1 /*
2  * Copyright (c) 2021 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 "parser.h"
18 #include "telescope.h"
19 
20 #include <stdlib.h>
21 #include <string.h>
22 
23 void
24 parser_init(struct tab *tab, parserfn fn)
25 {
26 	fn(&tab->buffer.page);
27 }
28 
29 int
30 parser_parse(struct tab *tab, const char *chunk, size_t len)
31 {
32 	return tab->buffer.page.parse(&tab->buffer.page, chunk, len);
33 }
34 
35 int
36 parser_free(struct tab *tab)
37 {
38 	int r;
39 
40 	r = tab->buffer.page.free(&tab->buffer.page);
41 
42 	/* fallback to the host as title if nothing else */
43 	if (*tab->buffer.page.title == '\0')
44 		strlcpy(tab->buffer.page.title, tab->uri.host,
45 		    sizeof(tab->buffer.page.title));
46 
47 	return r;
48 }
49 
50 int
51 parser_append(struct parser *p, const char *buf, size_t len)
52 {
53 	size_t newlen;
54 	char *t;
55 
56 	newlen = len + p->len;
57 	if ((t = calloc(1, newlen)) == NULL)
58 		return 0;
59 	memcpy(t, p->buf, p->len);
60 	memcpy(t + p->len, buf, len);
61 	free(p->buf);
62 	p->buf = t;
63 	p->len = newlen;
64 	return 1;
65 }
66 
67 int
68 parser_set_buf(struct parser *p, const char *buf, size_t len)
69 {
70 	char *tmp;
71 
72 	if (len == 0) {
73 		p->len = 0;
74 		free(p->buf);
75 		p->buf = NULL;
76 		return 1;
77 	}
78 
79 	/*
80 	 * p->buf and buf can (and probably almost always will)
81 	 * overlap!
82 	 */
83 
84 	if ((tmp = calloc(1, len)) == NULL)
85 		return 0;
86 	memcpy(tmp, buf, len);
87 	free(p->buf);
88 	p->buf = tmp;
89 	p->len = len;
90 	return 1;
91 }
92 
93 int
94 parser_foreach_line(struct parser *p, const char *buf, size_t size,
95     parsechunkfn fn)
96 {
97 	char		*b, *e;
98 	unsigned int	 ch;
99 	size_t		 i, l, len;
100 
101 	if (!parser_append(p, buf, size))
102 		return 0;
103 	b = p->buf;
104 	len = p->len;
105 
106 	if (!(p->flags & PARSER_IN_BODY) && len < 3)
107 		return 1;
108 
109 	if (!(p->flags & PARSER_IN_BODY)) {
110                 p->flags |= PARSER_IN_BODY;
111 
112 		/*
113 		 * drop the BOM: only UTF-8 is supported, and there
114 		 * it's useless; some editors may still add one
115 		 * though.
116 		 */
117 		if (memmem(b, len, "\xEF\xBB\xBF", 3) == b) {
118 			b += 3;
119 			len -= 3;
120 		}
121 	}
122 
123 	/* drop every "funny" ASCII character */
124 	for (i = 0; i < len; ) {
125 		ch = b[i];
126 		if ((ch >= ' ' || ch == '\n' || ch == '\t')
127 		    && ch != 127) { /* del */
128 			++i;
129 			continue;
130 		}
131 		memmove(&b[i], &b[i+1], len - i - 1);
132 		len--;
133 	}
134 
135 	while (len > 0) {
136 		if ((e = memmem((char*)b, len, "\n", 1)) == NULL)
137 			break;
138 		l = e - b;
139 
140 		if (!fn(p, b, l))
141 			return 0;
142 
143 		len -= l;
144 		b += l;
145 
146 		if (len > 0) {
147 			/* skip \n */
148 			len--;
149 			b++;
150 		}
151 	}
152 
153 	return parser_set_buf(p, b, len);
154 }