]>
Commit | Line | Data |
---|---|---|
46bc0e73 HWN |
1 | /* |
2 | Copyright 2020 Google LLC | |
3 | ||
4 | Use of this source code is governed by a BSD-style | |
5 | license that can be found in the LICENSE file or at | |
6 | https://developers.google.com/open-source/licenses/bsd | |
7 | */ | |
8 | ||
9 | #include "reader.h" | |
10 | ||
11 | #include "system.h" | |
12 | #include "block.h" | |
13 | #include "constants.h" | |
14 | #include "generic.h" | |
15 | #include "iter.h" | |
16 | #include "record.h" | |
17 | #include "reftable-error.h" | |
18 | #include "reftable-generic.h" | |
19 | #include "tree.h" | |
20 | ||
21 | uint64_t block_source_size(struct reftable_block_source *source) | |
22 | { | |
23 | return source->ops->size(source->arg); | |
24 | } | |
25 | ||
26 | int block_source_read_block(struct reftable_block_source *source, | |
27 | struct reftable_block *dest, uint64_t off, | |
28 | uint32_t size) | |
29 | { | |
30 | int result = source->ops->read_block(source->arg, dest, off, size); | |
31 | dest->source = *source; | |
32 | return result; | |
33 | } | |
34 | ||
35 | void block_source_close(struct reftable_block_source *source) | |
36 | { | |
37 | if (!source->ops) { | |
38 | return; | |
39 | } | |
40 | ||
41 | source->ops->close(source->arg); | |
42 | source->ops = NULL; | |
43 | } | |
44 | ||
45 | static struct reftable_reader_offsets * | |
46 | reader_offsets_for(struct reftable_reader *r, uint8_t typ) | |
47 | { | |
48 | switch (typ) { | |
49 | case BLOCK_TYPE_REF: | |
50 | return &r->ref_offsets; | |
51 | case BLOCK_TYPE_LOG: | |
52 | return &r->log_offsets; | |
53 | case BLOCK_TYPE_OBJ: | |
54 | return &r->obj_offsets; | |
55 | } | |
56 | abort(); | |
57 | } | |
58 | ||
59 | static int reader_get_block(struct reftable_reader *r, | |
60 | struct reftable_block *dest, uint64_t off, | |
61 | uint32_t sz) | |
62 | { | |
63 | if (off >= r->size) | |
64 | return 0; | |
65 | ||
66 | if (off + sz > r->size) { | |
67 | sz = r->size - off; | |
68 | } | |
69 | ||
70 | return block_source_read_block(&r->source, dest, off, sz); | |
71 | } | |
72 | ||
73 | uint32_t reftable_reader_hash_id(struct reftable_reader *r) | |
74 | { | |
75 | return r->hash_id; | |
76 | } | |
77 | ||
78 | const char *reader_name(struct reftable_reader *r) | |
79 | { | |
80 | return r->name; | |
81 | } | |
82 | ||
83 | static int parse_footer(struct reftable_reader *r, uint8_t *footer, | |
84 | uint8_t *header) | |
85 | { | |
86 | uint8_t *f = footer; | |
87 | uint8_t first_block_typ; | |
88 | int err = 0; | |
89 | uint32_t computed_crc; | |
90 | uint32_t file_crc; | |
91 | ||
92 | if (memcmp(f, "REFT", 4)) { | |
93 | err = REFTABLE_FORMAT_ERROR; | |
94 | goto done; | |
95 | } | |
96 | f += 4; | |
97 | ||
98 | if (memcmp(footer, header, header_size(r->version))) { | |
99 | err = REFTABLE_FORMAT_ERROR; | |
100 | goto done; | |
101 | } | |
102 | ||
103 | f++; | |
104 | r->block_size = get_be24(f); | |
105 | ||
106 | f += 3; | |
107 | r->min_update_index = get_be64(f); | |
108 | f += 8; | |
109 | r->max_update_index = get_be64(f); | |
110 | f += 8; | |
111 | ||
112 | if (r->version == 1) { | |
113 | r->hash_id = GIT_SHA1_FORMAT_ID; | |
114 | } else { | |
115 | r->hash_id = get_be32(f); | |
