Fix: complete error handling of babeltrace API
[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/context.h>
24 #include <babeltrace/context-internal.h>
25 #include <babeltrace/iterator-internal.h>
26 #include <babeltrace/iterator.h>
27 #include <babeltrace/prio_heap.h>
28 #include <babeltrace/ctf/metadata.h>
29 #include <babeltrace/ctf/events.h>
30 #include <inttypes.h>
31
32 static int babeltrace_filestream_seek(struct ctf_file_stream *file_stream,
33 const struct bt_iter_pos *begin_pos,
34 unsigned long stream_id);
35
36 struct stream_saved_pos {
37 /*
38 * Use file_stream pointer to check if the trace collection we
39 * restore to match the one we saved from, for each stream.
40 */
41 struct ctf_file_stream *file_stream;
42 size_t cur_index; /* current index in packet index */
43 ssize_t offset; /* offset from base, in bits. EOF for end of file. */
44 uint64_t current_real_timestamp;
45 uint64_t current_cycles_timestamp;
46 };
47
48 struct bt_saved_pos {
49 struct trace_collection *tc;
50 GArray *stream_saved_pos; /* Contains struct stream_saved_pos */
51 };
52
53 static int stream_read_event(struct ctf_file_stream *sin)
54 {
55 int ret;
56
57 ret = sin->pos.parent.event_cb(&sin->pos.parent, &sin->parent);
58 if (ret == EOF)
59 return EOF;
60 else if (ret) {
61 fprintf(stderr, "[error] Reading event failed.\n");
62 return ret;
63 }
64 return 0;
65 }
66
67 /*
68 * returns true if a < b, false otherwise.
69 */
70 static int stream_compare(void *a, void *b)
71 {
72 struct ctf_file_stream *s_a = a, *s_b = b;
73
74 if (s_a->parent.real_timestamp < s_b->parent.real_timestamp)
75 return 1;
76 else
77 return 0;
78 }
79
80 void bt_iter_free_pos(struct bt_iter_pos *iter_pos)
81 {
82 if (!iter_pos)
83 return;
84
85 if (iter_pos->type == BT_SEEK_RESTORE && iter_pos->u.restore) {
86 if (iter_pos->u.restore->stream_saved_pos) {
87 g_array_free(
88 iter_pos->u.restore->stream_saved_pos,
89 TRUE);
90 }
91 g_free(iter_pos->u.restore);
92 }
93 g_free(iter_pos);
94 }
95
96 /*
97 * seek_file_stream_by_timestamp
98 *
99 * Browse a filestream by index, if an index contains the timestamp passed in
100 * argument, seek inside the corresponding packet it until we find the event we
101 * are looking for (either the exact timestamp or the event just after the
102 * timestamp).
103 *
104 * Return 0 if the seek succeded, EOF if we didn't find any packet
105 * containing the timestamp, or a positive integer for error.
106 */
107 static int seek_file_stream_by_timestamp(struct ctf_file_stream *cfs,
108 uint64_t timestamp)
109 {
110 struct ctf_stream_pos *stream_pos;
111 struct packet_index *index;
112 int i, ret;
113
114 stream_pos = &cfs->pos;
115 for (i = 0; i < stream_pos->packet_real_index->len; i++) {
116 index = &g_array_index(stream_pos->packet_real_index,
117 struct packet_index, i);
118 if (index->timestamp_end < timestamp)
119 continue;
120
121 stream_pos->packet_seek(&stream_pos->parent, i, SEEK_SET);
122 do {
123 ret = stream_read_event(cfs);
124 } while (cfs->parent.real_timestamp < timestamp && ret == 0);
125
126 /* Can return either EOF, 0, or error (> 0). */
127 return ret;
128 }
129 /*
130 * Cannot find the timestamp within the stream packets, return
131 * EOF.
