1 /*
2  * Copyright (c) 2022 Omar Polo <op@omarpolo.com>
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 #include "compat.h"
18 
19 #include <stdlib.h>
20 #include <stdint.h>
21 #include <string.h>
22 
23 #include "telescope.h"
24 #include "mcache.h"
25 #include "parser.h"
26 #include "utils.h"
27 
28 const char *gemtext_prefixes[] = {
29 	[LINE_TEXT] = "",
30 	[LINE_TITLE_1] = "# ",
31 	[LINE_TITLE_2] = "## ",
32 	[LINE_TITLE_3] = "### ",
33 	[LINE_ITEM] = "* ",
34 	[LINE_QUOTE] = "> ",
35 	[LINE_PRE_START] = "``` ",
36 	[LINE_PRE_CONTENT] = "",
37 	[LINE_PRE_END] = "```",
38 };
39 
40 struct mcache {
41 	struct ohash	h;
42 	size_t		npages;
43 	size_t		tot;
44 } mcache;
45 
46 struct mcache_entry {
47 	const char	*parser_name;
48 	int		 trust;
49 	struct evbuffer	*evb;
50 	char		 url[];
51 };
52 
53 static void
54 mcache_free_entry(const char *url)
55 {
56 	struct mcache_entry	*e;
57 	unsigned int		 slot;
58 
59 	slot = ohash_qlookup(&mcache.h, url);
60 	if ((e = ohash_remove(&mcache.h, slot)) == NULL)
61 		return;
62 
63 	mcache.npages--;
64 	mcache.tot -= EVBUFFER_LENGTH(e->evb);
65 
66 	evbuffer_free(e->evb);
67 	free(e);
68 }
69 
70 void
71 mcache_init(void)
72 {
73 	struct ohash_info info = {
74 		.key_offset = offsetof(struct mcache_entry, url),
75 		.calloc = hash_calloc,
76 		.free = hash_free,
77 		.alloc = hash_alloc,
78 	};
79 
80 	ohash_init(&mcache.h, 5, &info);
81 }
82 
83 int
84 mcache_tab(struct tab *tab)
85 {
86 	struct mcache_entry	*e;
87 	struct line		*line;
88 	unsigned int		 slot;
89 	size_t			 l, len;
90 	const char		*url;
91 
92 	url = tab->hist_cur->h;
93 	l = strlen(url);
94 	len = sizeof(*e) + l + 1;
95 
96 	if ((e = calloc(1, len)) == NULL)
97 		return -1;
98 	e->parser_name = tab->buffer.page.name;
99 	e->trust = tab->trust;
100 	memcpy(e->url, url, l);
101 
102 	if ((e->evb = evbuffer_new()) == NULL)
103 		goto err;
104 
105 	TAILQ_FOREACH(line, &tab->buffer.page.head, lines) {
106 		const char	*text, *alt;
107 		int		 r;
108 
109 		if ((text = line->line) == NULL)
110 			text = "";
111 
112 		if ((alt = line->alt) == NULL)
113 			alt = "";
114 
115 		switch (line->type) {
116 		case LINE_TEXT:
117 		case LINE_TITLE_1:
118 		case LINE_TITLE_2:
119 		case LINE_TITLE_3:
120 		case LINE_ITEM:
121 		case LINE_QUOTE:
122 		case LINE_PRE_START:
123 		case LINE_PRE_CONTENT:
124 		case LINE_PRE_END:
125 			r = evbuffer_add_printf(e->evb, "%s%s\n",
126 			    gemtext_prefixes[line->type], text);
127 			break;
128 
129 		case LINE_LINK:
130 			r = evbuffer_add_printf(e->evb, "=> %s %s\n",
131 			    alt, text);
132 			break;
133 
134 		case LINE_PATCH:
135 		case LINE_PATCH_HDR:
136 		case LINE_PATCH_HUNK_HDR:
137 		case LINE_PATCH_ADD:
138 		case LINE_PATCH_DEL:
139 			/* TODO */
140 			r = -1;
141 			break;
142 
143 		case LINE_COMPL:
144 		case LINE_COMPL_CURRENT:
145 		case LINE_HELP:
146 		case LINE_DOWNLOAD:
147 		case LINE_DOWNLOAD_DONE:
148 		case LINE_DOWNLOAD_INFO:
149 		case LINE_FRINGE:
150 			/* not reached */
151 			abort();
152 		}
153 
154 		if (r == -1)
155 			goto err;
156 	}
157 
158 	/* free any previously cached copies of this page */
159 	mcache_free_entry(url);
160 
161 	slot = ohash_qlookup(&mcache.h, url);
162 	ohash_insert(&mcache.h, slot, e);
163 
164 	mcache.npages++;
165 	mcache.tot += EVBUFFER_LENGTH(e->evb);
166 
167 	return 0;
168 
169 err:
170 	if (e->evb != NULL)
171 		evbuffer_free(e->evb);
172 	free(e);
173 	return -1;
174 }
175 
176 int
177 mcache_lookup(const char *url, struct tab *tab)
178 {
179 	struct mcache_entry	*e;
180 	unsigned int		 slot;
181 
182 	slot = ohash_qlookup(&mcache.h, url);
183 	if ((e = ohash_find(&mcache.h, slot)) == NULL)
184 		return 0;
185 
186 	parser_init(tab, gemtext_initparser);
187 	if (!parser_parse(tab, EVBUFFER_DATA(e->evb), EVBUFFER_LENGTH(e->evb)))
188 		goto err;
189 	if (!parser_free(tab))
190 		goto err;
191 
192 	tab->buffer.page.name = e->parser_name;
193 	tab->trust = e->trust;
194 	return 1;
195 
196 err:
197 	parser_free(tab);
198 	erase_buffer(&tab->buffer);
199 	return 0;
200 }
201 
202 void
203 mcache_info(size_t *npages, size_t *tot)
204 {
205 	*npages = mcache.npages;
206 	*tot = mcache.tot;
207 }