API : seek by timestamp
[babeltrace.git] / lib / iterator.c
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.
19 */
20
21 #include <stdlib.h>
22 #include <babeltrace/babeltrace.h>
23 #include <babeltrace/callbacks-internal.h>
24 #include <babeltrace/context.h>
25 #include <babeltrace/context-internal.h>
26 #include <babeltrace/ctf/metadata.h>
27 #include <babeltrace/iterator-internal.h>
28 #include <babeltrace/iterator.h>
29 #include <babeltrace/prio_heap.h>
30 #include <inttypes.h>
31
32 struct stream_saved_pos {
33 /*
34 * Use file_stream pointer to check if the trace collection we
35 * restore to match the one we saved from, for each stream.
36 */
37 struct ctf_file_stream *file_stream;
38 size_t cur_index; /* current index in packet index */
39 ssize_t offset; /* offset from base, in bits. EOF for end of file. */
40 uint64_t current_timestamp;
41 };
42
43 struct bt_saved_pos {
44 struct trace_collection *tc;
45 GArray *stream_saved_pos; /* Contains struct stream_saved_pos */
46 };
47
48 static int stream_read_event(struct ctf_file_stream *sin)
49 {
50 int ret;
51
52 ret = sin->pos.parent.event_cb(&sin->pos.parent, &sin->parent);
53 if (ret == EOF)
54 return EOF;
55 else if (ret) {
56 fprintf(stderr, "[error] Reading event failed.\n");
57 return ret;
58 }
59 return 0;
60 }
61
62 /*
63 * returns true if a < b, false otherwise.
64 */
65 int stream_compare(void *a, void *b)
66 {
67 struct ctf_file_stream *s_a = a, *s_b = b;
68
69 if (s_a->parent.timestamp < s_b->parent.timestamp)
70 return 1;
71 else
72 return 0;
73 }
74
75 void bt_iter_free_pos(struct bt_iter_pos *iter_pos)
76 {
77 if (!iter_pos)
78 return;
79
80 if (iter_pos->u.restore) {
81 if (iter_pos->u.restore->stream_saved_pos) {
82 g_array_free(
83 iter_pos->u.restore->stream_saved_pos,
84 TRUE);
85 }
86 g_free(iter_pos->u.restore);
87 }
88 g_free(iter_pos);
89 }
90
91 /*
92 * seek_file_stream_by_timestamp
93 *
94 * Browse a filestream by index, if an index contains the timestamp passed in
95 * argument, seek inside the corresponding packet it until we find the event we
96 * are looking for (either the exact timestamp or the event just after the
97 * timestamp).
98 *
99 * Return 0 if the seek succeded and EOF if we didn't find any packet
100 * containing the timestamp.
101 */
102 static int seek_file_stream_by_timestamp(struct ctf_file_stream *cfs,
103 uint64_t timestamp)
104 {
105 struct ctf_stream_pos *stream_pos;
106 struct packet_index *index;
107 int i, ret;
108
109 stream_pos = &cfs->pos;
110 for (i = 0; i < stream_pos->packet_index->len; i++) {
111 index = &g_array_index(stream_pos->packet_index,
112 struct packet_index, i);
113 if (index->timestamp_begin >= timestamp ||
114 index->timestamp_end <= timestamp)
115 continue;
116
117 stream_pos->cur_index = i;
118 stream_pos->move_pos_slow(stream_pos, index->offset, SEEK_SET);
119 while (cfs->parent.timestamp < timestamp) {
120 ret = stream_read_event(cfs);
121 if (ret < 0)
122 break;
123 }
124 return 0;
125 }
126 return EOF;
127 }
128
129 /*
130 * seek_ctf_trace_by_timestamp : for each file stream, seek to the event with
131 * the corresponding timestamp
132 *
133 * Return 0 on success.
