1 /*
2 * Copyright (C) the libgit2 contributors. All rights reserved.
3 *
4 * This file is part of libgit2, distributed under the GNU GPL v2 with
5 * a Linking Exception. For full terms see the included COPYING file.
6 */
7
8 #include "common.h"
9
10 #include "git2/sys/filter.h"
11 #include "filter.h"
12 #include "buffer.h"
13 #include "buf_text.h"
14
ident_find_id(const char ** id_start,const char ** id_end,const char * start,size_t len)15 static int ident_find_id(
16 const char **id_start, const char **id_end, const char *start, size_t len)
17 {
18 const char *end = start + len, *found = NULL;
19
20 while (len > 3 && (found = memchr(start, '$', len)) != NULL) {
21 size_t remaining = (size_t)(end - found) - 1;
22 if (remaining < 3)
23 return GIT_ENOTFOUND;
24
25 start = found + 1;
26 len = remaining;
27
28 if (start[0] == 'I' && start[1] == 'd')
29 break;
30 }
31
32 if (len < 3 || !found)
33 return GIT_ENOTFOUND;
34 *id_start = found;
35
36 if ((found = memchr(start + 2, '$', len - 2)) == NULL)
37 return GIT_ENOTFOUND;
38
39 *id_end = found + 1;
40 return 0;
41 }
42
ident_insert_id(git_buf * to,const git_buf * from,const git_filter_source * src)43 static int ident_insert_id(
44 git_buf *to, const git_buf *from, const git_filter_source *src)
45 {
46 char oid[GIT_OID_HEXSZ+1];
47 const char *id_start, *id_end, *from_end = from->ptr + from->size;
48 size_t need_size;
49
50 /* replace $Id$ with blob id */
51
52 if (!git_filter_source_id(src))
53 return GIT_PASSTHROUGH;
54
55 git_oid_tostr(oid, sizeof(oid), git_filter_source_id(src));
56
57 if (ident_find_id(&id_start, &id_end, from->ptr, from->size) < 0)
58 return GIT_PASSTHROUGH;
59
60 need_size = (size_t)(id_start - from->ptr) +
61 5 /* "$Id: " */ + GIT_OID_HEXSZ + 2 /* " $" */ +
62 (size_t)(from_end - id_end);
63
64 if (git_buf_grow(to, need_size) < 0)
65 return -1;
66
67 git_buf_set(to, from->ptr, (size_t)(id_start - from->ptr));
68 git_buf_put(to, "$Id: ", 5);
69 git_buf_put(to, oid, GIT_OID_HEXSZ);
70 git_buf_put(to, " $", 2);
71 git_buf_put(to, id_end, (size_t)(from_end - id_end));
72
73 return git_buf_oom(to) ? -1 : 0;
74 }
75
ident_remove_id(git_buf * to,const git_buf * from)76 static int ident_remove_id(
77 git_buf *to, const git_buf *from)
78 {
79 const char *id_start, *id_end, *from_end = from->ptr + from->size;
80 size_t need_size;
81
82 if (ident_find_id(&id_start, &id_end, from->ptr, from->size) < 0)
83 return GIT_PASSTHROUGH;
84
85 need_size = (size_t)(id_start - from->ptr) +
86 4 /* "$Id$" */ + (size_t)(from_end - id_end);
87
88 if (git_buf_grow(to, need_size) < 0)
89 return -1;
90
91 git_buf_set(to, from->ptr, (size_t)(id_start - from->ptr));
92 git_buf_put(to, "$Id$", 4);
93 git_buf_put(to, id_end, (size_t)(from_end - id_end));
94
95 return git_buf_oom(to) ? -1 : 0;
96 }
97
ident_apply(git_filter * self,void ** payload,git_buf * to,const git_buf * from,const git_filter_source * src)98 static int ident_apply(
99 git_filter *self,
100 void **payload,
101 git_buf *to,
102 const git_buf *from,
103 const git_filter_source *src)
104 {
105 GIT_UNUSED(self); GIT_UNUSED(payload);
106
107 /* Don't filter binary files */
108 if (git_buf_text_is_binary(from))
109 return GIT_PASSTHROUGH;
110
111 if (git_filter_source_mode(src) == GIT_FILTER_SMUDGE)
112 return ident_insert_id(to, from, src);
113 else
114 return ident_remove_id(to, from);
115 }
116
git_ident_filter_new(void)117 git_filter *git_ident_filter_new(void)
118 {
119 git_filter *f = git__calloc(1, sizeof(git_filter));
120 if (f == NULL)
121 return NULL;
122
123 f->version = GIT_FILTER_VERSION;
124 f->attributes = "+ident"; /* apply to files with ident attribute set */
125 f->shutdown = git_filter_free;
126 f->apply = ident_apply;
127
128 return f;
129 }
130