116 | switch (r->hash_id) { | |
117 | case GIT_SHA1_FORMAT_ID: | |
118 | break; | |
119 | case GIT_SHA256_FORMAT_ID: | |
120 | break; | |
121 | default: | |
122 | err = REFTABLE_FORMAT_ERROR; | |
123 | goto done; | |
124 | } | |
125 | f += 4; | |
126 | } | |
127 | ||
128 | r->ref_offsets.index_offset = get_be64(f); | |
129 | f += 8; | |
130 | ||
131 | r->obj_offsets.offset = get_be64(f); | |
132 | f += 8; | |
133 | ||
134 | r->object_id_len = r->obj_offsets.offset & ((1 << 5) - 1); | |
135 | r->obj_offsets.offset >>= 5; | |
136 | ||
137 | r->obj_offsets.index_offset = get_be64(f); | |
138 | f += 8; | |
139 | r->log_offsets.offset = get_be64(f); | |
140 | f += 8; | |
141 | r->log_offsets.index_offset = get_be64(f); | |
142 | f += 8; | |
143 | ||
144 | computed_crc = crc32(0, footer, f - footer); | |
145 | file_crc = get_be32(f); | |
146 | f += 4; | |
147 | if (computed_crc != file_crc) { | |
148 | err = REFTABLE_FORMAT_ERROR; | |
149 | goto done; | |
150 | } | |
151 | ||
152 | first_block_typ = header[header_size(r->version)]; | |
153 | r->ref_offsets.is_present = (first_block_typ == BLOCK_TYPE_REF); | |
154 | r->ref_offsets.offset = 0; | |
155 | r->log_offsets.is_present = (first_block_typ == BLOCK_TYPE_LOG || | |
156 | r->log_offsets.offset > 0); | |
157 | r->obj_offsets.is_present = r->obj_offsets.offset > 0; | |
eff5832b HWN |
158 | if (r->obj_offsets.is_present && !r->object_id_len) { |
159 | err = REFTABLE_FORMAT_ERROR; | |
160 | goto done; | |
161 | } | |
162 | ||
46bc0e73 HWN |
163 | err = 0; |
164 | done: | |
165 | return err; | |
166 | } | |
167 | ||
168 | int init_reader(struct reftable_reader *r, struct reftable_block_source *source, | |
169 | const char *name) | |
170 | { | |
171 | struct reftable_block footer = { NULL }; | |
172 | struct reftable_block header = { NULL }; | |
173 | int err = 0; | |
174 | uint64_t file_size = block_source_size(source); | |
175 | ||
176 | /* Need +1 to read type of first block. */ | |
177 | uint32_t read_size = header_size(2) + 1; /* read v2 because it's larger. */ | |
178 | memset(r, 0, sizeof(struct reftable_reader)); | |
179 | ||
180 | if (read_size > file_size) { | |
181 | err = REFTABLE_FORMAT_ERROR; | |
182 | goto done; | |
183 | } | |
184 | ||
185 | err = block_source_read_block(source, &header, 0, read_size); | |
186 | if (err != read_size) { | |
187 | err = REFTABLE_IO_ERROR; | |
188 | goto done; | |
189 | } | |
190 | ||
191 | if (memcmp(header.data, "REFT", 4)) { | |
192 | err = REFTABLE_FORMAT_ERROR; | |
193 | goto done; | |
194 | } | |
195 | r->version = header.data[4]; | |
196 | if (r->version != 1 && r->version != 2) { | |
197 | err = REFTABLE_FORMAT_ERROR; | |
198 | goto done; | |
199 | } | |
200 | ||
201 | r->size = file_size - footer_size(r->version); | |
202 | r->source = *source; | |
203 | r->name = xstrdup(name); | |
204 | r->hash_id = 0; | |
205 | ||
206 | err = block_source_read_block(source, &footer, r->size, | |
207 | footer_size(r->version)); | |
208 | if (err != footer_size(r->version)) { | |
209 | err = REFTABLE_IO_ERROR; | |
210 | goto done; | |
211 | } | |
212 | ||
213 | err = parse_footer(r, footer.data, header.data); | |
214 | done: | |
215 | reftable_block_done(&footer); | |
216 | reftable_block_done(&header); | |
