C++ EMUFILE_FILE::fseek方法代码示例

void BackupDevice::ensure(u32 addr, u8 val, EMUFILE_FILE *fpOut)
{
	if (!fpOut && (addr < fsize)) return;

	EMUFILE_FILE *fp = fpOut?fpOut:fpMC;

#ifndef _DONT_SAVE_BACKUP
	fp->fseek(fsize, SEEK_SET);
#endif
	
	u32 padSize = pad_up_size(addr);
	u32 size = padSize - fsize;
	info.padSize = info.size = fsize = padSize;
	int type = searchFileSaveType(fsize);
	if (type != 0xFF) info.type = (type + 1);

#ifndef _DONT_SAVE_BACKUP
	if (size > 0)
	{
		u8 *tmp = new u8[size];
		memset(tmp, val, size);
		fwrite(tmp, 1, size, fp->get_fp());
		delete [] tmp;
	}

	//this is just for humans to read
	fp->fprintf(DESMUME_BACKUP_FOOTER_TXT);

	//and now the actual footer
	fp->write32le(addr);			//the size of data that has actually been written
	fp->write32le(padSize);			//the size we padded it to
	fp->write32le(info.type);		//save memory type
	fp->write32le(addr_size);
	fp->write32le(info.size);		//save memory size
	fp->write32le((u32)0);		//version number
	fp->fprintf("%s", kDesmumeSaveCookie); //this is what we'll use to recognize the desmume format save

	fp->fflush();

	fp->fseek(addr, SEEK_SET);
#endif
}

void BackupDevice::ensure(u32 addr, u8 val, EMUFILE_FILE *fpOut)
{
	if (!fpOut && (addr < fsize)) return;

	EMUFILE_FILE *fp = fpOut?fpOut:fpMC;

#ifndef _DONT_SAVE_BACKUP
	fp->fseek(fsize, SEEK_SET);
#endif
	
	u32 padSize = pad_up_size(addr);
	u32 size = padSize - fsize;
	info.padSize = info.size = fsize = padSize;
	int type = searchFileSaveType(fsize);
	if (type != 0xFF) info.type = (type + 1);

#ifndef _DONT_SAVE_BACKUP
	if (size > 0)
	{
		u8 *tmp = new u8[size];
		memset(tmp, val, size);
		fwrite(tmp, 1, size, fp->get_fp());
		delete [] tmp;
	}

	//this is just for humans to read
	fp->fprintf(DESMUME_BACKUP_FOOTER_TXT);

	//and now the actual footer
	fp->write32le(addr);			//the size of data that has actually been written
	fp->write32le(padSize);			//the size we padded it to
	fp->write32le(info.type);		//save memory type
	fp->write32le(addr_size);
	fp->write32le(info.size);		//save memory size
	fp->write32le((u32)0);		//version number
	fp->fprintf("%s", kDesmumeSaveCookie); //this is what we'll use to recognize the desmume format save

	fp->fflush();

	//this is a HORRIBLE IDEA.
	//leave the FP positioned to write the final byte
	//this is a HACK to make the basic read/write byte operation work when it calls ensure().
	//IDEALLY, no assumptions about the file pointer can be made.
	//but someone (actually, not really) so very carefully profiled the save IO code and discovered that not fseeking for every byte read/write was a great optimization.
	//so, now all this code is depending/assuming on the FP being kept in a precise position, and I dont think its smart to change the main user of this assumption to paper over this bug by making it fseek before read/write, while leaving other unknown assuming clients intact
	fpMC->fseek(addr-1, SEEK_SET);
#endif
}

FCEUFILE * FCEU_fopen(const char *path, const char *ipsfn, char *mode, char *ext, int index, const char** extensions)
{
	FILE *ipsfile=0;
	FCEUFILE *fceufp=0;

	bool read = (std::string)mode == "rb";
	bool write = (std::string)mode == "wb";
	if((read&&write) || (!read&&!write))
	{
		FCEU_PrintError("invalid file open mode specified (only wb and rb are supported)");
		return 0;
	}

	std::string archive,fname,fileToOpen;
	FCEU_SplitArchiveFilename(path,archive,fname,fileToOpen);
	

	//try to setup the ips file
	if(ipsfn && read)
		ipsfile=FCEUD_UTF8fopen(ipsfn,"rb");
	if(read)
	{
		ArchiveScanRecord asr = FCEUD_ScanArchive(fileToOpen);
		asr.files.FilterByExtension(extensions);
		if(!asr.isArchive())
		{
			//if the archive contained no files, try to open it the old fashioned way
			EMUFILE_FILE* fp = FCEUD_UTF8_fstream(fileToOpen,mode);
			if(!fp || (fp->get_fp() == NULL))
			{
				return 0;
			}

			//try to read a zip file
			{
				fceufp = TryUnzip(fileToOpen);
				if(fceufp) {
					delete fp;
					fceufp->filename = fileToOpen;
					fceufp->logicalPath = fileToOpen;
					fceufp->fullFilename = fileToOpen;
					fceufp->archiveIndex = -1;
					goto applyips;
				}
			}

