructs an instance with arbitrary {@link DataSource} and {@link DataSink} instances for |
||||
* reading and writing the cache. One use of this constructor is to allow data to be transformed |
||||
* before it is written to disk. |
||||
* |
||||
* @param cache The cache. |
||||
* @param upstreamDataSource A {@link DataSource} for reading data not in the cache. If null, |
||||
* reading will fail if a cache miss occurs. |
||||
* @param cacheReadDataSource A {@link DataSource} for reading data from the cache. |
||||
* @param cacheWriteDataSink A {@link DataSink} for writing data to the cache. If null, cache is |
||||
* accessed read-only. |
||||
* @param flags A combination of {@link #FLAG_BLOCK_ON_CACHE}, {@link #FLAG_IGNORE_CACHE_ON_ERROR} |
||||
* and {@link #FLAG_IGNORE_CACHE_FOR_UNSET_LENGTH_REQUESTS}, or 0. |
||||
* @param eventListener An optional {@link EventListener} to receive events. |
||||
*/ |
||||
public OkhttpCacheDataSource( |
||||
Cache cache, |
||||
@Nullable DataSource upstreamDataSource, |
||||
DataSource cacheReadDataSource, |
||||
@Nullable DataSink cacheWriteDataSink, |
||||
@Flags int flags, |
||||
@Nullable EventListener eventListener) { |
||||
this( |
||||
cache, |
||||
upstreamDataSource, |
||||
cacheReadDataSource, |
||||
cacheWriteDataSink, |
||||
flags, |
||||
eventListener, |
||||
/* cacheKeyFactory= */ null); |
||||
} |
||||
|
||||
/** |
||||
* Constructs an instance with arbitrary {@link DataSource} and {@link DataSink} instances for |
||||
* reading and writing the cache. One use of this constructor is to allow data to be transformed |
||||
* before it is written to disk. |
||||
* |
||||
* @param cache The cache. |
||||
* @param upstreamDataSource A {@link DataSource} for reading data not in the cache. If null, |
||||
* reading will fail if a cache miss occurs. |
||||
* @param cacheReadDataSource A {@link DataSource} for reading data from the cache. |
||||
* @param cacheWriteDataSink A {@link DataSink} for writing data to the cache. If null, cache is |
||||
* accessed read-only. |
||||
* @param flags A combination of {@link #FLAG_BLOCK_ON_CACHE}, {@link #FLAG_IGNORE_CACHE_ON_ERROR} |
||||
* and {@link #FLAG_IGNORE_CACHE_FOR_UNSET_LENGTH_REQUESTS}, or 0. |
||||
* @param eventListener An optional {@link EventListener} to receive events. |
||||
* @param cacheKeyFactory An optional factory for cache keys. |
||||
*/ |
||||
public OkhttpCacheDataSource( |
||||
Cache cache, |
||||
@Nullable DataSource upstreamDataSource, |
||||
DataSource cacheReadDataSource, |
||||
@Nullable DataSink cacheWriteDataSink, |
||||
@Flags int flags, |
||||
@Nullable EventListener eventListener, |
||||
@Nullable CacheKeyFactory cacheKeyFactory) { |
||||
this( |
||||
cache, |
||||
upstreamDataSource, |
||||
cacheReadDataSource, |
||||
cacheWriteDataSink, |
||||
cacheKeyFactory, |
||||
flags, |
||||
/* upstreamPriorityTaskManager= */ null, |
||||
/* upstreamPriority= */ C.PRIORITY_PLAYBACK, |
||||
eventListener); |
||||
} |
||||
|
||||
private OkhttpCacheDataSource( |
||||
Cache cache, |
||||
@Nullable DataSource upstreamDataSource, |
||||
DataSource cacheReadDataSource, |
||||
@Nullable DataSink cacheWriteDataSink, |
||||
@Nullable CacheKeyFactory cacheKeyFactory, |
||||
@Flags int flags, |
||||
@Nullable PriorityTaskManager upstreamPriorityTaskManager, |
||||
int upstreamPriority, |
||||
@Nullable EventListener eventListener) { |
||||
this.cache = cache; |
||||
this.cacheReadDataSource = cacheReadDataSource; |
||||
this.cacheKeyFactory = cacheKeyFactory != null ? cacheKeyFactory : CacheKeyFactory.DEFAULT; |
||||
this.blockOnCache = (flags & FLAG_BLOCK_ON_CACHE) != 0; |
