/src/libgit2/deps/reftable/writer.c
Line | Count | Source |
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 "writer.h" |
10 | | |
11 | | #include "system.h" |
12 | | |
13 | | #include "block.h" |
14 | | #include "constants.h" |
15 | | #include "record.h" |
16 | | #include "tree.h" |
17 | | #include "reftable-error.h" |
18 | | |
19 | | /* finishes a block, and writes it to storage */ |
20 | | static int writer_flush_block(struct reftable_writer *w); |
21 | | |
22 | | /* deallocates memory related to the index */ |
23 | | static void writer_clear_index(struct reftable_writer *w); |
24 | | |
25 | | /* finishes writing a 'r' (refs) or 'g' (reflogs) section */ |
26 | | static int writer_finish_public_section(struct reftable_writer *w); |
27 | | |
28 | | static struct reftable_block_stats * |
29 | | writer_reftable_block_stats(struct reftable_writer *w, uint8_t typ) |
30 | 0 | { |
31 | 0 | switch (typ) { |
32 | 0 | case 'r': |
33 | 0 | return &w->stats.ref_stats; |
34 | 0 | case 'o': |
35 | 0 | return &w->stats.obj_stats; |
36 | 0 | case 'i': |
37 | 0 | return &w->stats.idx_stats; |
38 | 0 | case 'g': |
39 | 0 | return &w->stats.log_stats; |
40 | 0 | } |
41 | 0 | abort(); |
42 | 0 | return NULL; |
43 | 0 | } |
44 | | |
45 | | /* write data, queuing the padding for the next write. Returns negative for |
46 | | * error. */ |
47 | | static int padded_write(struct reftable_writer *w, uint8_t *data, size_t len, |
48 | | int padding) |
49 | 0 | { |
50 | 0 | int n = 0; |
51 | 0 | if (w->pending_padding > 0) { |
52 | 0 | uint8_t *zeroed; |
53 | 0 | int n; |
54 | |
|
55 | 0 | zeroed = reftable_calloc(w->pending_padding, sizeof(*zeroed)); |
56 | 0 | if (!zeroed) |
57 | 0 | return -1; |
58 | | |
59 | 0 | n = w->write(w->write_arg, zeroed, w->pending_padding); |
60 | 0 | if (n < 0) { |
61 | 0 | reftable_free(zeroed); |
62 | 0 | return n; |
63 | 0 | } |
64 | | |
65 | 0 | w->pending_padding = 0; |
66 | 0 | reftable_free(zeroed); |
67 | 0 | } |
68 | | |
69 | 0 | w->pending_padding = padding; |
70 | 0 | n = w->write(w->write_arg, data, len); |
71 | 0 | if (n < 0) |
72 | 0 | return n; |
73 | 0 | n += padding; |
74 | 0 | return 0; |
75 | 0 | } |
76 | | |
77 | | static void options_set_defaults(struct reftable_write_options *opts) |
78 | 0 | { |
79 | 0 | if (opts->restart_interval == 0) { |
80 | 0 | opts->restart_interval = 16; |
81 | 0 | } |
82 | |
|
83 | 0 | if (opts->block_size == 0) { |
84 | 0 | opts->block_size = DEFAULT_BLOCK_SIZE; |
85 | 0 | } |
86 | 0 | } |
87 | | |
88 | | static int writer_version(struct reftable_writer *w) |
89 | 0 | { |
90 | 0 | return (w->hash_id == 0 || w->hash_id == REFTABLE_HASH_SHA1) ? |
91 | 0 | 1 : |
92 | 0 | 2; |
93 | 0 | } |
94 | | |
95 | | static int writer_write_header(struct reftable_writer *w, uint8_t *dest) |
96 | 0 | { |
97 | 0 | memcpy(dest, "REFT", 4); |
98 | |
|
99 | 0 | dest[4] = writer_version(w); |
100 | |
|
101 | 0 | reftable_put_be24(dest + 5, w->opts.block_size); |
102 | 0 | reftable_put_be64(dest + 8, w->min_update_index); |
103 | 0 | reftable_put_be64(dest + 16, w->max_update_index); |
104 | 0 | if (writer_version(w) == 2) { |
105 | 0 | uint32_t hash_id; |
106 | |
|
107 | 0 | switch (w->hash_id) { |
108 | 0 | case REFTABLE_HASH_SHA1: |
109 | 0 | hash_id = REFTABLE_FORMAT_ID_SHA1; |
110 | 0 | break; |
111 | 0 | case REFTABLE_HASH_SHA256: |
112 | 0 | hash_id = REFTABLE_FORMAT_ID_SHA256; |
113 | 0 | break; |
114 | 0 | default: |
115 | 0 | return -1; |
116 | 0 | } |
117 | | |
118 | 0 | reftable_put_be32(dest + 24, hash_id); |
119 | 0 | } |
120 | | |
121 | 0 | return header_size(writer_version(w)); |
122 | 0 | } |
123 | | |
124 | | static int writer_reinit_block_writer(struct reftable_writer *w, uint8_t typ) |
125 | 0 | { |
126 | 0 | int block_start = 0, ret; |
127 | |
|
128 | 0 | if (w->next == 0) |
