Java 类com.google.android.exoplayer2.upstream.cache.Cache.CacheException 实例源码

private static CacheDataSource buildCacheDataSource(Context context, DataSource upstreamSource,
    boolean useAesEncryption) throws CacheException {
  File cacheDir = context.getExternalCacheDir();
  Cache cache = new SimpleCache(new File(cacheDir, EXO_CACHE_DIR), new NoOpCacheEvictor());
  emptyCache(cache);

  // Source and cipher
  final String secretKey = "testKey:12345678";
  DataSource file = new FileDataSource();
  DataSource cacheReadDataSource = useAesEncryption
      ? new AesCipherDataSource(Util.getUtf8Bytes(secretKey), file) : file;

  // Sink and cipher
  CacheDataSink cacheSink = new CacheDataSink(cache, EXO_CACHE_MAX_FILESIZE);
  byte[] scratch = new byte[3897];
  DataSink cacheWriteDataSink = useAesEncryption
      ? new AesCipherDataSink(Util.getUtf8Bytes(secretKey), cacheSink, scratch) : cacheSink;

  return new CacheDataSource(cache,
      upstreamSource,
      cacheReadDataSource,
      cacheWriteDataSink,
      CacheDataSource.FLAG_BLOCK_ON_CACHE,
      null); // eventListener
}

/** Stores the index data to index file if there is a change. */
public void store() throws CacheException {
  if (!changed) {
    return;
  }
  writeFile();
  changed = false;
}

/**
 * Copies the given span with an updated last access time. Passed span becomes invalid after this
 * call.
 *
 * @param cacheSpan Span to be copied and updated.
 * @return a span with the updated last access time.
 * @throws CacheException If renaming of the underlying span file failed.
 */
public SimpleCacheSpan touch(SimpleCacheSpan cacheSpan) throws CacheException {
  // Remove the old span from the in-memory representation.
  Assertions.checkState(cachedSpans.remove(cacheSpan));
  // Obtain a new span with updated last access timestamp.
  SimpleCacheSpan newCacheSpan = cacheSpan.copyWithUpdatedLastAccessTime(id);
  // Rename the cache file
  if (!cacheSpan.file.renameTo(newCacheSpan.file)) {
    throw new CacheException("Renaming of " + cacheSpan.file + " to " + newCacheSpan.file
        + " failed.");
  }
  // Add the updated span back into the in-memory representation.
  cachedSpans.add(newCacheSpan);
  return newCacheSpan;
}

private void evictCache(Cache cache, long requiredSpace) {
  while (currentSize + requiredSpace > maxBytes) {
    try {
      cache.removeSpan(leastRecentlyUsed.first());
    } catch (CacheException e) {
      // do nothing.
    }
  }
}

/** Stores the index data to index file if there is a change. */
public void store() throws CacheException {
  if (!changed) {
    return;
  }
  writeFile();
  changed = false;
}

/**
 * Copies the given span with an updated last access time. Passed span becomes invalid after this
 * call.
 *
 * @param cacheSpan Span to be copied and updated.
 * @return a span with the updated last access time.
 * @throws CacheException If renaming of the underlying span file failed.
 */
public SimpleCacheSpan touch(SimpleCacheSpan cacheSpan) throws CacheException {
  // Remove the old span from the in-memory representation.
  Assertions.checkState(cachedSpans.remove(cacheSpan));
  // Obtain a new span with updated last access timestamp.
  SimpleCacheSpan newCacheSpan = cacheSpan.copyWithUpdatedLastAccessTime(id);
  // Rename the cache file
  if (!cacheSpan.file.renameTo(newCacheSpan.file)) {
    throw new CacheException("Renaming of " + cacheSpan.file + " to " + newCacheSpan.file
        + " failed.");
  }
  // Add the updated span back into the in-memory representation.
  cachedSpans.add(newCacheSpan);
  return newCacheSpan;
}

private void evictCache(Cache cache, long requiredSpace) {
  while (currentSize + requiredSpace > maxBytes) {
    try {
      cache.removeSpan(leastRecentlyUsed.first());
    } catch (CacheException e) {
      // do nothing.
    }
  }
}

