gitweb: Clearly distinguish regexp / exact match searches
[git/git.git] / builtin-unpack-objects.c
1 #include "builtin.h"
2 #include "cache.h"
3 #include "object.h"
4 #include "delta.h"
5 #include "pack.h"
6 #include "blob.h"
7 #include "commit.h"
8 #include "tag.h"
9 #include "tree.h"
10 #include "progress.h"
11
12 static int dry_run, quiet, recover, has_errors;
13 static const char unpack_usage[] = "git-unpack-objects [-n] [-q] [-r] < pack-file";
14
15 /* We always read in 4kB chunks. */
16 static unsigned char buffer[4096];
17 static unsigned int offset, len;
18 static off_t consumed_bytes;
19 static SHA_CTX ctx;
20
21 /*
22 * Make sure at least "min" bytes are available in the buffer, and
23 * return the pointer to the buffer.
24 */
25 static void *fill(int min)
26 {
27 if (min <= len)
28 return buffer + offset;
29 if (min > sizeof(buffer))
30 die("cannot fill %d bytes", min);
31 if (offset) {
32 SHA1_Update(&ctx, buffer, offset);
33 memmove(buffer, buffer + offset, len);
34 offset = 0;
35 }
36 do {
37 ssize_t ret = xread(0, buffer + len, sizeof(buffer) - len);
38 if (ret <= 0) {
39 if (!ret)
40 die("early EOF");
41 die("read error on input: %s", strerror(errno));
42 }
43 len += ret;
44 } while (len < min);
45 return buffer;
46 }
47
48 static void use(int bytes)
49 {
50 if (bytes > len)
51 die("used more bytes than were available");
52 len -= bytes;
53 offset += bytes;
54
55 /* make sure off_t is sufficiently large not to wrap */
56 if (consumed_bytes > consumed_bytes + bytes)
57 die("pack too large for current definition of off_t");
58 consumed_bytes += bytes;
59 }
60
61 static void *get_data(unsigned long size)
62 {
63 z_stream stream;
64 void *buf = xmalloc(size);
65
66 memset(&stream, 0, sizeof(stream));
67
68 stream.next_out = buf;
69 stream.avail_out = size;
70 stream.next_in = fill(1);
71 stream.avail_in = len;
72 inflateInit(&stream);
73
74 for (;;) {
75 int ret = inflate(&stream, 0);
76 use(len - stream.avail_in);
77 if (stream.total_out == size && ret == Z_STREAM_END)
78 break;
79 if (ret != Z_OK) {
80 error("inflate returned %d\n", ret);
81 free(buf);
82 buf = NULL;
83 if (!recover)
84 exit(1);
85 has_errors = 1;
86 break;
87 }
88 stream.next_in = fill(1);
89 stream.avail_in = len;
90 }
91 inflateEnd(&stream);
92 return buf;
93 }
94
95 struct delta_info {
96 unsigned char base_sha1[20];
97 unsigned nr;
98 off_t base_offset;
99 unsigned long size;
100 void *delta;
101 struct delta_info *next;
102 };
103
104 static struct delta_info *delta_list;
105
106 static void add_delta_to_list(unsigned nr, unsigned const char *base_sha1,
107 off_t base_offset,
108 void *delta, unsigned long size)
109 {
110 struct delta_info *info = xmalloc(sizeof(*info));
111
112 hashcpy(info->base_sha1, base_sha1);
113 info->base_offset = base_offset;
114 info->size = size;
115 info->delta = delta;
116 info->nr = nr;
117 info->next = delta_list;
118 delta_list = info;
119 }
120
121 struct obj_info {
122 off_t offset;
123 unsigned char sha1[20];
124 };
125
126 static struct obj_info *obj_list;
127
128 static void added_object(unsigned nr, enum object_type type,
129 void *data, unsigned long size);
130
131 static void write_object(unsigned nr, enum object_type type,
132 void *buf, unsigned long size)
