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->name = "text/plain";
62 	p->parse = &textplain_parse;
63 	p->free = &textplain_free;
64 
65 	emit_line(p, LINE_PRE_START, NULL, 0);
66 }
67 
68 static inline int
69 append(struct parser *p, const char *buf, size_t len)
70 {
71 	size_t newlen;
72 	char *t;
73 
74 	newlen = len + p->len;
75 	if ((t = calloc(1, newlen)) == NULL)
76 		return 0;
77 	memcpy(t, p->buf, p->len);
78 	memcpy(t + p->len, buf, len);
79 	free(p->buf);
80 	p->buf = t;
81 	p->len = newlen;
82 	return 1;
83 }
84 
85 static inline int
86 set_buf(struct parser *p, const char *buf, size_t len)
87 {
88 	free(p->buf);
89 	p->buf = NULL;
90 
91 	if (len == 0) {
92 		p->len = 0;
93 		return 1;
94 	}
95 
96 	if ((p->buf = calloc(1, len)) == NULL)
97 		return 0;
98 	memcpy(p->buf, buf, len);
99 	p->len = len;
100 	return 1;
101 }
102 
103 static int
104 textplain_parse(struct parser *p, const char *buf, size_t size)
105 {
106 	const char	*b, *e;
107 	size_t		 len, l;
108 	int		 r;
109 
110 	if (p->len == 0) {
111 		b = buf;
112 		len = size;
113 	} else {
114 		if (!append(p, buf, size))
115 			return 0;
116 		b = p->buf;
117 		len = p->len;
118 	}
119 
120 	while (len > 0) {
121 		if ((e = telescope_strnchr((char*)b, '\n', len)) == NULL)
122 			break;
123 		l = e - b;
124 
125 		r = emit_line(p, LINE_PRE_CONTENT, b, l);
126 		if (!r)
127 			return 0;
128 
129 		len -= l;
130 		b += l;
131 
132 		if (len > 0) {
133 			/* skip \n */
134 			len--;
135 			b++;
136 		}
137 	}
138 
139 	return set_buf(p, b, len);
140 }
141 
142 static int
143 textplain_free(struct parser *p)
144 {
145 	/* flush the buffer */
146 	if (p->len != 0) {
147 		if (!emit_line(p, LINE_PRE_CONTENT, p->buf, p->len))
148 			return 0;
149 	}
150 
151 	return emit_line(p, LINE_PRE_END, NULL, 0);
152 }