129 | 0 | block_start = header_size(writer_version(w)); |
130 | |
|
131 | 0 | reftable_buf_reset(&w->last_key); |
132 | 0 | ret = block_writer_init(&w->block_writer_data, typ, w->block, |
133 | 0 | w->opts.block_size, block_start, |
134 | 0 | hash_size(w->hash_id)); |
135 | 0 | if (ret < 0) |
136 | 0 | return ret; |
137 | | |
138 | 0 | w->block_writer = &w->block_writer_data; |
139 | 0 | w->block_writer->restart_interval = w->opts.restart_interval; |
140 | |
|
141 | 0 | return 0; |
142 | 0 | } |
143 | | |
144 | | int reftable_writer_new(struct reftable_writer **out, |
145 | | ssize_t (*writer_func)(void *, const void *, size_t), |
146 | | int (*flush_func)(void *), |
147 | | void *writer_arg, |
148 | | enum reftable_hash hash_id, |
149 | | const struct reftable_write_options *_opts) |
150 | 0 | { |
151 | 0 | struct reftable_write_options opts = {0}; |
152 | 0 | struct reftable_writer *wp; |
153 | |
|
154 | 0 | if (_opts) |
155 | 0 | opts = *_opts; |
156 | 0 | options_set_defaults(&opts); |
157 | 0 | if (opts.block_size >= (1 << 24)) |
158 | 0 | return REFTABLE_API_ERROR; |
159 | | |
160 | 0 | if (!hash_id) |
161 | 0 | hash_id = REFTABLE_HASH_SHA1; |
162 | |
|
163 | 0 | wp = reftable_calloc(1, sizeof(*wp)); |
164 | 0 | if (!wp) |
165 | 0 | return REFTABLE_OUT_OF_MEMORY_ERROR; |
166 | | |
167 | 0 | reftable_buf_init(&wp->block_writer_data.last_key); |
168 | 0 | reftable_buf_init(&wp->last_key); |
169 | 0 | reftable_buf_init(&wp->scratch); |
170 | 0 | REFTABLE_CALLOC_ARRAY(wp->block, opts.block_size); |
171 | 0 | if (!wp->block) { |
172 | 0 | reftable_free(wp); |
173 | 0 | return REFTABLE_OUT_OF_MEMORY_ERROR; |
174 | 0 | } |
175 | 0 | wp->write = writer_func; |
176 | 0 | wp->write_arg = writer_arg; |
177 | 0 | wp->opts = opts; |
178 | 0 | wp->hash_id = hash_id; |
179 | 0 | wp->flush = flush_func; |
180 | 0 | writer_reinit_block_writer(wp, REFTABLE_BLOCK_TYPE_REF); |
181 | |
|
182 | 0 | *out = wp; |
183 | |
|
184 | 0 | return 0; |
185 | 0 | } |
186 | | |
187 | | int reftable_writer_set_limits(struct reftable_writer *w, uint64_t min, |
188 | | uint64_t max) |
189 | 0 | { |
190 | | /* |
191 | | * Set the min/max update index limits for the reftable writer. |
192 | | * This must be called before adding any records, since: |
193 | | * - The 'next' field gets set after writing the first block. |
194 | | * - The 'last_key' field updates with each new record (but resets |
195 | | * after sections). |
196 | | * Returns REFTABLE_API_ERROR if called after writing has begun. |
197 | | */ |
198 | 0 | if (w->next || w->last_key.len) |
199 | 0 | return REFTABLE_API_ERROR; |
200 | | |
201 | 0 | w->min_update_index = min; |
202 | 0 | w->max_update_index = max; |
203 | |
|
204 | 0 | return 0; |
205 | 0 | } |
206 | | |
207 | | static void writer_release(struct reftable_writer *w) |
208 | 0 | { |
209 | 0 | if (w) { |
210 | 0 | reftable_free(w->block); |
211 | 0 | w->block = NULL; |
212 | 0 | block_writer_release(&w->block_writer_data); |
213 | 0 | w->block_writer = NULL; |
214 | 0 | writer_clear_index(w); |
215 | 0 | reftable_buf_release(&w->last_key); |
216 | 0 | reftable_buf_release(&w->scratch); |
217 | 0 | } |
218 | 0 | } |
219 | | |
220 | | void reftable_writer_free(struct reftable_writer *w) |
221 | 0 | { |
222 | 0 | writer_release(w); |
223 | 0 | reftable_free(w); |
224 | 0 | } |
225 | | |
226 | | struct obj_index_tree_node { |
227 | | struct reftable_buf hash; |
228 | | uint64_t *offsets; |
229 | | size_t offset_len; |
230 | | size_t offset_cap; |
231 | | }; |
232 | | |
233 | | #define OBJ_INDEX_TREE_NODE_INIT \ |
234 | 0 | { \ |
235 | 0 | .hash = REFTABLE_BUF_INIT \ |
236 | 0 | } |
237 | | |
238 | | static int obj_index_tree_node_compare(const void *a, const void *b) |
239 | 0 | { |
240 | 0 | return reftable_buf_cmp(&((const struct obj_index_tree_node *)a)->hash, |