217 | return err; | |
218 | } | |
219 | ||
220 | struct table_iter { | |
221 | struct reftable_reader *r; | |
222 | uint8_t typ; | |
223 | uint64_t block_off; | |
224 | struct block_iter bi; | |
225 | int is_finished; | |
226 | }; | |
227 | #define TABLE_ITER_INIT \ | |
228 | { \ | |
229 | .bi = {.last_key = STRBUF_INIT } \ | |
230 | } | |
231 | ||
232 | static void table_iter_copy_from(struct table_iter *dest, | |
233 | struct table_iter *src) | |
234 | { | |
235 | dest->r = src->r; | |
236 | dest->typ = src->typ; | |
237 | dest->block_off = src->block_off; | |
238 | dest->is_finished = src->is_finished; | |
239 | block_iter_copy_from(&dest->bi, &src->bi); | |
240 | } | |
241 | ||
242 | static int table_iter_next_in_block(struct table_iter *ti, | |
243 | struct reftable_record *rec) | |
244 | { | |
245 | int res = block_iter_next(&ti->bi, rec); | |
246 | if (res == 0 && reftable_record_type(rec) == BLOCK_TYPE_REF) { | |
66c0daba | 247 | rec->u.ref.update_index += ti->r->min_update_index; |
46bc0e73 HWN |
248 | } |
249 | ||
250 | return res; | |
251 | } | |
252 | ||
253 | static void table_iter_block_done(struct table_iter *ti) | |
254 | { | |
255 | if (!ti->bi.br) { | |
256 | return; | |
257 | } | |
258 | reftable_block_done(&ti->bi.br->block); | |
259 | FREE_AND_NULL(ti->bi.br); | |
260 | ||
261 | ti->bi.last_key.len = 0; | |
262 | ti->bi.next_off = 0; | |
263 | } | |
264 | ||
265 | static int32_t extract_block_size(uint8_t *data, uint8_t *typ, uint64_t off, | |
266 | int version) | |
267 | { | |
268 | int32_t result = 0; | |
269 | ||
270 | if (off == 0) { | |
271 | data += header_size(version); | |
272 | } | |
273 | ||
274 | *typ = data[0]; | |
275 | if (reftable_is_block_type(*typ)) { | |
276 | result = get_be24(data + 1); | |
277 | } | |
278 | return result; | |
279 | } | |
280 | ||
281 | int reader_init_block_reader(struct reftable_reader *r, struct block_reader *br, | |
282 | uint64_t next_off, uint8_t want_typ) | |
283 | { | |
284 | int32_t guess_block_size = r->block_size ? r->block_size : | |
285 | DEFAULT_BLOCK_SIZE; | |
286 | struct reftable_block block = { NULL }; | |
287 | uint8_t block_typ = 0; | |
288 | int err = 0; | |
289 | uint32_t header_off = next_off ? 0 : header_size(r->version); | |
290 | int32_t block_size = 0; | |
291 | ||
292 | if (next_off >= r->size) | |
293 | return 1; | |
294 | ||
295 | err = reader_get_block(r, &block, next_off, guess_block_size); | |
296 | if (err < 0) | |
24d4d38c | 297 | goto done; |
46bc0e73 HWN |
298 | |
299 | block_size = extract_block_size(block.data, &block_typ, next_off, | |
300 | r->version); | |
24d4d38c HWN |
301 | if (block_size < 0) { |
302 | err = block_size; | |
303 | goto done; | |
304 | } | |
46bc0e73 | 305 | if (want_typ != BLOCK_TYPE_ANY && block_typ != want_typ) { |
24d4d38c HWN |
306 | err = 1; |
307 | goto done; | |
46bc0e73 HWN |
308 | } |
309 | ||
310 | if (block_size > guess_block_size) { | |
311 | reftable_block_done(&block); | |
312 | err = reader_get_block(r, &block, next_off, block_size); | |
313 | if (err < 0) { | |
24d4d38c | 314 | goto done; |
46bc0e73 HWN |
315 | } |
316 | } | |
317 | ||
24d4d38c HWN |
318 | err = block_reader_init(br, &block, header_off, r->block_size, |
