Method RenameObject

tensorflow/core/platform/cloud/gcs_file_system.cc:1621–1662

Uses a GCS API command to copy the object and then deletes the old one.

// Uses a GCS API command to copy the object and then deletes the old one.
Status GcsFileSystem::RenameObject(const string& src, const string& target) {
  string src_bucket, src_object, target_bucket, target_object;
  TF_RETURN_IF_ERROR(ParseGcsPath(src, false, &src_bucket, &src_object));
  TF_RETURN_IF_ERROR(
      ParseGcsPath(target, false, &target_bucket, &target_object));

  std::unique_ptr<HttpRequest> request;
  TF_RETURN_IF_ERROR(CreateHttpRequest(&request));
  request->SetUri(strings::StrCat(kGcsUriBase, "b/", src_bucket, "/o/",
                                  request->EscapeString(src_object),
                                  "/rewriteTo/b/", target_bucket, "/o/",
                                  request->EscapeString(target_object)));
  request->SetPostEmptyBody();
  request->SetTimeouts(timeouts_.connect, timeouts_.idle, timeouts_.metadata);
  std::vector<char> output_buffer;
  request->SetResultBuffer(&output_buffer);
  TF_RETURN_WITH_CONTEXT_IF_ERROR(request->Send(), " when renaming ", src,
                                  " to ", target);
  // Flush the target from the caches.  The source will be flushed in the
  // DeleteFile call below.
  ClearFileCaches(target);
  Json::Value root;
  TF_RETURN_IF_ERROR(ParseJson(output_buffer, &root));
  bool done;
  TF_RETURN_IF_ERROR(GetBoolValue(root, "done", &done));
  if (!done) {
    // If GCS didn't complete rewrite in one call, this means that a large file
    // is being copied to a bucket with a different storage class or location,
    // which requires multiple rewrite calls.
    // TODO(surkov): implement multi-step rewrites.
    return errors::Unimplemented(
        "Couldn't rename ", src, " to ", target,
        ": moving large files between buckets with different "
        "locations or storage classes is not supported.");
  }

  // In case the delete API call failed, but the deletion actually happened
  // on the server side, we can't just retry the whole RenameFile operation
  // because the source object is already gone.
  return RetryingUtils::DeleteWithRetries(
      [this, &src]() { return DeleteFile(src); }, retry_config_);
}

Status GcsFileSystem::IsDirectory(const string& fname) {
  string bucket, object;