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Commit | Line | Data |
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bad50dc8 | 1 | #include "cache.h" |
74536958 | 2 | #include "object.h" |
8ee378a0 | 3 | #include "delta.h" |
bad50dc8 | 4 | |
74536958 | 5 | static int dry_run; |
bad50dc8 LT |
6 | static int nr_entries; |
7 | static const char *base_name; | |
8 | static const char unpack_usage[] = "git-unpack-objects basename"; | |
9 | ||
10 | struct pack_entry { | |
8ee378a0 | 11 | unsigned int offset; /* network byte order */ |
bad50dc8 LT |
12 | unsigned char sha1[20]; |
13 | }; | |
14 | ||
74536958 LT |
15 | static void *pack_base; |
16 | static unsigned long pack_size; | |
8ee378a0 JH |
17 | static void *index_base; |
18 | static unsigned long index_size; | |
74536958 | 19 | |
bad50dc8 LT |
20 | static struct pack_entry **pack_list; |
21 | ||
22 | static void *map_file(const char *suffix, unsigned long *sizep) | |
23 | { | |
24 | static char pathname[PATH_MAX]; | |
25 | unsigned long len; | |
26 | int fd; | |
27 | struct stat st; | |
28 | void *map; | |
29 | ||
30 | len = snprintf(pathname, PATH_MAX, "%s.%s", base_name, suffix); | |
31 | if (len >= PATH_MAX) | |
32 | die("bad pack base-name"); | |
33 | fd = open(pathname, O_RDONLY); | |
34 | if (fd < 0 || fstat(fd, &st)) | |
35 | die("unable to open '%s'", pathname); | |
36 | len = st.st_size; | |
37 | if (!len) | |
38 | die("bad pack file '%s'", pathname); | |
39 | map = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0); | |
40 | if (-1 == (int)(long)map) | |
41 | die("unable to mmap '%s'", pathname); | |
42 | close(fd); | |
43 | *sizep = len; | |
44 | return map; | |
45 | } | |
46 | ||
47 | static int sort_by_offset(const void *_a, const void *_b) | |
48 | { | |
49 | struct pack_entry *a = *(struct pack_entry **)_a; | |
50 | struct pack_entry *b = *(struct pack_entry **)_b; | |
51 | unsigned int o1, o2; | |
52 | ||
53 | o1 = ntohl(a->offset); | |
54 | o2 = ntohl(b->offset); | |
55 | return o1 < o2 ? -1 : 1; | |
56 | } | |
57 | ||
8ee378a0 | 58 | static int check_index(void) |
bad50dc8 | 59 | { |
8ee378a0 | 60 | unsigned int *array = index_base; |
bad50dc8 LT |
61 | unsigned int nr; |
62 | int i; | |
63 | ||
c38138cd | 64 | if (index_size < 4*256 + 20) |
bad50dc8 LT |
65 | return error("index file too small"); |
66 | nr = 0; | |
67 | for (i = 0; i < 256; i++) { | |
68 | unsigned int n = ntohl(array[i]); | |
69 | if (n < nr) | |
70 | return error("non-monotonic index"); | |
71 | nr = n; | |
72 | } | |
c38138cd LT |
73 | /* |
74 | * Total size: | |
75 | * - 256 index entries 4 bytes each | |
76 | * - 24-byte entries * nr (20-byte sha1 + 4-byte offset) | |
77 | * - 20-byte SHA1 file checksum | |
78 | */ | |
79 | if (index_size != 4*256 + nr * 24 + 20) | |
bad50dc8 | 80 | return error("wrong index file size"); |
bad50dc8 LT |
81 | |
82 | nr_entries = nr; | |
83 | pack_list = xmalloc(nr * sizeof(struct pack_entry *)); | |
84 | for (i = 0; i < nr; i++) | |
8ee378a0 | 85 | pack_list[i] = index_base + 4*256 + i*24; |
bad50dc8 LT |
86 | |
87 | qsort(pack_list, nr, sizeof(*pack_list), sort_by_offset); | |
88 | ||
89 | printf("%d entries\n", nr); | |
90 | return 0; | |
91 | } | |
92 | ||
8ee378a0 | 93 | static int unpack_non_delta_entry(struct pack_entry *entry, |
c4fb06c0 LT |
94 | int kind, |
95 | unsigned char *data, | |
96 | unsigned long size, | |
97 | unsigned long left) | |
74536958 | 98 | { |
c4fb06c0 | 99 | int st; |
8ee378a0 JH |
100 | z_stream stream; |
101 | char *buffer; | |
