Fix: Coverity warning CWE-457: Use of Uninitialized Variable
[babeltrace.git] / lib / iterator.c
CommitLineData
6f3077a2
JD
1/*
2 * iterator.c
3 *
4 * Babeltrace Library
5 *
6 * Copyright 2010-2011 EfficiOS Inc. and Linux Foundation
7 *
8 * Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
9 *
10 * Permission is hereby granted, free of charge, to any person obtaining a copy
11 * of this software and associated documentation files (the "Software"), to deal
12 * in the Software without restriction, including without limitation the rights
13 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
14 * copies of the Software, and to permit persons to whom the Software is
15 * furnished to do so, subject to the following conditions:
16 *
17 * The above copyright notice and this permission notice shall be included in
18 * all copies or substantial portions of the Software.
c462e188
MD
19 *
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
23 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
25 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
26 * SOFTWARE.
6f3077a2
JD
27 */
28
29#include <stdlib.h>
30#include <babeltrace/babeltrace.h>
95d36295 31#include <babeltrace/context.h>
08c22d05 32#include <babeltrace/context-internal.h>
6f3077a2 33#include <babeltrace/iterator-internal.h>
6204d33c 34#include <babeltrace/iterator.h>
6f3077a2 35#include <babeltrace/prio_heap.h>
e4195791 36#include <babeltrace/ctf/metadata.h>
9843982d 37#include <babeltrace/ctf/events.h>
90fcbacc 38#include <inttypes.h>
6f3077a2 39
55c21ea5
JD
40static int babeltrace_filestream_seek(struct ctf_file_stream *file_stream,
41 const struct bt_iter_pos *begin_pos,
42 unsigned long stream_id);
43
6f3077a2
JD
44struct stream_saved_pos {
45 /*
46 * Use file_stream pointer to check if the trace collection we
47 * restore to match the one we saved from, for each stream.
48 */
49 struct ctf_file_stream *file_stream;
50 size_t cur_index; /* current index in packet index */
51 ssize_t offset; /* offset from base, in bits. EOF for end of file. */
03798a93
JD
52 uint64_t current_real_timestamp;
53 uint64_t current_cycles_timestamp;
6f3077a2
JD
54};
55
e8c92a62 56struct bt_saved_pos {
6f3077a2
JD
57 struct trace_collection *tc;
58 GArray *stream_saved_pos; /* Contains struct stream_saved_pos */
59};
60
61static int stream_read_event(struct ctf_file_stream *sin)
62{
63 int ret;
64
65 ret = sin->pos.parent.event_cb(&sin->pos.parent, &sin->parent);
66 if (ret == EOF)
67 return EOF;
8793d9f8
JD
68 else if (ret == EAGAIN)
69 /* Stream is inactive for now (live reading). */
70 return EAGAIN;
6f3077a2 71 else if (ret) {
3394d22e 72 fprintf(stderr, "[error] Reading event failed.\n");
6f3077a2
JD
73 return ret;
74 }
75 return 0;
76}
77
78/*
6c9a50c0
MD
79 * Return true if a < b, false otherwise.
80 * If time stamps are exactly the same, compare by stream path. This
81 * ensures we get the same result between runs on the same trace
82 * collection on different environments.
83 * The result will be random for memory-mapped traces since there is no
84 * fixed path leading to those (they have empty path string).
6f3077a2 85 */
2002e48a 86static int stream_compare(void *a, void *b)
6f3077a2
JD
87{
88 struct ctf_file_stream *s_a = a, *s_b = b;
89
6c9a50c0 90 if (s_a->parent.real_timestamp < s_b->parent.real_timestamp) {
6f3077a2 91 return 1;
6c9a50c0 92 } else if (likely(s_a->parent.real_timestamp > s_b->parent.real_timestamp)) {
6f3077a2 93 return 0;
6c9a50c0
MD
94 } else {
95 return strcmp(s_a->parent.path, s_b->parent.path);
96 }
6f3077a2
JD
97}
98
90fcbacc
JD
99void bt_iter_free_pos(struct bt_iter_pos *iter_pos)
100{
6cba487f
MD
101 if (!iter_pos)
102 return;
103
5acdc773 104 if (iter_pos->type == BT_SEEK_RESTORE && iter_pos->u.restore) {
6cba487f
MD
105 if (iter_pos->u.restore->stream_saved_pos) {
106 g_array_free(
107 iter_pos->u.restore->stream_saved_pos,
108 TRUE);
90fcbacc 109 }
6cba487f 110 g_free(iter_pos->u.restore);
90fcbacc 111 }
6cba487f 112 g_free(iter_pos);
90fcbacc
JD
113}
114
dc81689e
JD
115/*
116 * seek_file_stream_by_timestamp
117 *
118 * Browse a filestream by index, if an index contains the timestamp passed in
119 * argument, seek inside the corresponding packet it until we find the event we
120 * are looking for (either the exact timestamp or the event just after the
121 * timestamp).