134 * If the timestamp is not part of any file stream, return EOF to inform the
135 * user the timestamp is out of the scope
136 */
137 static int seek_ctf_trace_by_timestamp(struct ctf_trace *tin,
138 uint64_t timestamp, struct ptr_heap *stream_heap)
139 {
140 int i, j, ret;
141 int found = EOF;
142
143 /* for each stream_class */
144 for (i = 0; i < tin->streams->len; i++) {
145 struct ctf_stream_class *stream_class;
146
147 stream_class = g_ptr_array_index(tin->streams, i);
148 /* for each file_stream */
149 for (j = 0; j < stream_class->streams->len; j++) {
150 struct ctf_stream *stream;
151 struct ctf_file_stream *cfs;
152
153 stream = g_ptr_array_index(stream_class->streams, j);
154 cfs = container_of(stream, struct ctf_file_stream,
155 parent);
156 ret = seek_file_stream_by_timestamp(cfs, timestamp);
157 if (ret == 0) {
158 /* Add to heap */
159 ret = heap_insert(stream_heap, cfs);
160 if (ret)
161 goto error;
162 found = 0;
163 }
164 }
165 }
166
167 return found;
168
169 error:
170 return -2;
171 }
172
173 int bt_iter_set_pos(struct bt_iter *iter, const struct bt_iter_pos *iter_pos)
174 {
175 struct trace_collection *tc;
176 int i, ret;
177
178 switch (iter_pos->type) {
179 case BT_SEEK_RESTORE:
180 if (!iter_pos->u.restore)
181 goto error_arg;
182
183 heap_free(iter->stream_heap);
184 ret = heap_init(iter->stream_heap, 0, stream_compare);
185 if (ret < 0)
186 goto error;
187
188 for (i = 0; i < iter_pos->u.restore->stream_saved_pos->len;
189 i++) {
190 struct stream_saved_pos *saved_pos;
191 struct ctf_stream_pos *stream_pos;
192 struct packet_index *index;
193 struct ctf_stream *stream;
194
195 saved_pos = &g_array_index(
196 iter_pos->u.restore->stream_saved_pos,
197 struct stream_saved_pos, i);
198 stream = &saved_pos->file_stream->parent;
199 stream_pos = &saved_pos->file_stream->pos;
200 index = &g_array_index(stream_pos->packet_index,
201 struct packet_index,
202 saved_pos->cur_index);
203
204 stream_pos->cur_index = saved_pos->cur_index;
205 stream_pos->move_pos_slow(stream_pos, index->offset,
206 SEEK_SET);
207
208 /*
209 * the timestamp needs to be restored after
210 * move_pos_slow, because this function resets
211 * the timestamp to the beginning of the packet
212 */
213 stream->timestamp = saved_pos->current_timestamp;
214 stream_pos->offset = saved_pos->offset;
215 stream_pos->last_offset = saved_pos->offset;
216
217 stream->prev_timestamp = 0;
218 stream->prev_timestamp_end = 0;
219 stream->consumed = 0;
220
221 printf_debug("restored to cur_index = %zd and "
222 "offset = %zd, timestamp = %" PRIu64 "\n",
223 stream_pos->cur_index,
224 stream_pos->offset, stream->timestamp);
225
226 stream_read_event(saved_pos->file_stream);
227
228 /* Add to heap */
229 ret = heap_insert(iter->stream_heap,
230 saved_pos->file_stream);
231 if (ret)
232 goto error;
233 }
234 case BT_SEEK_TIME:
235 tc = iter->ctx->tc;
236
237 if (!iter_pos->u.seek_time)
238 goto error_arg;
239
240 heap_free(iter->stream_heap);
241 ret = heap_init(iter->stream_heap, 0, stream_compare);
242 if (ret < 0)
243 goto error;
244
245 /* for each trace in the trace_collection */
246 for (i = 0; i < tc->array->len; i++) {
247 struct ctf_trace *tin;
248 struct trace_descriptor *td_read;
249
250 td_read = g_ptr_array_index(tc->array, i);
251 tin = container_of(td_read, struct ctf_trace, parent);
252
253 ret = seek_ctf_trace_by_timestamp(tin,
254 iter_pos->u.seek_time,
255 iter->stream_heap);
256 if (ret < 0)
257 goto error;
258 }
259 return 0;
260 default:
261 /* not implemented */
262 goto error_arg;
263 }
264
265 return 0;
266
267 error_arg:
268 ret = -EINVAL;
269 error:
270 heap_free(iter->stream_heap);
271 if (heap_init(iter->stream_heap, 0, stream_compare) < 0) {
272 heap_free(iter->stream_heap);
273 g_free(iter->stream_heap);
274 iter->stream_heap = NULL;
275 ret = -ENOMEM;
276 }
277 return ret;
278 }
279
280 struct bt_iter_pos *bt_iter_get_pos(struct bt_iter *iter)
281 {
282 struct bt_iter_pos *pos;
283 struct trace_collection *tc = iter->ctx->tc;
284 int i, stream_class_id, stream_id;
285
286 pos = g_new0(struct bt_iter_pos, 1);
287 pos->u.restore = g_new0(struct bt_saved_pos, 1);
288 pos->u.restore->tc = tc;
289 pos->u.restore->stream_saved_pos = g_array_new(FALSE, TRUE,
290 sizeof(struct stream_saved_pos));
291 if (!pos->u.restore->stream_saved_pos)
292 goto error;
293
294 for (i = 0; i < tc->array->len; i++) {
295 struct ctf_trace *tin;
296 struct trace_descriptor *td_read;
297
298 td_read = g_ptr_array_index(tc->array, i);
299 tin = container_of(td_read, struct ctf_trace, parent);
300
301 for (stream_class_id = 0; stream_class_id < tin->streams->len;
302 stream_class_id++) {
303 struct ctf_stream_class *stream_class;
304
305 stream_class = g_ptr_array_index(tin->streams,
306 stream_class_id);
307 for (stream_id = 0;
308 stream_id < stream_class->streams->len;
309 stream_id++) {
310 struct ctf_stream *stream;
311 struct ctf_file_stream *cfs;
312 struct stream_saved_pos saved_pos;
313
314 stream = g_ptr_array_index(
315 stream_class->streams,
316 stream_id);
317 cfs = container_of(stream,
318 struct ctf_file_stream,
319 parent);
320
321 saved_pos.file_stream = cfs;
322 saved_pos.cur_index = cfs->pos.cur_index;
323
324 /*
325 * It is possible that an event was read during
326 * the last restore, never consumed and its
327 * position saved again. For this case, we
328 * need to check if the event really was
329 * consumed by the caller otherwise it is lost.
