base/data_pack.h

// Copyright (c) 2008 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// DataPack represents a read-only view onto an on-disk file that contains
// (key, value) pairs of data.  It's used to store static resources like
// translation strings and images.

#ifndef BASE_DATA_PACK_H_
#define BASE_DATA_PACK_H_

#include "base/basictypes.h"
#include "base/scoped_ptr.h"

namespace file_util {
  class MemoryMappedFile;
}
class FilePath;
class StringPiece;

namespace base {

class DataPack {
 public:
  DataPack();
  ~DataPack();

  // Load a pack file from |path|, returning false on error.
  bool Load(const FilePath& path);

  // Get resource by id |resource_id|, filling in |data|.
  // The data is owned by the DataPack object and should not be modified.
  // Returns false if the resource id isn't found.
  bool Get(uint32_t resource_id, StringPiece* data);

 private:
  // The memory-mapped data.
  scoped_ptr<file_util::MemoryMappedFile> mmap_;

  // Number of resources in the data.
  size_t resource_count_;

  DISALLOW_COPY_AND_ASSIGN(DataPack);
};

}  // namespace base

#endif  // BASE_DATA_PACK_H_