241 | 0 | &((const struct obj_index_tree_node *)b)->hash); |
242 | 0 | } |
243 | | |
244 | | static int writer_index_hash(struct reftable_writer *w, struct reftable_buf *hash) |
245 | 0 | { |
246 | 0 | uint64_t off = w->next; |
247 | 0 | struct obj_index_tree_node want = { .hash = *hash }; |
248 | 0 | struct obj_index_tree_node *key; |
249 | 0 | struct tree_node *node; |
250 | |
|
251 | 0 | node = tree_search(w->obj_index_tree, &want, &obj_index_tree_node_compare); |
252 | 0 | if (!node) { |
253 | 0 | struct obj_index_tree_node empty = OBJ_INDEX_TREE_NODE_INIT; |
254 | 0 | int err; |
255 | |
|
256 | 0 | key = reftable_malloc(sizeof(*key)); |
257 | 0 | if (!key) |
258 | 0 | return REFTABLE_OUT_OF_MEMORY_ERROR; |
259 | | |
260 | 0 | *key = empty; |
261 | |
|
262 | 0 | reftable_buf_reset(&key->hash); |
263 | 0 | err = reftable_buf_add(&key->hash, hash->buf, hash->len); |
264 | 0 | if (err < 0) { |
265 | 0 | reftable_free(key); |
266 | 0 | return err; |
267 | 0 | } |
268 | 0 | tree_insert(&w->obj_index_tree, key, |
269 | 0 | &obj_index_tree_node_compare); |
270 | 0 | } else { |
271 | 0 | key = node->key; |
272 | 0 | } |
273 | | |
274 | 0 | if (key->offset_len > 0 && key->offsets[key->offset_len - 1] == off) |
275 | 0 | return 0; |
276 | | |
277 | 0 | REFTABLE_ALLOC_GROW_OR_NULL(key->offsets, key->offset_len + 1, |
278 | 0 | key->offset_cap); |
279 | 0 | if (!key->offsets) |
280 | 0 | return REFTABLE_OUT_OF_MEMORY_ERROR; |
281 | 0 | key->offsets[key->offset_len++] = off; |
282 | |
|
283 | 0 | return 0; |
284 | 0 | } |
285 | | |
286 | | static int writer_add_record(struct reftable_writer *w, |
287 | | struct reftable_record *rec) |
288 | 0 | { |
289 | 0 | int err; |
290 | |
|
291 | 0 | err = reftable_record_key(rec, &w->scratch); |
292 | 0 | if (err < 0) |
293 | 0 | goto done; |
294 | | |
295 | 0 | if (reftable_buf_cmp(&w->last_key, &w->scratch) >= 0) { |
296 | 0 | err = REFTABLE_API_ERROR; |
297 | 0 | goto done; |
298 | 0 | } |
299 | | |
300 | 0 | reftable_buf_reset(&w->last_key); |
301 | 0 | err = reftable_buf_add(&w->last_key, w->scratch.buf, w->scratch.len); |
302 | 0 | if (err < 0) |
303 | 0 | goto done; |
304 | | |
305 | 0 | if (!w->block_writer) { |
306 | 0 | err = writer_reinit_block_writer(w, reftable_record_type(rec)); |
307 | 0 | if (err < 0) |
308 | 0 | goto done; |
309 | 0 | } |
310 | | |
311 | 0 | if (block_writer_type(w->block_writer) != reftable_record_type(rec)) |
312 | 0 | return REFTABLE_API_ERROR; |
313 | | |
314 | | /* |
315 | | * Try to add the record to the writer. If this succeeds then we're |
316 | | * done. Otherwise the block writer may have hit the block size limit |
317 | | * and needs to be flushed. |
318 | | */ |
319 | 0 | err = block_writer_add(w->block_writer, rec); |
320 | 0 | if (err == 0) |
321 | 0 | goto done; |
322 | | |
323 | 0 | if (err != REFTABLE_ENTRY_TOO_BIG_ERROR) |
324 | 0 | goto done; |
325 | | /* |
326 | | * The current block is full, so we need to flush and reinitialize the |
327 | | * writer to start writing the next block. |
328 | | */ |
329 | 0 | err = writer_flush_block(w); |
330 | 0 | if (err < 0) |
331 | 0 | goto done; |
332 | 0 | err = writer_reinit_block_writer(w, reftable_record_type(rec)); |
333 | 0 | if (err < 0) |
334 | 0 | goto done; |
335 | | |
336 | | /* |
337 | | * Try to add the record to the writer again. If this still fails then |
338 | | * the record does not fit into the block size. |
339 | | */ |
340 | 0 | err = block_writer_add(w->block_writer, rec); |
341 | 0 | if (err) |
342 | 0 | goto done; |
343 | | |
344 | 0 | done: |
345 | 0 | return err; |
346 | 0 | } |
347 | | |
348 | | int reftable_writer_add_ref(struct reftable_writer *w, |
349 | | struct reftable_ref_record *ref) |
350 | 0 | { |
351 | 0 | struct reftable_record rec = { |