/** Stores the index data to index file if there is a change. */
public void store() throws CacheException {
  if (!changed) {
    return;
  }
  writeFile();
  changed = false;
}

/**
 * Copies the given span with an updated last access time. Passed span becomes invalid after this
 * call.
 *
 * @param cacheSpan Span to be copied and updated.
 * @return a span with the updated last access time.
 * @throws CacheException If renaming of the underlying span file failed.
 */
public SimpleCacheSpan touch(SimpleCacheSpan cacheSpan) throws CacheException {
  // Remove the old span from the in-memory representation.
  Assertions.checkState(cachedSpans.remove(cacheSpan));
  // Obtain a new span with updated last access timestamp.
  SimpleCacheSpan newCacheSpan = cacheSpan.copyWithUpdatedLastAccessTime(id);
  // Rename the cache file
  if (!cacheSpan.file.renameTo(newCacheSpan.file)) {
    throw new CacheException("Renaming of " + cacheSpan.file + " to " + newCacheSpan.file
        + " failed.");
  }
  // Add the updated span back into the in-memory representation.
  cachedSpans.add(newCacheSpan);
  return newCacheSpan;
}

private void evictCache(Cache cache, long requiredSpace) {
  while (currentSize + requiredSpace > maxBytes && !leastRecentlyUsed.isEmpty()) {
    try {
      cache.removeSpan(leastRecentlyUsed.first());
    } catch (CacheException e) {
      // do nothing.
    }
  }
}

@Test
public void testExceptionDuringEvictionByLeastRecentlyUsedCacheEvictorNotHang() throws Exception {
  CachedContentIndex index = Mockito.spy(new CachedContentIndex(cacheDir));
  SimpleCache simpleCache =
      new SimpleCache(cacheDir, new LeastRecentlyUsedCacheEvictor(20), index);

  // Add some content.
  CacheSpan cacheSpan = simpleCache.startReadWrite(KEY_1, 0);
  addCache(simpleCache, KEY_1, 0, 15);

  // Make index.store() throw exception from now on.
  doAnswer(new Answer<Object>() {
    @Override
    public Object answer(InvocationOnMock invocation) throws Throwable {
      throw new Cache.CacheException("SimpleCacheTest");
    }
  }).when(index).store();

  // Adding more content will make LeastRecentlyUsedCacheEvictor evict previous content.
  try {
    addCache(simpleCache, KEY_1, 15, 15);
    Assert.fail("Exception was expected");
  } catch (CacheException e) {
    // do nothing.
  }

  simpleCache.releaseHoleSpan(cacheSpan);

  // Although store() has failed, it should remove the first span and add the new one.
  NavigableSet<CacheSpan> cachedSpans = simpleCache.getCachedSpans(KEY_1);
  assertThat(cachedSpans).isNotNull();
  assertThat(cachedSpans).hasSize(1);
  assertThat(cachedSpans.pollFirst().position).isEqualTo(15);
}

private static void emptyCache(Cache cache) throws CacheException {
  for (String key : cache.getKeys()) {
    for (CacheSpan span : cache.getCachedSpans(key)) {
      cache.removeSpan(span);
    }
  }
  // Sanity check that the cache really is empty now.
  assertThat(cache.getKeys().isEmpty()).isTrue();
}

private void handleBeforeThrow(IOException exception) {
  if (currentDataSource == cacheReadDataSource || exception instanceof CacheException) {
    seenCacheError = true;
  }
}

private void handleBeforeThrow(IOException exception) {
  if (currentDataSource == cacheReadDataSource || exception instanceof CacheException) {
    seenCacheError = true;
  }
}

private void handleBeforeThrow(IOException exception) {
  if (currentDataSource == cacheReadDataSource || exception instanceof CacheException) {
    seenCacheError = true;
  }
}