// 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 "base/base_export.h"
#include "base/basictypes.h"
#include "base/platform_file.h"
#include "build/build_config.h"
#if defined(OS_WIN)
#include <windows.h>
#endif
namespace base {
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 will take
// ownership of |file| and close it when done.
bool Initialize(PlatformFile 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* 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:
// Open the given file and pass it to MapFileToMemoryInternal().
bool MapFileToMemory(const FilePath& file_name);
// 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 MapFileToMemoryInternal();
// Closes all open handles. Later we may want to make this public.
void CloseHandles();
#if defined(OS_WIN)
// MapFileToMemoryInternal calls this function. It provides the ability to
// pass in flags which control the mapped section.
bool MapFileToMemoryInternalEx(int flags);
HANDLE file_mapping_;
#endif
PlatformFile file_;
uint8* data_;
size_t length_;
DISALLOW_COPY_AND_ASSIGN(MemoryMappedFile);
};
} // namespace base
#endif // BASE_FILES_MEMORY_MAPPED_FILE_H_