||||
this.ignoreCacheOnError = (flags & FLAG_IGNORE_CACHE_ON_ERROR) != 0; |
||||
this.ignoreCacheForUnsetLengthRequests = |
||||
(flags & FLAG_IGNORE_CACHE_FOR_UNSET_LENGTH_REQUESTS) != 0; |
||||
if (upstreamDataSource != null) { |
||||
if (upstreamPriorityTaskManager != null) { |
||||
upstreamDataSource = |
||||
new PriorityDataSource( |
||||
upstreamDataSource, upstreamPriorityTaskManager, upstreamPriority); |
||||
} |
||||
this.upstreamDataSource = upstreamDataSource; |
||||
this.cacheWriteDataSource = |
||||
cacheWriteDataSink != null |
||||
? new TeeDataSource(upstreamDataSource, cacheWriteDataSink) |
||||
: null; |
||||
} else { |
||||
this.upstreamDataSource = DummyDataSource.INSTANCE; |
||||
this.cacheWriteDataSource = null; |
||||
} |
||||
this.eventListener = eventListener; |
||||
} |
||||
|
||||
/** |
||||
* Returns the {@link Cache} used by this instance. |
||||
*/ |
||||
public Cache getCache() { |
||||
return cache; |
||||
} |
||||
|
||||
/** |
||||
* Returns the {@link CacheKeyFactory} used by this instance. |
||||
*/ |
||||
public CacheKeyFactory getCacheKeyFactory() { |
||||
return cacheKeyFactory; |
||||
} |
||||
|
||||
@Override |
||||
public void addTransferListener(TransferListener transferListener) { |
||||
checkNotNull(transferListener); |
||||
cacheReadDataSource.addTransferListener(transferListener); |
||||
upstreamDataSource.addTransferListener(transferListener); |
||||
} |
||||
|
||||
@Override |
||||
public long open(DataSpec dataSpec) throws IOException { |
||||
try { |
||||
String key = cacheKeyFactory.buildCacheKey(dataSpec); |
||||
DataSpec requestDataSpec = dataSpec.buildUpon().setKey(key).build(); |
||||
this.requestDataSpec = requestDataSpec; |
||||
actualUri = getRedirectedUriOrDefault(cache, key, /* defaultUri= */ requestDataSpec.uri); |
||||
readPosition = dataSpec.position; |
||||
|
||||
int reason = shouldIgnoreCacheForRequest(dataSpec); |
||||
currentRequestIgnoresCache = reason != CACHE_NOT_IGNORED; |
||||
if (currentRequestIgnoresCache) { |
||||
notifyCacheIgnored(reason); |
||||
} |
||||
|
||||
if (currentRequestIgnoresCache) { |
||||
bytesRemaining = C.LENGTH_UNSET; |
||||
} else { |
||||
bytesRemaining = ContentMetadata.getContentLength(cache.getContentMetadata(key)); |
||||
if (bytesRemaining != C.LENGTH_UNSET) { |
||||
bytesRemaining -= dataSpec.position; |
||||
if (bytesRemaining < 0) { |
||||
throw new DataSourceException( |
||||
PlaybackException.ERROR_CODE_IO_READ_POSITION_OUT_OF_RANGE); |
||||
} |
||||
} |
||||
} |
||||
if (dataSpec.length != C.LENGTH_UNSET) { |
||||
bytesRemaining = |
||||
bytesRemaining == C.LENGTH_UNSET |
||||
? dataSpec.length |
||||
: min(bytesRemaining, dataSpec.length); |
||||
} |
||||
if (bytesRemaining > 0 || bytesRemaining == C.LENGTH_UNSET) { |
||||
openNextSource(requestDataSpec, false); |
||||
} |
||||
return dataSpec.length != C.LENGTH_UNSET ? dataSpec.length : bytesRemaining; |
||||
} catch (Throwable e) { |
||||
handleBeforeThrow(e); |
||||
throw e; |
||||
} |
||||
} |
||||
|
||||
@Override |
||||
public int read(byte[] buffer, int offset, int length) throws IOException { |
||||
DataSpec requestDataSpec = checkNotNull(this.requestDataSpec); |
||||
DataSpec currentDataSpec = checkNotNull(this.currentDataSpec); |
||||
if (length == 0) { |
||||
return 0; |
||||
} |
||||
if (bytesRemaining == 0) { |
||||
return C.RESULT_END_OF_INPUT; |
||||
} |
||||
try { |
||||
if (readPosition >= checkCachePosition) { |
||||
openNextSource(requestDataSpec, true); |
||||
} |
||||
int bytesRead = checkNotNull(currentDataSource).read(buffer, offset, length); |
||||
if (bytesRead != C.RESULT_END_OF_INPUT) { |
