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// Copyright 2013 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.
#ifndef BASE_FILES_MEMORY_MAPPED_FILE_H_
#define BASE_FILES_MEMORY_MAPPED_FILE_H_
#include "butil/base_export.h"
#include "butil/basictypes.h"
#include "butil/files/file.h"
#include "butil/build_config.h"
#if defined(OS_WIN)
#include <windows.h>
#endif
namespace butil {
class FilePath;
class BASE_EXPORT MemoryMappedFile {
public:
// The default constructor sets all members to invalid/null values.
MemoryMappedFile();
~MemoryMappedFile();
// Opens an existing file and maps it into memory. Access is restricted to
// read only. If this object already points to a valid memory mapped file
// then this method will fail and return false. If it cannot open the file,
// the file does not exist, or the memory mapping fails, it will return false.
// Later we may want to allow the user to specify access.
bool Initialize(const FilePath& file_name);
// As above, but works with an already-opened file. MemoryMappedFile takes
// ownership of |file| and closes it when done.
bool Initialize(File file);
#if defined(OS_WIN)
// Opens an existing file and maps it as an image section. Please refer to
// the Initialize function above for additional information.
bool InitializeAsImageSection(const FilePath& file_name);
#endif // OS_WIN
const uint8_t* data() const { return data_; }
size_t length() const { return length_; }
// Is file_ a valid file handle that points to an open, memory mapped file?
bool IsValid() const;
private:
// Map the file to memory, set data_ to that memory address. Return true on
// success, false on any kind of failure. This is a helper for Initialize().
bool MapFileToMemory();
// Closes all open handles.
void CloseHandles();
File file_;
uint8_t* data_;
size_t length_;
#if defined(OS_WIN)
win::ScopedHandle file_mapping_;
bool image_; // Map as an image.
#endif
DISALLOW_COPY_AND_ASSIGN(MemoryMappedFile);
};
} // namespace butil
#endif // BASE_FILES_MEMORY_MAPPED_FILE_H_