132 */
133 return EOF;
134 }
135
136 /*
137 * seek_ctf_trace_by_timestamp : for each file stream, seek to the event with
138 * the corresponding timestamp
139 *
140 * Return 0 on success.
141 * If the timestamp is not part of any file stream, return EOF to inform the
142 * user the timestamp is out of the scope.
143 * On other errors, return positive value.
144 */
145 static int seek_ctf_trace_by_timestamp(struct ctf_trace *tin,
146 uint64_t timestamp, struct ptr_heap *stream_heap)
147 {
148 int i, j, ret;
149 int found = 0;
150
151 /* for each stream_class */
152 for (i = 0; i < tin->streams->len; i++) {
153 struct ctf_stream_declaration *stream_class;
154
155 stream_class = g_ptr_array_index(tin->streams, i);
156 if (!stream_class)
157 continue;
158 /* for each file_stream */
159 for (j = 0; j < stream_class->streams->len; j++) {
160 struct ctf_stream_definition *stream;
161 struct ctf_file_stream *cfs;
162
163 stream = g_ptr_array_index(stream_class->streams, j);
164 if (!stream)
165 continue;
166 cfs = container_of(stream, struct ctf_file_stream,
167 parent);
168 ret = seek_file_stream_by_timestamp(cfs, timestamp);
169 if (ret == 0) {
170 /* Add to heap */
171 ret = heap_insert(stream_heap, cfs);
172 if (ret) {
173 /* Return positive error. */
174 return -ret;
175 }
176 found = 1;
177 } else if (ret > 0) {
178 /*
179 * Error in seek (not EOF), failure.
180 */
181 return ret;
182 }
183 /* on EOF just do not put stream into heap. */
184 }
185 }
186
187 return found ? 0 : EOF;
188 }
189
190 int bt_iter_set_pos(struct bt_iter *iter, const struct bt_iter_pos *iter_pos)
191 {
192 struct trace_collection *tc;
193 int i, ret;
194
195 if (!iter || !iter_pos)
196 return -EINVAL;
197
198 switch (iter_pos->type) {
199 case BT_SEEK_RESTORE:
200 if (!iter_pos->u.restore)
201 return -EINVAL;
202
203 heap_free(iter->stream_heap);
204 ret = heap_init(iter->stream_heap, 0, stream_compare);
205 if (ret < 0)
206 goto error_heap_init;
207
208 for (i = 0; i < iter_pos->u.restore->stream_saved_pos->len;
209 i++) {
210 struct stream_saved_pos *saved_pos;
211 struct ctf_stream_pos *stream_pos;
212 struct ctf_stream_definition *stream;
213
214 saved_pos = &g_array_index(
215 iter_pos->u.restore->stream_saved_pos,
216 struct stream_saved_pos, i);
217 stream = &saved_pos->file_stream->parent;
218 stream_pos = &saved_pos->file_stream->pos;
219
220 stream_pos->packet_seek(&stream_pos->parent,
221 saved_pos->cur_index, SEEK_SET);
222
223 /*
224 * the timestamp needs to be restored after
225 * packet_seek, because this function resets
226 * the timestamp to the beginning of the packet
227 */
228 stream->real_timestamp = saved_pos->current_real_timestamp;
229 stream->cycles_timestamp = saved_pos->current_cycles_timestamp;
230 stream_pos->offset = saved_pos->offset;
231 stream_pos->last_offset = LAST_OFFSET_POISON;
232
233 stream->prev_real_timestamp = 0;
234 stream->prev_real_timestamp_end = 0;
235 stream->prev_cycles_timestamp = 0;
236 stream->prev_cycles_timestamp_end = 0;
237
238 printf_debug("restored to cur_index = %zd and "
239 "offset = %zd, timestamp = %" PRIu64 "\n",
240 stream_pos->cur_index,
241 stream_pos->offset, stream->real_timestamp);
242
243 stream_read_event(saved_pos->file_stream);
244
245 /* Add to heap */
246 ret = heap_insert(iter->stream_heap,
247 saved_pos->file_stream);
248 if (ret)
249 goto error;
250 }
251 return 0;
252 case BT_SEEK_TIME:
253 tc = iter->ctx->tc;
254
255 heap_free(iter->stream_heap);
256 ret = heap_init(iter->stream_heap, 0, stream_compare);
257 if (ret < 0)
258 goto error_heap_init;
259
260 /* for each trace in the trace_collection */
261 for (i = 0; i < tc->array->len; i++) {
262 struct ctf_trace *tin;
263 struct trace_descriptor *td_read;
264
265 td_read = g_ptr_array_index(tc->array, i);
266 if (!td_read)
267 continue;
268 tin = container_of(td_read, struct ctf_trace, parent);
269
270 ret = seek_ctf_trace_by_timestamp(tin,
271 iter_pos->u.seek_time,
272 iter->stream_heap);
273 /*
274 * Positive errors are failure. Negative value
275 * is EOF (for which we continue with other
276 * traces). 0 is success. Note: on EOF, it just
277 * means that no stream has been added to the
278 * iterator for that trace, which is fine.
