CMSSW Reference Manual

the user must create a DaqData object providing as input the data in the form of a vector of unsigned integers. The input data are all the values necessary to specify one (or more) object of the given format, which is the templated type. In case more than one object of the same given format should be put in the buffer, then the values of the second object must follow in the vector those of the first object and so on. DaqData will then compress these values in a bitstream according to the desired format. The bitstream is always aligned to the byte. The user, after successful compression, can request the pointer to the beginning of the buffer of bytes that represent the raw data (method Buffer() ) and the length of this buffer (method Size() ).

the user must create a DaqData object providing as input a pointer to a buffer of bytes and the length in bytes of this buffer. DaqData will then extract the values (unsigned integers) present in the buffer according to a proper format, which is again the templated type. After successful uncompression of the buffer, the user can request the number of objects of the given format that were present in the buffer ( method Nobjects() ) and retrieve the individual values characterizing these objects ( method getValue() ).

WARNING: at the moment the interpretation of a buffer of bytes proceeds through the constructor of DaqData. This operation implies more than one copy of the data, which is not the most efficient way of accomplishing the task. In a future version of DaqData, more efficient methods will be made available.

Constructor & Destructor Documentation

template<class Format>

DaqData< Format >::DaqData ( std::vector< unsigned int > & v ) [inline]

Definition at line 60 of file DaqData.h.

References DaqData< Format >::buffer_, DaqData< Format >::compressObject(), GenMuonPlsPt100GeV_cfg::cout, DaqData< Format >::data_, lat::endl(), i, int, name, DaqData< Format >::nobjects_, p, s, and DaqData< Format >::size_.

00060                                        : size_(0), buffer_(0), nobjects_(0) {
00061 
00062     try {
00063 
00064       if (v.size() == 0)  throw string("DaqData: empty input data vector provided: ");     
00065 
00066       int Nfields = Format::getNumberOfFields();
00067       if (v.size()%Nfields != 0)  throw string("DaqData: ERROR. You must provide a number of input values compatibles with the requested format: ");
00068 
00069 
00070       int ObjSize = Format::getFieldLastBit(Nfields-1)+1;
00071       nobjects_ = v.size()/Nfields;
00072       //      cout<<"Going to create "<<nobjects_<< " objects of type "<<typeid(Format).name()<<endl;
00073 
00074       
00075       size_ = (int) ceil(((double)(ObjSize*nobjects_))/8);
00076       buffer_= new  char[size_];      
00077       //   cout<<"The buffer will be "<<size_ <<" bytes long"<<endl; 
00078 
00079       std::vector<unsigned int>::iterator vit = v.begin();
00080       char * p = buffer_;
00081       int bitsalreadyfilled = 0;
00082 
00083       int Totbytes=1;
00084 
00085       for(int i=0; i<nobjects_; i++) {
00086 
00087         //additional bytes necessary to accomodate the current object
00088         int Nbytes = (int) ceil((double)(Format::getFieldLastBit(Nfields-1)+1-8+bitsalreadyfilled)/8); 
00089 
00090         if ((Totbytes+=Nbytes)  > size_) throw string("Exceeded allocated buffer size");
00091         
00092         compressObject(p, vit, bitsalreadyfilled);
00093 
00094         // cout<<"Successfully compressed object "<< i <<endl; 
00095           
00096         data_.insert(std::pair< int, std::vector<unsigned int> >(i,std::vector<unsigned int>(vit-Nfields,vit) ));
00097 
00098         //the second term is necessary in the case the last byte has been fully used 
00099         p+=(Nbytes+(8-bitsalreadyfilled)/8) ;
00100         Totbytes+=(8-bitsalreadyfilled)/8 ;
00101       }
00102       if(bitsalreadyfilled==0) Totbytes--;
00103 
00104       /*
00105        cout << "Compression successful. "<< Totbytes<<" bytes compressed in total"<< endl;
00106        cout<< "Buffer pointer: "<<hex<< buffer_<< dec << "Size of buffer= "<< size_<<endl;
00107       for(int i=0; i<nobjects_; i++) {
00108         cout << "Object # "<< i << " fields: " <<endl;
00109         for(int j=0; j<Format::getNumberOfFields(); j++) cout << getValue(j,i) <<endl;
00110       }
00111       */
00112 
00113     }
00114 
00115     catch (std::string s){
00116 
00117       cout<<"DaqData - Exception caught: " << s <<endl;
00118       cout<<"Object compression failed! No data has been constructed for format: "<< string(typeid(Format).name())<<endl; 
00119       
00120     }
00121 
00122   }

template<class Format>

DaqData< Format >::DaqData	(	const unsigned char *	ptr,
		int	sizeinbytes
	)			`[inline]`

Definition at line 125 of file DaqData.h.

