sys/src/libString/s_grow.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include "String.h"
   4
   5 /* grow a String's allocation by at least `incr' bytes */
   6 extern String*
   7 s_grow(String *s, int incr)
   8 {
   9         char *cp;
  10         int size;
  11
  12         if(s->fixed)
  13                 sysfatal("s_grow of constant string");
  14         s = s_unique(s);
  15
  16         /*
  17          *  take a larger increment to avoid mallocing too often
  18          */
  19         size = s->end-s->base;
  20         if(size/2 < incr)
  21                 size += incr;
  22         else
  23                 size += size/2;
  24
  25         cp = realloc(s->base, size);
  26         if (cp == 0)
  27                 sysfatal("s_grow: %r");
  28         s->ptr = (s->ptr - s->base) + cp;
  29         s->end = cp + size;
  30         s->base = cp;
  31
  32         return s;
  33 }
  34