319 | hash_size(r->hash_id)); | |
320 | done: | |
321 | reftable_block_done(&block); | |
322 | ||
323 | return err; | |
46bc0e73 HWN |
324 | } |
325 | ||
326 | static int table_iter_next_block(struct table_iter *dest, | |
327 | struct table_iter *src) | |
328 | { | |
329 | uint64_t next_block_off = src->block_off + src->bi.br->full_block_size; | |
330 | struct block_reader br = { 0 }; | |
331 | int err = 0; | |
332 | ||
333 | dest->r = src->r; | |
334 | dest->typ = src->typ; | |
335 | dest->block_off = next_block_off; | |
336 | ||
337 | err = reader_init_block_reader(src->r, &br, next_block_off, src->typ); | |
338 | if (err > 0) { | |
339 | dest->is_finished = 1; | |
340 | return 1; | |
341 | } | |
342 | if (err != 0) | |
343 | return err; | |
344 | else { | |
345 | struct block_reader *brp = | |
346 | reftable_malloc(sizeof(struct block_reader)); | |
347 | *brp = br; | |
348 | ||
349 | dest->is_finished = 0; | |
350 | block_reader_start(brp, &dest->bi); | |
351 | } | |
352 | return 0; | |
353 | } | |
354 | ||
355 | static int table_iter_next(struct table_iter *ti, struct reftable_record *rec) | |
356 | { | |
357 | if (reftable_record_type(rec) != ti->typ) | |
358 | return REFTABLE_API_ERROR; | |
359 | ||
360 | while (1) { | |
361 | struct table_iter next = TABLE_ITER_INIT; | |
362 | int err = 0; | |
363 | if (ti->is_finished) { | |
364 | return 1; | |
365 | } | |
366 | ||
367 | err = table_iter_next_in_block(ti, rec); | |
368 | if (err <= 0) { | |
369 | return err; | |
370 | } | |
371 | ||
372 | err = table_iter_next_block(&next, ti); | |
373 | if (err != 0) { | |
374 | ti->is_finished = 1; | |
375 | } | |
376 | table_iter_block_done(ti); | |
377 | if (err != 0) { | |
378 | return err; | |
379 | } | |
380 | table_iter_copy_from(ti, &next); | |
381 | block_iter_close(&next.bi); | |
382 | } | |
383 | } | |
384 | ||
385 | static int table_iter_next_void(void *ti, struct reftable_record *rec) | |
386 | { | |
387 | return table_iter_next(ti, rec); | |
388 | } | |
389 | ||
390 | static void table_iter_close(void *p) | |
391 | { | |
392 | struct table_iter *ti = p; | |
393 | table_iter_block_done(ti); | |
394 | block_iter_close(&ti->bi); | |
395 | } | |
396 | ||
397 | static struct reftable_iterator_vtable table_iter_vtable = { | |
398 | .next = &table_iter_next_void, | |
399 | .close = &table_iter_close, | |
400 | }; | |
401 | ||
402 | static void iterator_from_table_iter(struct reftable_iterator *it, | |
403 | struct table_iter *ti) | |
404 | { | |
405 | assert(!it->ops); | |
406 | it->iter_arg = ti; | |
407 | it->ops = &table_iter_vtable; | |
408 | } | |
409 | ||
410 | static int reader_table_iter_at(struct reftable_reader *r, | |
411 | struct table_iter *ti, uint64_t off, | |
412 | uint8_t typ) | |
413 | { | |
414 | struct block_reader br = { 0 }; | |
415 | struct block_reader *brp = NULL; | |
416 | ||
417 | int err = reader_init_block_reader(r, &br, off, typ); | |
418 | if (err != 0) | |
419 | return err; | |
420 | ||
421 | brp = reftable_malloc(sizeof(struct block_reader)); | |
422 | *brp = br; | |
423 | ti->r = r; | |
424 | ti->typ = block_reader_type(brp); | |
425 | ti->block_off = off; | |
426 | block_reader_start(brp, &ti->bi); | |
427 | return 0; | |
428 | } | |
429 | ||
