syzygy/grinder/indexed_frequency_data_serializer.h

// Copyright 2013 Google Inc. 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.
//
// Declares the IndexedFrequencyDataSerializer class.

#ifndef SYZYGY_GRINDER_INDEXED_FREQUENCY_DATA_SERIALIZER_H_
#define SYZYGY_GRINDER_INDEXED_FREQUENCY_DATA_SERIALIZER_H_

#include <map>
#include <vector>

#include "base/values.h"
#include "syzygy/grinder/basic_block_util.h"
#include "syzygy/grinder/grinder.h"

namespace grinder {

// This class serializes and deserializes a
// basic_block_util::IndexedFrequencyMap, containing frequency information for
// one or more modules, to/from a JSON file.
//
// The JSON file has the following structure.
//
//     [
//       // Basic-block frequencies for module 1. Note that the module
//       // information refers to the original module, as opposed to the
//       // instrumented copy.
//       {
//         "metadata": {
//           "command_line": "\"foo.exe\"",
//           "creation_time": "Wed, 19 Sep 2012 17:33:52 GMT",
//           "toolchain_version": {
//             "major": 0,
//             "minor": 2,
//             "build": 7,
//             "patch": 0,
//             "last_change": "0"
//           },
//           "module_signature": {
//             "path": "C:\\foo\\bar.dll",
//             "base_address": 1904279552,
//             "module_size": 180224,
//             "module_time_date_stamp": "0x46F7885059FE32",
//             "module_checksum": "0x257AF"
//           }
//         },
//         "informations": {
//           "num_entries": 100,
//           "num_columns": 3,
//           "data_type": 1,
//           "frequency_size": 4
//         },
//         // Basic-block frequencies list, encoded as sequence of frequencies
//         // [offset, frequency1, frequency2, ...], where offset is the RVA to
//         // the first instruction byte of the basic block in the original
//         // image.
//         "frequencies": [
//           [100, 10000, 12, 1],
//           [200, 123456, 124, 12]
//         ]
//       },
//       // Basic-block frequencies list for module 2.
//       ...
//     ]
class IndexedFrequencyDataSerializer {
 public:
  typedef basic_block_util::ModuleIndexedFrequencyMap ModuleIndexedFrequencyMap;

  IndexedFrequencyDataSerializer();

  // Sets the pretty-printing status.
  void set_pretty_print(bool value) { pretty_print_ = value; }

  // Saves the given frequency map to a file at @p file_path.
  bool SaveAsJson(const ModuleIndexedFrequencyMap& frequency_map,
                  const base::FilePath& file_path);

  // Saves the given frequency map to a file previously opened for writing.
  bool SaveAsJson(const ModuleIndexedFrequencyMap& frequency_map,
                  FILE* file);

  // Populates a frequency map from a JSON file, given by @p file_path.
  bool LoadFromJson(const base::FilePath& file_path,
                    ModuleIndexedFrequencyMap* frequency_map);

 protected:
  // Populates a frequency map from JSON data. Exposed for unit-testing
  // purposes.
  bool PopulateFromJsonValue(const base::Value* json_value,
                             ModuleIndexedFrequencyMap* frequency_map);

  // If true, the JSON output will be pretty printed for easier human
  // consumption.
  bool pretty_print_;

 private:
  DISALLOW_COPY_AND_ASSIGN(IndexedFrequencyDataSerializer);
};

}  // namespace grinder

#endif  // SYZYGY_GRINDER_INDEXED_FREQUENCY_DATA_SERIALIZER_H_