330 */
331 if (stream->consumed)
332 saved_pos.offset = cfs->pos.offset;
333 else
334 saved_pos.offset = cfs->pos.last_offset;
335
336 saved_pos.current_timestamp = stream->timestamp;
337
338 g_array_append_val(
339 pos->u.restore->stream_saved_pos,
340 saved_pos);
341
342 printf_debug("stream : %" PRIu64 ", cur_index : %zd, "
343 "offset : %zd, "
344 "timestamp = %" PRIu64 "\n",
345 stream->stream_id, saved_pos.cur_index,
346 saved_pos.offset,
347 saved_pos.current_timestamp);
348 }
349 }
350 }
351
352 return pos;
353
354 error:
355 return NULL;
356 }
357
358 struct bt_iter_pos *bt_iter_create_time_pos(struct bt_iter *iter,
359 uint64_t timestamp)
360 {
361 struct bt_iter_pos *pos;
362
363 pos = g_new0(struct bt_iter_pos, 1);
364 pos->type = BT_SEEK_TIME;
365 pos->u.seek_time = timestamp;
366 return pos;
367 }
368
369 /*
370 * babeltrace_filestream_seek: seek a filestream to given position.
371 *
372 * The stream_id parameter is only useful for BT_SEEK_RESTORE.
373 */
374 static int babeltrace_filestream_seek(struct ctf_file_stream *file_stream,
375 const struct bt_iter_pos *begin_pos,
376 unsigned long stream_id)
377 {
378 int ret = 0;
379
380 switch (begin_pos->type) {
381 case BT_SEEK_CUR:
382 /*
383 * just insert into the heap we should already know
384 * the timestamps
385 */
386 break;
387 case BT_SEEK_BEGIN:
388 file_stream->pos.move_pos_slow(&file_stream->pos, 0, SEEK_SET);
389 ret = stream_read_event(file_stream);
390 break;
391 case BT_SEEK_TIME:
392 case BT_SEEK_RESTORE:
393 case BT_SEEK_END:
394 default:
395 assert(0); /* Not yet defined */
396 }
397
398 return ret;
399 }
400
401 /*
402 * bt_iter_seek: seek iterator to given position.
403 */
404 int bt_iter_seek(struct bt_iter *iter,
405 const struct bt_iter_pos *begin_pos)
406 {
407 int i, stream_id;
408 int ret = 0;
409 struct trace_collection *tc = iter->ctx->tc;
410
411 for (i = 0; i < tc->array->len; i++) {
412 struct ctf_trace *tin;
413 struct trace_descriptor *td_read;
414
415 td_read = g_ptr_array_index(tc->array, i);
416 tin = container_of(td_read, struct ctf_trace, parent);
417
418 /* Populate heap with each stream */
419 for (stream_id = 0; stream_id < tin->streams->len;
420 stream_id++) {
421 struct ctf_stream_class *stream;
422 int filenr;
423
424 stream = g_ptr_array_index(tin->streams, stream_id);
425 for (filenr = 0; filenr < stream->streams->len;
426 filenr++) {
427 struct ctf_file_stream *file_stream;
428
429 file_stream = g_ptr_array_index(stream->streams,
430 filenr);
431 ret = babeltrace_filestream_seek(file_stream, begin_pos,
432 stream_id);
433 if (ret < 0)
434 goto end;
435 }
436 }
437 }
438 end:
439 return ret;
440 }
441
442 struct bt_iter *bt_iter_create(struct bt_context *ctx,
443 struct bt_iter_pos *begin_pos,
444 struct bt_iter_pos *end_pos)
445 {
446 int i, stream_id;
447 int ret = 0;
448 struct bt_iter *iter;
449
450 iter = g_new0(struct bt_iter, 1);
451 iter->stream_heap = g_new(struct ptr_heap, 1);
452 iter->end_pos = end_pos;
453 iter->callbacks = g_array_new(0, 1, sizeof(struct bt_stream_callbacks));
454 iter->recalculate_dep_graph = 0;
455 iter->main_callbacks.callback = NULL;
456 iter->dep_gc = g_ptr_array_new();
457 bt_context_get(ctx);
458 iter->ctx = ctx;
459
460 ret = heap_init(iter->stream_heap, 0, stream_compare);
461 if (ret < 0)
462 goto error_heap_init;
463
464 for (i = 0; i < ctx->tc->array->len; i++) {
465 struct ctf_trace *tin;
