TensorFlow: minor change functions in Env interface.

Switches to return a std::unique_ptr<> to convey transfer of ownership.
Keeps existing functions temporarily for backwards compatibility.

Change file_system.h interface to switch entirely to the new interface,
change all callers. If this breaks someone in the public, the interface
change should be straightforward.
Change: 125127028

1 files changed, 12 insertions, 13 deletions

diff --git a/tensorflow/core/util/memmapped_file_system.cc b/tensorflow/core/util/memmapped_file_system.cc
index a276421226..6d02595b8a 100644
--- a/tensorflow/core/util/memmapped_file_system.cc
+++ b/tensorflow/core/util/memmapped_file_system.cc
@@ -87,8 +87,8 @@ bool MemmappedFileSystem::FileExists(const string& fname) {
   return dir_element != directory_.end();
 }
 
-Status MemmappedFileSystem::NewRandomAccessFile(const string& filename,
-                                                RandomAccessFile** result) {
+Status MemmappedFileSystem::NewRandomAccessFile(
+    const string& filename, std::unique_ptr<RandomAccessFile>* result) {
   if (!mapped_memory_) {
     return errors::FailedPrecondition("MemmappedEnv is not initialized");
   }
@@ -96,14 +96,14 @@ Status MemmappedFileSystem::NewRandomAccessFile(const string& filename,
   if (dir_element == directory_.end()) {
     return errors::NotFound("Region ", filename, " is not found");
   }
-  *result = new RandomAccessFileFromMemmapped(
+  result->reset(new RandomAccessFileFromMemmapped(
       GetMemoryWithOffset(dir_element->second.offset),
-      dir_element->second.length);
+      dir_element->second.length));
   return Status::OK();
 }
 
 Status MemmappedFileSystem::NewReadOnlyMemoryRegionFromFile(
-    const string& filename, ReadOnlyMemoryRegion** result) {
+    const string& filename, std::unique_ptr<ReadOnlyMemoryRegion>* result) {
   if (!mapped_memory_) {
     return errors::FailedPrecondition("MemmappedEnv is not initialized");
   }
@@ -111,9 +111,9 @@ Status MemmappedFileSystem::NewReadOnlyMemoryRegionFromFile(
   if (dir_element == directory_.end()) {
     return errors::NotFound("Region ", filename, " is not found");
   }
-  *result = new ReadOnlyMemoryRegionFromMemmapped(
+  result->reset(new ReadOnlyMemoryRegionFromMemmapped(
       GetMemoryWithOffset(dir_element->second.offset),
-      dir_element->second.length);
+      dir_element->second.length));
   return Status::OK();
 }
 
@@ -130,12 +130,12 @@ Status MemmappedFileSystem::GetFileSize(const string& filename, uint64* size) {
 }
 
 Status MemmappedFileSystem::NewWritableFile(const string& filename,
-                                            WritableFile** wf) {
+                                            std::unique_ptr<WritableFile>* wf) {
   return errors::Unimplemented("memmapped format doesn't support writing");
 }
 
-Status MemmappedFileSystem::NewAppendableFile(const string& filename,
-                                              WritableFile** result) {
+Status MemmappedFileSystem::NewAppendableFile(
+    const string& filename, std::unique_ptr<WritableFile>* result) {
   return errors::Unimplemented("memmapped format doesn't support writing");
 }
 
@@ -170,9 +170,8 @@ constexpr char MemmappedFileSystem::kMemmappedPackageDefaultGraphDef[];
 
 Status MemmappedFileSystem::InitializeFromFile(Env* env,
                                                const string& filename) {
-  ReadOnlyMemoryRegion* region;
-  TF_RETURN_IF_ERROR(env->NewReadOnlyMemoryRegionFromFile(filename, &region));
-  mapped_memory_.reset(region);
+  TF_RETURN_IF_ERROR(
+      env->NewReadOnlyMemoryRegionFromFile(filename, &mapped_memory_));
   directory_.clear();
   if (mapped_memory_->length() <= sizeof(uint64)) {
     return errors::DataLoss("Corrupted memmapped model file: ", filename,