430 | static int reader_start(struct reftable_reader *r, struct table_iter *ti, | |
431 | uint8_t typ, int index) | |
432 | { | |
433 | struct reftable_reader_offsets *offs = reader_offsets_for(r, typ); | |
434 | uint64_t off = offs->offset; | |
435 | if (index) { | |
436 | off = offs->index_offset; | |
437 | if (off == 0) { | |
438 | return 1; | |
439 | } | |
440 | typ = BLOCK_TYPE_INDEX; | |
441 | } | |
442 | ||
443 | return reader_table_iter_at(r, ti, off, typ); | |
444 | } | |
445 | ||
21a40847 | 446 | static int reader_seek_linear(struct table_iter *ti, |
46bc0e73 HWN |
447 | struct reftable_record *want) |
448 | { | |
449 | struct reftable_record rec = | |
450 | reftable_new_record(reftable_record_type(want)); | |
451 | struct strbuf want_key = STRBUF_INIT; | |
452 | struct strbuf got_key = STRBUF_INIT; | |
453 | struct table_iter next = TABLE_ITER_INIT; | |
454 | int err = -1; | |
455 | ||
456 | reftable_record_key(want, &want_key); | |
457 | ||
458 | while (1) { | |
459 | err = table_iter_next_block(&next, ti); | |
460 | if (err < 0) | |
461 | goto done; | |
462 | ||
463 | if (err > 0) { | |
464 | break; | |
465 | } | |
466 | ||
467 | err = block_reader_first_key(next.bi.br, &got_key); | |
468 | if (err < 0) | |
469 | goto done; | |
470 | ||
471 | if (strbuf_cmp(&got_key, &want_key) > 0) { | |
472 | table_iter_block_done(&next); | |
473 | break; | |
474 | } | |
475 | ||
476 | table_iter_block_done(ti); | |
477 | table_iter_copy_from(ti, &next); | |
478 | } | |
479 | ||
480 | err = block_iter_seek(&ti->bi, &want_key); | |
481 | if (err < 0) | |
482 | goto done; | |
483 | err = 0; | |
484 | ||
485 | done: | |
486 | block_iter_close(&next.bi); | |
66c0daba | 487 | reftable_record_release(&rec); |
46bc0e73 HWN |
488 | strbuf_release(&want_key); |
489 | strbuf_release(&got_key); | |
490 | return err; | |
491 | } | |
492 | ||
493 | static int reader_seek_indexed(struct reftable_reader *r, | |
494 | struct reftable_iterator *it, | |
495 | struct reftable_record *rec) | |
496 | { | |
66c0daba HWN |
497 | struct reftable_record want_index = { |
498 | .type = BLOCK_TYPE_INDEX, .u.idx = { .last_key = STRBUF_INIT } | |
499 | }; | |
500 | struct reftable_record index_result = { | |
501 | .type = BLOCK_TYPE_INDEX, | |
502 | .u.idx = { .last_key = STRBUF_INIT }, | |
503 | }; | |
46bc0e73 HWN |
504 | struct table_iter index_iter = TABLE_ITER_INIT; |
505 | struct table_iter next = TABLE_ITER_INIT; | |
506 | int err = 0; | |
507 | ||
66c0daba | 508 | reftable_record_key(rec, &want_index.u.idx.last_key); |
46bc0e73 HWN |
509 | err = reader_start(r, &index_iter, reftable_record_type(rec), 1); |
510 | if (err < 0) | |
511 | goto done; | |
512 | ||
21a40847 | 513 | err = reader_seek_linear(&index_iter, &want_index); |
46bc0e73 | 514 | while (1) { |
66c0daba | 515 | err = table_iter_next(&index_iter, &index_result); |
46bc0e73 HWN |
516 | table_iter_block_done(&index_iter); |
517 | if (err != 0) | |
518 | goto done; | |
519 | ||
66c0daba HWN |
520 | err = reader_table_iter_at(r, &next, index_result.u.idx.offset, |
521 | 0); | |
46bc0e73 HWN |
522 | if (err != 0) |
523 | goto done; | |
524 | ||
66c0daba | 525 | err = block_iter_seek(&next.bi, &want_index.u.idx.last_key); |
46bc0e73 HWN |
