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Commit | Line | Data |
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8b0eca7c DH |
1 | #include "cache.h" |
2 | #include "pack.h" | |
aa7e44bf GB |
3 | #include "csum-file.h" |
4 | ||
5 | uint32_t pack_idx_default_version = 1; | |
6 | uint32_t pack_idx_off32_limit = 0x7fffffff; | |
7 | ||
8 | static int sha1_compare(const void *_a, const void *_b) | |
9 | { | |
10 | struct pack_idx_entry *a = *(struct pack_idx_entry **)_a; | |
11 | struct pack_idx_entry *b = *(struct pack_idx_entry **)_b; | |
12 | return hashcmp(a->sha1, b->sha1); | |
13 | } | |
14 | ||
15 | /* | |
16 | * On entry *sha1 contains the pack content SHA1 hash, on exit it is | |
17 | * the SHA1 hash of sorted object names. The objects array passed in | |
18 | * will be sorted by SHA1 on exit. | |
19 | */ | |
20 | const char *write_idx_file(const char *index_name, struct pack_idx_entry **objects, int nr_objects, unsigned char *sha1) | |
21 | { | |
22 | struct sha1file *f; | |
23 | struct pack_idx_entry **sorted_by_sha, **list, **last; | |
24 | off_t last_obj_offset = 0; | |
25 | uint32_t array[256]; | |
26 | int i, fd; | |
27 | SHA_CTX ctx; | |
28 | uint32_t index_version; | |
29 | ||
30 | if (nr_objects) { | |
31 | sorted_by_sha = objects; | |
32 | list = sorted_by_sha; | |
33 | last = sorted_by_sha + nr_objects; | |
34 | for (i = 0; i < nr_objects; ++i) { | |
35 | if (objects[i]->offset > last_obj_offset) | |
36 | last_obj_offset = objects[i]->offset; | |
37 | } | |
38 | qsort(sorted_by_sha, nr_objects, sizeof(sorted_by_sha[0]), | |
39 | sha1_compare); | |
40 | } | |
41 | else | |
42 | sorted_by_sha = list = last = NULL; | |
43 | ||
44 | if (!index_name) { | |
45 | static char tmpfile[PATH_MAX]; | |
46 | snprintf(tmpfile, sizeof(tmpfile), | |
47 | "%s/tmp_idx_XXXXXX", get_object_directory()); | |
48 | fd = mkstemp(tmpfile); | |
49 | index_name = xstrdup(tmpfile); | |
50 | } else { | |
51 | unlink(index_name); | |
52 | fd = open(index_name, O_CREAT|O_EXCL|O_WRONLY, 0600); | |
53 | } | |
54 | if (fd < 0) | |
55 | die("unable to create %s: %s", index_name, strerror(errno)); | |
56 | f = sha1fd(fd, index_name); | |
57 | ||
58 | /* if last object's offset is >= 2^31 we should use index V2 */ | |
59 | index_version = (last_obj_offset >> 31) ? 2 : pack_idx_default_version; | |
60 | ||
61 | /* index versions 2 and above need a header */ | |
62 | if (index_version >= 2) { | |
63 | struct pack_idx_header hdr; | |
64 | hdr.idx_signature = htonl(PACK_IDX_SIGNATURE); | |
65 | hdr.idx_version = htonl(index_version); | |
66 | sha1write(f, &hdr, sizeof(hdr)); | |
67 | } | |
68 | ||
69 | /* | |
70 | * Write the first-level table (the list is sorted, | |
71 | * but we use a 256-entry lookup to be able to avoid | |
72 | * having to do eight extra binary search iterations). | |
73 | */ | |
74 | for (i = 0; i < 256; i++) { | |
75 | struct pack_idx_entry **next = list; | |
76 | while (next < last) { | |
77 | struct pack_idx_entry *obj = *next; | |
78 | if (obj->sha1[0] != i) | |
79 | break; | |
80 | next++; | |
81 | } | |
82 | array[i] = htonl(next - sorted_by_sha); | |
83 | list = next; | |
84 | } | |
85 | sha1write(f, array, 256 * 4); | |
86 | ||
