bsnes/nall/file.hpp

332 lines
9.2 KiB
C++

#pragma once
#include <nall/platform.hpp>
#include <nall/file-system-object.hpp>
#include <nall/stdint.hpp>
#include <nall/string.hpp>
#include <nall/utility.hpp>
#include <nall/varint.hpp>
#include <nall/hash/sha256.hpp>
#include <nall/stream/memory.hpp>
namespace nall {
struct file : file_system_object, varint {
enum class mode : uint { read, write, modify, append, readwrite = modify, writeread = append };
enum class index : uint { absolute, relative };
static auto copy(const string& sourcename, const string& targetname) -> bool {
file rd, wr;
if(rd.open(sourcename, mode::read) == false) return false;
if(wr.open(targetname, mode::write) == false) return false;
for(uint n = 0; n < rd.size(); n++) wr.write(rd.read());
return true;
}
//attempt to rename file first
//this will fail if paths point to different file systems; fall back to copy+remove in this case
static auto move(const string& sourcename, const string& targetname) -> bool {
if(rename(sourcename, targetname)) return true;
if(!writable(sourcename)) return false;
if(copy(sourcename, targetname)) {
remove(sourcename);
return true;
}
return false;
}
static auto truncate(const string& filename, uint size) -> bool {
#if defined(API_POSIX)
return truncate(filename, size) == 0;
#elif defined(API_WINDOWS)
if(auto fp = _wfopen(utf16_t(filename), L"rb+")) {
bool result = _chsize(fileno(fp), size) == 0;
fclose(fp);
return result;
}
return false;
#endif
}
//returns false if specified filename is a directory
static auto exists(const string& filename) -> bool {
#if defined(API_POSIX)
struct stat data;
if(stat(filename, &data) != 0) return false;
#elif defined(API_WINDOWS)
struct __stat64 data;
if(_wstat64(utf16_t(filename), &data) != 0) return false;
#endif
return !(data.st_mode & S_IFDIR);
}
static auto size(const string& filename) -> uintmax {
#if defined(API_POSIX)
struct stat data;
stat(filename, &data);
#elif defined(API_WINDOWS)
struct __stat64 data;
_wstat64(utf16_t(filename), &data);
#endif
return S_ISREG(data.st_mode) ? data.st_size : 0u;
}
static auto read(const string& filename) -> vector<uint8> {
vector<uint8> memory;
file fp;
if(fp.open(filename, mode::read)) {
memory.resize(fp.size());
fp.read(memory.data(), memory.size());
}
return memory;
}
static auto read(const string& filename, uint8* data, uint size) -> bool {
file fp;
if(fp.open(filename, mode::read) == false) return false;
fp.read(data, size);
fp.close();
return true;
}
static auto write(const string& filename, const string& text) -> bool {
return write(filename, (const uint8*)text.data(), text.size());
}
static auto write(const string& filename, const vector<uint8>& buffer) -> bool {
return write(filename, buffer.data(), buffer.size());
}
static auto write(const string& filename, const uint8* data, uint size) -> bool {
file fp;
if(fp.open(filename, mode::write) == false) return false;
fp.write(data, size);
fp.close();
return true;
}
static auto create(const string& filename) -> bool {
//create an empty file (will replace existing files)
file fp;
if(fp.open(filename, mode::write) == false) return false;
fp.close();
return true;
}
static auto sha256(const string& filename) -> string {
auto buffer = read(filename);
return Hash::SHA256(buffer.data(), buffer.size()).digest();
}
auto read() -> uint8 {
if(!fp) return 0xff; //file not open
if(file_mode == mode::write) return 0xff; //reads not permitted
if(file_offset >= file_size) return 0xff; //cannot read past end of file
buffer_sync();
return buffer[(file_offset++) & buffer_mask];
}
auto readl(uint length = 1) -> uintmax {
uintmax data = 0;
for(int i = 0; i < length; i++) {
data |= (uintmax)read() << (i << 3);
}
return data;
}
auto readm(uint length = 1) -> uintmax {
uintmax data = 0;
while(length--) {
data <<= 8;
data |= read();
}
return data;
}
auto reads(uint length) -> string {
string result;
result.resize(length);
for(auto& byte : result) byte = read();
return result;
}
auto read(uint8* buffer, uint length) -> void {
while(length--) *buffer++ = read();
}
auto write(uint8 data) -> void {
if(!fp) return; //file not open
if(file_mode == mode::read) return; //writes not permitted