279 */
280 if (ret != 0 && ret != EOF)
281 goto error;
282 }
283 return 0;
284 case BT_SEEK_BEGIN:
285 tc = iter->ctx->tc;
286 heap_free(iter->stream_heap);
287 ret = heap_init(iter->stream_heap, 0, stream_compare);
288 if (ret < 0)
289 goto error_heap_init;
290
291 for (i = 0; i < tc->array->len; i++) {
292 struct ctf_trace *tin;
293 struct trace_descriptor *td_read;
294 int stream_id;
295
296 td_read = g_ptr_array_index(tc->array, i);
297 if (!td_read)
298 continue;
299 tin = container_of(td_read, struct ctf_trace, parent);
300
301 /* Populate heap with each stream */
302 for (stream_id = 0; stream_id < tin->streams->len;
303 stream_id++) {
304 struct ctf_stream_declaration *stream;
305 int filenr;
306
307 stream = g_ptr_array_index(tin->streams,
308 stream_id);
309 if (!stream)
310 continue;
311 for (filenr = 0; filenr < stream->streams->len;
312 filenr++) {
313 struct ctf_file_stream *file_stream;
314 file_stream = g_ptr_array_index(
315 stream->streams,
316 filenr);
317 if (!file_stream)
318 continue;
319 ret = babeltrace_filestream_seek(
320 file_stream, iter_pos,
321 stream_id);
322 if (ret != 0 && ret != EOF) {
323 goto error;
324 }
325 ret = heap_insert(iter->stream_heap, file_stream);
326 if (ret)
327 goto error;
328 }
329 }
330 }
331 break;
332 default:
333 /* not implemented */
334 return -EINVAL;
335 }
336
337 return 0;
338
339 error:
340 heap_free(iter->stream_heap);
341 error_heap_init:
342 if (heap_init(iter->stream_heap, 0, stream_compare) < 0) {
343 heap_free(iter->stream_heap);
344 g_free(iter->stream_heap);
345 iter->stream_heap = NULL;
346 ret = -ENOMEM;
347 }
348
349 return ret;
350 }
351
352 struct bt_iter_pos *bt_iter_get_pos(struct bt_iter *iter)
353 {
354 struct bt_iter_pos *pos;
355 struct trace_collection *tc;
356 struct ctf_file_stream *file_stream = NULL, *removed;
357 struct ptr_heap iter_heap_copy;
358 int ret;
359
360 if (!iter)
361 return NULL;
362
363 tc = iter->ctx->tc;
364 pos = g_new0(struct bt_iter_pos, 1);
365 pos->type = BT_SEEK_RESTORE;
366 pos->u.restore = g_new0(struct bt_saved_pos, 1);
367 pos->u.restore->tc = tc;
368 pos->u.restore->stream_saved_pos = g_array_new(FALSE, TRUE,
369 sizeof(struct stream_saved_pos));
370 if (!pos->u.restore->stream_saved_pos)
371 goto error;
372
373 ret = heap_copy(&iter_heap_copy, iter->stream_heap);
374 if (ret < 0)
375 goto error_heap;
376
377 /* iterate over each stream in the heap */
378 file_stream = heap_maximum(&iter_heap_copy);
379 while (file_stream != NULL) {
380 struct stream_saved_pos saved_pos;
381
382 assert(file_stream->pos.last_offset != LAST_OFFSET_POISON);
383 saved_pos.offset = file_stream->pos.last_offset;
384 saved_pos.file_stream = file_stream;
385 saved_pos.cur_index = file_stream->pos.cur_index;
386
