tensorflow/core/grappler/optimizers/data/function_utils.cc

/* 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.
==============================================================================*/

#include "tensorflow/core/grappler/optimizers/data/function_utils.h"

#include "tensorflow/core/framework/device_base.h"
#include "tensorflow/core/framework/op_def.pb.h"
#include "tensorflow/core/util/ptr_util.h"

namespace tensorflow {
namespace grappler {
namespace function_utils {
namespace {

template <typename Predicate, typename Collection>
std::vector<int> GetElementIndicesWithPredicate(const Predicate& predicate,
                                                const Collection& collection) {
  std::vector<int> indices = {};
  unsigned idx = 0;
  for (auto&& element : collection) {
    if (predicate(element)) {
      indices.push_back(idx);
    }
    idx++;
  }
  return indices;
}

}  // namespace

FunctionDefTensorDesc::FunctionDefTensorDesc(const string& node_name,
                                             const string& output, int position)
    : node_name(node_name), node_output(output), position(position) {
  full_str = strings::StrCat(node_name, ":", node_output, ":", position);
}

FunctionDefTensorDesc::FunctionDefTensorDesc(const string& input) {
  // Parses node_name:node_output:position string into its components.
  full_str = input;
  StringPiece capture;
  StringPiece remaining;

  // Parse "node_name"
  if (strings::Scanner(input)
          .One(strings::Scanner::LETTER_DIGIT_DOT_UNDERSCORE)
          .Any(strings::Scanner::LETTER_DIGIT_DASH_DOT_SLASH_UNDERSCORE)
          .GetResult(&remaining, &capture)) {
    node_name = string(capture.data(), capture.size());
  }

  // Parse "node_output" if it exists
  if (strings::Scanner(remaining)
          .OneLiteral(":")
          .RestartCapture()
          .One(strings::Scanner::LETTER)
          .Any(strings::Scanner::LETTER_DIGIT_UNDERSCORE)
          .GetResult(&remaining, &capture)) {
    node_output = string(capture.data(), capture.size());
  }

  // Parse "position" if it exists
  if (strings::Scanner(remaining)
          .OneLiteral(":")
          .RestartCapture()
          .Many(strings::Scanner::DIGIT)
          .GetResult(nullptr, &capture)) {
    CHECK(strings::safe_strto32(capture, &position));
  }
}

// TODO(rachelim): Create a utility class similar to MutableGraphView for
// FunctionDefs, and use that to manipulate functions. It'll be more
// performant if we kept mappings of nodes->inputs/outputs, so that we don't
// have to search over all nodes each time.
// Note that we're not using GrapplerFunctionItem because it doesn't cover
// some of our desired uses (eg changing the outputs of a function), and the
// FunctionDef -> GraphDef conversion isn't really necessary in this case.
void ReplaceReferences(const string& from, const string& to,
                       FunctionDef* func) {
  for (NodeDef& n : *func->mutable_node_def()) {
    std::replace(n.mutable_input()->begin(), n.mutable_input()->end(), from,
                 to);
  }

  for (auto& p : *func->mutable_ret()) {
    if (p.second == from) {
      p.second = to;
    }
  }
}

void AddFunctionOutputWithUniqueName(StringPiece prefix,
                                     StringPiece output_tensor_name,
                                     FunctionDef* function, DataType dt) {
  string name = string(prefix);
  int id = function->signature().output_arg_size();
  while (ContainsFunctionOutputWithName(name, *function)) {
    name = strings::StrCat(prefix, "/_", id);
    ++id;
  }
  auto* output = function->mutable_signature()->mutable_output_arg()->Add();
  output->set_name(name);
  output->set_type(dt);

  (*function->mutable_ret())[name] = string(output_tensor_name);
}

NodeDef* AddNode(StringPiece name, StringPiece op,
                 const std::vector<string>& inputs,
                 const std::vector<std::pair<string, AttrValue>>& attributes,
                 FunctionDef* fd) {
  NodeDef* node = fd->add_node_def();
  if (!name.empty()) {
    node->set_name(string(name));
  } else {
    SetUniqueFunctionNodeName(op, fd, node);
  }
  node->set_op(string(op));
  for (const string& input : inputs) {
    node->add_input(input);
  }
  for (auto attr : attributes) {
    (*node->mutable_attr())[attr.first] = attr.second;
  }
  return node;
}

bool ContainsFunctionNodeWithName(StringPiece name,
                                  const FunctionDef& function) {
  return FindFunctionNodeWithName(name, function) != -1;
}

bool ContainsFunctionNodeWithOp(StringPiece op, const FunctionDef& function) {
  return FindFunctionNodeWithOp(op, function) != -1;
}

bool ContainsFunctionOutputWithName(StringPiece name,
                                    const FunctionDef& function) {
  return FindFunctionOutputWithName(name, function) != -1;
}

int FindFunctionInputWithName(StringPiece name, const FunctionDef& function) {
  std::vector<int> indices = GetElementIndicesWithPredicate(
      [&name](const OpDef_ArgDef& arg) { return arg.name() == name; },
      function.signature().input_arg());
  return indices.empty() ? -1 : indices.front();
}

int FindFunctionOutputWithName(StringPiece name, const FunctionDef& function) {
  std::vector<int> indices = GetElementIndicesWithPredicate(
      [&name](const OpDef_ArgDef& arg) { return arg.name() == name; },
      function.signature().output_arg());
  return indices.empty() ? -1 : indices.front();
}

int FindFunctionNodeWithName(StringPiece name, const FunctionDef& function) {
  std::vector<int> indices = GetElementIndicesWithPredicate(
      [&name](const NodeDef& node) { return node.name() == name; },
      function.node_def());
  return indices.empty() ? -1 : indices.front();
}

int FindFunctionNodeWithOp(StringPiece op, const FunctionDef& function) {
  std::vector<int> indices = GetElementIndicesWithPredicate(
      [&op](const NodeDef& node) { return node.op() == op; },
      function.node_def());

  return indices.empty() ? -1 : indices.front();
}

void SetUniqueFunctionNodeName(StringPiece prefix, FunctionDef* function,
                               NodeDef* node) {
  string name = string(prefix);
  int id = function->node_def_size();
  while (ContainsFunctionNodeWithName(name, *function)) {
    name = strings::StrCat(prefix, "/_", id);
    ++id;
  }
  node->set_name(std::move(name));
}

}  // end namespace function_utils
}  // end namespace grappler
}  // end namespace tensorflow