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/x-patch parser
19  */
20 
21 #include <stdlib.h>
22 #include <string.h>
23 
24 #include "telescope.h"
25 #include "parser.h"
26 #include "utils.h"
27 
28 static int	tpatch_parse(struct parser *, const char *, size_t);
29 static int	tpatch_emit_line(struct parser *, const char *, size_t);
30 static int	tpatch_foreach_line(struct parser *, const char *, size_t);
31 static int	tpatch_free(struct parser *);
32 
33 void
34 textpatch_initparser(struct parser *p)
35 {
36 	memset(p, 0, sizeof(*p));
37 
38 	p->name = "text/x-patch";
39 	p->parse = &tpatch_parse;
40 	p->free = &tpatch_free;
41 
42 	p->flags = PARSER_IN_PATCH_HDR;
43 
44 	TAILQ_INIT(&p->head);
45 }
46 
47 static int
48 tpatch_parse(struct parser *p, const char *buf, size_t size)
49 {
50 	return parser_foreach_line(p, buf, size, tpatch_foreach_line);
51 }
52 
53 static int
54 tpatch_emit_line(struct parser *p, const char *line, size_t linelen)
55 {
56 	struct line *l;
57 
58 	if ((l = calloc(1, sizeof(*l))) == NULL)
59 		return 0;
60 
61 	if (p->flags & PARSER_IN_PATCH_HDR)
62 		l->type = LINE_PATCH_HDR;
63 	else
64 		l->type = LINE_PATCH;
65 
66 	if (linelen != 0) {
67 		if ((l->line = calloc(1, linelen+1)) == NULL) {
68 			free(l);
69 			return 0;
70 		}
71 
72 		memcpy(l->line, line, linelen);
73 
74 		if (!(p->flags & PARSER_IN_PATCH_HDR))
75 			switch (*l->line) {
76 			case '+':
77 				l->type = LINE_PATCH_ADD;
78 				break;
79 			case '-':
80 				l->type = LINE_PATCH_DEL;
81 				break;
82 			case '@':
83 				l->type = LINE_PATCH_HUNK_HDR;
84 				break;
85 			case ' ':
86 				/* context lines */
87 				break;
88 			default:
89 				/*
90 				 * A single patch file can have more
91 				 * than one "header" if touches more
92 				 * than one file.
93 				 */
94 				l->type = LINE_PATCH_HDR;
95 				p->flags |= PARSER_IN_PATCH_HDR;
96 				break;
97 			}
98 
99 		if (!strncmp(l->line, "+++", 3))
100 			p->flags &= ~PARSER_IN_PATCH_HDR;
101 	}
102 
103 	TAILQ_INSERT_TAIL(&p->head, l, lines);
104 
105 	return 1;
106 }
107 
108 static int
109 tpatch_foreach_line(struct parser *p, const char *line, size_t linelen)
110 {
111 	return tpatch_emit_line(p, line, linelen);
112 }
113 
114 static int
115 tpatch_free(struct parser *p)
116 {
117 	if (p->len != 0)
118 		return tpatch_emit_line(p, p->buf, p->len);
119 	return 1;
120 }