Break FileSystem's dependency on ThreadPool.

PiperOrigin-RevId: 191092932

1 files changed, 51 insertions, 0 deletions

diff --git a/tensorflow/core/platform/file_system_helper.h b/tensorflow/core/platform/file_system_helper.h
new file mode 100644
index 0000000000..8d812b0e38
--- /dev/null
+++ b/tensorflow/core/platform/file_system_helper.h
@@ -0,0 +1,51 @@
+/* Copyright 2018 The TensorFlow Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+==============================================================================*/
+
+#ifndef TENSORFLOW_CORE_PLATFORM_FILE_SYSTEM_HELPER_H_
+#define TENSORFLOW_CORE_PLATFORM_FILE_SYSTEM_HELPER_H_
+
+#include <string>
+#include <vector>
+
+#include "tensorflow/core/lib/core/status.h"
+
+namespace tensorflow {
+
+class FileSystem;
+class Env;
+
+namespace internal {
+
+// Given a pattern, stores in 'results' the set of paths (in the given file
+// system) that match that pattern.
+//
+// This helper may be used by implementations of FileSystem::GetMatchingPaths()
+// in order to provide parallel scanning of subdirectories (except on iOS).
+//
+// Arguments:
+//   fs: may not be null and will be used to identify directories and list
+//       their contents.
+//   env: may not be null and will be used to check if a match has been found.
+//   pattern: see FileSystem::GetMatchingPaths() for details.
+//   results: will be cleared and may not be null.
+//
+// Returns an error status if any call to 'fs' failed.
+Status GetMatchingPaths(FileSystem* fs, Env* env, const string& pattern,
+                        std::vector<string>* results);
+
+}  // namespace internal
+}  // namespace tensorflow
+
+#endif  // TENSORFLOW_CORE_PLATFORM_FILE_SYSTEM_HELPER_H_