352 | 0 | .type = REFTABLE_BLOCK_TYPE_REF, |
353 | 0 | .u = { |
354 | 0 | .ref = *ref |
355 | 0 | }, |
356 | 0 | }; |
357 | 0 | int err; |
358 | |
|
359 | 0 | if (!ref->refname || |
360 | 0 | ref->update_index < w->min_update_index || |
361 | 0 | ref->update_index > w->max_update_index) |
362 | 0 | return REFTABLE_API_ERROR; |
363 | | |
364 | 0 | rec.u.ref.update_index -= w->min_update_index; |
365 | |
|
366 | 0 | err = writer_add_record(w, &rec); |
367 | 0 | if (err < 0) |
368 | 0 | goto out; |
369 | | |
370 | 0 | if (!w->opts.skip_index_objects && reftable_ref_record_val1(ref)) { |
371 | 0 | reftable_buf_reset(&w->scratch); |
372 | 0 | err = reftable_buf_add(&w->scratch, (char *)reftable_ref_record_val1(ref), |
373 | 0 | hash_size(w->hash_id)); |
374 | 0 | if (err < 0) |
375 | 0 | goto out; |
376 | | |
377 | 0 | err = writer_index_hash(w, &w->scratch); |
378 | 0 | if (err < 0) |
379 | 0 | goto out; |
380 | 0 | } |
381 | | |
382 | 0 | if (!w->opts.skip_index_objects && reftable_ref_record_val2(ref)) { |
383 | 0 | reftable_buf_reset(&w->scratch); |
384 | 0 | err = reftable_buf_add(&w->scratch, reftable_ref_record_val2(ref), |
385 | 0 | hash_size(w->hash_id)); |
386 | 0 | if (err < 0) |
387 | 0 | goto out; |
388 | | |
389 | 0 | err = writer_index_hash(w, &w->scratch); |
390 | 0 | if (err < 0) |
391 | 0 | goto out; |
392 | 0 | } |
393 | | |
394 | 0 | err = 0; |
395 | |
|
396 | 0 | out: |
397 | 0 | return err; |
398 | 0 | } |
399 | | |
400 | | int reftable_writer_add_refs(struct reftable_writer *w, |
401 | | struct reftable_ref_record *refs, size_t n) |
402 | 0 | { |
403 | 0 | int err = 0; |
404 | |
|
405 | 0 | if (n) |
406 | 0 | qsort(refs, n, sizeof(*refs), reftable_ref_record_compare_name); |
407 | |
|
408 | 0 | for (size_t i = 0; err == 0 && i < n; i++) |
409 | 0 | err = reftable_writer_add_ref(w, &refs[i]); |
410 | |
|
411 | 0 | return err; |
412 | 0 | } |
413 | | |
414 | | static int reftable_writer_add_log_verbatim(struct reftable_writer *w, |
415 | | struct reftable_log_record *log) |
416 | 0 | { |
417 | 0 | struct reftable_record rec = { |
418 | 0 | .type = REFTABLE_BLOCK_TYPE_LOG, |
419 | 0 | .u = { |
420 | 0 | .log = *log, |
421 | 0 | }, |
422 | 0 | }; |
423 | 0 | if (w->block_writer && |
424 | 0 | block_writer_type(w->block_writer) == REFTABLE_BLOCK_TYPE_REF) { |
425 | 0 | int err = writer_finish_public_section(w); |
426 | 0 | if (err < 0) |
427 | 0 | return err; |
428 | 0 | } |
429 | | |
430 | 0 | w->next -= w->pending_padding; |
431 | 0 | w->pending_padding = 0; |
432 | 0 | return writer_add_record(w, &rec); |
433 | 0 | } |
434 | | |
435 | | int reftable_writer_add_log(struct reftable_writer *w, |
436 | | struct reftable_log_record *log) |
437 | 0 | { |
438 | 0 | char *input_log_message = NULL; |
439 | 0 | struct reftable_buf cleaned_message = REFTABLE_BUF_INIT; |
440 | 0 | int err = 0; |
441 | |
|
442 | 0 | if (log->value_type == REFTABLE_LOG_DELETION) |
443 | 0 | return reftable_writer_add_log_verbatim(w, log); |
444 | | |
445 | | /* |
446 | | * Verify only the upper limit of the update_index. Each reflog entry |
447 | | * is tied to a specific update_index. Entries in the reflog can be |
448 | | * replaced by adding a new entry with the same update_index, |
449 | | * effectively canceling the old one. |
450 | | * |
451 | | * Consequently, reflog updates may include update_index values lower |
452 | | * than the writer's min_update_index. |
453 | | */ |
454 | 0 | if (log->update_index > w->max_update_index) |
455 | 0 | return REFTABLE_API_ERROR; |
456 | | |
457 | 0 | if (!log->refname) |
458 | 0 | return REFTABLE_API_ERROR; |
459 | | |
460 | 0 | input_log_message = log->value.update.message; |
461 | 0 | if (!w->opts.exact_log_message && log->value.update.message) { |
