Change HandleFromInput() to return a `const ResourceHandle&` and avoid copying that type.

This avoids unnecessary string copies and deallocations in the ReadVariableOp, and similar ops.

PiperOrigin-RevId: 212652588

2 files changed, 3 insertions, 3 deletions

diff --git a/tensorflow/core/framework/resource_mgr.cc b/tensorflow/core/framework/resource_mgr.cc
index 0a19861efd..ebdaaec153 100644
--- a/tensorflow/core/framework/resource_mgr.cc
+++ b/tensorflow/core/framework/resource_mgr.cc
@@ -271,7 +271,7 @@ string ContainerInfo::DebugString() const {
                          "]");
 }
 
-ResourceHandle HandleFromInput(OpKernelContext* ctx, int input) {
+const ResourceHandle& HandleFromInput(OpKernelContext* ctx, int input) {
   return ctx->input(input).flat<ResourceHandle>()(0);
 }
 
diff --git a/tensorflow/core/framework/resource_mgr.h b/tensorflow/core/framework/resource_mgr.h
index f8a587c9b5..f87dc1e39d 100644
--- a/tensorflow/core/framework/resource_mgr.h
+++ b/tensorflow/core/framework/resource_mgr.h
@@ -79,7 +79,7 @@ class ResourceBase : public core::RefCounted {
   virtual string DebugString() = 0;
 
   // Returns memory used by this resource.
-  virtual int64 MemoryUsed() const { return 0; };
+  virtual int64 MemoryUsed() const { return 0; }
 };
 
 // Container used for per-step resources.
@@ -234,7 +234,7 @@ ResourceHandle MakePerStepResourceHandle(OpKernelContext* ctx,
                                          const string& name);
 
 // Returns a resource handle from a numbered op input.
-ResourceHandle HandleFromInput(OpKernelContext* ctx, int input);
+const ResourceHandle& HandleFromInput(OpKernelContext* ctx, int input);
 Status HandleFromInput(OpKernelContext* ctx, StringPiece input,
                        ResourceHandle* handle);