1 /*
2 * Copyright (c) 2011 Tim van der Molen <tim@kariliq.nl>
3 *
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
16
17 #ifdef __OpenBSD__
18 #include <sys/queue.h>
19 #else
20 #include "compat/queue.h"
21 #endif
22
23 #include <stdlib.h>
24 #include <string.h>
25
26 #include "siren.h"
27
28 struct history_entry {
29 char *line;
30 TAILQ_ENTRY(history_entry) entries;
31 };
32
33 TAILQ_HEAD(history_list, history_entry);
34
35 struct history {
36 struct history_list list;
37 struct history_entry *current_entry;
38 };
39
40 void
history_add(struct history * h,const char * line)41 history_add(struct history *h, const char *line)
42 {
43 struct history_entry *e;
44
45 /* Only add the entry if it is different from the last one. */
46 if ((e = TAILQ_FIRST(&h->list)) == NULL || strcmp(e->line, line)) {
47 e = xmalloc(sizeof *e);
48 e->line = xstrdup(line);
49 TAILQ_INSERT_HEAD(&h->list, e, entries);
50 }
51 }
52
53 void
history_free(struct history * h)54 history_free(struct history *h)
55 {
56 struct history_entry *e;
57
58 while ((e = TAILQ_FIRST(&h->list)) != NULL) {
59 TAILQ_REMOVE(&h->list, e, entries);
60 free(e->line);
61 free(e);
62 }
63 free(h);
64 }
65
66 const char *
history_get_next(struct history * h)67 history_get_next(struct history *h)
68 {
69 if (h->current_entry == NULL) {
70 if ((h->current_entry = TAILQ_FIRST(&h->list)) == NULL)
71 /* History is empty. */
72 return NULL;
73 } else {
74 if (h->current_entry == TAILQ_LAST(&h->list, history_list))
75 /* End of history reached. */
76 return NULL;
77 h->current_entry = TAILQ_NEXT(h->current_entry, entries);
78 }
79
80 return h->current_entry->line;
81 }
82
83 const char *
history_get_prev(struct history * h)84 history_get_prev(struct history *h)
85 {
86 if (h->current_entry == NULL)
87 return NULL;
88
89 if ((h->current_entry = TAILQ_PREV(h->current_entry, history_list,
90 entries)) == NULL)
91 return NULL;
92
93 return h->current_entry->line;
94 }
95
96 struct history *
history_init(void)97 history_init(void)
98 {
99 struct history *h;
100
101 h = xmalloc(sizeof *h);
102 TAILQ_INIT(&h->list);
103 h->current_entry = NULL;
104
105 return h;
106 }
107
108 void
history_rewind(struct history * h)109 history_rewind(struct history *h)
110 {
111 h->current_entry = NULL;
112 }
113