466 struct trace_descriptor *td_read;
467
468 td_read = g_ptr_array_index(ctx->tc->array, i);
469 tin = container_of(td_read, struct ctf_trace, parent);
470
471 /* Populate heap with each stream */
472 for (stream_id = 0; stream_id < tin->streams->len;
473 stream_id++) {
474 struct ctf_stream_class *stream;
475 int filenr;
476
477 stream = g_ptr_array_index(tin->streams, stream_id);
478 if (!stream)
479 continue;
480 for (filenr = 0; filenr < stream->streams->len;
481 filenr++) {
482 struct ctf_file_stream *file_stream;
483
484 file_stream = g_ptr_array_index(stream->streams,
485 filenr);
486
487 if (begin_pos) {
488 ret = babeltrace_filestream_seek(file_stream, begin_pos,
489 stream_id);
490 if (ret == EOF) {
491 ret = 0;
492 continue;
493 } else if (ret) {
494 goto error;
495 }
496 }
497 /* Add to heap */
498 ret = heap_insert(iter->stream_heap, file_stream);
499 if (ret)
500 goto error;
501 }
502 }
503 }
504
505 return iter;
506
507 error:
508 heap_free(iter->stream_heap);
509 error_heap_init:
510 g_free(iter->stream_heap);
511 g_free(iter);
512 return NULL;
513 }
514
515 void bt_iter_destroy(struct bt_iter *iter)
516 {
517 struct bt_stream_callbacks *bt_stream_cb;
518 struct bt_callback_chain *bt_chain;
519 int i, j;
520
521 if (iter->stream_heap) {
522 heap_free(iter->stream_heap);
523 g_free(iter->stream_heap);
524 }
525
526 /* free all events callbacks */
527 if (iter->main_callbacks.callback)
528 g_array_free(iter->main_callbacks.callback, TRUE);
529
530 /* free per-event callbacks */
531 for (i = 0; i < iter->callbacks->len; i++) {
532 bt_stream_cb = &g_array_index(iter->callbacks,
533 struct bt_stream_callbacks, i);
534 if (!bt_stream_cb || !bt_stream_cb->per_id_callbacks)
535 continue;
536 for (j = 0; j < bt_stream_cb->per_id_callbacks->len; j++) {
537 bt_chain = &g_array_index(bt_stream_cb->per_id_callbacks,
538 struct bt_callback_chain, j);
539 if (bt_chain->callback) {
540 g_array_free(bt_chain->callback, TRUE);
541 }
542 }
543 g_array_free(bt_stream_cb->per_id_callbacks, TRUE);
544 }
545
546 bt_context_put(iter->ctx);
547
548 g_free(iter);
549 }
550
551 int bt_iter_next(struct bt_iter *iter)
552 {
553 struct ctf_file_stream *file_stream, *removed;
554 int ret;
555
556 file_stream = heap_maximum(iter->stream_heap);
557 if (!file_stream) {
558 /* end of file for all streams */
559 ret = 0;
560 goto end;
561 }
562
563 ret = stream_read_event(file_stream);
564 if (ret == EOF) {
565 removed = heap_remove(iter->stream_heap);
566 assert(removed == file_stream);
567 ret = 0;
568 goto end;
569 } else if (ret) {
570 goto end;
571 }
572 /* Reinsert the file stream into the heap, and rebalance. */
573 removed = heap_replace_max(iter->stream_heap, file_stream);
574 assert(removed == file_stream);
575
576 end:
577 return ret;
578 }
579
580 int bt_iter_read_event(struct bt_iter *iter,
581 struct ctf_stream **stream,
582 struct ctf_stream_event **event)
583 {
584 struct ctf_file_stream *file_stream;
585 int ret = 0;
586
587 file_stream = heap_maximum(iter->stream_heap);
588 if (!file_stream) {
589 /* end of file for all streams */
590 ret = EOF;
591 goto end;
592 }
593 *stream = &file_stream->parent;
594 *event = g_ptr_array_index((*stream)->events_by_id, (*stream)->event_id);
595
596 if ((*stream)->stream_id > iter->callbacks->len)
597 goto end;
598
599 process_callbacks(iter, *stream);
600
601 end:
602 return ret;
603 }
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