References GenMuonPlsPt100GeV_cfg::cout, DaqData< Format >::data_, lat::endl(), i, int, name, DaqData< Format >::nobjects_, p, s, and DaqData< Format >::uncompressObject().

00126                            : size_(0), buffer_(0), nobjects_(0) {
00127 
00128 
00129     try {
00130 
00131       if (sizeinbytes==0) throw std::string("Buffer size is zero");
00132 
00133       int Nfields = Format::getNumberOfFields();
00134       int ObjSize = Format::getFieldLastBit(Nfields-1)+1;
00135       nobjects_ = (sizeinbytes*8)/ObjSize;
00136 
00137       // cout<<"Going to create "<<nobjects_<< " objects of type "<<typeid(Format).name()<<endl;
00138       // cout<<"The buffer will be "<<size_ <<" bytes long"<<endl;      
00139 
00140       if ((sizeinbytes*8)%ObjSize != 0) {
00141         cout<<"DaqData: there will be  " << (sizeinbytes*8)%ObjSize <<" meaningless bits at the end of the buffer"<<endl;
00142       }
00143 
00144       //     buffer_ = new char[sizeinbytes];
00145       //     memmove(buffer_,ptr,sizeinbytes);
00146 
00147       //      char * p = buffer_;
00148 
00149       const unsigned char * p = ptr;
00150       int bitsalreadyfilled = 0;
00151       
00152       int Totbytes=1;
00153 
00154       for(int i=0; i<nobjects_; i++) {
00155 
00156         std::vector<unsigned int> objdata;
00157         objdata.reserve(Nfields);
00158 
00159         //additional bytes necessary to accomodate the current object
00160         int Nbytes = (int) ceil((double)(Format::getFieldLastBit(Nfields-1)+1-8+bitsalreadyfilled)/8); 
00161 
00162 
00163         if ((Totbytes+=Nbytes) > sizeinbytes) throw std::string("Exceeded allocated buffer size");
00164 
00165         
00166         uncompressObject(p, objdata, bitsalreadyfilled);
00167      
00168         //      cout<<"Successfully uncompressed object "<< i <<endl; 
00169         data_.insert(std::pair< int, std::vector<unsigned int> >(i,objdata) );
00170 
00171         //the second term is necessary in the case the last byte has been fully used 
00172         p+= (Nbytes + (8-bitsalreadyfilled)/8);
00173         Totbytes+= (8-bitsalreadyfilled)/8;
00174 
00175       }
00176 
00177       if(bitsalreadyfilled==0) Totbytes--;
00178 
00179       /*
00180       cout << "Uncompression succeeded. "<< Totbytes<<" bytes uncompressed in total"<< endl;
00181       cout<< "Buffer pointer: "<<hex<< buffer_<< dec<< "Size of buffer= "<< size_<<endl;
00182 
00183       for(int i=0; i<nobjects_; i++) {
00184         cout << "Object # "<< i << " fields: " <<endl;
00185         for(int j=0; j<Format::getNumberOfFields(); j++) cout << getValue(j,i) <<endl;
00186       }
00187       */
00188 
00189     }
00190     catch (std::string s){
00191 
00192       std::cout<<"DaqData - Exception caught: " << s <<std::endl;
00193       std::cout<<"Object uncompression failed! No data has been constructed for format: "<<std::string(typeid(Format).name())<<endl; 
00194       
00195     }
00196 
00197   }

template<class Format>

DaqData< Format >::DaqData ( const DaqData< Format > & a ) [inline]

Definition at line 200 of file DaqData.h.

