Implement fast ParseExample.

Change: 131338565

1 files changed, 88 insertions, 0 deletions

diff --git a/tensorflow/core/util/example_proto_fast_parsing.h b/tensorflow/core/util/example_proto_fast_parsing.h
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+/* Copyright 2016 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 THIRD_PARTY_TENSORFLOW_CORE_UTIL_EXAMPLE_PROTO_FAST_PARSING_H_
+#define THIRD_PARTY_TENSORFLOW_CORE_UTIL_EXAMPLE_PROTO_FAST_PARSING_H_
+
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+#include "tensorflow/core/example/example.pb.h"
+#include "tensorflow/core/framework/allocator.h"
+#include "tensorflow/core/framework/graph.pb.h"
+#include "tensorflow/core/framework/op_kernel.h"
+#include "tensorflow/core/framework/tensor.h"
+#include "tensorflow/core/framework/types.h"
+#include "tensorflow/core/lib/gtl/array_slice.h"
+#include "tensorflow/core/platform/types.h"
+#include "tensorflow/core/util/sparse/sparse_tensor.h"
+
+namespace tensorflow {
+namespace example {
+
+// FastParseExampleConfig defines how to parse features in Example.
+// Each sub-config is responsible for one feature identified with feautre_name.
+// FastParseExampleConfig can't have two sub-configs with the same feature_name.
+// dtype identifies the type of output vector and the kind of Feature expected
+// in Example.
+struct FastParseExampleConfig {
+  struct Dense {
+    string feature_name;
+    DataType dtype;
+    // These 2 fields correspond exactly to dense_shapes and dense_defaults in
+    // ParseExample op.
+    // Documentation is avaliable in: tensorflow/core/ops/parsing_ops.cc
+    TensorShape shape;
+    Tensor default_value;
+  };
+
+  struct Sparse {
+    string feature_name;
+    DataType dtype;
+  };
+
+  std::vector<Dense> dense;
+  std::vector<Sparse> sparse;
+};
+
+// This is exactly the output of TF's ParseExample Op.
+// Documentation is avaliable in: tensorflow/core/ops/parsing_ops.cc
+struct Result {
+  std::vector<Tensor> sparse_indices;
+  std::vector<Tensor> sparse_values;
+  std::vector<Tensor> sparse_shapes;
+  std::vector<Tensor> dense_values;
+};
+
+// Parses a batch of serialized Example protos and converts them into result
+// according to given config.
+// Given example names have to either be empty or the same size as serialized.
+// example_names are used only for error messages.
+Status FastParseExample(const FastParseExampleConfig& config,
+                        gtl::ArraySlice<string> serialized,
+                        gtl::ArraySlice<string> example_names,
+                        thread::ThreadPool* thread_pool, Result* result);
+
+// This function parses serialized Example and populates given example.
+// It uses the same specialized parser as FastParseExample which is efficient.
+// But then constructs Example which is relatively slow.
+// It is exported here as a convenient API to test parser part separately.
+bool TestFastParse(const string& serialized, Example* example);
+
+}  // namespace example
+}  // namespace tensorflow
+
+#endif  // THIRD_PARTY_TENSORFLOW_CORE_UTIL_EXAMPLE_PROTO_FAST_PARSING_H_