133 {
134 if (write_sha1_file(buf, size, typename(type), obj_list[nr].sha1) < 0)
135 die("failed to write object");
136 added_object(nr, type, buf, size);
137 }
138
139 static void resolve_delta(unsigned nr, enum object_type type,
140 void *base, unsigned long base_size,
141 void *delta, unsigned long delta_size)
142 {
143 void *result;
144 unsigned long result_size;
145
146 result = patch_delta(base, base_size,
147 delta, delta_size,
148 &result_size);
149 if (!result)
150 die("failed to apply delta");
151 free(delta);
152 write_object(nr, type, result, result_size);
153 free(result);
154 }
155
156 static void added_object(unsigned nr, enum object_type type,
157 void *data, unsigned long size)
158 {
159 struct delta_info **p = &delta_list;
160 struct delta_info *info;
161
162 while ((info = *p) != NULL) {
163 if (!hashcmp(info->base_sha1, obj_list[nr].sha1) ||
164 info->base_offset == obj_list[nr].offset) {
165 *p = info->next;
166 p = &delta_list;
167 resolve_delta(info->nr, type, data, size,
168 info->delta, info->size);
169 free(info);
170 continue;
171 }
172 p = &info->next;
173 }
174 }
175
176 static void unpack_non_delta_entry(enum object_type type, unsigned long size,
177 unsigned nr)
178 {
179 void *buf = get_data(size);
180
181 if (!dry_run && buf)
182 write_object(nr, type, buf, size);
183 free(buf);
184 }
185
186 static void unpack_delta_entry(enum object_type type, unsigned long delta_size,
187 unsigned nr)
188 {
189 void *delta_data, *base;
190 unsigned long base_size;
191 unsigned char base_sha1[20];
192
193 if (type == OBJ_REF_DELTA) {
194 hashcpy(base_sha1, fill(20));
195 use(20);
196 delta_data = get_data(delta_size);
197 if (dry_run || !delta_data) {
198 free(delta_data);
199 return;
200 }
201 if (!has_sha1_file(base_sha1)) {
202 hashcpy(obj_list[nr].sha1, null_sha1);
203 add_delta_to_list(nr, base_sha1, 0, delta_data, delta_size);
204 return;
205 }
206 } else {
207 unsigned base_found = 0;
208 unsigned char *pack, c;
209 off_t base_offset;
210 unsigned lo, mid, hi;
211
212 pack = fill(1);
213 c = *pack;
214 use(1);
215 base_offset = c & 127;
216 while (c & 128) {
217 base_offset += 1;
218 if (!base_offset || MSB(base_offset, 7))
219 die("offset value overflow for delta base object");
220 pack = fill(1);
221 c = *pack;
222 use(1);
223 base_offset = (base_offset << 7) + (c & 127);
224 }
225 base_offset = obj_list[nr].offset - base_offset;
226
227 delta_data = get_data(delta_size);
228 if (dry_run || !delta_data) {
229 free(delta_data);
230 return;
231 }
232 lo = 0;
233 hi = nr;
234 while (lo < hi) {
235 mid = (lo + hi)/2;
236 if (base_offset < obj_list[mid].offset) {
237 hi = mid;
238 } else if (base_offset > obj_list[mid].offset) {
239 lo = mid + 1;
240 } else {
241 hashcpy(base_sha1, obj_list[mid].sha1);
242 base_found = !is_null_sha1(base_sha1);
243 break;
244 }
245 }
246 if (!base_found) {
247 /* The delta base object is itself a delta that
248 has not been resolved yet. */
249 hashcpy(obj_list[nr].sha1, null_sha1);
250 add_delta_to_list(nr, null_sha1, base_offset, delta_data, delta_size);
251 return;
252 }
253 }
254
255 base = read_sha1_file(base_sha1, &type, &base_size);
256 if (!base) {
257 error("failed to read delta-pack base object %s",
258 sha1_to_hex(base_sha1));
