Adding FileSystem::Stat to the core filesystem API. Implemented versions of it for all subclasses except for GCS File System for now.

Change: 127282696

1 files changed, 25 insertions, 0 deletions

diff --git a/tensorflow/core/platform/file_system.h b/tensorflow/core/platform/file_system.h
index c080ad5ec3..f372b379f5 100644
--- a/tensorflow/core/platform/file_system.h
+++ b/tensorflow/core/platform/file_system.h
@@ -34,6 +34,16 @@ class RandomAccessFile;
 class ReadOnlyMemoryRegion;
 class WritableFile;
 
+struct FileStatistics {
+  // The length of the file or -1 if finding file length is not supported.
+  int64 length;
+  // The last modified time in nanoseconds.
+  int64 mtime_nsec;
+  // This field contains more than just the permissions bits.  More information
+  // can be found on the man page for stat(2).
+  mode_t mode;
+};
+
 /// A generic interface for accessing a file system.
 class FileSystem {
  public:
@@ -60,6 +70,8 @@ class FileSystem {
   virtual Status GetChildren(const string& dir,
                              std::vector<string>* result) = 0;
 
+  virtual Status Stat(const string& fname, FileStatistics* stat) = 0;
+
   virtual Status DeleteFile(const string& fname) = 0;
 
   virtual Status CreateDir(const string& dirname) = 0;
@@ -73,6 +85,15 @@ class FileSystem {
   // Translate an URI to a filename usable by the FileSystem implementation. The
   // implementation in this class returns the name as-is.
   virtual string TranslateName(const string& name) const;
+
+  // Returns whether the given path is a directory or not.
+  // Typical return codes (not guaranteed exhaustive):
+  //  * OK - The path exists and is a directory.
+  //  * FAILED_PRECONDITION - The path exists and is not a directory.
+  //  * NOT_FOUND - The path entry does not exist.
+  //  * PERMISSION_DENIED - Insufficient permissions.
+  //  * UNIMPLEMENTED - The file factory doesn't support directories.
+  virtual Status IsDirectory(const string& fname);
 };
 
 // Degenerate file system that provides no implementations.
@@ -129,6 +150,10 @@ class NullFileSystem : public FileSystem {
   Status RenameFile(const string& src, const string& target) override {
     return errors::Unimplemented("RenameFile unimplemented");
   }
+
+  Status Stat(const string& fname, FileStatistics* stat) override {
+    return errors::Unimplemented("Stat unimplemented");
+  }
 };
 
 /// A file abstraction for randomly reading the contents of a file.