||||
if (isReadingFromCache()) { |
||||
totalCachedBytesRead += bytesRead; |
||||
} |
||||
readPosition += bytesRead; |
||||
currentDataSourceBytesRead += bytesRead; |
||||
if (bytesRemaining != C.LENGTH_UNSET) { |
||||
bytesRemaining -= bytesRead; |
||||
} |
||||
} else if (isReadingFromUpstream() |
||||
&& (currentDataSpec.length == C.LENGTH_UNSET |
||||
|| currentDataSourceBytesRead < currentDataSpec.length)) { |
||||
// We've encountered RESULT_END_OF_INPUT from the upstream DataSource at a position not
|
||||
// imposed by the current DataSpec. This must mean that we've reached the end of the
|
||||
// resource.
|
||||
setNoBytesRemainingAndMaybeStoreLength(castNonNull(requestDataSpec.key)); |
||||
} else if (bytesRemaining > 0 || bytesRemaining == C.LENGTH_UNSET) { |
||||
closeCurrentSource(); |
||||
openNextSource(requestDataSpec, false); |
||||
return read(buffer, offset, length); |
||||
} |
||||
return bytesRead; |
||||
} catch (Throwable e) { |
||||
handleBeforeThrow(e); |
||||
throw e; |
||||
} |
||||
} |
||||
|
||||
@Override |
||||
@Nullable |
||||
public Uri getUri() { |
||||
return actualUri; |
||||
} |
||||
|
||||
@Override |
||||
public Map<String, List<String>> getResponseHeaders() { |
||||
// TODO: Implement.
|
||||
return isReadingFromUpstream() |
||||
? upstreamDataSource.getResponseHeaders() |
||||
: Collections.emptyMap(); |
||||
} |
||||
|
||||
@Override |
||||
public void close() throws IOException { |
||||
requestDataSpec = null; |
||||
actualUri = null; |
||||
readPosition = 0; |
||||
notifyBytesRead(); |
||||
try { |
||||
closeCurrentSource(); |
||||
} catch (Throwable e) { |
||||
handleBeforeThrow(e); |
||||
throw e; |
||||
} |
||||
} |
||||
|
||||
/** |
||||
* Opens the next source. If the cache contains data spanning the current read position then |
||||
* {@link #cacheReadDataSource} is opened to read from it. Else {@link #upstreamDataSource} is |
||||
* opened to read from the upstream source and write into the cache. |
||||
* |
||||
* <p>There must not be a currently open source when this method is called, except in the case |
||||
* that {@code checkCache} is true. If {@code checkCache} is true then there must be a currently |
||||
* open source, and it must be {@link #upstreamDataSource}. It will be closed and a new source |
||||
* opened if it's possible to switch to reading from or writing to the cache. If a switch isn't |
||||
* possible then the current source is left unchanged. |
||||
* |
||||
* @param requestDataSpec The original {@link DataSpec} to build upon for the next source. |
||||
* @param checkCache If true tries to switch to reading from or writing to cache instead of |
||||
* reading from {@link #upstreamDataSource}, which is the currently open source. |
||||
*/ |
||||
private void openNextSource(DataSpec requestDataSpec, boolean checkCache) throws IOException { |
||||
@Nullable CacheSpan nextSpan; |
||||
String key = castNonNull(requestDataSpec.key); |
||||
if (currentRequestIgnoresCache) { |
||||
nextSpan = null; |
||||
} else if (blockOnCache) { |
||||
try { |
||||
nextSpan = cache.startReadWrite(key, readPosition, bytesRemaining); |
||||
} catch (InterruptedException e) { |
||||
Thread.currentThread().interrupt(); |
||||
throw new InterruptedIOException(); |
||||
} |
||||
} else { |
||||
nextSpan = cache.startReadWriteNonBlocking(key, readPosition, bytesRemaining); |
||||
} |
||||
|
||||
DataSpec nextDataSpec; |
||||
DataSource nextDataSource; |
||||
if (nextSpan == null) { |
||||
// The data is locked in the cache, or we're ignoring the cache. Bypass the cache and read
|
||||
// from upstream.