462 | 0 | err = reftable_buf_addstr(&cleaned_message, log->value.update.message); |
463 | 0 | if (err < 0) |
464 | 0 | goto done; |
465 | | |
466 | 0 | while (cleaned_message.len && |
467 | 0 | cleaned_message.buf[cleaned_message.len - 1] == '\n') { |
468 | 0 | err = reftable_buf_setlen(&cleaned_message, |
469 | 0 | cleaned_message.len - 1); |
470 | 0 | if (err < 0) |
471 | 0 | goto done; |
472 | 0 | } |
473 | 0 | if (strchr(cleaned_message.buf, '\n')) { |
474 | | /* multiple lines not allowed. */ |
475 | 0 | err = REFTABLE_API_ERROR; |
476 | 0 | goto done; |
477 | 0 | } |
478 | | |
479 | 0 | err = reftable_buf_addstr(&cleaned_message, "\n"); |
480 | 0 | if (err < 0) |
481 | 0 | goto done; |
482 | | |
483 | 0 | log->value.update.message = cleaned_message.buf; |
484 | 0 | } |
485 | | |
486 | 0 | err = reftable_writer_add_log_verbatim(w, log); |
487 | 0 | log->value.update.message = input_log_message; |
488 | 0 | done: |
489 | 0 | reftable_buf_release(&cleaned_message); |
490 | 0 | return err; |
491 | 0 | } |
492 | | |
493 | | int reftable_writer_add_logs(struct reftable_writer *w, |
494 | | struct reftable_log_record *logs, size_t n) |
495 | 0 | { |
496 | 0 | int err = 0; |
497 | |
|
498 | 0 | if (n) |
499 | 0 | qsort(logs, n, sizeof(*logs), reftable_log_record_compare_key); |
500 | |
|
501 | 0 | for (size_t i = 0; err == 0 && i < n; i++) |
502 | 0 | err = reftable_writer_add_log(w, &logs[i]); |
503 | |
|
504 | 0 | return err; |
505 | 0 | } |
506 | | |
507 | | static int writer_finish_section(struct reftable_writer *w) |
508 | 0 | { |
509 | 0 | struct reftable_block_stats *bstats = NULL; |
510 | 0 | uint8_t typ = block_writer_type(w->block_writer); |
511 | 0 | uint64_t index_start = 0; |
512 | 0 | int max_level = 0; |
513 | 0 | size_t threshold = w->opts.unpadded ? 1 : 3; |
514 | 0 | int before_blocks = w->stats.idx_stats.blocks; |
515 | 0 | int err; |
516 | |
|
517 | 0 | err = writer_flush_block(w); |
518 | 0 | if (err < 0) |
519 | 0 | return err; |
520 | | |
521 | | /* |
522 | | * When the section we are about to index has a lot of blocks then the |
523 | | * index itself may span across multiple blocks, as well. This would |
524 | | * require a linear scan over index blocks only to find the desired |
525 | | * indexed block, which is inefficient. Instead, we write a multi-level |
526 | | * index where index records of level N+1 will refer to index blocks of |
527 | | * level N. This isn't constant time, either, but at least logarithmic. |
528 | | * |
529 | | * This loop handles writing this multi-level index. Note that we write |
530 | | * the lowest-level index pointing to the indexed blocks first. We then |
531 | | * continue writing additional index levels until the current level has |
532 | | * less blocks than the threshold so that the highest level will be at |
533 | | * the end of the index section. |
534 | | * |
535 | | * Readers are thus required to start reading the index section from |
536 | | * its end, which is why we set `index_start` to the beginning of the |
537 | | * last index section. |
538 | | */ |
539 | 0 | while (w->index_len > threshold) { |
540 | 0 | struct reftable_index_record *idx = NULL; |
541 | 0 | size_t i, idx_len; |
542 | |
|
543 | 0 | max_level++; |
544 | 0 | index_start = w->next; |
545 | 0 | err = writer_reinit_block_writer(w, REFTABLE_BLOCK_TYPE_INDEX); |
546 | 0 | if (err < 0) |
547 | 0 | return err; |
548 | | |
549 | 0 | idx = w->index; |
550 | 0 | idx_len = w->index_len; |
551 | |
|
552 | 0 | w->index = NULL; |
553 | 0 | w->index_len = 0; |
554 | 0 | w->index_cap = 0; |
555 | 0 | for (i = 0; i < idx_len; i++) { |
556 | 0 | struct reftable_record rec = { |
557 | 0 | .type = REFTABLE_BLOCK_TYPE_INDEX, |
558 | 0 | .u = { |
559 | 0 | .idx = idx[i], |
560 | 0 | }, |
561 | 0 | }; |
562 | |
|
563 | 0 | err = writer_add_record(w, &rec); |
