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// Copyright 2016 The Bazel Authors. All rights reserved.
//
// 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.
#ifndef BAZEL_SRC_TOOLS_SINGLEJAR_MAPPED_FILE_H_
#define BAZEL_SRC_TOOLS_SINGLEJAR_MAPPED_FILE_H_ 1
#include <cstddef>
#include <string>
#include "src/tools/singlejar/port.h"
/*
* A mapped read-only file with auto closing.
*
* MappedFile::Open maps a file with specified name to memory as read-only.
* It is assumed that the address space is large enough for that.
* MappedFile::Close deletes the mapping. The destructor calls it, too.
* A predictable set of methods provide conversion between file offsets and
* mapped addresses, returns map size, etc.
*/
class MappedFile {
public:
MappedFile();
~MappedFile() { Close(); }
bool Open(const std::string &path);
bool MapExisting(unsigned char *mapped_start, unsigned char *mapped_end) {
mapped_start_ = mapped_start;
mapped_end_ = mapped_end;
return true;
}
void Close();
bool mapped(const void *addr) const {
return mapped_start_ <= addr && addr < mapped_end_;
}
const unsigned char *start() const { return mapped_start_; }
const unsigned char *end() const { return mapped_end_; }
const unsigned char *address(off64_t offset) const {
return mapped_start_ + offset;
}
off64_t offset(const void *address) const {
return reinterpret_cast<const unsigned char *>(address) - mapped_start_;
}
#ifndef _WIN32
// Not used on Windows, only in Google's own code. Don't add more usage of it.
// It is not available on Windows because Windows' implementation does not
// use fd at all and adding it would just make the implementation too
// complicated.
int fd() const { return fd_; }
#endif
size_t size() const { return mapped_end_ - mapped_start_; }
private:
bool is_open() const;
unsigned char *mapped_start_;
unsigned char *mapped_end_;
#ifdef _WIN32
/* HANDLE */ void *hFile_;
/* HANDLE */ void *hMapFile_;
#else
int fd_;
#endif
};
#endif // BAZEL_SRC_TOOLS_SINGLEJAR_MAPPED_FILE_H_