References DaqData< Format >::Buffer(), DaqData< Format >::buffer_, DaqData< Format >::data_, DaqData< Format >::getValue(), i, j, DaqData< Format >::Nobjects(), DaqData< Format >::nobjects_, DaqData< Format >::Size(), and DaqData< Format >::size_.

00200                              {
00201 
00202     size_ = a.Size();
00203     buffer_ = new char[size_];
00204     memmove(buffer_,a.Buffer(),size_);    
00205     nobjects_ = a.Nobjects();
00206 
00207     for(int i=0; i<nobjects_; i++) {
00208       std::vector<unsigned int> vec;
00209       for(int j=0; j<Format::getNumberOfFields(); j++) vec.push_back(a.getValue(j,i)); 
00210       data_.insert(std::pair< int, std::vector<unsigned int> >(i, vec));
00211     }
00212 
00213   }

template<class Format>

DaqData< Format >::~DaqData ( ) [inline]

Definition at line 216 of file DaqData.h.

References DaqData< Format >::buffer_.

00216             {
00217 
00218     // cout<<"Deleting DaqData of type "<<typeid(Format).name()<<endl;
00219     if (buffer_!=0) delete [] buffer_;
00220 
00221   };

Member Function Documentation

template<class Format>

char* DaqData< Format >::Buffer ( ) const [inline]

Definition at line 224 of file DaqData.h.

References DaqData< Format >::buffer_.

Referenced by DaqData< Format >::DaqData().

00224 {return buffer_;}

template<class Format>

void DaqData< Format >::compressObject	(	const unsigned char *	ptr,
		std::vector< unsigned int >::iterator &	vit,
		int &	bitsalreadyfilled
	)			`[inline, private]`

Definition at line 375 of file DaqData.h.

References int, and funct::pow().

Referenced by DaqData< Format >::DaqData().

