mirror of
https://github.com/openXC7/prjxray.git
synced 2026-09-07 03:21:46 +02:00
Carlos Venegas Arrabé
a2c712e588
lib/memory_mapped_file.cc used POSIX open/fstat/mmap, which does not exist under mingw-w64, blocking a native Windows build of the prjxray tools. Add an #ifdef _WIN32 branch using CreateFileA/CreateFileMappingA/MapViewOfFile; the POSIX path is byte-for-byte unchanged. One behavioural note: a zero-length file cannot be mapped on Windows, so that case returns an object with nullptr data and zero size to preserve the "file exists" contract of InitWithFile.
107 lines
2.6 KiB
C++
107 lines
2.6 KiB
C++
/*
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* Copyright (C) 2017-2020 The Project X-Ray Authors.
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*
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* Use of this source code is governed by a ISC-style
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* license that can be found in the LICENSE file or at
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* https://opensource.org/licenses/ISC
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*
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* SPDX-License-Identifier: ISC
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*/
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#include <prjxray/memory_mapped_file.h>
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#ifdef _WIN32
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#include <windows.h>
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#else
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#include <fcntl.h>
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#include <sys/mman.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <unistd.h>
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#endif
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namespace prjxray {
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std::unique_ptr<MemoryMappedFile> MemoryMappedFile::InitWithFile(
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const std::string& path) {
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#ifdef _WIN32
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HANDLE file = CreateFileA(path.c_str(), GENERIC_READ, FILE_SHARE_READ,
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NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL,
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NULL);
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if (file == INVALID_HANDLE_VALUE)
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return nullptr;
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LARGE_INTEGER file_size;
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if (!GetFileSizeEx(file, &file_size)) {
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CloseHandle(file);
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return nullptr;
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}
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// A zero-length file cannot be mapped; return an object (to indicate
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// the file exists) with a nullptr and zero length.
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if (file_size.QuadPart == 0) {
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CloseHandle(file);
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return std::unique_ptr<MemoryMappedFile>(
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new MemoryMappedFile(nullptr, 0));
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}
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HANDLE mapping =
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CreateFileMappingA(file, NULL, PAGE_READONLY, 0, 0, NULL);
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// The view keeps the file/mapping alive, so the handles can be closed.
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CloseHandle(file);
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if (mapping == NULL)
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return nullptr;
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void* file_map = MapViewOfFile(mapping, FILE_MAP_READ, 0, 0, 0);
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CloseHandle(mapping);
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if (file_map == NULL)
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return nullptr;
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return std::unique_ptr<MemoryMappedFile>(new MemoryMappedFile(
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file_map, static_cast<size_t>(file_size.QuadPart)));
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#else
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int fd = open(path.c_str(), O_RDONLY, 0);
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if (fd == -1)
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return nullptr;
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struct stat statbuf;
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if (fstat(fd, &statbuf) < 0) {
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close(fd);
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return nullptr;
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}
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// mmap() will fail with EINVAL if length==0. If this file is
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// zero-length, return an object (to indicate the file exists) but
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// load it with a nullptr and zero length.
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if (statbuf.st_size == 0) {
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close(fd);
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return std::unique_ptr<MemoryMappedFile>(
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new MemoryMappedFile(nullptr, 0));
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}
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void* file_map =
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mmap(NULL, statbuf.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
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// If mmap() succeeded, the fd is no longer needed as the mapping will
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// keep the file open. If mmap() failed, the fd needs to be closed
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// anyway.
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close(fd);
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if (file_map == MAP_FAILED)
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return nullptr;
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return std::unique_ptr<MemoryMappedFile>(
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new MemoryMappedFile(file_map, statbuf.st_size));
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#endif
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}
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MemoryMappedFile::~MemoryMappedFile() {
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#ifdef _WIN32
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if (data_)
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UnmapViewOfFile(data_);
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#else
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munmap(data_, size_);
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#endif
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}
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} // namespace prjxray
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