bsnes/nall/filemap.hpp

215 lines
4.9 KiB
C++

#pragma once
#include <nall/file.hpp>
#include <nall/stdint.hpp>
#include <nall/windows/utf8.hpp>
#include <stdio.h>
#include <stdlib.h>
#if defined(_WIN32)
#include <windows.h>
#else
#include <fcntl.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#endif
namespace nall {
struct filemap {
enum class mode : unsigned { read, write, readwrite, writeread };
filemap() { p_ctor(); }
filemap(const string& filename, mode mode_) { p_ctor(); p_open(filename, mode_); }
~filemap() { p_dtor(); }
explicit operator bool() const { return open(); }
auto open() const -> bool { return p_open(); }
auto open(const string& filename, mode mode_) -> bool { return p_open(filename, mode_); }
auto close() -> void { return p_close(); }
auto size() const -> unsigned { return p_size; }
auto data() -> uint8_t* { return p_handle; }
auto data() const -> const uint8_t* { return p_handle; }
private:
uint8_t* p_handle = nullptr;
unsigned p_size = 0;
#if defined(API_WINDOWS)
//=============
//MapViewOfFile
//=============
HANDLE p_filehandle;
HANDLE p_maphandle;
auto p_open() const -> bool {
return p_handle;
}
auto p_open(const string& filename, mode mode_) -> bool {
if(file::exists(filename) && file::size(filename) == 0) {
p_handle = nullptr;
p_size = 0;
return true;
}
int desired_access, creation_disposition, flprotect, map_access;
switch(mode_) {
default: return false;
case mode::read:
desired_access = GENERIC_READ;
creation_disposition = OPEN_EXISTING;
flprotect = PAGE_READONLY;
map_access = FILE_MAP_READ;
break;
case mode::write:
//write access requires read access
desired_access = GENERIC_WRITE;
creation_disposition = CREATE_ALWAYS;
flprotect = PAGE_READWRITE;
map_access = FILE_MAP_ALL_ACCESS;
break;
case mode::readwrite:
desired_access = GENERIC_READ | GENERIC_WRITE;
creation_disposition = OPEN_EXISTING;
flprotect = PAGE_READWRITE;
map_access = FILE_MAP_ALL_ACCESS;
break;
case mode::writeread:
desired_access = GENERIC_READ | GENERIC_WRITE;
creation_disposition = CREATE_NEW;
flprotect = PAGE_READWRITE;
map_access = FILE_MAP_ALL_ACCESS;
break;
}
p_filehandle = CreateFileW(utf16_t(filename), desired_access, FILE_SHARE_READ, nullptr,
creation_disposition, FILE_ATTRIBUTE_NORMAL, nullptr);
if(p_filehandle == INVALID_HANDLE_VALUE) return false;
p_size = GetFileSize(p_filehandle, nullptr);
p_maphandle = CreateFileMapping(p_filehandle, nullptr, flprotect, 0, p_size, nullptr);
if(p_maphandle == INVALID_HANDLE_VALUE) {
CloseHandle(p_filehandle);
p_filehandle = INVALID_HANDLE_VALUE;
return false;
}
p_handle = (uint8_t*)MapViewOfFile(p_maphandle, map_access, 0, 0, p_size);
return p_handle;
}
auto p_close() -> void {
if(p_handle) {
UnmapViewOfFile(p_handle);
p_handle = nullptr;
}
if(p_maphandle != INVALID_HANDLE_VALUE) {
CloseHandle(p_maphandle);
p_maphandle = INVALID_HANDLE_VALUE;
}
if(p_filehandle != INVALID_HANDLE_VALUE) {
CloseHandle(p_filehandle);
p_filehandle = INVALID_HANDLE_VALUE;
}
}
auto p_ctor() -> void {
p_filehandle = INVALID_HANDLE_VALUE;
p_maphandle = INVALID_HANDLE_VALUE;
}
auto p_dtor() -> void {
close();
}
#else
//====
//mmap
//====
int p_fd;
auto p_open() const -> bool {
return p_handle;
}
auto p_open(const string& filename, mode mode_) -> bool {
if(file::exists(filename) && file::size(filename) == 0) {
p_handle = nullptr;
p_size = 0;
return true;
}
int open_flags, mmap_flags;
switch(mode_) {
default: return false;
case mode::read:
open_flags = O_RDONLY;
mmap_flags = PROT_READ;
break;
case mode::write:
open_flags = O_RDWR | O_CREAT; //mmap() requires read access
mmap_flags = PROT_WRITE;
break;
case mode::readwrite:
open_flags = O_RDWR;
mmap_flags = PROT_READ | PROT_WRITE;
break;
case mode::writeread:
open_flags = O_RDWR | O_CREAT;
mmap_flags = PROT_READ | PROT_WRITE;
break;
}
p_fd = ::open(filename, open_flags, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
if(p_fd < 0) return false;
struct stat p_stat;
fstat(p_fd, &p_stat);
p_size = p_stat.st_size;
p_handle = (uint8_t*)mmap(nullptr, p_size, mmap_flags, MAP_SHARED, p_fd, 0);
if(p_handle == MAP_FAILED) {
p_handle = nullptr;
::close(p_fd);
p_fd = -1;
return false;
}
return p_handle;
}
auto p_close() -> void {
if(p_handle) {
munmap(p_handle, p_size);
p_handle = nullptr;
}
if(p_fd >= 0) {
::close(p_fd);
p_fd = -1;
}
}
auto p_ctor() -> void {
p_fd = -1;
}
auto p_dtor() -> void {
p_close();
}
#endif
};
}