122 *
e32cb1e4
MD
123 * Return 0 if the seek succeded, EOF if we didn't find any packet
124 * containing the timestamp, or a positive integer for error.
f7ed6563
MD
125 *
126 * TODO: this should be turned into a binary search! It is currently
127 * doing a linear search in the packets. This is a O(n) operation on a
128 * very frequent code path.
dc81689e
JD
129 */
130static int seek_file_stream_by_timestamp(struct ctf_file_stream *cfs,
131 uint64_t timestamp)
132{
133 struct ctf_stream_pos *stream_pos;
134 struct packet_index *index;
135 int i, ret;
136
137 stream_pos = &cfs->pos;
992e8cc0
MD
138 for (i = 0; i < stream_pos->packet_index->len; i++) {
139 index = &g_array_index(stream_pos->packet_index,
dc81689e 140 struct packet_index, i);
992e8cc0 141 if (index->ts_real.timestamp_end < timestamp)
dc81689e
JD
142 continue;
143
20d0dcf9 144 stream_pos->packet_seek(&stream_pos->parent, i, SEEK_SET);
5d2a5af2 145 do {
dc81689e 146 ret = stream_read_event(cfs);
03798a93 147 } while (cfs->parent.real_timestamp < timestamp && ret == 0);
5d2a5af2 148
e32cb1e4
MD
149 /* Can return either EOF, 0, or error (> 0). */
150 return ret;
dc81689e 151 }
e32cb1e4
MD
152 /*
153 * Cannot find the timestamp within the stream packets, return
154 * EOF.
155 */
dc81689e
JD
156 return EOF;
157}
158
159/*
160 * seek_ctf_trace_by_timestamp : for each file stream, seek to the event with
161 * the corresponding timestamp
162 *
163 * Return 0 on success.
164 * If the timestamp is not part of any file stream, return EOF to inform the
e32cb1e4
MD
165 * user the timestamp is out of the scope.
166 * On other errors, return positive value.
dc81689e
JD
167 */
168static int seek_ctf_trace_by_timestamp(struct ctf_trace *tin,
169 uint64_t timestamp, struct ptr_heap *stream_heap)
170{
171 int i, j, ret;
e32cb1e4 172 int found = 0;
dc81689e
JD
173
174 /* for each stream_class */
175 for (i = 0; i < tin->streams->len; i++) {
f380e105 176 struct ctf_stream_declaration *stream_class;
dc81689e
JD
177
178 stream_class = g_ptr_array_index(tin->streams, i);
e32cb1e4
MD
179 if (!stream_class)
180 continue;
dc81689e
JD
181 /* for each file_stream */
182 for (j = 0; j < stream_class->streams->len; j++) {
9e88d150 183 struct ctf_stream_definition *stream;
dc81689e
JD
184 struct ctf_file_stream *cfs;
185
186 stream = g_ptr_array_index(stream_class->streams, j);
e32cb1e4
MD
187 if (!stream)
188 continue;
dc81689e
JD
189 cfs = container_of(stream, struct ctf_file_stream,
190 parent);
191 ret = seek_file_stream_by_timestamp(cfs, timestamp);
192 if (ret == 0) {
193 /* Add to heap */
dd06413f 194 ret = bt_heap_insert(stream_heap, cfs);
e32cb1e4
MD
195 if (ret) {
196 /* Return positive error. */
197 return -ret;
198 }
199 found = 1;
200 } else if (ret > 0) {
201 /*
202 * Error in seek (not EOF), failure.