|
||||
nextDataSource = upstreamDataSource; |
||||
nextDataSpec = |
||||
requestDataSpec.buildUpon().setPosition(readPosition).setLength(bytesRemaining).build(); |
||||
} else if (nextSpan.isCached) { |
||||
// Data is cached in a span file starting at nextSpan.position.
|
||||
Uri fileUri = Uri.fromFile(castNonNull(nextSpan.file)); |
||||
long filePositionOffset = nextSpan.position; |
||||
long positionInFile = readPosition - filePositionOffset; |
||||
long length = nextSpan.length - positionInFile; |
||||
if (bytesRemaining != C.LENGTH_UNSET) { |
||||
length = min(length, bytesRemaining); |
||||
} |
||||
nextDataSpec = |
||||
requestDataSpec |
||||
.buildUpon() |
||||
.setUri(fileUri) |
||||
.setUriPositionOffset(filePositionOffset) |
||||
.setPosition(positionInFile) |
||||
.setLength(length) |
||||
.build(); |
||||
nextDataSource = cacheReadDataSource; |
||||
} else { |
||||
// Data is not cached, and data is not locked, read from upstream with cache backing.
|
||||
long length; |
||||
if (nextSpan.isOpenEnded()) { |
||||
length = bytesRemaining; |
||||
} else { |
||||
length = nextSpan.length; |
||||
if (bytesRemaining != C.LENGTH_UNSET) { |
||||
length = min(length, bytesRemaining); |
||||
} |
||||
} |
||||
nextDataSpec = |
||||
requestDataSpec.buildUpon().setPosition(readPosition).setLength(length).build(); |
||||
if (cacheWriteDataSource != null) { |
||||
nextDataSource = cacheWriteDataSource; |
||||
} else { |
||||
nextDataSource = upstreamDataSource; |
||||
cache.releaseHoleSpan(nextSpan); |
||||
nextSpan = null; |
||||
} |
||||
} |
||||
|
||||
checkCachePosition = |
||||
!currentRequestIgnoresCache && nextDataSource == upstreamDataSource |
||||
? readPosition + MIN_READ_BEFORE_CHECKING_CACHE |
||||
: Long.MAX_VALUE; |
||||
if (checkCache) { |
||||
Assertions.checkState(isBypassingCache()); |
||||
if (nextDataSource == upstreamDataSource) { |
||||
// Continue reading from upstream.
|
||||
return; |
||||
} |
||||
// We're switching to reading from or writing to the cache.
|
||||
try { |
||||
closeCurrentSource(); |
||||
} catch (Throwable e) { |
||||
if (castNonNull(nextSpan).isHoleSpan()) { |
||||
// Release the hole span before throwing, else we'll hold it forever.
|
||||
cache.releaseHoleSpan(nextSpan); |
||||
} |
||||
throw e; |
||||
} |
||||
} |
||||
|
||||
if (nextSpan != null && nextSpan.isHoleSpan()) { |
||||
currentHoleSpan = nextSpan; |
||||
} |
||||
currentDataSource = nextDataSource; |
||||
currentDataSpec = nextDataSpec; |
||||
currentDataSourceBytesRead = 0; |
||||
long resolvedLength = nextDataSource.open(nextDataSpec); |
||||
|
||||
// Update bytesRemaining, actualUri and (if writing to cache) the cache metadata.