102 | unsigned char sha1[20]; | |
103 | char *type_s; | |
8ee378a0 | 104 | |
8ee378a0 | 105 | printf("%s %c %lu\n", sha1_to_hex(entry->sha1), kind, size); |
c4fb06c0 LT |
106 | if (dry_run) |
107 | return 0; | |
8ee378a0 JH |
108 | |
109 | buffer = xmalloc(size + 1); | |
110 | buffer[size] = 0; | |
111 | memset(&stream, 0, sizeof(stream)); | |
c4fb06c0 LT |
112 | stream.next_in = data; |
113 | stream.avail_in = left; | |
8ee378a0 JH |
114 | stream.next_out = buffer; |
115 | stream.avail_out = size; | |
116 | ||
117 | inflateInit(&stream); | |
118 | st = inflate(&stream, Z_FINISH); | |
119 | inflateEnd(&stream); | |
120 | if ((st != Z_STREAM_END) || stream.total_out != size) | |
121 | goto err_finish; | |
122 | switch (kind) { | |
123 | case 'C': type_s = "commit"; break; | |
124 | case 'T': type_s = "tree"; break; | |
125 | case 'B': type_s = "blob"; break; | |
126 | default: goto err_finish; | |
127 | } | |
128 | if (write_sha1_file(buffer, size, type_s, sha1) < 0) | |
129 | die("failed to write %s (%s)", | |
130 | sha1_to_hex(entry->sha1), type_s); | |
131 | printf("%s %s\n", sha1_to_hex(sha1), type_s); | |
132 | if (memcmp(sha1, entry->sha1, 20)) | |
133 | die("resulting %s have wrong SHA1", type_s); | |
134 | ||
135 | finish: | |
136 | st = 0; | |
137 | free(buffer); | |
138 | return st; | |
139 | err_finish: | |
140 | st = -1; | |
141 | goto finish; | |
142 | } | |
143 | ||
144 | static int find_pack_entry(unsigned char *sha1, struct pack_entry **ent) | |
145 | { | |
146 | int *level1_ofs = index_base; | |
147 | int hi = ntohl(level1_ofs[*sha1]); | |
148 | int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1])); | |
149 | void *index = index_base + 4*256; | |
150 | ||
151 | do { | |
152 | int mi = (lo + hi) / 2; | |
153 | int cmp = memcmp(index + 24 * mi + 4, sha1, 20); | |
154 | if (!cmp) { | |
155 | *ent = index + 24 * mi; | |
156 | return 1; | |
157 | } | |
c4fb06c0 | 158 | if (cmp > 0) |
8ee378a0 JH |
159 | hi = mi; |
160 | else | |
c4fb06c0 | 161 | lo = mi+1; |
8ee378a0 JH |
162 | } while (lo < hi); |
163 | return 0; | |
164 | } | |
165 | ||
166 | /* forward declaration for a mutually recursive function */ | |
167 | static void unpack_entry(struct pack_entry *); | |
168 | ||
c4fb06c0 LT |
169 | static int unpack_delta_entry(struct pack_entry *entry, |
170 | unsigned char *base_sha1, | |
171 | unsigned long delta_size, | |
172 | unsigned long left) | |
8ee378a0 | 173 | { |
c4fb06c0 LT |
174 | void *data, *delta_data, *result, *base; |
175 | unsigned long data_size, result_size, base_size; | |
8ee378a0 JH |
176 | z_stream stream; |
177 | int st; | |
178 | char type[20]; | |
179 | unsigned char sha1[20]; | |
180 | ||
c4fb06c0 LT |
181 | if (left < 20) |
182 | die("truncated pack file"); | |
183 | data = base_sha1 + 20; | |
184 | data_size = left - 20; | |
185 | printf("%s D %lu", sha1_to_hex(entry->sha1), delta_size); | |
186 | printf(" %s\n", sha1_to_hex(base_sha1)); | |
187 | ||
188 | if (dry_run) | |
189 | return 0; | |
8ee378a0 | 190 | |
c4fb06c0 | 191 | /* pack+5 is the base sha1, unless we have it, we need to |
8ee378a0 JH |
192 | * unpack it first. |
193 | */ | |
c4fb06c0 | 194 | if (!has_sha1_file(base_sha1)) { |
8ee378a0 | 195 | struct pack_entry *base; |
c4fb06c0 | 196 | if (!find_pack_entry(base_sha1, &base)) |
8ee378a0 JH |
197 | die("cannot find delta-pack base object"); |
198 | unpack_entry(base); | |
199 | } | |
c4fb06c0 | 200 | delta_data = xmalloc(delta_size); |
8ee378a0 JH |
201 | |
202 | memset(&stream, 0, sizeof(stream)); | |
203 | ||