203 */
204 return ret;
dc81689e 205 }
e32cb1e4 206 /* on EOF just do not put stream into heap. */
dc81689e
JD
207 }
208 }
209
e32cb1e4 210 return found ? 0 : EOF;
dc81689e
JD
211}
212
f7ed6563
MD
213/*
214 * Find timestamp of last event in the stream.
215 *
216 * Return value: 0 if OK, positive error value on error, EOF if no
217 * events were found.
218 */
219static int find_max_timestamp_ctf_file_stream(struct ctf_file_stream *cfs,
220 uint64_t *timestamp_end)
221{
222 int ret, count = 0, i;
223 uint64_t timestamp = 0;
224 struct ctf_stream_pos *stream_pos;
225
226 stream_pos = &cfs->pos;
227 /*
228 * We start by the last packet, and iterate backwards until we
229 * either find at least one event, or we reach the first packet
230 * (some packets can be empty).
231 */
992e8cc0 232 for (i = stream_pos->packet_index->len - 1; i >= 0; i--) {
f7ed6563
MD
233 stream_pos->packet_seek(&stream_pos->parent, i, SEEK_SET);
234 count = 0;
235 /* read each event until we reach the end of the stream */
236 do {
237 ret = stream_read_event(cfs);
238 if (ret == 0) {
239 count++;
240 timestamp = cfs->parent.real_timestamp;
241 }
242 } while (ret == 0);
243
244 /* Error */
245 if (ret > 0)
246 goto end;
247 assert(ret == EOF);
248 if (count)
249 break;
250 }
251
252 if (count) {
253 *timestamp_end = timestamp;
254 ret = 0;
255 } else {
256 /* Return EOF if no events were found */
257 ret = EOF;
258 }
259end:
260 return ret;
261}
262
263/*
264 * Find the stream within a stream class that contains the event with
265 * the largest timestamp, and save that timestamp.
266 *
267 * Return 0 if OK, EOF if no events were found in the streams, or
268 * positive value on error.
269 */
270static int find_max_timestamp_ctf_stream_class(
271 struct ctf_stream_declaration *stream_class,
272 struct ctf_file_stream **cfsp,
273 uint64_t *max_timestamp)
274{
38380786 275 int ret = EOF, i, found = 0;
f7ed6563
MD
276
277 for (i = 0; i < stream_class->streams->len; i++) {
278 struct ctf_stream_definition *stream;
279 struct ctf_file_stream *cfs;
280 uint64_t current_max_ts = 0;
281
282 stream = g_ptr_array_index(stream_class->streams, i);
283 if (!stream)
284 continue;
285 cfs = container_of(stream, struct ctf_file_stream, parent);
286 ret = find_max_timestamp_ctf_file_stream(cfs, &current_max_ts);
287 if (ret == EOF)
288 continue;
289 if (ret != 0)
290 break;
291 if (current_max_ts >= *max_timestamp) {
292 *max_timestamp = current_max_ts;
293 *cfsp = cfs;
38380786 294 found = 1;
f7ed6563
MD
295 }
296 }
297 assert(ret >= 0 || ret == EOF);
38380786
YB
298 if (found) {
299 return 0;
300 }
f7ed6563
MD
301 return ret;
302}
303
304/*
305 * seek_last_ctf_trace_collection: seek trace collection to last event.
306 *
307 * Return 0 if OK, EOF if no events were found, or positive error value
308 * on error.
