src/buffer.c

   1 /* gAlan - Graphical Audio Language
   2  * Copyright (C) 1999 Tony Garnock-Jones
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  17  */
  18
  19 #include <stdlib.h>
  20 #include <stdio.h>
  21 #include <string.h>
  22
  23 #include "buffer.h"
  24
  25 BUFFER newbuf(int initial_length) {
  26   BUFFER buf = malloc(sizeof(Buffer));
  27
  28   buf->buflength = initial_length;
  29   buf->pos = 0;
  30   buf->buf = malloc(initial_length);
  31   memset(buf->buf, 0, initial_length);
  32
  33   return buf;
  34 }
  35
  36 BUFFER dupbuf(BUFFER buf) {
  37   BUFFER n = malloc(sizeof(Buffer));
  38
  39   n->buflength = buf->buflength;
  40   n->pos = buf->pos;
  41   n->buf = malloc(buf->buflength);
  42   memcpy(n->buf, buf->buf, buf->buflength);
  43
  44   return n;
  45 }
  46
  47 void killbuf(BUFFER buf) {
  48   free(buf->buf);
  49   free(buf);
  50 }
  51
  52 void buf_append(BUFFER buf, char ch) {
  53   if (buf->pos >= buf->buflength) {
  54     char *newbuf = malloc(buf->buflength + 128);
  55
  56     if (newbuf == NULL) {
  57       fprintf(stderr, "buf_append: could not grow buffer\n");
  58       exit(1);
  59     }
  60
  61     memset(newbuf, 0, buf->buflength + 128);
  62     memcpy(newbuf, buf->buf, buf->buflength);
  63     free(buf->buf);
  64     buf->buf = newbuf;
  65     buf->buflength += 128;
  66   }
  67
  68   buf->buf[buf->pos++] = ch;
  69 }
  70
  71 void buf_insert(BUFFER buf, char ch, int pos) {
  72   int i;
  73
  74   if (pos < 0)
  75     pos = 0;
  76   if (pos > buf->pos)
  77     pos = buf->pos;
  78
  79   buf_append(buf, 0);
  80   for (i = buf->pos; i > pos; i--)
  81     buf->buf[i] = buf->buf[i-1];
  82   buf->buf[pos] = ch;
  83 }
  84
  85 void buf_delete(BUFFER buf, int pos) {
  86   int i;
  87
  88   if (pos < 0)
  89     pos = 0;
  90   if (pos >= buf->pos)
  91     pos = buf->pos - 1;
  92
  93   for (i = pos; i < buf->pos; i++)
  94     buf->buf[i] = buf->buf[i+1];
  95   buf->buf[buf->pos - 1] = '\0';
  96   buf->pos--;
  97 }