387 saved_pos.current_real_timestamp = file_stream->parent.real_timestamp;
388 saved_pos.current_cycles_timestamp = file_stream->parent.cycles_timestamp;
389
390 g_array_append_val(
391 pos->u.restore->stream_saved_pos,
392 saved_pos);
393
394 printf_debug("stream : %" PRIu64 ", cur_index : %zd, "
395 "offset : %zd, "
396 "timestamp = %" PRIu64 "\n",
397 file_stream->parent.stream_id,
398 saved_pos.cur_index, saved_pos.offset,
399 saved_pos.current_real_timestamp);
400
401 /* remove the stream from the heap copy */
402 removed = heap_remove(&iter_heap_copy);
403 assert(removed == file_stream);
404
405 file_stream = heap_maximum(&iter_heap_copy);
406 }
407 heap_free(&iter_heap_copy);
408 return pos;
409
410 error_heap:
411 g_array_free(pos->u.restore->stream_saved_pos, TRUE);
412 error:
413 g_free(pos);
414 return NULL;
415 }
416
417 struct bt_iter_pos *bt_iter_create_time_pos(struct bt_iter *iter,
418 uint64_t timestamp)
419 {
420 struct bt_iter_pos *pos;
421
422 if (!iter)
423 return NULL;
424
425 pos = g_new0(struct bt_iter_pos, 1);
426 pos->type = BT_SEEK_TIME;
427 pos->u.seek_time = timestamp;
428 return pos;
429 }
430
431 /*
432 * babeltrace_filestream_seek: seek a filestream to given position.
433 *
434 * The stream_id parameter is only useful for BT_SEEK_RESTORE.
435 */
436 static int babeltrace_filestream_seek(struct ctf_file_stream *file_stream,
437 const struct bt_iter_pos *begin_pos,
438 unsigned long stream_id)
439 {
440 int ret = 0;
441
442 if (!file_stream || !begin_pos)
443 return -EINVAL;
444
445 switch (begin_pos->type) {
446 case BT_SEEK_CUR:
447 /*
448 * just insert into the heap we should already know
449 * the timestamps
450 */
451 break;
452 case BT_SEEK_BEGIN:
453 file_stream->pos.packet_seek(&file_stream->pos.parent,
454 0, SEEK_SET);
455 ret = stream_read_event(file_stream);
456 break;
457 case BT_SEEK_TIME:
458 case BT_SEEK_RESTORE:
459 case BT_SEEK_END:
460 default:
461 assert(0); /* Not yet defined */
462 }
463
464 return ret;
465 }
466
467 int bt_iter_init(struct bt_iter *iter,
468 struct bt_context *ctx,
469 const struct bt_iter_pos *begin_pos,
470 const struct bt_iter_pos *end_pos)
471 {
472 int i, stream_id;
473 int ret = 0;
474
475 if (!iter || !ctx)
476 return -EINVAL;
477
478 if (ctx->current_iterator) {
479 ret = -1;
480 goto error_ctx;
481 }
482
483 iter->stream_heap = g_new(struct ptr_heap, 1);
484 iter->end_pos = end_pos;
485 bt_context_get(ctx);
486 iter->ctx = ctx;
487
488 ret = heap_init(iter->stream_heap, 0, stream_compare);
489 if (ret < 0)
490 goto error_heap_init;
491
492 for (i = 0; i < ctx->tc->array->len; i++) {
493 struct ctf_trace *tin;
494 struct trace_descriptor *td_read;
495
496 td_read = g_ptr_array_index(ctx->tc->array, i);
497 if (!td_read)
498 continue;