00375                                                                                                                  {
00376 
00377     int Nfields = Format::getNumberOfFields();
00378 
00379     int bitstoaccomodate=Format::getFieldLastBit(0)+1; // of current field
00380     
00381     if (*vit > pow(2.,bitstoaccomodate)-1) throw string("The value is too large to fit in the field ");
00382  
00383     int ifield = 0;
00384 
00385     //Lower all bits but those already filled
00386     *ptr &= 0xff + 1 - (unsigned int)pow(2.,8-bitsalreadyfilled);
00387 
00388     while (ifield < Nfields) {
00389 
00390 
00391       if(bitstoaccomodate > 8 - bitsalreadyfilled ) {
00392 
00393         // cout<<"Field cannot be compressed from what left in current byte"<<endl;
00394         // cout <<"bitstoaccomodate= "<<bitstoaccomodate<<" bitsalreadyfilled= "<<bitsalreadyfilled<<" ifield="<< ifield<<" Nfields="<<Nfields<<endl;
00395 
00396         *ptr += (((*vit) >> (bitstoaccomodate - (8 - bitsalreadyfilled))) & 0xff);
00397         // cout<< "value: "<< hex << *vit <<" - " << dec <<  *vit<< endl;
00398         // cout<< "byte: "<< hex << (unsigned int)(*ptr) <<" - "<< dec << (unsigned int)(*ptr) << endl;
00399 
00400 
00401         bitstoaccomodate -= (8-bitsalreadyfilled);
00402         bitsalreadyfilled = 0;
00403         ptr++;
00404         *ptr &= 0xff + 1 - (unsigned int)pow(2.,8-bitsalreadyfilled);
00405 
00406         // cout <<"bitstoaccomodate= "<<bitstoaccomodate<<" bitsalreadyfilled= "<<bitsalreadyfilled<<" ifield="<< ifield<<" Nfields="<<Nfields<<endl;
00407 
00408       } 
00409 
00410       else if(bitstoaccomodate < (8 - bitsalreadyfilled) && bitstoaccomodate >0){
00411 
00412         // cout<<"Field can be compressed in the current byte, which will not be completely filled"<<endl;
00413 
00414         *ptr += ( (((*vit) << 8-bitstoaccomodate) & 0xff) >> (bitsalreadyfilled) );
00415 
00416         // cout <<"bitstoaccomodate= "<<bitstoaccomodate<<" bitsalreadyfilled= "<<bitsalreadyfilled<<" ifield="<< ifield<<" Nfields="<<Nfields<<endl;
00417         // cout<< "value: "<< hex << *vit <<" - " << dec <<  *vit<< endl;
00418         // cout<< "byte: "<< hex << (unsigned int)(*ptr) <<" - "<< dec << (unsigned int)(*ptr) << endl;
00419 
00420         vit++;
00421         bitsalreadyfilled+=bitstoaccomodate;
00422 
00423         // cout<<"Field completed"<<endl;
00424 
00425         if(ifield==Nfields-1) return;
00426 
00427         // cout<<"Compressing new Field"<<endl;
00428        
00429         ifield++;
00430         bitstoaccomodate=Format::getFieldLastBit(ifield)-Format::getFieldLastBit(ifield-1); 
00431         if (*vit > pow(2.,bitstoaccomodate)-1) throw string("The value is too large to fit in the field ");
00432 
00433         // cout <<"bitstoaccomodate= "<<bitstoaccomodate<<" bitsalreadyfilled= "<<bitsalreadyfilled<<" ifield="<< ifield<<" Nfields="<<Nfields<<endl;
00434 
00435       }
00436 
00437       else if(bitstoaccomodate == (8 - bitsalreadyfilled) && bitstoaccomodate >0){
00438 
00439         // cout<<"Field can be compressed in the current byte, which will be completely filled"<<endl;
00440 
00441 
00442         *ptr += ( (((*vit) << 8-bitstoaccomodate) & 0xff) >> (bitsalreadyfilled) );
00443 
00444         // cout <<"bitstoaccomodate= "<<bitstoaccomodate<<" bitsalreadyfilled= "<<bitsalreadyfilled<<" ifield="<< ifield<<" Nfields="<<Nfields<<endl;
00445         // cout<< "value: "<< hex << *vit <<" - " << dec <<  *vit<< endl;
00446         // cout<< "byte: "<< hex << (unsigned int)(*ptr) <<" - "<< dec << (unsigned int)(*ptr) << endl;
00447 
00448         vit++;
00449         bitsalreadyfilled=0;
00450 
00451         // cout<<"Field completed"<<endl;
00452 
00453         if(ifield==Nfields-1) return;
00454 
00455         // cout<<"Compressing new Field"<<endl;
00456 
00457         ptr++;
00458         *ptr &= 0xff + 1 - (unsigned int)pow(2.,8-bitsalreadyfilled);
00459 
00460         ifield++;
00461         bitstoaccomodate=Format::getFieldLastBit(ifield)-Format::getFieldLastBit(ifield-1);     
00462 
00463         if (*vit > pow(2.,bitstoaccomodate)-1) throw string("The value is too large to fit in the field ");
00464 
00465         // cout <<"bitstoaccomodate= "<<bitstoaccomodate<<" bitsalreadyfilled= "<<bitsalreadyfilled<<" ifield="<< ifield<<" Nfields="<<Nfields<<endl;
00466 
00467       }
00468       else throw string(" unexpected situation during compression");
00469 
00470     } //end of cycle over fields
00471     
00472   }

template<class Format>

unsigned int DaqData< Format >::getValue	(	int	indfield,
		int	indobj = `0`
	)			const `[inline]`

Definition at line 236 of file DaqData.h.

References GenMuonPlsPt100GeV_cfg::cout, DaqData< Format >::data_, lat::endl(), it, and DaqData< Format >::nobjects_.

Referenced by DaqData< Format >::DaqData().

00236                                                           {
00237     
00238     if (indobj<nobjects_ && indfield < Format::getNumberOfFields()) {
00239       std::map < int, std::vector<unsigned int> >::const_iterator it = data_.find(indobj);
00240       if (it != data_.end()) return ((*it).second)[indfield];
00241       else {
00242         cout<<"DaqData - Strange: object should exist but was not found "<<endl;
00243         return 0;
00244       }
00245     }
00246     else  cout<<"DaqData - Non existent field or object"<<endl;
00247     return 0;
00248 
00249   }

template<class Format>

int DaqData< Format >::Nobjects ( ) const [inline]

Definition at line 228 of file DaqData.h.

References DaqData< Format >::nobjects_.

Referenced by DaqData< Format >::DaqData().

