littleendian_strings.cxx

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#include <cstring>
#include "Rtypes.h"
#include "RawData/littleendian_strings.h"

//____________________________________________________________________________

UInt_t nwords_in_string(const Char_t* x) {
   // add 1 for \0, pad up to the next Int_t
   UInt_t csize = strlen(x);
   return ((csize+1)+(sizeof(Int_t)-1))/sizeof(Int_t);
}

//____________________________________________________________________________
void pack_string_in_lel(Int_t* dest_i ,const Char_t* src_c) {
   // Put string in an array of little endian long words (32 bit)
   // pad out to full word as necessary
   // Assume destination has sufficient space

   UInt_t nchar = strlen(src_c);
   UInt_t nwd   = nwords_in_string(src_c);

   Char_t* dest_c = (Char_t*) dest_i;

   dest_i[nwd-1] = 0;           // pad out last full word to zeros
   memcpy(dest_c,src_c,nchar);  // copy up to '\0'

   // byte swap as necessary to get little endian ordering
   for (UInt_t i=0; i<nwd; ++i) 
      dest_i[i] = (Int_t)minos_htolel((UInt_t)dest_i[i]);
}

//____________________________________________________________________________
Char_t* unpack_lel_to_string(const Int_t* src_i, UInt_t nwd) {
   // return the string that is packed into an array of little endian
   // long words (32 bit)
   // NOTE: the user is responsible for deleting this memory
  
   const UInt_t cperl = sizeof(Int_t)/sizeof(Char_t);

   UInt_t nchar = nwd*cperl;

   Char_t* dest_c = new Char_t [nchar];
   Int_t*  dest_i = (Int_t*) dest_c;
   const Char_t* src_c  = (const Char_t*) src_i;
   memcpy(dest_c,src_c,nchar);

   // byte swap as necessary to deal with original little endian-ness
   for (UInt_t i=0; i<nwd; ++i) 
      dest_i[i] = (Int_t)minos_letohl((UInt_t)dest_i[i]);

   return dest_c;
}

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