309 */
310static int seek_last_ctf_trace_collection(struct trace_collection *tc,
311 struct ctf_file_stream **cfsp)
312{
313 int i, j, ret;
314 int found = 0;
315 uint64_t max_timestamp = 0;
316
317 if (!tc)
318 return 1;
319
320 /* For each trace in the trace_collection */
321 for (i = 0; i < tc->array->len; i++) {
322 struct ctf_trace *tin;
1b8455b7 323 struct bt_trace_descriptor *td_read;
f7ed6563
MD
324
325 td_read = g_ptr_array_index(tc->array, i);
326 if (!td_read)
327 continue;
328 tin = container_of(td_read, struct ctf_trace, parent);
329 /* For each stream_class in the trace */
330 for (j = 0; j < tin->streams->len; j++) {
331 struct ctf_stream_declaration *stream_class;
332
333 stream_class = g_ptr_array_index(tin->streams, j);
334 if (!stream_class)
335 continue;
336 ret = find_max_timestamp_ctf_stream_class(stream_class,
337 cfsp, &max_timestamp);
338 if (ret > 0)
339 goto end;
340 if (ret == 0)
341 found = 1;
342 assert(ret == EOF || ret == 0);
343 }
344 }
345 /*
346 * Now we know in which file stream the last event is located,
347 * and we know its timestamp.
348 */
349 if (!found) {
350 ret = EOF;
351 } else {
352 ret = seek_file_stream_by_timestamp(*cfsp, max_timestamp);
353 assert(ret == 0);
354 }
355end:
356 return ret;
357}
358
90fcbacc
JD
359int bt_iter_set_pos(struct bt_iter *iter, const struct bt_iter_pos *iter_pos)
360{
dc81689e 361 struct trace_collection *tc;
90fcbacc
JD
362 int i, ret;
363
7f89ddce
MD
364 if (!iter || !iter_pos)
365 return -EINVAL;
366
dc81689e
JD
367 switch (iter_pos->type) {
368 case BT_SEEK_RESTORE:
369 if (!iter_pos->u.restore)
7344374e 370 return -EINVAL;
dc81689e 371
dd06413f
JD
372 bt_heap_free(iter->stream_heap);
373 ret = bt_heap_init(iter->stream_heap, 0, stream_compare);
90fcbacc 374 if (ret < 0)
bed54c92 375 goto error_heap_init;
90fcbacc
JD
376
377 for (i = 0; i < iter_pos->u.restore->stream_saved_pos->len;
378 i++) {
379 struct stream_saved_pos *saved_pos;
380 struct ctf_stream_pos *stream_pos;
9e88d150 381 struct ctf_stream_definition *stream;
90fcbacc
JD
382
383 saved_pos = &g_array_index(
384 iter_pos->u.restore->stream_saved_pos,
385 struct stream_saved_pos, i);
386 stream = &saved_pos->file_stream->parent;
387 stream_pos = &saved_pos->file_stream->pos;
90fcbacc 388
06789ffd 389 stream_pos->packet_seek(&stream_pos->parent,
20d0dcf9 390 saved_pos->cur_index, SEEK_SET);
90fcbacc
JD
391
392 /*
393 * the timestamp needs to be restored after
06789ffd 394 * packet_seek, because this function resets
90fcbacc
JD
395 * the timestamp to the beginning of the packet
396 */
03798a93
JD
397 stream->real_timestamp = saved_pos->current_real_timestamp;
398 stream->cycles_timestamp = saved_pos->current_cycles_timestamp;
90fcbacc 399 stream_pos->offset = saved_pos->offset;
3a25e036 400 stream_pos->last_offset = LAST_OFFSET_POISON;
90fcbacc 401
03798a93
JD
402 stream->prev_real_timestamp = 0;
403 stream->prev_real_timestamp_end = 0;
404 stream->prev_cycles_timestamp = 0;
405 stream->prev_cycles_timestamp_end = 0;
90fcbacc 406
fef3bf22
MD
407 printf_debug("restored to cur_index = %" PRId64 " and "
408 "offset = %" PRId64 ", timestamp = %" PRIu64 "\n",
90fcbacc 409 stream_pos->cur_index,
03798a93 410 stream_pos->offset, stream->real_timestamp);
90fcbacc 411
28fcbaca
MD
412 ret = stream_read_event(saved_pos->file_stream);
413 if (ret != 0) {
414 goto error;
415 }
90fcbacc
JD
416
417 /* Add to heap */
dd06413f 418 ret = bt_heap_insert(iter->stream_heap,
90fcbacc
JD
419 saved_pos->file_stream);
420 if (ret)
421 goto error;
422 }
5acdc773 423 return 0;
dc81689e
JD
424 case BT_SEEK_TIME:
425 tc = iter->ctx->tc;
426
dd06413f
JD
427 bt_heap_free(iter->stream_heap);
428 ret = bt_heap_init(iter->stream_heap, 0, stream_compare);
dc81689e 429 if (ret < 0)
bed54c92 430 goto error_heap_init;
dc81689e
JD
431
432 /* for each trace in the trace_collection */
433 for (i = 0; i < tc->array->len; i++) {
434 struct ctf_trace *tin;
1b8455b7 435 struct bt_trace_descriptor *td_read;
dc81689e
JD
436
437 td_read = g_ptr_array_index(tc->array, i);
e32cb1e4
MD
438 if (!td_read)
439 continue;
dc81689e
JD
440 tin = container_of(td_read, struct ctf_trace, parent);
441
442 ret = seek_ctf_trace_by_timestamp(tin,
443 iter_pos->u.seek_time,
444 iter->stream_heap);
e32cb1e4
MD
445 /*
446 * Positive errors are failure. Negative value
447 * is EOF (for which we continue with other
448 * traces). 0 is success. Note: on EOF, it just
449 * means that no stream has been added to the
450 * iterator for that trace, which is fine.
