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 /*
18  * A streaming text/plain "parser."
19  */
20 
21 #include "telescope.h"
22 
23 #include <stdlib.h>
24 #include <string.h>
25 
26 static int	textplain_parse(struct parser*, const char*, size_t);
27 static int	textplain_free(struct parser*);
28 
29 static inline int
30 emit_line(struct parser *p, enum line_type type, const char *line, size_t len)
31 {
32 	struct line *l;
33 
34 	if ((l = calloc(1, sizeof(*l))) == NULL)
35 		return 0;
36 
37 	l->type = type;
38 
39 	if (len != 0) {
40 		if ((l->line = calloc(1, len+1)) == NULL) {
41 			free(l);
42 			return 0;
43 		}
44 
45 		memcpy(l->line, line, len);
46 	}
47 
48 	if (TAILQ_EMPTY(&p->head))
49 		TAILQ_INSERT_HEAD(&p->head, l, lines);
50 	else
51 		TAILQ_INSERT_TAIL(&p->head, l, lines);
52 
53 	return 1;
54 }
55 
56 void
57 textplain_initparser(struct parser *p)
58 {
59 	memset(p, 0, sizeof(*p));
60 
61 	p->parse = &textplain_parse;
62 	p->free = &textplain_free;
63 
64 	emit_line(p, LINE_PRE_START, NULL, 0);
65 }
66 
67 static inline int
68 append(struct parser *p, const char *buf, size_t len)
69 {
70 	size_t newlen;
71 	char *t;
72 
73 	newlen = len + p->len;
74 	if ((t = calloc(1, newlen)) == NULL)
75 		return 0;
76 	memcpy(t, p->buf, p->len);
77 	memcpy(t + p->len, buf, len);
78 	free(p->buf);
79 	p->buf = t;
80 	p->len = newlen;
81 	return 1;
82 }
83 
84 static inline int
85 set_buf(struct parser *p, const char *buf, size_t len)
86 {
87 	free(p->buf);
88 	p->buf = NULL;
89 
90 	if (len == 0) {
91 		p->len = 0;
92 		return 1;
93 	}
94 
95 	if ((p->buf = calloc(1, len)) == NULL)
96 		return 0;
97 	memcpy(p->buf, buf, len);
98 	p->len = len;
99 	return 1;
100 }
101 
102 static int
103 textplain_parse(struct parser *p, const char *buf, size_t size)
104 {
105 	const char	*b, *e;
106 	size_t		 len, l;
107 	int		 r;
108 
109 	if (p->len == 0) {
110 		b = buf;
111 		len = size;
112 	} else {
113 		if (!append(p, buf, size))
114 			return 0;
115 		b = p->buf;
116 		len = p->len;
117 	}
118 
119 	while (len > 0) {
120 		if ((e = telescope_strnchr((char*)b, '\n', len)) == NULL)
121 			break;
122 		l = e - b;
123 
124 		r = emit_line(p, LINE_PRE_CONTENT, b, l);
125 		if (!r)
126 			return 0;
127 
128 		len -= l;
129 		b += l;
130 
131 		if (len > 0) {
132 			/* skip \n */
133 			len--;
134 			b++;
135 		}
136 	}
137 
138 	return set_buf(p, b, len);
139 }
140 
141 static int
142 textplain_free(struct parser *p)
143 {
144 	/* flush the buffer */
145 	if (p->len != 0) {
146 		if (!emit_line(p, LINE_PRE_CONTENT, p->buf, p->len))
147 			return 0;
148 	}
149 
150 	return emit_line(p, LINE_PRE_END, NULL, 0);
151 }