87 | /* compute the SHA1 hash of sorted object names. */ | |
88 | SHA1_Init(&ctx); | |
89 | ||
90 | /* | |
91 | * Write the actual SHA1 entries.. | |
92 | */ | |
93 | list = sorted_by_sha; | |
94 | for (i = 0; i < nr_objects; i++) { | |
95 | struct pack_idx_entry *obj = *list++; | |
96 | if (index_version < 2) { | |
97 | uint32_t offset = htonl(obj->offset); | |
98 | sha1write(f, &offset, 4); | |
99 | } | |
100 | sha1write(f, obj->sha1, 20); | |
101 | SHA1_Update(&ctx, obj->sha1, 20); | |
102 | } | |
103 | ||
104 | if (index_version >= 2) { | |
105 | unsigned int nr_large_offset = 0; | |
106 | ||
107 | /* write the crc32 table */ | |
108 | list = sorted_by_sha; | |
109 | for (i = 0; i < nr_objects; i++) { | |
110 | struct pack_idx_entry *obj = *list++; | |
111 | uint32_t crc32_val = htonl(obj->crc32); | |
112 | sha1write(f, &crc32_val, 4); | |
113 | } | |
114 | ||
115 | /* write the 32-bit offset table */ | |
116 | list = sorted_by_sha; | |
117 | for (i = 0; i < nr_objects; i++) { | |
118 | struct pack_idx_entry *obj = *list++; | |
119 | uint32_t offset = (obj->offset <= pack_idx_off32_limit) ? | |
120 | obj->offset : (0x80000000 | nr_large_offset++); | |
121 | offset = htonl(offset); | |
122 | sha1write(f, &offset, 4); | |
123 | } | |
124 | ||
125 | /* write the large offset table */ | |
126 | list = sorted_by_sha; | |
127 | while (nr_large_offset) { | |
128 | struct pack_idx_entry *obj = *list++; | |
129 | uint64_t offset = obj->offset; | |
130 | if (offset > pack_idx_off32_limit) { | |
131 | uint32_t split[2]; | |
132 | split[0] = htonl(offset >> 32); | |
133 | split[1] = htonl(offset & 0xffffffff); | |
134 | sha1write(f, split, 8); | |
135 | nr_large_offset--; | |
136 | } | |
137 | } | |
138 | } | |
139 | ||
140 | sha1write(f, sha1, 20); | |
141 | sha1close(f, NULL, 1); | |
142 | SHA1_Final(sha1, &ctx); | |
143 | return index_name; | |
144 | } | |
8b0eca7c DH |
145 | |
146 | void fixup_pack_header_footer(int pack_fd, | |
147 | unsigned char *pack_file_sha1, | |
148 | const char *pack_name, | |
149 | uint32_t object_count) | |
150 | { | |
151 | static const int buf_sz = 128 * 1024; | |
152 | SHA_CTX c; | |
153 | struct pack_header hdr; | |
154 | char *buf; | |
155 | ||
156 | if (lseek(pack_fd, 0, SEEK_SET) != 0) | |
157 | die("Failed seeking to start: %s", strerror(errno)); | |
158 | if (read_in_full(pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr)) | |
159 | die("Unable to reread header of %s: %s", pack_name, strerror(errno)); | |
160 | if (lseek(pack_fd, 0, SEEK_SET) != 0) | |
161 | die("Failed seeking to start: %s", strerror(errno)); | |
162 | hdr.hdr_entries = htonl(object_count); | |
163 | write_or_die(pack_fd, &hdr, sizeof(hdr)); | |
164 | ||
165 | SHA1_Init(&c); | |
166 | SHA1_Update(&c, &hdr, sizeof(hdr)); | |
167 | ||
168 | buf = xmalloc(buf_sz); | |
169 | for (;;) { | |
2924415f | 170 | ssize_t n = xread(pack_fd, buf, buf_sz); |
8b0eca7c DH |
171 | if (!n) |
172 | break; | |
173 | if (n < 0) | |
174 | die("Failed to checksum %s: %s", pack_name, strerror(errno)); | |
175 | SHA1_Update(&c, buf, n); | |
176 | } | |
177 | free(buf); | |
178 | ||
179 | SHA1_Final(pack_file_sha1, &c); | |
180 | write_or_die(pack_fd, pack_file_sha1, 20); | |
181 | } |