526 | if (err < 0) |
527 | goto done; | |
528 | ||
529 | if (next.typ == reftable_record_type(rec)) { | |
530 | err = 0; | |
531 | break; | |
532 | } | |
533 | ||
534 | if (next.typ != BLOCK_TYPE_INDEX) { | |
535 | err = REFTABLE_FORMAT_ERROR; | |
536 | break; | |
537 | } | |
538 | ||
539 | table_iter_copy_from(&index_iter, &next); | |
540 | } | |
541 | ||
542 | if (err == 0) { | |
543 | struct table_iter empty = TABLE_ITER_INIT; | |
544 | struct table_iter *malloced = | |
545 | reftable_calloc(sizeof(struct table_iter)); | |
546 | *malloced = empty; | |
547 | table_iter_copy_from(malloced, &next); | |
548 | iterator_from_table_iter(it, malloced); | |
549 | } | |
550 | done: | |
551 | block_iter_close(&next.bi); | |
552 | table_iter_close(&index_iter); | |
66c0daba HWN |
553 | reftable_record_release(&want_index); |
554 | reftable_record_release(&index_result); | |
46bc0e73 HWN |
555 | return err; |
556 | } | |
557 | ||
558 | static int reader_seek_internal(struct reftable_reader *r, | |
559 | struct reftable_iterator *it, | |
560 | struct reftable_record *rec) | |
561 | { | |
562 | struct reftable_reader_offsets *offs = | |
563 | reader_offsets_for(r, reftable_record_type(rec)); | |
564 | uint64_t idx = offs->index_offset; | |
565 | struct table_iter ti = TABLE_ITER_INIT; | |
566 | int err = 0; | |
567 | if (idx > 0) | |
568 | return reader_seek_indexed(r, it, rec); | |
569 | ||
570 | err = reader_start(r, &ti, reftable_record_type(rec), 0); | |
571 | if (err < 0) | |
572 | return err; | |
21a40847 | 573 | err = reader_seek_linear(&ti, rec); |
46bc0e73 HWN |
574 | if (err < 0) |
575 | return err; | |
576 | else { | |
577 | struct table_iter *p = | |
578 | reftable_malloc(sizeof(struct table_iter)); | |
579 | *p = ti; | |
580 | iterator_from_table_iter(it, p); | |
581 | } | |
582 | ||
583 | return 0; | |
584 | } | |
585 | ||
586 | static int reader_seek(struct reftable_reader *r, struct reftable_iterator *it, | |
587 | struct reftable_record *rec) | |
588 | { | |
589 | uint8_t typ = reftable_record_type(rec); | |
590 | ||
591 | struct reftable_reader_offsets *offs = reader_offsets_for(r, typ); | |
592 | if (!offs->is_present) { | |
593 | iterator_set_empty(it); | |
594 | return 0; | |
595 | } | |
596 | ||
597 | return reader_seek_internal(r, it, rec); | |
598 | } | |
599 | ||
600 | int reftable_reader_seek_ref(struct reftable_reader *r, | |
601 | struct reftable_iterator *it, const char *name) | |
602 | { | |
66c0daba HWN |
603 | struct reftable_record rec = { |
604 | .type = BLOCK_TYPE_REF, | |
605 | .u.ref = { | |
606 | .refname = (char *)name, | |
607 | }, | |
46bc0e73 | 608 | }; |
46bc0e73 HWN |
609 | return reader_seek(r, it, &rec); |
610 | } | |
611 | ||
612 | int reftable_reader_seek_log_at(struct reftable_reader *r, | |
613 | struct reftable_iterator *it, const char *name, | |
614 | uint64_t update_index) | |
615 | { | |
66c0daba HWN |
616 | struct reftable_record rec = { .type = BLOCK_TYPE_LOG, |
617 | .u.log = { | |
618 | .refname = (char *)name, | |
619 | .update_index = update_index, | |
620 | } }; | |
46bc0e73 HWN |
621 | return reader_seek(r, it, &rec); |
622 | } | |
623 | ||
624 | int reftable_reader_seek_log(struct reftable_reader *r, | |