00228                        {
00229     return nobjects_;
00230     /*    cout<<"Nobjects()"<<endl;
00231     int Nfields = Format::getNumberOfFields();
00232     return size_/(Format::getFieldLastBit(Nfields-1)+1);
00233     */
00234   }

template<class Format>

int DaqData< Format >::Size ( ) const [inline]

Definition at line 226 of file DaqData.h.

References DaqData< Format >::size_.

Referenced by DaqData< Format >::DaqData().

00226 {return size_;}

template<class Format>

void DaqData< Format >::uncompressObject	(	const unsigned char *	ptr,
		std::vector< unsigned int > &	objdata,
		int &	bitsalreadyfilled
	)			`[inline, private]`

Definition at line 253 of file DaqData.h.

References value.

Referenced by DaqData< Format >::DaqData().

00255                                                  {
00256 
00257     int Nfields = Format::getNumberOfFields();
00258 
00259     int bitstoaccomodate=Format::getFieldLastBit(0)+1; // of current field
00260 
00261     int ifield = 0;
00262     unsigned int value = 0; 
00263 
00264     while (ifield < Nfields) {
00265 
00266       if(bitstoaccomodate > 8 - bitsalreadyfilled ) {
00267 
00268         // cout<<"can't complete value from current byte"<<endl;
00269         // cout <<"bitstoaccomodate= "<<bitstoaccomodate<<" bitsalreadyfilled= "<<bitsalreadyfilled<<" ifield="<< ifield<<" Nfields="<<Nfields<<endl;
00270 
00271         //1)The syntax below could be faster. 
00272         //  To be checked as soon as time available(check started with prog test4.C) .
00273         //2)check if all cast to unsigned int are really necessary(done, they are not).
00274         //3)Instead of using pow(2,1;2;3;4;5..), a faster enum could be used
00275         //Lower all bits but those not yet read
00276         //value += ( (*ptr & ((unsigned int)pow(2.,8-bitsalreadyfilled)-1)) << bitstoaccomodate + bitsalreadyfilled - 8 ) ;
00277         //              if(bitstoaccomodate > 8) value += ( ((((unsigned int)(*ptr)) << bitsalreadyfilled) & 0xff) << (bitstoaccomodate - 8) );
00278         //      else value += ( ((((unsigned int)(*ptr)) << bitsalreadyfilled) & 0xff) >> (8 - bitstoaccomodate) );
00279 
00280 
00281         if(bitstoaccomodate > 8) value += ( ( (*ptr << bitsalreadyfilled) & 0xff ) << (bitstoaccomodate - 8) );
00282         else value += ( ( (*ptr << bitsalreadyfilled) & 0xff) >> (8 - bitstoaccomodate) );
00283         
00284 
00285         // cout<< "value: "<< hex << value << " - " << dec <<  value<< endl;
00286         // cout<< "byte: "<< hex << (unsigned int)(*ptr) << " - " << dec << (unsigned int)(*ptr) << endl;
00287 
00288 
00289         ptr++;
00290         bitstoaccomodate -= (8-bitsalreadyfilled);
00291         bitsalreadyfilled = 0;
00292 
00293         // cout <<"bitstoaccomodate= "<<bitstoaccomodate<<" bitsalreadyfilled= "<<bitsalreadyfilled<<" ifield="<< ifield<<" Nfields="<<Nfields<<endl;
00294         
00295       } 
00296 
00297       else if(bitstoaccomodate < (8 - bitsalreadyfilled) && bitstoaccomodate >0){
00298         // cout<<"value can be completed from current byte, which still contain info"<<endl;
00299 
00300         // cout <<"bitstoaccomodate= "<<bitstoaccomodate<<" bitsalreadyfilled= "<<bitsalreadyfilled<<" ifield="<< ifield<<" Nfields="<<Nfields<<endl;
00301 
00302         //1)The syntax below could be faster. 
00303         //  To be checked as soon as time available.
00304         //2)check if all cast to unsigned int are really necessary.
00305         //3)Instead of using pow(2,1;2;3;4;5..), a faster enum could be used
00306         //Lower all bits but those not yet read
00307         //value += (*ptr & ((unsigned int)pow(2.,8-bitsalreadyfilled)-1)) >> (8 - bitstoaccomodate - bitsalreadyfilled);
00308 
00309         value += ( ( (*ptr << bitsalreadyfilled) & 0xff ) >> (8 - bitstoaccomodate) ) ;