buffer_sync();
buffer[(file_offset++) & buffer_mask] = data;
buffer_dirty = true;
if(file_offset > file_size) file_size = file_offset;
}
auto writel(uintmax data, uint length = 1) -> void {
while(length--) {
write(data);
data >>= 8;
}
}
auto writem(uintmax data, uint length = 1) -> void {
for(int i = length - 1; i >= 0; i--) {
write(data >> (i << 3));
}
}
auto writes(const string& s) -> void {
for(auto byte : s) write(byte);
}
auto write(const uint8* buffer, uint length) -> void {
while(length--) write(*buffer++);
}
template<typename... Args> auto print(Args... args) -> void {
string data(args...);
const char* p = data;
while(*p) write(*p++);
}
auto flush() -> void {
buffer_flush();
fflush(fp);
}
auto seek(int offset, index index_ = index::absolute) -> void {
if(!fp) return; //file not open
buffer_flush();
intmax req_offset = file_offset;
switch(index_) {
case index::absolute: req_offset = offset; break;
case index::relative: req_offset += offset; break;
}
if(req_offset < 0) req_offset = 0; //cannot seek before start of file
if(req_offset > file_size) {
if(file_mode == mode::read) { //cannot seek past end of file
req_offset = file_size;
} else { //pad file to requested location
file_offset = file_size;
while(file_size < req_offset) write(0x00);
}
}
file_offset = req_offset;
}
auto offset() const -> uint {
if(!fp) return 0; //file not open
return file_offset;
}
auto size() const -> uint {
if(!fp) return 0; //file not open
return file_size;
}
auto truncate(uint size) -> bool {
if(!fp) return false; //file not open
#if defined(API_POSIX)
return ftruncate(fileno(fp), size) == 0;
#elif defined(API_WINDOWS)
return _chsize(fileno(fp), size) == 0;
#endif
}
auto end() -> bool {
if(!fp) return true; //file not open
return file_offset >= file_size;
}
auto open() const -> bool {
return fp;
}
explicit operator bool() const {
return open();
}
auto open(const string& filename, mode mode_) -> bool {
if(fp) return false;
switch(file_mode = mode_) {
#if defined(API_POSIX)
case mode::read: fp = fopen(filename, "rb" ); break;
case mode::write: fp = fopen(filename, "wb+"); break; //need read permission for buffering
case mode::readwrite: fp = fopen(filename, "rb+"); break;
case mode::writeread: fp = fopen(filename, "wb+"); break;
#elif defined(API_WINDOWS)
case mode::read: fp = _wfopen(utf16_t(filename), L"rb" ); break;
case mode::write: fp = _wfopen(utf16_t(filename), L"wb+"); break;
case mode::readwrite: fp = _wfopen(utf16_t(filename), L"rb+"); break;
case mode::writeread: fp = _wfopen(utf16_t(filename), L"wb+"); break;
#endif
}
if(!fp) return false;
buffer_offset = -1; //invalidate buffer
file_offset = 0;
fseek(fp, 0, SEEK_END);
file_size = ftell(fp);
fseek(fp, 0, SEEK_SET);
return true;
}
auto close() -> void {
if(!fp) return;
buffer_flush();
fclose(fp);
fp = nullptr;
}
auto operator=(const file&) -> file& = delete;
file(const file&) = delete;
file() = default;
file(const string& filename, mode mode_) {
open(filename, mode_);
}
~file() {
close();
}
private:
enum { buffer_size = 1 << 12, buffer_mask = buffer_size - 1 };
char buffer[buffer_size] = {0};
int buffer_offset = -1; //invalidate buffer
bool buffer_dirty = false;
FILE* fp = nullptr;
uint file_offset = 0;
uint file_size = 0;
mode file_mode = mode::read;
auto buffer_sync() -> void {
if(!fp) return; //file not open
if(buffer_offset != (file_offset & ~buffer_mask)) {
buffer_flush();
buffer_offset = file_offset & ~buffer_mask;
fseek(fp, buffer_offset, SEEK_SET);
uint length = (buffer_offset + buffer_size) <= file_size ? buffer_size : (file_size & buffer_mask);
if(length) auto unused = fread(buffer, 1, length, fp);
}
}
auto buffer_flush() -> void {
if(!fp) return; //file not open
if(file_mode == mode::read) return; //buffer cannot be written to
if(buffer_offset < 0) return; //buffer unused
if(buffer_dirty == false) return; //buffer unmodified since read
fseek(fp, buffer_offset, SEEK_SET);
uint length = (buffer_offset + buffer_size) <= file_size ? buffer_size : (file_size & buffer_mask);
if(length) auto unused = fwrite(buffer, 1, length, fp);
buffer_offset = -1; //invalidate buffer
buffer_dirty = false;
}
};
}