625 | struct reftable_iterator *it, const char *name) | |
626 | { | |
627 | uint64_t max = ~((uint64_t)0); | |
628 | return reftable_reader_seek_log_at(r, it, name, max); | |
629 | } | |
630 | ||
631 | void reader_close(struct reftable_reader *r) | |
632 | { | |
633 | block_source_close(&r->source); | |
634 | FREE_AND_NULL(r->name); | |
635 | } | |
636 | ||
637 | int reftable_new_reader(struct reftable_reader **p, | |
638 | struct reftable_block_source *src, char const *name) | |
639 | { | |
640 | struct reftable_reader *rd = | |
641 | reftable_calloc(sizeof(struct reftable_reader)); | |
642 | int err = init_reader(rd, src, name); | |
643 | if (err == 0) { | |
644 | *p = rd; | |
645 | } else { | |
646 | block_source_close(src); | |
647 | reftable_free(rd); | |
648 | } | |
649 | return err; | |
650 | } | |
651 | ||
652 | void reftable_reader_free(struct reftable_reader *r) | |
653 | { | |
33e92243 HWN |
654 | if (!r) |
655 | return; | |
46bc0e73 HWN |
656 | reader_close(r); |
657 | reftable_free(r); | |
658 | } | |
659 | ||
660 | static int reftable_reader_refs_for_indexed(struct reftable_reader *r, | |
661 | struct reftable_iterator *it, | |
662 | uint8_t *oid) | |
663 | { | |
66c0daba HWN |
664 | struct reftable_record want = { |
665 | .type = BLOCK_TYPE_OBJ, | |
666 | .u.obj = { | |
667 | .hash_prefix = oid, | |
668 | .hash_prefix_len = r->object_id_len, | |
669 | }, | |
46bc0e73 | 670 | }; |
46bc0e73 | 671 | struct reftable_iterator oit = { NULL }; |
66c0daba HWN |
672 | struct reftable_record got = { |
673 | .type = BLOCK_TYPE_OBJ, | |
674 | .u.obj = { 0 }, | |
675 | }; | |
46bc0e73 HWN |
676 | int err = 0; |
677 | struct indexed_table_ref_iter *itr = NULL; | |
678 | ||
679 | /* Look through the reverse index. */ | |
66c0daba | 680 | err = reader_seek(r, &oit, &want); |
46bc0e73 HWN |
681 | if (err != 0) |
682 | goto done; | |
683 | ||
684 | /* read out the reftable_obj_record */ | |
66c0daba | 685 | err = iterator_next(&oit, &got); |
46bc0e73 HWN |
686 | if (err < 0) |
687 | goto done; | |
688 | ||
66c0daba HWN |
689 | if (err > 0 || memcmp(want.u.obj.hash_prefix, got.u.obj.hash_prefix, |
690 | r->object_id_len)) { | |
46bc0e73 HWN |
691 | /* didn't find it; return empty iterator */ |
692 | iterator_set_empty(it); | |
693 | err = 0; | |
694 | goto done; | |
695 | } | |
696 | ||
697 | err = new_indexed_table_ref_iter(&itr, r, oid, hash_size(r->hash_id), | |
66c0daba HWN |
698 | got.u.obj.offsets, |
699 | got.u.obj.offset_len); | |
46bc0e73 HWN |
700 | if (err < 0) |
701 | goto done; | |
66c0daba | 702 | got.u.obj.offsets = NULL; |
46bc0e73 HWN |
703 | iterator_from_indexed_table_ref_iter(it, itr); |
704 | ||
705 | done: | |
706 | reftable_iterator_destroy(&oit); | |
66c0daba | 707 | reftable_record_release(&got); |
46bc0e73 HWN |
708 | return err; |
709 | } | |
710 | ||
711 | static int reftable_reader_refs_for_unindexed(struct reftable_reader *r, | |
712 | struct reftable_iterator *it, | |
713 | uint8_t *oid) | |
714 | { | |
715 | struct table_iter ti_empty = TABLE_ITER_INIT; | |
716 | struct table_iter *ti = reftable_calloc(sizeof(struct table_iter)); | |
717 | struct filtering_ref_iterator *filter = NULL; | |
718 | struct filtering_ref_iterator empty = FILTERING_REF_ITERATOR_INIT; | |
