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/*
* Copyright (C) 2018 The Android Open Source Project
*
* 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.
*/
#pragma once
#include <sys/types.h>
#include <memory>
#include "android-base/macros.h"
#include "android-base/off64_t.h"
#include "android-base/unique_fd.h"
#if defined(_WIN32)
#include <windows.h>
#define PROT_READ 1
#define PROT_WRITE 2
using os_handle = HANDLE;
#else
#include <sys/mman.h>
using os_handle = int;
#endif
namespace android {
namespace base {
/**
* A region of a file mapped into memory (for grepping: also known as MmapFile or file mapping).
*/
class MappedFile {
public:
/**
* Creates a new mapping of the file pointed to by `fd`. Unlike the underlying OS primitives,
* `offset` does not need to be page-aligned. If `PROT_WRITE` is set in `prot`, the mapping
* will be writable, otherwise it will be read-only. Mappings are always `MAP_SHARED`.
*/
static std::unique_ptr<MappedFile> FromFd(borrowed_fd fd, off64_t offset, size_t length,
int prot);
/**
* Same thing, but using the raw OS file handle instead of a CRT wrapper.
*/
static std::unique_ptr<MappedFile> FromOsHandle(os_handle h, off64_t offset, size_t length,
int prot);
/**
* Removes the mapping.
*/
~MappedFile();
/**
* Not copyable but movable.
*/
MappedFile(MappedFile&& other);
MappedFile& operator=(MappedFile&& other);
char* data() const { return base_ + offset_; }
size_t size() const { return size_; }
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(MappedFile);
void Close();
char* base_;
size_t size_;
size_t offset_;
#if defined(_WIN32)
MappedFile(char* base, size_t size, size_t offset, HANDLE handle)
: base_(base), size_(size), offset_(offset), handle_(handle) {}
HANDLE handle_;
#else
MappedFile(char* base, size_t size, size_t offset) : base_(base), size_(size), offset_(offset) {}
#endif
};
} // namespace base
} // namespace android