sbuf.c

   1 /* variable length string buffer */
   2 #include <stdarg.h>
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <string.h>
   6 #include "roff.h"
   7
   8 #define ALIGN(n, a)     (((n) + (a) - 1) & ~((a) - 1))
   9 #define SBUFSZ          512
  10
  11 static void sbuf_extend(struct sbuf *sbuf, int amount)
  12 {
  13         sbuf->sz = ALIGN(amount, SBUFSZ);
  14         sbuf->s = mextend(sbuf->s, sbuf->n, sbuf->sz, sizeof(sbuf->s[0]));
  15 }
  16
  17 void sbuf_init(struct sbuf *sbuf)
  18 {
  19         memset(sbuf, 0, sizeof(*sbuf));
  20         sbuf_extend(sbuf, SBUFSZ);
  21 }
  22
  23 void sbuf_add(struct sbuf *sbuf, int c)
  24 {
  25         if (sbuf->n + 2 >= sbuf->sz)
  26                 sbuf_extend(sbuf, sbuf->sz * 2);
  27         sbuf->s[sbuf->n++] = c;
  28 }
  29
  30 void sbuf_append(struct sbuf *sbuf, char *s)
  31 {
  32         int len = strlen(s);
  33         if (sbuf->n + len + 1 >= sbuf->sz)
  34                 sbuf_extend(sbuf, sbuf->n + len + 1);
  35         memcpy(sbuf->s + sbuf->n, s, len);
  36         sbuf->n += len;
  37 }
  38
  39 void sbuf_printf(struct sbuf *sbuf, char *s, ...)
  40 {
  41         char buf[ILNLEN];
  42         va_list ap;
  43         va_start(ap, s);
  44         vsnprintf(buf, sizeof(buf), s, ap);
  45         va_end(ap);
  46         sbuf_append(sbuf, buf);
  47 }
  48
  49 int sbuf_empty(struct sbuf *sbuf)
  50 {
  51         return !sbuf->n;
  52 }
  53
  54 char *sbuf_buf(struct sbuf *sbuf)
  55 {
  56         sbuf->s[sbuf->n] = '\0';
  57         return sbuf->s;
  58 }
  59
  60 int sbuf_len(struct sbuf *sbuf)
  61 {
  62         return sbuf->n;
  63 }
  64
  65 /* shorten the sbuf */
  66 void sbuf_cut(struct sbuf *sbuf, int n)
  67 {
  68         if (sbuf->n > n)
  69                 sbuf->n = n;
  70 }
  71
  72 void sbuf_done(struct sbuf *sbuf)
  73 {
  74         free(sbuf->s);
  75 }
  76
  77 char *sbuf_out(struct sbuf *sbuf)
  78 {
  79         char *s = sbuf->s;
  80         memset(sbuf, 0, sizeof(*sbuf));
  81         return s;
  82 }