1 /* ebuf.c - an expanding buffer */
2
3 /* Copyright 1993 Mark Russell, University of Kent at Canterbury
4 *
5 * You can do what you like with this source code as long as
6 * you don't try to make money out of it and you include an
7 * unaltered copy of this message (including the copyright).
8 */
9
10 char ukcprog_ebuf_sccsid[] = "$Id: ebuf.c,v 1.7 1995/11/26 15:59:21 mtr Exp $ UKC";
11
12 #include <stdlib.h>
13 #include <string.h>
14
15 #include "ukcprog.h"
16
17 struct ebuf_s {
18 bool eb_errors_are_fatal;
19 char *eb_buf;
20 size_t eb_bufsize;
21 size_t eb_pos;
22 };
23
24 ebuf_t *
ebuf_create(errors_are_fatal)25 ebuf_create(errors_are_fatal)
26 bool errors_are_fatal;
27 {
28 ebuf_t *eb;
29 char *buf;
30 size_t bufsize;
31
32 bufsize = 100;
33
34 if (errors_are_fatal) {
35 eb = (ebuf_t *)e_malloc(sizeof(ebuf_t));
36 buf = e_malloc(bufsize);
37 }
38 else {
39 if ((eb = (ebuf_t *)malloc(sizeof(ebuf_t))) == NULL)
40 return NULL;
41 if ((buf = malloc(bufsize)) == NULL) {
42 free((char *)eb);
43 return NULL;
44 }
45 }
46
47 eb->eb_errors_are_fatal = errors_are_fatal;
48 eb->eb_buf = buf;
49 eb->eb_bufsize = bufsize;
50 eb->eb_pos = 0;
51
52 return eb;
53 }
54
55 void
ebuf_reset(eb)56 ebuf_reset(eb)
57 ebuf_t *eb;
58 {
59 eb->eb_pos = 0;
60 }
61
62 /* We would like this to take a pointer to a size_t, but that would
63 * break existing code (when compiling with gcc). Maybe later.
64 */
65 voidptr
ebuf_get(eb,p_len)66 ebuf_get(eb, p_len)
67 ebuf_t *eb;
68 int *p_len;
69 {
70 if (p_len != NULL)
71 *p_len = eb->eb_pos;
72 return eb->eb_buf;
73 }
74
75 ebuf_t *
ebuf_start(eb,errors_are_fatal)76 ebuf_start(eb, errors_are_fatal)
77 ebuf_t *eb;
78 bool errors_are_fatal;
79 {
80 if (eb == NULL)
81 eb = ebuf_create(errors_are_fatal);
82 else
83 ebuf_reset(eb);
84
85 return eb;
86 }
87
88 void
ebuf_free(eb)89 ebuf_free(eb)
90 ebuf_t *eb;
91 {
92 free(eb->eb_buf);
93 free((char *)eb);
94 }
95
96 int
ebuf_add(eb,buf,count)97 ebuf_add(eb, buf, count)
98 ebuf_t *eb;
99 constvoidptr buf;
100 size_t count;
101 {
102 size_t size;
103
104 for (size = eb->eb_bufsize; eb->eb_pos + count > size; size *= 2)
105 ;
106
107 if (size != eb->eb_bufsize) {
108 if ((eb->eb_buf = realloc(eb->eb_buf, size)) == NULL) {
109 if (eb->eb_errors_are_fatal)
110 panic("realloc failed in ebuf_add");
111 return -1;
112 }
113 eb->eb_bufsize = size;
114 }
115
116 memcpy(eb->eb_buf + eb->eb_pos, buf, count);
117 eb->eb_pos += count;
118
119 return 0;
120 }
121
122 int
ebuf_addstr(eb,str)123 ebuf_addstr(eb, str)
124 ebuf_t *eb;
125 const char *str;
126 {
127 return ebuf_add(eb, str, strlen(str));
128 }
129