Skip evaluation of TensorFlow model if inputs are empty

PhysicsTools/TensorFlow/interface/TensorFlow.h

@@ -106,6 +106,8 @@ namespace tensorflow {
   // version of the function above that accepts a const session
   bool closeSession(const Session*& session);
 
+  bool checkEmptyInputs(const NamedTensorList& inputs);
+
   // run the session with inputs and outputNames, store output tensors, and control the underlying
   // thread pool using threadPoolOptions
   // used for thread scheduling with custom thread pool options

PhysicsTools/TensorFlow/src/TensorFlow.cc

@@ -256,6 +256,19 @@ namespace tensorflow {
     return state;
   }
 
+  bool checkEmptyInputs(const NamedTensorList& inputs) {
+    // check for empty tensors in the inputs
+    bool isEmpty = false;
+    for (const auto& input : inputs) {
+      // Checking using the shape
+      if (input.second.shape().num_elements() == 0) {
+        isEmpty = true;
+        break;
+      }
+    }
+    return isEmpty;
+  }
+
   void run(Session* session,
            const NamedTensorList& inputs,
            const std::vector<std::string>& outputNames,
@@ -268,6 +281,10 @@ namespace tensorflow {
     // create empty run options
     RunOptions runOptions;
 
+    // Check if the inputs are empty
+    if (checkEmptyInputs(inputs))
+      return;
+
     // run and check the status
     Status status = session->Run(runOptions, inputs, outputNames, {}, outputs, nullptr, threadPoolOptions);
     if (!status.ok()) {

PhysicsTools/TensorFlow/test/BuildFile.xml

@@ -144,6 +144,13 @@
   <use name="PhysicsTools/TensorFlow"/>
 </bin>
 
+<bin name="testTFEmptyInputs" file="testRunner.cpp,testEmptyInputs.cc">
+  <use name="boost_filesystem"/>
+  <use name="cppunit"/>
+  <use name="PhysicsTools/TensorFlow"/>
+</bin>
+
+
 
 <iftool name="cuda">
   <bin name="testTFVisibleDevicesCUDA" file="testRunner.cpp,testVisibleDevicesCUDA.cc">

PhysicsTools/TensorFlow/test/testEmptyInputs.cc

@@ -0,0 +1,57 @@
+/*
+ * Tests for working with empty inputs
+ *
+ */
+
+#include <stdexcept>
+#include <cppunit/extensions/HelperMacros.h>
+
+#include "PhysicsTools/TensorFlow/interface/TensorFlow.h"
+
+#include "testBase.h"
+
+class testEmptyInputs : public testBase {
+  CPPUNIT_TEST_SUITE(testEmptyInputs);
+  CPPUNIT_TEST(test);
+  CPPUNIT_TEST_SUITE_END();
+
+public:
+  std::string pyScript() const override;
+  void test() override;
+};
+
+CPPUNIT_TEST_SUITE_REGISTRATION(testEmptyInputs);
+
+std::string testEmptyInputs::pyScript() const { return "createconstantgraph.py"; }
+
+void testEmptyInputs::test() {
+  std::string pbFile = dataPath_ + "/constantgraph.pb";
+
+  std::cout << "Testing CPU backend" << std::endl;
+  tensorflow::Backend backend = tensorflow::Backend::cpu;
+
+  // load the graph
+  tensorflow::Options options{backend};
+  tensorflow::GraphDef* graphDef = tensorflow::loadGraphDef(pbFile);
+  CPPUNIT_ASSERT(graphDef != nullptr);
+
+  // create a new session and add the graphDef
+  const tensorflow::Session* session = tensorflow::createSession(graphDef, options);
+  CPPUNIT_ASSERT(session != nullptr);
+
+  // example evaluation with empty tensor
+  tensorflow::Tensor input(tensorflow::DT_FLOAT, {1, 0});
+  tensorflow::Tensor scale(tensorflow::DT_FLOAT, {});
+  scale.scalar<float>()() = 1.0;
+  std::vector<tensorflow::Tensor> outputs;
+
+  // run using the convenience helper
+  outputs.clear();
+  tensorflow::run(session, {{"input", input}, {"scale", scale}}, {"output"}, &outputs);
+  CPPUNIT_ASSERT(outputs.size() == 0);
+
+  // cleanup
+  CPPUNIT_ASSERT(tensorflow::closeSession(session));
+  CPPUNIT_ASSERT(session == nullptr);
+  delete graphDef;
+}