浅谈Glide缓存key的问题

EngineKey key = keyFactory.buildKey(id, signature, width, height, loadProvider.getCacheDecoder(),
        loadProvider.getSourceDecoder(), transformation, loadProvider.getEncoder(),
        transcoder, loadProvider.getSourceEncoder());

    EngineJob engineJob = engineJobFactory.build(key, isMemoryCacheable);
    DecodeJob<T, Z, R> decodeJob = new DecodeJob<T, Z, R>(key, width, height, fetcher, loadProvider, transformation,
        transcoder, diskCacheProvider, diskCacheStrategy, priority);
    EngineRunnable runnable = new EngineRunnable(engineJob, decodeJob, priority);
    jobs.put(key, engineJob);
    engineJob.addCallback(cb);
    engineJob.start(runnable);

 resource = decode();
private Resource<?> decode() throws Exception {
    if (isDecodingFromCache()) {
      return decodeFromCache();
    } else {
      return decodeFromSource();
    }
  }

  private boolean isDecodingFromCache() {
    return stage == Stage.CACHE;
  }

 if (resource == null) {
      onLoadFailed(exception);
    } else {
      onLoadComplete(resource);
    }

private void onLoadFailed(Exception e) {
    if (isDecodingFromCache()) {
      stage = Stage.SOURCE;
      manager.submitForSource(this);
    } else {
      manager.onException(e);
    }
  }

 private Resource<T> decodeFromSourceData(A data) throws IOException {
    final Resource<T> decoded;
    if (diskCacheStrategy.cacheSource()) {
      decoded = cacheAndDecodeSourceData(data);
    } else {
      long startTime = LogTime.getLogTime();
      decoded = loadProvider.getSourceDecoder().decode(data, width, height);
      if (Log.isLoggable(TAG, Log.VERBOSE)) {
        logWithTimeAndKey("Decoded from source", startTime);
      }
    }