ppsspp/Common/Serialize/Serializer.h
2023-02-14 22:46:32 +01:00

334 lines
8.4 KiB
C++

// Copyright (C) 2003 Dolphin Project.
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 2.0 or later versions.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License 2.0 for more details.
// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/
// Official SVN repository and contact information can be found at
// http://code.google.com/p/dolphin-emu/
#pragma once
#include "ppsspp_config.h"
// Extremely simple serialization framework.
// Currently mis-named, a native ChunkFile is something different (a RIFF file)
// (mis)-features:
// + Super fast
// + Very simple
// + Same code is used for serialization and deserializaition (in most cases)
// + Sections can be versioned for backwards/forwards compatibility
// - Serialization code for anything complex has to be manually written.
#include <string>
#include <cstring>
#include <vector>
#include <cstdlib>
#include "Common/CommonTypes.h"
#include "Common/Log.h"
#include "Common/File/Path.h"
namespace File {
class IOFile;
};
template <class T>
struct LinkedListItem : public T
{
LinkedListItem<T> *next;
};
class PointerWrap;
class PointerWrapSection
{
public:
PointerWrapSection(PointerWrap &p, int ver, const char *title) : p_(p), ver_(ver), title_(title) {}
~PointerWrapSection();
bool operator == (const int &v) const { return ver_ == v; }
bool operator != (const int &v) const { return ver_ != v; }
bool operator <= (const int &v) const { return ver_ <= v; }
bool operator >= (const int &v) const { return ver_ >= v; }
bool operator < (const int &v) const { return ver_ < v; }
bool operator > (const int &v) const { return ver_ > v; }
operator bool() const {
return ver_ > 0;
}
int Version() const {
return ver_;
}
private:
PointerWrap &p_;
int ver_;
const char *title_;
};
// For measure vs write detailed verification
struct SerializeCheckpoint {
char title[17]; // 16-byte section header, plus a zero terminator for debug printing.
size_t offset;
SerializeCheckpoint(char _title[16], size_t off) {
memcpy(title, _title, 16);
title[16] = 0;
offset = off;
}
bool Matches(const char *_title, size_t off) const {
return memcmp(title, _title, 16) == 0 && off == offset;
}
};
// Wrapper class
class PointerWrap
{
public:
enum Mode {
MODE_READ = 1, // load
MODE_WRITE, // save
MODE_MEASURE, // calculate size
MODE_VERIFY, // compare
MODE_NOOP, // don't do anything. Useful to cleanly doing stuff once we've hit an error.
};
enum Error {
ERROR_NONE = 0,
ERROR_WARNING = 1,
ERROR_FAILURE = 2,
};
u8 **ptr;
Mode mode;
Error error = ERROR_NONE;
PointerWrap(u8 **ptr_, Mode mode_) : ptr(ptr_), ptrStart_(*ptr), mode(mode_) {
if (mode == MODE_MEASURE) {
checkpoints_.reserve(750);
}
}
void RewindForWrite(u8 *writePtr);
bool CheckAfterWrite();
// The returned object can be compared against the version that was loaded.
// This can be used to support versions as old as minVer.
// Version = 0 means the section was not found.
PointerWrapSection Section(const char *title, int minVer, int ver);
PointerWrapSection Section(const char *title, int ver) {
return Section(title, ver, ver);
}
void SetMode(Mode mode_) { mode = mode_; }
Mode GetMode() const { return mode; }
u8 **GetPPtr() { return ptr; }
void SetError(Error error_);
const char *GetBadSectionTitle() const {
return firstBadSectionTitle_;
}
// Same as DoVoid, except doesn't advance pointer if it doesn't match on read.
bool ExpectVoid(void *data, int size);
void DoVoid(void *data, int size);
void DoMarker(const char *prevName, u32 arbitraryNumber = 0x42);
size_t Offset() const { return *ptr - ptrStart_; }
private:
const char *firstBadSectionTitle_ = nullptr;
u8 *ptrStart_;
std::vector<SerializeCheckpoint> checkpoints_;
size_t curCheckpoint_ = 0;
size_t measuredSize_ = 0;
};
class CChunkFileReader
{
public:
enum Error {
ERROR_NONE,
ERROR_BAD_FILE,
ERROR_BROKEN_STATE,
ERROR_BAD_ALLOC,
};
// May fail badly if ptr doesn't point to valid data.
template<class T>
static Error LoadPtr(u8 *ptr, T &_class, std::string *errorString)
{
PointerWrap p(&ptr, PointerWrap::MODE_READ);
_class.DoState(p);
if (p.error != p.ERROR_FAILURE) {
return ERROR_NONE;
} else {
std::string badSectionTitle = p.GetBadSectionTitle() ? p.GetBadSectionTitle() : "(unknown bad section)";
*errorString = std::string("Failure at ") + badSectionTitle;
return ERROR_BROKEN_STATE;
}
}
template<class T>
static size_t MeasurePtr(T &_class)
{
u8 *ptr = nullptr;
PointerWrap p(&ptr, PointerWrap::MODE_MEASURE);
_class.DoState(p);
return (size_t)ptr;
}
// If *saved is null, will allocate storage using malloc.