			//try to read a gzipped file
			{
				uint32 magic;
				
				magic = fp->fgetc();
				magic|=fp->fgetc()<<8;
				magic|=fp->fgetc()<<16;
				fp->fseek(0,SEEK_SET);

				if(magic==0x088b1f) {
					 // maybe gzip... 

					void* gzfile = gzopen(fileToOpen.c_str(),"rb");
					if(gzfile) {
						delete fp;

						int size;
						for(size=0; gzgetc(gzfile) != EOF; size++) {}
						EMUFILE_MEMORY* ms = new EMUFILE_MEMORY(size);
						gzseek(gzfile,0,SEEK_SET);
						gzread(gzfile,ms->buf(),size);
						gzclose(gzfile);

						fceufp = new FCEUFILE();
						fceufp->filename = fileToOpen;
						fceufp->logicalPath = fileToOpen;
						fceufp->fullFilename = fileToOpen;
						fceufp->archiveIndex = -1;
						fceufp->stream = ms;
						fceufp->size = size;
						goto applyips;
					}
				}
			}

		
			//open a plain old file
			fceufp = new FCEUFILE();
			fceufp->filename = fileToOpen;
			fceufp->logicalPath = fileToOpen;
			fceufp->fullFilename = fileToOpen;
			fceufp->archiveIndex = -1;
			fceufp->stream = fp;
			FCEU_fseek(fceufp,0,SEEK_END);
			fceufp->size = FCEU_ftell(fceufp);
			FCEU_fseek(fceufp,0,SEEK_SET);
			goto applyips;
		}
		else
		{
			//open an archive file
			if(archive == "")
				if(index != -1)
					fceufp = FCEUD_OpenArchiveIndex(asr, fileToOpen, index);
//.........这里部分代码省略.........

void BackupDevice::loadfile()
{
	//never use save files if we are in movie mode
	if(isMovieMode) return;
	if(filename.length() ==0) return; //No sense crashing if no filename supplied

	EMUFILE_FILE* inf = new EMUFILE_FILE(filename.c_str(),"rb");
	if(inf->fail())
	{
		delete inf;
		//no dsv found; we need to try auto-importing a file with .sav extension 
		printf("DeSmuME .dsv save file not found. Trying to load an old raw .sav file.\n");
		
		//change extension to sav
		char tmp[MAX_PATH];
		strcpy(tmp,filename.c_str());
		tmp[strlen(tmp)-3] = 0;
		strcat(tmp,"sav");

		inf = new EMUFILE_FILE(tmp,"rb");
		if(inf->fail())
		{
			delete inf;
			printf("Missing save file %s\n",filename.c_str());
			return;
		}
		delete inf;

		if (!load_no_gba(tmp))
			load_raw(tmp);
	}
	else
	{
		//scan for desmume save footer
		const s32 cookieLen = (s32)strlen(kDesmumeSaveCookie);
		char *sigbuf = new char[cookieLen];
		inf->fseek(-cookieLen, SEEK_END);
		inf->fread(sigbuf,cookieLen);
		int cmp = memcmp(sigbuf,kDesmumeSaveCookie,cookieLen);
		delete[] sigbuf;
		if(cmp)
		{
			//maybe it is a misnamed raw save file. try loading it that way
			printf("Not a DeSmuME .dsv save file. Trying to load as raw.\n");
			delete inf;
			if (!load_no_gba(filename.c_str()))
				load_raw(filename.c_str());
			return;
		}
		//desmume format
		inf->fseek(-cookieLen, SEEK_END);
		inf->fseek(-4, SEEK_CUR);
		u32 version = 0xFFFFFFFF;
		read32le(&version,inf);
		if(version!=0) {
			printf("Unknown save file format\n");
			return;
		}
		inf->fseek(-24, SEEK_CUR);
		read32le(&info.size,inf);
		read32le(&info.padSize,inf);
		read32le(&info.type,inf);
		read32le(&info.addr_size,inf);
		read32le(&info.mem_size,inf);

		u32 left = 0;
		if (CommonSettings.autodetectBackupMethod == 1)
		{
			if (advsc.isLoaded())
			{
				info.type = advsc.getSaveType();
				if (info.type != 0xFF || info.type != 0xFE)
				{
					u32 adv_size = save_types[info.type+1][1];
					if (info.size > adv_size)
						info.size = adv_size;
					else
						if (info.size < adv_size)
						{
							left = adv_size - info.size;
							info.size = adv_size;
						}
				}
			}
		}
		//establish the save data
		resize(info.size);
		inf->fseek(0, SEEK_SET);
		if(info.size>0)
			inf->fread(&data[0],info.size - left); //read all the raw data we have
		state = RUNNING;
		addr_size = info.addr_size;
		//none of the other fields are used right now


		if (CommonSettings.autodetectBackupMethod != 1 && info.type == 0) 
		{
			info.type = searchFileSaveType(info.size);
			if (info.type == 0xFF) info.type = 0;
		}
//.........这里部分代码省略.........