ImagePipeline.java 文件源码

/**
 * Submits a request for prefetching to the disk cache.
 *
 * <p> Beware that if your network fetcher doesn't support priorities prefetch requests may slow
 * down images which are immediately required on screen.
 *
 * @param imageRequest the request to submit
 * @param priority custom priority for the fetch
 * @return a DataSource that can safely be ignored.
 */
public DataSource<Void> prefetchToDiskCache(
    ImageRequest imageRequest,
    Object callerContext,
    Priority priority) {
  if (!mIsPrefetchEnabledSupplier.get()) {
    return DataSources.immediateFailedDataSource(PREFETCH_EXCEPTION);
  }
  try {
    Producer<Void> producerSequence =
        mProducerSequenceFactory.getEncodedImagePrefetchProducerSequence(imageRequest);
    return submitPrefetchRequest(
        producerSequence,
        imageRequest,
        ImageRequest.RequestLevel.FULL_FETCH,
        callerContext,
        priority);
  } catch (Exception exception) {
    return DataSources.immediateFailedDataSource(exception);
  }
}