564 | 0 | if (err < 0) |
565 | 0 | return err; |
566 | 0 | } |
567 | | |
568 | 0 | err = writer_flush_block(w); |
569 | 0 | if (err < 0) |
570 | 0 | return err; |
571 | | |
572 | 0 | for (i = 0; i < idx_len; i++) |
573 | 0 | reftable_buf_release(&idx[i].last_key); |
574 | 0 | reftable_free(idx); |
575 | 0 | } |
576 | | |
577 | | /* |
578 | | * The index may still contain a number of index blocks lower than the |
579 | | * threshold. Clear it so that these entries don't leak into the next |
580 | | * index section. |
581 | | */ |
582 | 0 | writer_clear_index(w); |
583 | |
|
584 | 0 | bstats = writer_reftable_block_stats(w, typ); |
585 | 0 | bstats->index_blocks = w->stats.idx_stats.blocks - before_blocks; |
586 | 0 | bstats->index_offset = index_start; |
587 | 0 | bstats->max_index_level = max_level; |
588 | | |
589 | | /* Reinit lastKey, as the next section can start with any key. */ |
590 | 0 | reftable_buf_reset(&w->last_key); |
591 | |
|
592 | 0 | return 0; |
593 | 0 | } |
594 | | |
595 | | struct common_prefix_arg { |
596 | | struct reftable_buf *last; |
597 | | size_t max; |
598 | | }; |
599 | | |
600 | | static void update_common(void *void_arg, void *key) |
601 | 0 | { |
602 | 0 | struct common_prefix_arg *arg = void_arg; |
603 | 0 | struct obj_index_tree_node *entry = key; |
604 | 0 | if (arg->last) { |
605 | 0 | size_t n = common_prefix_size(&entry->hash, arg->last); |
606 | 0 | if (n > arg->max) |
607 | 0 | arg->max = n; |
608 | 0 | } |
609 | 0 | arg->last = &entry->hash; |
610 | 0 | } |
611 | | |
612 | | struct write_record_arg { |
613 | | struct reftable_writer *w; |
614 | | int err; |
615 | | }; |
616 | | |
617 | | static void write_object_record(void *void_arg, void *key) |
618 | 0 | { |
619 | 0 | struct write_record_arg *arg = void_arg; |
620 | 0 | struct obj_index_tree_node *entry = key; |
621 | 0 | struct reftable_record |
622 | 0 | rec = { .type = REFTABLE_BLOCK_TYPE_OBJ, |
623 | 0 | .u.obj = { |
624 | 0 | .hash_prefix = (uint8_t *)entry->hash.buf, |
625 | 0 | .hash_prefix_len = arg->w->stats.object_id_len, |
626 | 0 | .offsets = entry->offsets, |
627 | 0 | .offset_len = entry->offset_len, |
628 | 0 | } }; |
629 | 0 | if (arg->err < 0) |
630 | 0 | goto done; |
631 | | |
632 | | /* |
633 | | * Try to add the record to the writer. If this succeeds then we're |
634 | | * done. Otherwise the block writer may have hit the block size limit |
635 | | * and needs to be flushed. |
636 | | */ |
637 | 0 | arg->err = block_writer_add(arg->w->block_writer, &rec); |
638 | 0 | if (arg->err == 0) |
639 | 0 | goto done; |
640 | | |
641 | 0 | if (arg->err != REFTABLE_ENTRY_TOO_BIG_ERROR) |
642 | 0 | goto done; |
643 | | |
644 | | /* |
645 | | * The current block is full, so we need to flush and reinitialize the |
646 | | * writer to start writing the next block. |
647 | | */ |
648 | 0 | arg->err = writer_flush_block(arg->w); |
649 | 0 | if (arg->err < 0) |
650 | 0 | goto done; |
651 | | |
652 | 0 | arg->err = writer_reinit_block_writer(arg->w, REFTABLE_BLOCK_TYPE_OBJ); |
653 | 0 | if (arg->err < 0) |
654 | 0 | goto done; |
655 | | |
656 | | /* |
657 | | * If this still fails then we may need to reset record's offset |
658 | | * length to reduce the data size to be written. |
659 | | */ |
660 | 0 | arg->err = block_writer_add(arg->w->block_writer, &rec); |
661 | 0 | if (arg->err == 0) |
662 | 0 | goto done; |
663 | | |
664 | 0 | if (arg->err != REFTABLE_ENTRY_TOO_BIG_ERROR) |
665 | 0 | goto done; |
666 | | |
667 | 0 | rec.u.obj.offset_len = 0; |
668 | 0 | arg->err = block_writer_add(arg->w->block_writer, &rec); |
669 | | |
670 | | /* Should be able to write into a fresh block. */ |
671 | 0 | assert(arg->err == 0); |
672 | |
|
673 | 0 | done:; |
674 | 0 | } |
675 | | |