451 */
452 if (ret != 0 && ret != EOF)
dc81689e
JD
453 goto error;
454 }
455 return 0;
55c21ea5
JD
456 case BT_SEEK_BEGIN:
457 tc = iter->ctx->tc;
dd06413f
JD
458 bt_heap_free(iter->stream_heap);
459 ret = bt_heap_init(iter->stream_heap, 0, stream_compare);
db8a4511 460 if (ret < 0)
bed54c92 461 goto error_heap_init;
db8a4511 462
55c21ea5
JD
463 for (i = 0; i < tc->array->len; i++) {
464 struct ctf_trace *tin;
1b8455b7 465 struct bt_trace_descriptor *td_read;
55c21ea5
JD
466 int stream_id;
467
468 td_read = g_ptr_array_index(tc->array, i);
e32cb1e4
MD
469 if (!td_read)
470 continue;
55c21ea5
JD
471 tin = container_of(td_read, struct ctf_trace, parent);
472
473 /* Populate heap with each stream */
474 for (stream_id = 0; stream_id < tin->streams->len;
475 stream_id++) {
f380e105 476 struct ctf_stream_declaration *stream;
55c21ea5
JD
477 int filenr;
478
479 stream = g_ptr_array_index(tin->streams,
480 stream_id);
481 if (!stream)
482 continue;
483 for (filenr = 0; filenr < stream->streams->len;
484 filenr++) {
485 struct ctf_file_stream *file_stream;
486 file_stream = g_ptr_array_index(
487 stream->streams,
488 filenr);
e32cb1e4
MD
489 if (!file_stream)
490 continue;
55c21ea5
JD
491 ret = babeltrace_filestream_seek(
492 file_stream, iter_pos,
493 stream_id);
e32cb1e4
MD
494 if (ret != 0 && ret != EOF) {
495 goto error;
496 }
08ac0e08
MD
497 if (ret == EOF) {
498 /* Do not add EOF streams */
499 continue;
500 }
dd06413f 501 ret = bt_heap_insert(iter->stream_heap, file_stream);
db8a4511
JD
502 if (ret)
503 goto error;
55c21ea5
JD
504 }
505 }
506 }
507 break;
f7ed6563
MD
508 case BT_SEEK_LAST:
509 {
4b8de153 510 struct ctf_file_stream *cfs = NULL;
f7ed6563
MD
511
512 tc = iter->ctx->tc;
513 ret = seek_last_ctf_trace_collection(tc, &cfs);
4b8de153 514 if (ret != 0 || !cfs)
f7ed6563
MD
515 goto error;
516 /* remove all streams from the heap */
dd06413f 517 bt_heap_free(iter->stream_heap);
f7ed6563 518 /* Create a new empty heap */
dd06413f 519 ret = bt_heap_init(iter->stream_heap, 0, stream_compare);
f7ed6563
MD
520 if (ret < 0)
521 goto error;
522 /* Insert the stream that contains the last event */
dd06413f 523 ret = bt_heap_insert(iter->stream_heap, cfs);
f7ed6563
MD
524 if (ret)
525 goto error;
526 break;
527 }
dc81689e
JD
528 default:
529 /* not implemented */
7344374e 530 return -EINVAL;
90fcbacc
JD
531 }
532
533 return 0;
dc81689e 534
90fcbacc 535error:
dd06413f 536 bt_heap_free(iter->stream_heap);
bed54c92 537error_heap_init:
dd06413f
JD
538 if (bt_heap_init(iter->stream_heap, 0, stream_compare) < 0) {
539 bt_heap_free(iter->stream_heap);
dc81689e
JD
540 g_free(iter->stream_heap);
541 iter->stream_heap = NULL;
542 ret = -ENOMEM;
543 }
bed54c92 544
dc81689e 545 return ret;
90fcbacc
JD
546}
