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// Copyright (c) the JPEG XL Project Authors. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include "mmap.h"
#include <cstdint>
#include <memory>
#include "lib/jxl/base/common.h"
#if defined(__unix__) || defined(__unix) || \
defined(__APPLE__) && defined(__MACH__)
#include <fcntl.h>
#include <sys/mman.h>
#include <unistd.h>
namespace jxl {
struct MemoryMappedFileImpl {
static StatusOr<std::unique_ptr<MemoryMappedFileImpl>> Init(
const char* path) {
auto f = make_unique<MemoryMappedFileImpl>();
f->fd = open(path, O_RDONLY);
if (f->fd == -1) {
return JXL_FAILURE("Cannot open file %s", path);
}
f->mmap_len = lseek(f->fd, 0, SEEK_END);
lseek(f->fd, 0, SEEK_SET);
f->ptr = mmap(nullptr, f->mmap_len, PROT_READ, MAP_SHARED, f->fd, 0);
if (f->ptr == MAP_FAILED) {
return JXL_FAILURE("mmap failure");
}
return f;
}
const uint8_t* data() const { return reinterpret_cast<const uint8_t*>(ptr); }
size_t size() const { return mmap_len; }
~MemoryMappedFileImpl() {
if (fd != -1) {
close(fd);
}
if (ptr != nullptr) {
munmap(ptr, mmap_len);
}
}
int fd = -1;
size_t mmap_len = 0;
void* ptr = nullptr;
};
} // namespace jxl
#elif defined(_WIN32)
#include <string.h>
#include <windows.h>
namespace {
struct HandleDeleter {
void operator()(const HANDLE handle) const {
if (handle != INVALID_HANDLE_VALUE) {
CloseHandle(handle);
}
}
};
using HandleUniquePtr =
std::unique_ptr<std::remove_pointer<HANDLE>::type, HandleDeleter>;
} // namespace
namespace jxl {
struct MemoryMappedFileImpl {
static StatusOr<std::unique_ptr<MemoryMappedFileImpl>> Init(
const char* path) {
auto f = make_unique<MemoryMappedFileImpl>();
std::wstring stemp = std::wstring(path, path + strlen(path));
f->handle.reset(CreateFileW(stemp.c_str(), GENERIC_READ, FILE_SHARE_READ,
nullptr, OPEN_EXISTING,
FILE_FLAG_SEQUENTIAL_SCAN, nullptr));
if (f->handle.get() == INVALID_HANDLE_VALUE) {
return JXL_FAILURE("Cannot open file %s", path);
}
if (!GetFileSizeEx(f->handle.get(), &f->fsize)) {
return JXL_FAILURE("Cannot get file size (%s)", path);
}
f->handle_mapping.reset(CreateFileMappingW(f->handle.get(), nullptr,
PAGE_READONLY, 0, 0, nullptr));
if (f->handle_mapping == nullptr) {
return JXL_FAILURE("Cannot create memory mapping (%s)", path);
}
f->ptr = MapViewOfFile(f->handle_mapping.get(), FILE_MAP_READ, 0, 0, 0);
return f;
}
~MemoryMappedFileImpl() { UnmapViewOfFile(ptr); }
const uint8_t* data() const { return reinterpret_cast<const uint8_t*>(ptr); }
size_t size() const { return fsize.QuadPart; }
HandleUniquePtr handle;
HandleUniquePtr handle_mapping;
LARGE_INTEGER fsize;
void* ptr = nullptr;
};
} // namespace jxl
#else
namespace jxl {
struct MemoryMappedFileImpl {
static StatusOr<std::unique_ptr<MemoryMappedFileImpl>> Init(
const char* path) {
return JXL_FAILURE("Memory mapping not supported on this system");
}
const uint8_t* data() const { return nullptr; }
size_t size() const { return 0; }
};
} // namespace jxl
#endif
namespace jxl {
StatusOr<MemoryMappedFile> MemoryMappedFile::Init(const char* path) {
JXL_ASSIGN_OR_RETURN(auto mmf, MemoryMappedFileImpl::Init(path));
MemoryMappedFile ret;
ret.impl_ = std::move(mmf);
return ret;
}
MemoryMappedFile::MemoryMappedFile() = default;
MemoryMappedFile::~MemoryMappedFile() = default;
MemoryMappedFile::MemoryMappedFile(MemoryMappedFile&&) noexcept = default;
MemoryMappedFile& MemoryMappedFile::operator=(MemoryMappedFile&&) noexcept =
default;
const uint8_t* MemoryMappedFile::data() const { return impl_->data(); }
size_t MemoryMappedFile::size() const { return impl_->size(); }
} // namespace jxl