Introduce op version into TFLite

PiperOrigin-RevId: 196448769

1 files changed, 95 insertions, 0 deletions

diff --git a/tensorflow/contrib/lite/op_resolver.h b/tensorflow/contrib/lite/op_resolver.h
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+++ b/tensorflow/contrib/lite/op_resolver.h
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+/* 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_CONTRIB_LITE_OP_RESOLVER_H_
+#define TENSORFLOW_CONTRIB_LITE_OP_RESOLVER_H_
+
+#include <unordered_map>
+#include "tensorflow/contrib/lite/context.h"
+#include "tensorflow/contrib/lite/schema/schema_generated.h"
+
+namespace tflite {
+
+// Abstract interface that returns TfLiteRegistrations given op codes or custom
+// op names. This is the mechanism that ops being referenced in the flatbuffer
+// model are mapped to executable function pointers (TfLiteRegistrations).
+class OpResolver {
+ public:
+  // Finds the op registration for a builtin operator by enum code.
+  virtual TfLiteRegistration* FindOp(tflite::BuiltinOperator op,
+                                     int version) const = 0;
+  // Finds the op registration of a custom operator by op name.
+  virtual TfLiteRegistration* FindOp(const char* op, int version) const = 0;
+  virtual ~OpResolver() {}
+};
+
+// Some versions of gcc doesn't support partial specialization in class scope,
+// so these are defined in a namescope.
+namespace op_resolver_hasher {
+template <typename V>
+struct ValueHasher {
+  size_t operator()(const V& v) const { return std::hash<V>()(v); }
+};
+
+template <>
+struct ValueHasher<tflite::BuiltinOperator> {
+  size_t operator()(const tflite::BuiltinOperator& v) const {
+    return std::hash<int>()(static_cast<int>(v));
+  }
+};
+
+template <typename T>
+struct OperatorKeyHasher {
+  size_t operator()(const T& x) const {
+    size_t a = ValueHasher<typename T::first_type>()(x.first);
+    size_t b = ValueHasher<typename T::second_type>()(x.second);
+    // Hash combinator used by TensorFlow core.
+    return a ^ (b + 0x9e3779b97f4a7800ULL + (a << 10) + (a >> 4));
+  }
+};
+}  // namespace op_resolver_hasher
+
+// An OpResolver that is mutable, also used as the op in gen_op_registration.
+// A typical usage:
+//   MutableOpResolver resolver;
+//   resolver.AddBuiltin(BuiltinOperator_ADD, Register_ADD());
+//   resolver.AddCustom("CustomOp", Register_CUSTOM_OP());
+//   InterpreterBuilder(model, resolver)(&interpreter);
+class MutableOpResolver : public OpResolver {
+ public:
+  ~MutableOpResolver() override;
+
+  TfLiteRegistration* FindOp(tflite::BuiltinOperator op,
+                             int version) const override;
+  TfLiteRegistration* FindOp(const char* op, int version) const override;
+  void AddBuiltin(tflite::BuiltinOperator op, TfLiteRegistration* registration,
+                  int min_version = 1, int max_version = 1);
+  void AddCustom(const char* name, TfLiteRegistration* registration,
+                 int min_version = 1, int max_version = 1);
+
+ private:
+  typedef std::pair<tflite::BuiltinOperator, int> BuiltinOperatorKey;
+  typedef std::pair<std::string, int> CustomOperatorKey;
+
+  std::unordered_map<BuiltinOperatorKey, TfLiteRegistration*,
+                     op_resolver_hasher::OperatorKeyHasher<BuiltinOperatorKey> >
+      builtins_;
+  std::unordered_map<CustomOperatorKey, TfLiteRegistration*,
+                     op_resolver_hasher::OperatorKeyHasher<CustomOperatorKey> >
+      custom_ops_;
+};
+
+}  // namespace tflite
+
+#endif  // TENSORFLOW_CONTRIB_LITE_OP_RESOLVER_H_