// If it's not null, it will be used, but only hope can save you from overruns at the end. For libretro.
template<class T>
static Error MeasureAndSavePtr(T &_class, u8 **saved, size_t *savedSize)
{
u8 *ptr = nullptr;
PointerWrap p(&ptr, PointerWrap::MODE_MEASURE);
_class.DoState(p);
_assert_(p.error == PointerWrap::ERROR_NONE);
size_t measuredSize = p.Offset();
u8 *data;
if (*saved) {
data = *saved;
} else {
data = (u8 *)malloc(measuredSize);
if (!data)
return ERROR_BAD_ALLOC;
}
p.RewindForWrite(data);
_class.DoState(p);
if (p.CheckAfterWrite()) {
*saved = data;
*savedSize = measuredSize;
return ERROR_NONE;
} else {
if (!*saved) {
free(data);
}
return ERROR_BROKEN_STATE;
}
}
// Duplicate of the above but takes and modifies a vector. Less invasive
// than modifying the rewind manager to keep things in something else than vectors.
template<class T>
static Error MeasureAndSavePtr(T &_class, std::vector<u8> *saved)
{
u8 *ptr = nullptr;
PointerWrap p(&ptr, PointerWrap::MODE_MEASURE);
_class.DoState(p);
_assert_(p.error == PointerWrap::ERROR_NONE);
size_t measuredSize = p.Offset();
saved->resize(measuredSize);
u8 *data = saved->data();
p.RewindForWrite(data);
_class.DoState(p);
if (p.CheckAfterWrite()) {
return ERROR_NONE;
} else {
saved->clear();
return ERROR_BROKEN_STATE;
}
}
// Load file template
template<class T>
static Error Load(const Path &filename, std::string *gitVersion, T& _class, std::string *failureReason)
{
*failureReason = "LoadStateWrongVersion";
u8 *ptr = nullptr;
size_t sz;
Error error = LoadFile(filename, gitVersion, ptr, sz, failureReason);
if (error == ERROR_NONE) {
failureReason->clear();
error = LoadPtr(ptr, _class, failureReason);
delete [] ptr;
INFO_LOG(SAVESTATE, "ChunkReader: Done loading '%s'", filename.c_str());
} else {
WARN_LOG(SAVESTATE, "ChunkReader: Error found during load of '%s'", filename.c_str());
}
return error;
}
// Save file template
template<class T>
static Error Save(const Path &filename, const std::string &title, const char *gitVersion, T& _class)
{
u8 *buffer = nullptr;
size_t sz = 0;
Error error = MeasureAndSavePtr(_class, &buffer, &sz);
// SaveFile takes ownership of buffer (malloc/free)
if (error == ERROR_NONE)
error = SaveFile(filename, title, gitVersion, buffer, sz);
return error;
}
template <class T>
static Error Verify(T& _class)
{
u8 *ptr = 0;
// Step 1: Measure the space required.
PointerWrap p(&ptr, PointerWrap::MODE_MEASURE);
_class.DoState(p);
size_t const sz = (size_t)ptr;
std::vector<u8> buffer(sz);
// Step 2: Dump the state.
ptr = &buffer[0];
p.SetMode(PointerWrap::MODE_WRITE);
_class.DoState(p);
// Step 3: Verify the state.
ptr = &buffer[0];
p.SetMode(PointerWrap::MODE_VERIFY);
_class.DoState(p);
return ERROR_NONE;
}
static Error GetFileTitle(const Path &filename, std::string *title);
private:
struct SChunkHeader
{
int Revision;
int Compress;
u32 ExpectedSize;
u32 UncompressedSize;
char GitVersion[32];
};
enum {
REVISION_MIN = 4,
REVISION_TITLE = 5,
REVISION_CURRENT = REVISION_TITLE,
};
static Error LoadFile(const Path &filename, std::string *gitVersion, u8 *&buffer, size_t &sz, std::string *failureReason);
static Error SaveFile(const Path &filename, const std::string &title, const char *gitVersion, u8 *buffer, size_t sz);
static Error LoadFileHeader(File::IOFile &pFile, SChunkHeader &header, std::string *title);
};