c4fb06c0 LT |
204 | stream.next_in = data; |
205 | stream.avail_in = data_size; | |
8ee378a0 | 206 | stream.next_out = delta_data; |
c4fb06c0 | 207 | stream.avail_out = delta_size; |
8ee378a0 JH |
208 | |
209 | inflateInit(&stream); | |
c4fb06c0 | 210 | st = inflate(&stream, Z_FINISH); |
8ee378a0 | 211 | inflateEnd(&stream); |
c4fb06c0 LT |
212 | if ((st != Z_STREAM_END) || stream.total_out != delta_size) |
213 | die("delta data unpack failed"); | |
8ee378a0 | 214 | |
c4fb06c0 | 215 | base = read_sha1_file(base_sha1, type, &base_size); |
8ee378a0 | 216 | if (!base) |
c4fb06c0 | 217 | die("failed to read delta-pack base object %s", sha1_to_hex(base_sha1)); |
8ee378a0 JH |
218 | result = patch_delta(base, base_size, |
219 | delta_data, delta_size, | |
220 | &result_size); | |
221 | if (!result) | |
222 | die("failed to apply delta"); | |
223 | free(delta_data); | |
224 | ||
225 | if (write_sha1_file(result, result_size, type, sha1) < 0) | |
226 | die("failed to write %s (%s)", | |
227 | sha1_to_hex(entry->sha1), type); | |
228 | free(result); | |
229 | printf("%s %s\n", sha1_to_hex(sha1), type); | |
230 | if (memcmp(sha1, entry->sha1, 20)) | |
231 | die("resulting %s have wrong SHA1", type); | |
232 | return 0; | |
233 | } | |
234 | ||
235 | static void unpack_entry(struct pack_entry *entry) | |
236 | { | |
c4fb06c0 | 237 | unsigned long offset, size, left; |
74536958 LT |
238 | unsigned char *pack; |
239 | ||
240 | /* Have we done this one already due to deltas based on it? */ | |
241 | if (lookup_object(entry->sha1)) | |
242 | return; | |
243 | ||
244 | offset = ntohl(entry->offset); | |
245 | if (offset > pack_size - 5) | |
246 | die("object offset outside of pack file"); | |
247 | pack = pack_base + offset; | |
c4fb06c0 LT |
248 | size = (pack[1] << 24) + (pack[2] << 16) + (pack[3] << 8) + pack[4]; |
249 | left = pack_size - offset - 5; | |
74536958 LT |
250 | switch (*pack) { |
251 | case 'C': case 'T': case 'B': | |
c4fb06c0 | 252 | unpack_non_delta_entry(entry, *pack, pack+5, size, left); |
74536958 LT |
253 | break; |
254 | case 'D': | |
c4fb06c0 | 255 | unpack_delta_entry(entry, pack+5, size, left); |
74536958 LT |
256 | break; |
257 | default: | |
258 | die("corrupted pack file"); | |
259 | } | |
260 | } | |
261 | ||
262 | /* | |
263 | * We unpack from the end, older files first. Now, usually | |
264 | * there are deltas etc, so we'll not actually write the | |
265 | * objects in that order, but we might as well try.. | |
266 | */ | |
267 | static void unpack_all(void) | |
268 | { | |
269 | int i = nr_entries; | |
270 | ||
271 | while (--i >= 0) { | |
272 | struct pack_entry *entry = pack_list[i]; | |
273 | unpack_entry(entry); | |
274 | } | |
275 | } | |
276 | ||
bad50dc8 LT |
277 | int main(int argc, char **argv) |
278 | { | |
279 | int i; | |
bad50dc8 LT |
280 | |
281 | for (i = 1 ; i < argc; i++) { | |
282 | const char *arg = argv[i]; | |
283 | ||
284 | if (*arg == '-') { | |
74536958 LT |
285 | if (!strcmp(arg, "-n")) { |
286 | dry_run = 1; | |
287 | continue; | |
288 | } | |
bad50dc8 LT |
289 | usage(unpack_usage); |
290 | } | |
291 | if (base_name) | |
292 | usage(unpack_usage); | |
293 | base_name = arg; | |
294 | } | |
295 | if (!base_name) | |
296 | usage(unpack_usage); | |
8ee378a0 | 297 | index_base = map_file("idx", &index_size); |
74536958 | 298 | pack_base = map_file("pack", &pack_size); |
8ee378a0 | 299 | if (check_index() < 0) |
bad50dc8 | 300 | die("bad index file"); |
74536958 | 301 | unpack_all(); |
bad50dc8 LT |
302 | return 0; |
303 | } |