676 | | static void object_record_free(void *void_arg REFTABLE_UNUSED, void *key) |
677 | 0 | { |
678 | 0 | struct obj_index_tree_node *entry = key; |
679 | |
|
680 | 0 | REFTABLE_FREE_AND_NULL(entry->offsets); |
681 | 0 | reftable_buf_release(&entry->hash); |
682 | 0 | reftable_free(entry); |
683 | 0 | } |
684 | | |
685 | | static int writer_dump_object_index(struct reftable_writer *w) |
686 | 0 | { |
687 | 0 | struct write_record_arg closure = { .w = w }; |
688 | 0 | struct common_prefix_arg common = { |
689 | 0 | .max = 1, /* obj_id_len should be >= 2. */ |
690 | 0 | }; |
691 | 0 | int err; |
692 | |
|
693 | 0 | if (w->obj_index_tree) |
694 | 0 | infix_walk(w->obj_index_tree, &update_common, &common); |
695 | 0 | w->stats.object_id_len = common.max + 1; |
696 | |
|
697 | 0 | err = writer_reinit_block_writer(w, REFTABLE_BLOCK_TYPE_OBJ); |
698 | 0 | if (err < 0) |
699 | 0 | return err; |
700 | | |
701 | 0 | if (w->obj_index_tree) |
702 | 0 | infix_walk(w->obj_index_tree, &write_object_record, &closure); |
703 | |
|
704 | 0 | if (closure.err < 0) |
705 | 0 | return closure.err; |
706 | 0 | return writer_finish_section(w); |
707 | 0 | } |
708 | | |
709 | | static int writer_finish_public_section(struct reftable_writer *w) |
710 | 0 | { |
711 | 0 | uint8_t typ = 0; |
712 | 0 | int err = 0; |
713 | |
|
714 | 0 | if (!w->block_writer) |
715 | 0 | return 0; |
716 | | |
717 | 0 | typ = block_writer_type(w->block_writer); |
718 | 0 | err = writer_finish_section(w); |
719 | 0 | if (err < 0) |
720 | 0 | return err; |
721 | 0 | if (typ == REFTABLE_BLOCK_TYPE_REF && !w->opts.skip_index_objects && |
722 | 0 | w->stats.ref_stats.index_blocks > 0) { |
723 | 0 | err = writer_dump_object_index(w); |
724 | 0 | if (err < 0) |
725 | 0 | return err; |
726 | 0 | } |
727 | | |
728 | 0 | if (w->obj_index_tree) { |
729 | 0 | infix_walk(w->obj_index_tree, &object_record_free, NULL); |
730 | 0 | tree_free(w->obj_index_tree); |
731 | 0 | w->obj_index_tree = NULL; |
732 | 0 | } |
733 | |
|
734 | 0 | w->block_writer = NULL; |
735 | 0 | return 0; |
736 | 0 | } |
737 | | |
738 | | int reftable_writer_close(struct reftable_writer *w) |
739 | 0 | { |
740 | 0 | uint8_t footer[72]; |
741 | 0 | uint8_t *p = footer; |
742 | 0 | int err = writer_finish_public_section(w); |
743 | 0 | int empty_table = w->next == 0; |
744 | 0 | if (err != 0) |
745 | 0 | goto done; |
746 | 0 | w->pending_padding = 0; |
747 | 0 | if (empty_table) { |
748 | | /* Empty tables need a header anyway. */ |
749 | 0 | uint8_t header[28]; |
750 | 0 | int n = writer_write_header(w, header); |
751 | 0 | err = padded_write(w, header, n, 0); |
752 | 0 | if (err < 0) |
753 | 0 | goto done; |
754 | 0 | } |
755 | | |
756 | 0 | p += writer_write_header(w, footer); |
757 | 0 | reftable_put_be64(p, w->stats.ref_stats.index_offset); |
758 | 0 | p += 8; |
759 | 0 | reftable_put_be64(p, (w->stats.obj_stats.offset) << 5 | w->stats.object_id_len); |
760 | 0 | p += 8; |
761 | 0 | reftable_put_be64(p, w->stats.obj_stats.index_offset); |
762 | 0 | p += 8; |
763 | |
|
764 | 0 | reftable_put_be64(p, w->stats.log_stats.offset); |
765 | 0 | p += 8; |
766 | 0 | reftable_put_be64(p, w->stats.log_stats.index_offset); |
767 | 0 | p += 8; |
768 | |
|
769 | 0 | reftable_put_be32(p, crc32(0, footer, p - footer)); |
770 | 0 | p += 4; |
771 | |
|
772 | 0 | err = w->flush(w->write_arg); |
773 | 0 | if (err < 0) { |
774 | 0 | err = REFTABLE_IO_ERROR; |
775 | 0 | goto done; |
776 | 0 | } |
777 | | |
778 | 0 | err = padded_write(w, footer, footer_size(writer_version(w)), 0); |
779 | 0 | if (err < 0) |
780 | 0 | goto done; |
781 | | |
782 | 0 | if (empty_table) { |
783 | 0 | err = REFTABLE_EMPTY_TABLE_ERROR; |
784 | 0 | goto done; |
785 | 0 | } |
786 | | |
787 | 0 | done: |
788 | 0 | writer_release(w); |
789 | 0 | return err; |
790 | 0 | } |
791 | | |
