94 lines
2.5 KiB
C++
94 lines
2.5 KiB
C++
/*
|
|
* 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
|