|
||||
ContentMetadataMutations mutations = new ContentMetadataMutations(); |
||||
if (nextDataSpec.length == C.LENGTH_UNSET && resolvedLength != C.LENGTH_UNSET) { |
||||
bytesRemaining = resolvedLength; |
||||
ContentMetadataMutations.setContentLength(mutations, readPosition + bytesRemaining); |
||||
} |
||||
if (isReadingFromUpstream()) { |
||||
actualUri = nextDataSource.getUri(); |
||||
boolean isRedirected = !requestDataSpec.uri.equals(actualUri); |
||||
ContentMetadataMutations.setRedirectedUri(mutations, isRedirected ? actualUri : null); |
||||
} |
||||
if (isWritingToCache()) { |
||||
cache.applyContentMetadataMutations(key, mutations); |
||||
} |
||||
} |
||||
|
||||
private void setNoBytesRemainingAndMaybeStoreLength(String key) throws IOException { |
||||
bytesRemaining = 0; |
||||
if (isWritingToCache()) { |
||||
ContentMetadataMutations mutations = new ContentMetadataMutations(); |
||||
ContentMetadataMutations.setContentLength(mutations, readPosition); |
||||
cache.applyContentMetadataMutations(key, mutations); |
||||
} |
||||
} |
||||
|
||||
private static Uri getRedirectedUriOrDefault(Cache cache, String key, Uri defaultUri) { |
||||
@Nullable Uri redirectedUri = ContentMetadata.getRedirectedUri(cache.getContentMetadata(key)); |
||||
return redirectedUri != null ? redirectedUri : defaultUri; |
||||
} |
||||
|
||||
private boolean isReadingFromUpstream() { |
||||
return !isReadingFromCache(); |
||||
} |
||||
|
||||
private boolean isBypassingCache() { |
||||
return currentDataSource == upstreamDataSource; |
||||
} |
||||
|
||||
private boolean isReadingFromCache() { |
||||
return currentDataSource == cacheReadDataSource; |
||||
} |
||||
|
||||
private boolean isWritingToCache() { |
||||
return currentDataSource == cacheWriteDataSource; |
||||
} |
||||
|
||||
private void closeCurrentSource() throws IOException { |
||||
if (currentDataSource == null) { |
||||
return; |
||||
} |
||||
try { |
||||
currentDataSource.close(); |
||||
} finally { |
||||
currentDataSpec = null; |
||||
currentDataSource = null; |
||||
if (currentHoleSpan != null) { |
||||
cache.releaseHoleSpan(currentHoleSpan); |
||||
currentHoleSpan = null; |
||||
} |
||||
} |
||||
} |
||||
|
||||
private void handleBeforeThrow(Throwable exception) { |
||||
if (isReadingFromCache() || exception instanceof CacheException) { |
||||
seenCacheError = true; |
||||
} |
||||
} |
||||
|
||||
private int shouldIgnoreCacheForRequest(DataSpec dataSpec) { |
||||
if (ignoreCacheOnError && seenCacheError) { |
||||
return CACHE_IGNORED_REASON_ERROR; |
||||
} else if (ignoreCacheForUnsetLengthRequests && dataSpec.length == C.LENGTH_UNSET) { |
||||
return CACHE_IGNORED_REASON_UNSET_LENGTH; |
||||
} else { |
||||
return CACHE_NOT_IGNORED; |
||||
} |
||||
} |
||||
|
||||
private void notifyCacheIgnored(@CacheIgnoredReason int reason) { |
||||
if (eventListener != null) { |
||||
eventListener.onCacheIgnored(reason); |
||||
} |
||||
} |
||||
|
||||
private void notifyBytesRead() { |
||||
if (eventListener != null && totalCachedBytesRead > 0) { |
||||
eventListener.onCachedBytesRead(cache.getCacheSpace(), totalCachedBytesRead); |
||||
totalCachedBytesRead = 0; |
||||
} |
||||
} |
||||
} |
||||
Loading…
Reference in new issue