719 | int oid_len = hash_size(r->hash_id); | |
720 | int err; | |
721 | ||
722 | *ti = ti_empty; | |
723 | err = reader_start(r, ti, BLOCK_TYPE_REF, 0); | |
724 | if (err < 0) { | |
725 | reftable_free(ti); | |
726 | return err; | |
727 | } | |
728 | ||
729 | filter = reftable_malloc(sizeof(struct filtering_ref_iterator)); | |
730 | *filter = empty; | |
731 | ||
732 | strbuf_add(&filter->oid, oid, oid_len); | |
733 | reftable_table_from_reader(&filter->tab, r); | |
734 | filter->double_check = 0; | |
735 | iterator_from_table_iter(&filter->it, ti); | |
736 | ||
737 | iterator_from_filtering_ref_iterator(it, filter); | |
738 | return 0; | |
739 | } | |
740 | ||
741 | int reftable_reader_refs_for(struct reftable_reader *r, | |
742 | struct reftable_iterator *it, uint8_t *oid) | |
743 | { | |
744 | if (r->obj_offsets.is_present) | |
745 | return reftable_reader_refs_for_indexed(r, it, oid); | |
746 | return reftable_reader_refs_for_unindexed(r, it, oid); | |
747 | } | |
748 | ||
749 | uint64_t reftable_reader_max_update_index(struct reftable_reader *r) | |
750 | { | |
751 | return r->max_update_index; | |
752 | } | |
753 | ||
754 | uint64_t reftable_reader_min_update_index(struct reftable_reader *r) | |
755 | { | |
756 | return r->min_update_index; | |
757 | } | |
758 | ||
759 | /* generic table interface. */ | |
760 | ||
761 | static int reftable_reader_seek_void(void *tab, struct reftable_iterator *it, | |
762 | struct reftable_record *rec) | |
763 | { | |
764 | return reader_seek(tab, it, rec); | |
765 | } | |
766 | ||
767 | static uint32_t reftable_reader_hash_id_void(void *tab) | |
768 | { | |
769 | return reftable_reader_hash_id(tab); | |
770 | } | |
771 | ||
772 | static uint64_t reftable_reader_min_update_index_void(void *tab) | |
773 | { | |
774 | return reftable_reader_min_update_index(tab); | |
775 | } | |
776 | ||
777 | static uint64_t reftable_reader_max_update_index_void(void *tab) | |
778 | { | |
779 | return reftable_reader_max_update_index(tab); | |
780 | } | |
781 | ||
782 | static struct reftable_table_vtable reader_vtable = { | |
783 | .seek_record = reftable_reader_seek_void, | |
784 | .hash_id = reftable_reader_hash_id_void, | |
785 | .min_update_index = reftable_reader_min_update_index_void, | |
786 | .max_update_index = reftable_reader_max_update_index_void, | |
787 | }; | |
788 | ||
789 | void reftable_table_from_reader(struct reftable_table *tab, | |
790 | struct reftable_reader *reader) | |
791 | { | |
792 | assert(!tab->ops); | |
793 | tab->ops = &reader_vtable; | |
794 | tab->table_arg = reader; | |
795 | } | |
796 | ||
797 | ||
798 | int reftable_reader_print_file(const char *tablename) | |
799 | { | |
800 | struct reftable_block_source src = { NULL }; | |
801 | int err = reftable_block_source_from_file(&src, tablename); | |
802 | struct reftable_reader *r = NULL; | |
803 | struct reftable_table tab = { NULL }; | |
804 | if (err < 0) | |
805 | goto done; | |
806 | ||
807 | err = reftable_new_reader(&r, &src, tablename); | |
808 | if (err < 0) | |
809 | goto done; | |
810 | ||
811 | reftable_table_from_reader(&tab, r); | |
812 | err = reftable_table_print(&tab); | |
813 | done: | |
814 | reftable_reader_free(r); | |
815 | return err; | |
816 | } |