Add hash digest to tracker and check with filestore.

def ReceiveFileHash(self, responses):
    """Add hash digest to tracker and check with filestore."""
    index = responses.request_data["index"]
    if not responses.success:
      self.Log("Failed to hash file: %s", responses.status)
      self.state.pending_hashes.pop(index, None)
      # Report the error.
      self._FileFetchFailed(index, "HashFile")
      return

    self.state.files_hashed += 1
    response = responses.First()
    if response.HasField("hash"):
      hash_obj = response.hash
    else:
      # Deprecate this method of returning hashes.
      hash_obj = rdf_crypto.Hash()

      if len(response.results) < 1 or response.results[0]["name"] != "generic":
        self.Log("Failed to hash file: %s", self.state.indexed_pathspecs[index])
        self.state.pending_hashes.pop(index, None)
        return

      result = response.results[0]

      try:
        for hash_type in ["md5", "sha1", "sha256"]:
          value = result.GetItem(hash_type)
          setattr(hash_obj, hash_type, value)
      except AttributeError:
        self.Log("Failed to hash file: %s", self.state.indexed_pathspecs[index])
        self.state.pending_hashes.pop(index, None)
        return

    try:
      tracker = self.state.pending_hashes[index]
    except KeyError:
      # Hashing the file failed, but we did stat it.
      self._FileFetchFailed(index, responses.request.request.name)
      return

    tracker["hash_obj"] = hash_obj
    tracker["bytes_read"] = response.bytes_read

    self.state.files_hashed_since_check += 1
    if self.state.files_hashed_since_check >= self.MIN_CALL_TO_FILE_STORE:
      self._CheckHashesWithFileStore()