00310 
00311         // cout<< "value: "<< hex << value << " - " << dec <<  value<< endl;
00312         // cout<< "byte: "<< hex << (unsigned int)(*ptr) << " - " << dec << (unsigned int)(*ptr) << endl;
00313 
00314 
00315         objdata.push_back(value);
00316         value = 0;
00317         bitsalreadyfilled+=bitstoaccomodate;
00318 
00319         // cout<<"Field completed"<<endl;
00320 
00321         if(ifield==Nfields-1) return;
00322        
00323         // cout<<"Uncompressing new Field"<<endl;
00324 
00325         ifield++;
00326         bitstoaccomodate=Format::getFieldLastBit(ifield)-Format::getFieldLastBit(ifield-1); 
00327         
00328         // cout <<"bitstoaccomodate= "<<bitstoaccomodate<<" bitsalreadyfilled= "<<bitsalreadyfilled<<" ifield="<< ifield<<" Nfields="<<Nfields<<endl;
00329 
00330       }
00331 
00332       else if(bitstoaccomodate == (8 - bitsalreadyfilled) && bitstoaccomodate >0){
00333         // cout<<"value can be completed from what left in current byte"<<endl; 
00334         // cout <<"bitstoaccomodate= "<<bitstoaccomodate<<" bitsalreadyfilled= "<<bitsalreadyfilled<<" ifield="<< ifield<<" Nfields="<<Nfields<<endl;
00335 
00336         //1)The syntax below could be faster. 
00337         //  To be checked as soon as time available.
00338         //2)check if all cast to unsigned int are really necessary.
00339         //3)Instead of using pow(2,1;2;3;4;5..), a faster enum could be used
00340         //Lower all bits but those not yet read
00341         //      value += *ptr & ((unsigned int)pow(2.,8-bitsalreadyfilled)-1);
00342 
00343         value += ( ( (*ptr << bitsalreadyfilled) & 0xff ) >> (8 - bitstoaccomodate) ) ;
00344 
00345         // cout<< "value: "<< hex << value << " - " << dec <<  value<< endl;
00346         // cout<< "byte: "<< hex << (unsigned int)(*ptr) << " - " << dec << (unsigned int)(*ptr) << endl;
00347 
00348 
00349         objdata.push_back(value);
00350         value = 0;
00351         bitsalreadyfilled=0;
00352 
00353         // cout<<"Field completed"<<endl;
00354 
00355         if(ifield==Nfields-1) return;
00356 
00357         // cout<<"Uncompressing new Field"<<endl;
00358 
00359         ptr++;
00360         ifield++;
00361         bitstoaccomodate=Format::getFieldLastBit(ifield)-Format::getFieldLastBit(ifield-1);     
00362 
00363         // cout <<"bitstoaccomodate= "<<bitstoaccomodate<<" bitsalreadyfilled= "<<bitsalreadyfilled<<" ifield="<< ifield<<" Nfields="<<Nfields<<endl;
00364 
00365       }
00366       else throw std::string(" unexpected situation during uncompression");
00367 
00368     } //end of cycle over fields
00369     
00370   }


Public Member Functions
char *	Buffer () const
	DaqData (const DaqData &a)
	DaqData (const unsigned char *ptr, int sizeinbytes)
	DaqData (std::vector< unsigned int > &v)
unsigned int	getValue (int indfield, int indobj=0) const
int	Nobjects () const
int	Size () const
	~DaqData ()
Private Member Functions
void	compressObject (const unsigned char *ptr, std::vector< unsigned int >::iterator &vit, int &bitsalreadyfilled)
void	uncompressObject (const unsigned char *ptr, std::vector< unsigned int > &objdata, int &bitsalreadyfilled)
Private Attributes
unsigned char *	buffer_
std::map< int, std::vector < unsigned int > >	data_
int	nobjects_
int	size_

DaqData< Format > Class Template Reference

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

template<class Format>
class DaqData< Format >

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

DaqData< Format > Class Template Reference

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

template<class Format> class DaqData< Format >

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

template<class Format>
class DaqData< Format >