259 if (!recover)
260 exit(1);
261 has_errors = 1;
262 return;
263 }
264 resolve_delta(nr, type, base, base_size, delta_data, delta_size);
265 free(base);
266 }
267
268 static void unpack_one(unsigned nr)
269 {
270 unsigned shift;
271 unsigned char *pack, c;
272 unsigned long size;
273 enum object_type type;
274
275 obj_list[nr].offset = consumed_bytes;
276
277 pack = fill(1);
278 c = *pack;
279 use(1);
280 type = (c >> 4) & 7;
281 size = (c & 15);
282 shift = 4;
283 while (c & 0x80) {
284 pack = fill(1);
285 c = *pack;
286 use(1);
287 size += (c & 0x7f) << shift;
288 shift += 7;
289 }
290
291 switch (type) {
292 case OBJ_COMMIT:
293 case OBJ_TREE:
294 case OBJ_BLOB:
295 case OBJ_TAG:
296 unpack_non_delta_entry(type, size, nr);
297 return;
298 case OBJ_REF_DELTA:
299 case OBJ_OFS_DELTA:
300 unpack_delta_entry(type, size, nr);
301 return;
302 default:
303 error("bad object type %d", type);
304 has_errors = 1;
305 if (recover)
306 return;
307 exit(1);
308 }
309 }
310
311 static void unpack_all(void)
312 {
313 int i;
314 struct progress *progress = NULL;
315 struct pack_header *hdr = fill(sizeof(struct pack_header));
316 unsigned nr_objects = ntohl(hdr->hdr_entries);
317
318 if (ntohl(hdr->hdr_signature) != PACK_SIGNATURE)
319 die("bad pack file");
320 if (!pack_version_ok(hdr->hdr_version))
321 die("unknown pack file version %d", ntohl(hdr->hdr_version));
322 use(sizeof(struct pack_header));
323
324 if (!quiet)
325 progress = start_progress("Unpacking objects", nr_objects);
326 obj_list = xmalloc(nr_objects * sizeof(*obj_list));
327 for (i = 0; i < nr_objects; i++) {
328 unpack_one(i);
329 display_progress(progress, i + 1);
330 }
331 stop_progress(&progress);
332
333 if (delta_list)
334 die("unresolved deltas left after unpacking");
335 }
336
337 int cmd_unpack_objects(int argc, const char **argv, const char *prefix)
338 {
339 int i;
340 unsigned char sha1[20];
341
342 git_config(git_default_config);
343
344 quiet = !isatty(2);
345
346 for (i = 1 ; i < argc; i++) {
347 const char *arg = argv[i];
348
349 if (*arg == '-') {
350 if (!strcmp(arg, "-n")) {
351 dry_run = 1;
352 continue;
353 }
354 if (!strcmp(arg, "-q")) {
355 quiet = 1;
356 continue;
357 }
358 if (!strcmp(arg, "-r")) {
359 recover = 1;
360 continue;
361 }
362 if (!prefixcmp(arg, "--pack_header=")) {
363 struct pack_header *hdr;
364 char *c;
365
366 hdr = (struct pack_header *)buffer;
367 hdr->hdr_signature = htonl(PACK_SIGNATURE);
368 hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
369 if (*c != ',')
370 die("bad %s", arg);
371 hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
372 if (*c)
373 die("bad %s", arg);
374 len = sizeof(*hdr);
375 continue;
376 }
377 usage(unpack_usage);
378 }
379
380 /* We don't take any non-flag arguments now.. Maybe some day */
381 usage(unpack_usage);
382 }
383 SHA1_Init(&ctx);
384 unpack_all();
385 SHA1_Update(&ctx, buffer, offset);
386 SHA1_Final(sha1, &ctx);
387 if (hashcmp(fill(20), sha1))
388 die("final sha1 did not match");
389 use(20);
390
391 /* Write the last part of the buffer to stdout */
392 while (len) {
393 int ret = xwrite(1, buffer + offset, len);
394 if (ret <= 0)
395 break;
396 len -= ret;
397 offset += ret;
398 }
399
400 /* All done */
401 return has_errors;
402 }