dos_compilers/Zortech C++ v206/TOOLS/SOURCE/DYNARR.CPP
2024-07-02 07:30:38 -07:00

55 lines
1.8 KiB
C++

#include <string.h>
#include "dynarr.hpp"
typedef void (* PFC)(int,char *);
extern void default_error(int,char *);
PFC dynarr_handler = default_error; // set handler to default
int dynarr::resize(unsigned newsize) // change the size of the storage block
{ // this will always be an increase
char *p = new char[newsize*es];
if (!p)
return -1; // signal failure
memset(p,'\0',newsize*es); // set all to zero
memmove(p,body,elems*es); // then copy in existing elements
delete body; // zap the old storage
body = p; // and point to new
elems = newsize; // adjust the element count
return 0;
}
dynarr::dynarr(unsigned n,unsigned elemsize)
{
elems = n;
es = elemsize;
dummy = new char[es]; // used on allocation error
if (!dummy)
goto err1;
body = new char[es*elems]; // allocate requested storage (default one)
if (!body) {
err1:
dynarr_handler(ENOMEM,"dynarr - not enough memory");
return; // call whatever error handler is installed
}
memset(body,'\0',es*elems); // initialize storage to zero
}
char *dynarr::access(unsigned i)
{
if (i >= elems) { // requested index outside current storage
if (resize(i+1)) { // elems is 1 > index
dynarr_handler(ENOMEM,"dynarr - not enough memory");
return dummy; // give access to something safe
}
}
return body+i*es; // pointer to appropriate block
}
PFC set_dynarr_handler(PFC handler)
{ // function to set error handling
PFC local = dynarr_handler;
dynarr_handler = handler;
return local;
}