547
548struct bt_iter_pos *bt_iter_get_pos(struct bt_iter *iter)
549{
550 struct bt_iter_pos *pos;
7f89ddce 551 struct trace_collection *tc;
6fabd7af
JD
552 struct ctf_file_stream *file_stream = NULL, *removed;
553 struct ptr_heap iter_heap_copy;
554 int ret;
90fcbacc 555
7f89ddce
MD
556 if (!iter)
557 return NULL;
558
559 tc = iter->ctx->tc;
90fcbacc 560 pos = g_new0(struct bt_iter_pos, 1);
5acdc773 561 pos->type = BT_SEEK_RESTORE;
90fcbacc 562 pos->u.restore = g_new0(struct bt_saved_pos, 1);
90fcbacc
JD
563 pos->u.restore->tc = tc;
564 pos->u.restore->stream_saved_pos = g_array_new(FALSE, TRUE,
565 sizeof(struct stream_saved_pos));
566 if (!pos->u.restore->stream_saved_pos)
567 goto error;
568
dd06413f 569 ret = bt_heap_copy(&iter_heap_copy, iter->stream_heap);
6fabd7af
JD
570 if (ret < 0)
571 goto error_heap;
90fcbacc 572
6fabd7af 573 /* iterate over each stream in the heap */
dd06413f 574 file_stream = bt_heap_maximum(&iter_heap_copy);
6fabd7af
JD
575 while (file_stream != NULL) {
576 struct stream_saved_pos saved_pos;
90fcbacc 577
6fabd7af
JD
578 assert(file_stream->pos.last_offset != LAST_OFFSET_POISON);
579 saved_pos.offset = file_stream->pos.last_offset;
580 saved_pos.file_stream = file_stream;
581 saved_pos.cur_index = file_stream->pos.cur_index;
90fcbacc 582
03798a93
JD
583 saved_pos.current_real_timestamp = file_stream->parent.real_timestamp;
584 saved_pos.current_cycles_timestamp = file_stream->parent.cycles_timestamp;
90fcbacc 585
6fabd7af
JD
586 g_array_append_val(
587 pos->u.restore->stream_saved_pos,
588 saved_pos);
90fcbacc 589
6fabd7af
JD
590 printf_debug("stream : %" PRIu64 ", cur_index : %zd, "
591 "offset : %zd, "
592 "timestamp = %" PRIu64 "\n",
593 file_stream->parent.stream_id,
594 saved_pos.cur_index, saved_pos.offset,
03798a93 595 saved_pos.current_real_timestamp);
6fabd7af
JD
596
597 /* remove the stream from the heap copy */
dd06413f 598 removed = bt_heap_remove(&iter_heap_copy);
6fabd7af
JD
599 assert(removed == file_stream);
600
dd06413f 601 file_stream = bt_heap_maximum(&iter_heap_copy);
6fabd7af 602 }
dd06413f 603 bt_heap_free(&iter_heap_copy);
90fcbacc
JD
604 return pos;
605
6fabd7af
JD
606error_heap:
607 g_array_free(pos->u.restore->stream_saved_pos, TRUE);
90fcbacc 608error:
6fabd7af 609 g_free(pos);
90fcbacc
JD
610 return NULL;
611}
612
dc81689e
JD
613struct bt_iter_pos *bt_iter_create_time_pos(struct bt_iter *iter,
614 uint64_t timestamp)
615{
616 struct bt_iter_pos *pos;
617
7f89ddce
MD
618 if (!iter)
619 return NULL;
620
dc81689e
JD
621 pos = g_new0(struct bt_iter_pos, 1);
622 pos->type = BT_SEEK_TIME;
623 pos->u.seek_time = timestamp;
624 return pos;
625}
626
6f3077a2
JD
627/*
628 * babeltrace_filestream_seek: seek a filestream to given position.
