text: // Copyright 2010-2020, Google Inc.
  // All rights reserved.
  //
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //     * Redistributions of source code must retain the above copyright
  // notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  // copyright notice, this list of conditions and the following disclaimer
  // in the documentation and/or other materials provided with the
  // distribution.
  //     * Neither the name of Google Inc. nor the names of its
  // contributors may be used to endorse or promote products derived from
  // this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  #include "dictionary/file/dictionary_file.h"
  
  #include <string>
  #include <vector>
  
  #include "base/logging.h"
  #include "base/mmap.h"
  #include "dictionary/file/codec_interface.h"
  #include "dictionary/file/section.h"
  #include "absl/memory/memory.h"
  #include "absl/strings/str_cat.h"
  
  namespace mozc {
  namespace dictionary {
  
  DictionaryFile::DictionaryFile(const DictionaryFileCodecInterface *file_codec)
      : file_codec_(file_codec) {
    DCHECK(file_codec_);
  }
  
  DictionaryFile::~DictionaryFile() = default;
  
  mozc::Status DictionaryFile::OpenFromFile(const std::string &file) {
    mapping_ = absl::make_unique<Mmap>();
    if (!mapping_->Open(file.c_str())) {
      return mozc::UnknownError(
          absl::StrCat("dictionary_file.cc: Failed to mmap ", file));
    }
    return OpenFromImage(mapping_->begin(), mapping_->size());
  }
  
  mozc::Status DictionaryFile::OpenFromImage(const char *image, int length) {
    sections_.clear();
    return file_codec_->ReadSections(image, length, &sections_);
  }
  
  const char *DictionaryFile::GetSection(const std::string &section_name,
                                         int *len) const {
    DCHECK(len);
    const std::string name = file_codec_->GetSectionName(section_name);
    for (const auto &section : sections_) {
      if (section.name == name) {
        *len = section.len;
        return section.ptr;
      }
    }
    return nullptr;
  }
  
  }  // namespace dictionary
  }  // namespace mozc
  