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 "compat.h"
22 
23 #include <stdlib.h>
24 #include <string.h>
25 
26 #include "parser.h"
27 #include "utils.h"
28 
29 static int	tpatch_parse(struct parser *, const char *, size_t);
30 static int	tpatch_emit_line(struct parser *, const char *, size_t);
31 static int	tpatch_foreach_line(struct parser *, const char *, size_t);
32 static int	tpatch_free(struct parser *);
33 
34 void
35 textpatch_initparser(struct parser *p)
36 {
37 	memset(p, 0, sizeof(*p));
38 
39 	p->name = "text/x-patch";
40 	p->parse = &tpatch_parse;
41 	p->free = &tpatch_free;
42 
43 	p->flags = PARSER_IN_PATCH_HDR;
44 
45 	TAILQ_INIT(&p->head);
46 }
47 
48 static int
49 tpatch_parse(struct parser *p, const char *buf, size_t size)
50 {
51 	return parser_foreach_line(p, buf, size, tpatch_foreach_line);
52 }
53 
54 static int
55 tpatch_emit_line(struct parser *p, const char *line, size_t linelen)
56 {
57 	struct line *l;
58 
59 	if ((l = calloc(1, sizeof(*l))) == NULL)
60 		return 0;
61 
62 	if (p->flags & PARSER_IN_PATCH_HDR)
63 		l->type = LINE_PATCH_HDR;
64 	else
65 		l->type = LINE_PATCH;
66 
67 	if (linelen != 0) {
68 		if ((l->line = calloc(1, linelen+1)) == NULL) {
69 			free(l);
70 			return 0;
71 		}
72 
73 		memcpy(l->line, line, linelen);
74 
75 		if (!(p->flags & PARSER_IN_PATCH_HDR))
76 			switch (*l->line) {
77 			case '+':
78 				l->type = LINE_PATCH_ADD;
79 				break;
80 			case '-':
81 				l->type = LINE_PATCH_DEL;
82 				break;
83 			case '@':
84 				l->type = LINE_PATCH_HUNK_HDR;
85 				break;
86 			case ' ':
87 				/* context lines */
88 				break;
89 			default:
90 				/*
91 				 * A single patch file can have more
92 				 * than one "header" if touches more
93 				 * than one file.
94 				 */
95 				l->type = LINE_PATCH_HDR;
96 				p->flags |= PARSER_IN_PATCH_HDR;
97 				break;
98 			}
99 
100 		if (!strncmp(l->line, "+++", 3))
101 			p->flags &= ~PARSER_IN_PATCH_HDR;
102 	}
103 
104 	TAILQ_INSERT_TAIL(&p->head, l, lines);
105 
106 	return 1;
107 }
108 
109 static int
110 tpatch_foreach_line(struct parser *p, const char *line, size_t linelen)
111 {
112 	return tpatch_emit_line(p, line, linelen);
113 }
114 
115 static int
116 tpatch_free(struct parser *p)
117 {
118 	if (p->len != 0)
119 		return tpatch_emit_line(p, p->buf, p->len);
120 	return 1;
121 }