629 *
630 * The stream_id parameter is only useful for BT_SEEK_RESTORE.
631 */
632static int babeltrace_filestream_seek(struct ctf_file_stream *file_stream,
e8c92a62 633 const struct bt_iter_pos *begin_pos,
6f3077a2
JD
634 unsigned long stream_id)
635{
636 int ret = 0;
637
7f89ddce
MD
638 if (!file_stream || !begin_pos)
639 return -EINVAL;
640
6f3077a2
JD
641 switch (begin_pos->type) {
642 case BT_SEEK_CUR:
643 /*
644 * just insert into the heap we should already know
645 * the timestamps
646 */
647 break;
648 case BT_SEEK_BEGIN:
06789ffd 649 file_stream->pos.packet_seek(&file_stream->pos.parent,
d6425aaf 650 0, SEEK_SET);
6f3077a2
JD
651 ret = stream_read_event(file_stream);
652 break;
653 case BT_SEEK_TIME:
654 case BT_SEEK_RESTORE:
6f3077a2
JD
655 default:
656 assert(0); /* Not yet defined */
657 }
658
659 return ret;
660}
661
b587c608
JD
662int bt_iter_add_trace(struct bt_iter *iter,
663 struct bt_trace_descriptor *td_read)
664{
665 struct ctf_trace *tin;
788b424d 666 int stream_id, ret = 0;
b587c608
JD
667
668 tin = container_of(td_read, struct ctf_trace, parent);
669
670 /* Populate heap with each stream */
671 for (stream_id = 0; stream_id < tin->streams->len;
672 stream_id++) {
673 struct ctf_stream_declaration *stream;
674 int filenr;
675
676 stream = g_ptr_array_index(tin->streams, stream_id);
677 if (!stream)
678 continue;
679 for (filenr = 0; filenr < stream->streams->len;
680 filenr++) {
681 struct ctf_file_stream *file_stream;
682 struct bt_iter_pos pos;
683
684 file_stream = g_ptr_array_index(stream->streams,
685 filenr);
686 if (!file_stream)
687 continue;
688
689 pos.type = BT_SEEK_BEGIN;
690 ret = babeltrace_filestream_seek(file_stream,
691 &pos, stream_id);
692
693 if (ret == EOF) {
694 ret = 0;
695 continue;
696 } else if (ret != 0 && ret != EAGAIN) {
697 goto error;
698 }
699 /* Add to heap */
700 ret = bt_heap_insert(iter->stream_heap, file_stream);
701 if (ret)
702 goto error;
703 }
704 }
705
706error:
707 return ret;
708}
709
e4195791
MD
710int bt_iter_init(struct bt_iter *iter,
711 struct bt_context *ctx,
04ae3991
MD
712 const struct bt_iter_pos *begin_pos,
713 const struct bt_iter_pos *end_pos)
6f3077a2 714{
b587c608 715 int i;
6f3077a2 716 int ret = 0;
6f3077a2 717
7f89ddce
MD
718 if (!iter || !ctx)
719 return -EINVAL;
720
e003e871
JD
721 if (ctx->current_iterator) {
722 ret = -1;
723 goto error_ctx;
724 }
725
6f3077a2 726 iter->stream_heap = g_new(struct ptr_heap, 1);
6f3077a2 727 iter->end_pos = end_pos;
6cba487f 728 bt_context_get(ctx);
95d36295 729 iter->ctx = ctx;
6f3077a2 730
dd06413f 731 ret = bt_heap_init(iter->stream_heap, 0, stream_compare);
6f3077a2
JD
732 if (ret < 0)
733 goto error_heap_init;
734
95d36295 735 for (i = 0; i < ctx->tc->array->len; i++) {
1b8455b7 736 struct bt_trace_descriptor *td_read;
6f3077a2 737
95d36295 738 td_read = g_ptr_array_index(ctx->tc->array, i);
e32cb1e4
MD
739 if (!td_read)
740 continue;
b587c608
JD
741 ret = bt_iter_add_trace(iter, td_read);
