libowfat/stralloc/stralloc_ready.c

#include "stralloc.h"
#include <stdlib.h>

/* stralloc_ready makes sure that sa has enough space allocated to hold
 * len bytes: If sa is not allocated, stralloc_ready allocates at least
 * len bytes of space, and returns 1. If sa is already allocated, but
 * not enough to hold len bytes, stralloc_ready allocates at least len
 * bytes of space, copies the old string into the new space, frees the
 * old space, and returns 1. Note that this changes sa.s. */
int stralloc_ready(stralloc *sa,size_t len) {
  register size_t wanted=len+(len>>3)+30; /* heuristic from djb */
  if (!sa->s || sa->a<len) {
    register char* tmp;
    if (!(tmp=realloc(sa->s,wanted)))
      return 0;
    sa->a=wanted;
    sa->s=tmp;
  }
  return 1;
}