792 | | static void writer_clear_index(struct reftable_writer *w) |
793 | 0 | { |
794 | 0 | for (size_t i = 0; w->index && i < w->index_len; i++) |
795 | 0 | reftable_buf_release(&w->index[i].last_key); |
796 | 0 | REFTABLE_FREE_AND_NULL(w->index); |
797 | 0 | w->index_len = 0; |
798 | 0 | w->index_cap = 0; |
799 | 0 | } |
800 | | |
801 | | static int writer_flush_nonempty_block(struct reftable_writer *w) |
802 | 0 | { |
803 | 0 | struct reftable_index_record index_record = { |
804 | 0 | .last_key = REFTABLE_BUF_INIT, |
805 | 0 | }; |
806 | 0 | uint8_t typ = block_writer_type(w->block_writer); |
807 | 0 | struct reftable_block_stats *bstats; |
808 | 0 | int raw_bytes, padding = 0, err; |
809 | 0 | uint64_t block_typ_off; |
810 | | |
811 | | /* |
812 | | * Finish the current block. This will cause the block writer to emit |
813 | | * restart points and potentially compress records in case we are |
814 | | * writing a log block. |
815 | | * |
816 | | * Note that this is still happening in memory. |
817 | | */ |
818 | 0 | raw_bytes = block_writer_finish(w->block_writer); |
819 | 0 | if (raw_bytes < 0) |
820 | 0 | return raw_bytes; |
821 | | |
822 | | /* |
823 | | * By default, all records except for log records are padded to the |
824 | | * block size. |
825 | | */ |
826 | 0 | if (!w->opts.unpadded && typ != REFTABLE_BLOCK_TYPE_LOG) |
827 | 0 | padding = w->opts.block_size - raw_bytes; |
828 | |
|
829 | 0 | bstats = writer_reftable_block_stats(w, typ); |
830 | 0 | block_typ_off = (bstats->blocks == 0) ? w->next : 0; |
831 | 0 | if (block_typ_off > 0) |
832 | 0 | bstats->offset = block_typ_off; |
833 | 0 | bstats->entries += w->block_writer->entries; |
834 | 0 | bstats->restarts += w->block_writer->restart_len; |
835 | 0 | bstats->blocks++; |
836 | 0 | w->stats.blocks++; |
837 | | |
838 | | /* |
839 | | * If this is the first block we're writing to the table then we need |
840 | | * to also write the reftable header. |
841 | | */ |
842 | 0 | if (!w->next) |
843 | 0 | writer_write_header(w, w->block); |
844 | |
|
845 | 0 | err = padded_write(w, w->block, raw_bytes, padding); |
846 | 0 | if (err < 0) |
847 | 0 | return err; |
848 | | |
849 | | /* |
850 | | * Add an index record for every block that we're writing. If we end up |
851 | | * having more than a threshold of index records we will end up writing |
852 | | * an index section in `writer_finish_section()`. Each index record |
853 | | * contains the last record key of the block it is indexing as well as |
854 | | * the offset of that block. |
855 | | * |
856 | | * Note that this also applies when flushing index blocks, in which |
857 | | * case we will end up with a multi-level index. |
858 | | */ |
859 | 0 | REFTABLE_ALLOC_GROW_OR_NULL(w->index, w->index_len + 1, w->index_cap); |
860 | 0 | if (!w->index) |
861 | 0 | return REFTABLE_OUT_OF_MEMORY_ERROR; |
862 | | |
863 | 0 | index_record.offset = w->next; |
864 | 0 | reftable_buf_reset(&index_record.last_key); |
865 | 0 | err = reftable_buf_add(&index_record.last_key, w->block_writer->last_key.buf, |
866 | 0 | w->block_writer->last_key.len); |
867 | 0 | if (err < 0) |
868 | 0 | return err; |
869 | 0 | w->index[w->index_len] = index_record; |
870 | 0 | w->index_len++; |
871 | |
|
872 | 0 | w->next += padding + raw_bytes; |
873 | 0 | w->block_writer = NULL; |
874 | |
|
875 | 0 | return 0; |
876 | 0 | } |
877 | | |
878 | | static int writer_flush_block(struct reftable_writer *w) |
879 | 0 | { |
880 | 0 | if (!w->block_writer) |
881 | 0 | return 0; |
882 | 0 | if (w->block_writer->entries == 0) |
883 | 0 | return 0; |
884 | 0 | return writer_flush_nonempty_block(w); |
885 | 0 | } |
886 | | |
887 | | const struct reftable_stats *reftable_writer_stats(struct reftable_writer *w) |
888 | 0 | { |
889 | 0 | return &w->stats; |
890 | 0 | } |