742 if (ret < 0)
743 goto error;
6f3077a2
JD
744 }
745
e003e871 746 ctx->current_iterator = iter;
d899d6de
JG
747 if (begin_pos && begin_pos->type != BT_SEEK_BEGIN) {
748 ret = bt_iter_set_pos(iter, begin_pos);
749 }
750
751 return ret;
6f3077a2
JD
752
753error:
dd06413f 754 bt_heap_free(iter->stream_heap);
6f3077a2
JD
755error_heap_init:
756 g_free(iter->stream_heap);
bed54c92 757 iter->stream_heap = NULL;
e003e871 758error_ctx:
e4195791 759 return ret;
6f3077a2
JD
760}
761
e4195791 762struct bt_iter *bt_iter_create(struct bt_context *ctx,
04ae3991
MD
763 const struct bt_iter_pos *begin_pos,
764 const struct bt_iter_pos *end_pos)
e4195791
MD
765{
766 struct bt_iter *iter;
767 int ret;
768
7f89ddce
MD
769 if (!ctx)
770 return NULL;
771
e4195791
MD
772 iter = g_new0(struct bt_iter, 1);
773 ret = bt_iter_init(iter, ctx, begin_pos, end_pos);
774 if (ret) {
775 g_free(iter);
776 return NULL;
777 }
778 return iter;
779}
780
781void bt_iter_fini(struct bt_iter *iter)
6f3077a2 782{
7f89ddce 783 assert(iter);
dc81689e 784 if (iter->stream_heap) {
dd06413f 785 bt_heap_free(iter->stream_heap);
dc81689e
JD
786 g_free(iter->stream_heap);
787 }
e003e871 788 iter->ctx->current_iterator = NULL;
95d36295 789 bt_context_put(iter->ctx);
e4195791 790}
95d36295 791
e4195791
MD
792void bt_iter_destroy(struct bt_iter *iter)
793{
7f89ddce 794 assert(iter);
e4195791 795 bt_iter_fini(iter);
90fcbacc 796 g_free(iter);
6f3077a2
JD
797}
798
e8c92a62 799int bt_iter_next(struct bt_iter *iter)
6f3077a2
JD
800{
801 struct ctf_file_stream *file_stream, *removed;
802 int ret;
803
7f89ddce
MD
804 if (!iter)
805 return -EINVAL;
806
dd06413f 807 file_stream = bt_heap_maximum(iter->stream_heap);
6f3077a2
JD
808 if (!file_stream) {
809 /* end of file for all streams */
810 ret = 0;
811 goto end;
812 }
813
814 ret = stream_read_event(file_stream);
815 if (ret == EOF) {
dd06413f 816 removed = bt_heap_remove(iter->stream_heap);
6f3077a2
JD
817 assert(removed == file_stream);
818 ret = 0;
819 goto end;
8793d9f8
JD
820 } else if (ret == EAGAIN) {
821 /*
500634be
JD
822 * Live streaming: the stream is inactive for now, we
823 * just updated the timestamp_end to skip over this
824 * stream up to a certain point in time.
825 *
826 * Since we can't guarantee that a stream will ever have
827 * any activity, we can't rely on the fact that
828 * bt_iter_next will be called for each stream and deal
829 * with inactive streams. So instead, we return 0 here
830 * to the caller and let the read API handle the
831 * retry case.
8793d9f8 832 */
500634be 833 ret = 0;
8793d9f8 834 goto reinsert;
6f3077a2
JD
835 } else if (ret) {
836 goto end;
837 }
8793d9f8
JD
838
839reinsert:
6f3077a2 840 /* Reinsert the file stream into the heap, and rebalance. */
dd06413f 841 removed = bt_heap_replace_max(iter->stream_heap, file_stream);
6f3077a2 842 assert(removed == file_stream);
6f3077a2
JD
843end:
844 return ret;
845}
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