499 tin = container_of(td_read, struct ctf_trace, parent);
500
501 /* Populate heap with each stream */
502 for (stream_id = 0; stream_id < tin->streams->len;
503 stream_id++) {
504 struct ctf_stream_declaration *stream;
505 int filenr;
506
507 stream = g_ptr_array_index(tin->streams, stream_id);
508 if (!stream)
509 continue;
510 for (filenr = 0; filenr < stream->streams->len;
511 filenr++) {
512 struct ctf_file_stream *file_stream;
513
514 file_stream = g_ptr_array_index(stream->streams,
515 filenr);
516 if (!file_stream)
517 continue;
518 if (begin_pos) {
519 ret = babeltrace_filestream_seek(
520 file_stream,
521 begin_pos,
522 stream_id);
523 } else {
524 struct bt_iter_pos pos;
525 pos.type = BT_SEEK_BEGIN;
526 ret = babeltrace_filestream_seek(
527 file_stream, &pos,
528 stream_id);
529 }
530 if (ret == EOF) {
531 ret = 0;
532 continue;
533 } else if (ret) {
534 goto error;
535 }
536 /* Add to heap */
537 ret = heap_insert(iter->stream_heap, file_stream);
538 if (ret)
539 goto error;
540 }
541 }
542 }
543
544 ctx->current_iterator = iter;
545 return 0;
546
547 error:
548 heap_free(iter->stream_heap);
549 error_heap_init:
550 g_free(iter->stream_heap);
551 iter->stream_heap = NULL;
552 error_ctx:
553 return ret;
554 }
555
556 struct bt_iter *bt_iter_create(struct bt_context *ctx,
557 const struct bt_iter_pos *begin_pos,
558 const struct bt_iter_pos *end_pos)
559 {
560 struct bt_iter *iter;
561 int ret;
562
563 if (!ctx)
564 return NULL;
565
566 iter = g_new0(struct bt_iter, 1);
567 ret = bt_iter_init(iter, ctx, begin_pos, end_pos);
568 if (ret) {
569 g_free(iter);
570 return NULL;
571 }
572 return iter;
573 }
574
575 void bt_iter_fini(struct bt_iter *iter)
576 {
577 assert(iter);
578 if (iter->stream_heap) {
579 heap_free(iter->stream_heap);
580 g_free(iter->stream_heap);
581 }
582 iter->ctx->current_iterator = NULL;
583 bt_context_put(iter->ctx);
584 }
585
586 void bt_iter_destroy(struct bt_iter *iter)
587 {
588 assert(iter);
589 bt_iter_fini(iter);
590 g_free(iter);
591 }
592
593 int bt_iter_next(struct bt_iter *iter)
594 {
595 struct ctf_file_stream *file_stream, *removed;
596 int ret;
597
598 if (!iter)
599 return -EINVAL;
600
601 file_stream = heap_maximum(iter->stream_heap);
602 if (!file_stream) {
603 /* end of file for all streams */
604 ret = 0;
605 goto end;
606 }
607
608 ret = stream_read_event(file_stream);
609 if (ret == EOF) {
610 removed = heap_remove(iter->stream_heap);
611 assert(removed == file_stream);
612 ret = 0;
613 goto end;
614 } else if (ret) {
615 goto end;
616 }
617 /* Reinsert the file stream into the heap, and rebalance. */
618 removed = heap_replace_max(iter->stream_heap, file_stream);
619 assert(removed == file_stream);
620
621 end:
622 return ret;
623 }
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