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 <babeltrace/ctf/events.h>
  31 #include <inttypes.h>
  32
  33 struct stream_saved_pos {
  34         /*
  35          * Use file_stream pointer to check if the trace collection we
  36          * restore to match the one we saved from, for each stream.
  37          */
  38         struct ctf_file_stream *file_stream;
  39         size_t cur_index;       /* current index in packet index */
  40         ssize_t offset;         /* offset from base, in bits. EOF for end of file. */
  41         uint64_t current_timestamp;
  42 };
  43
  44 struct bt_saved_pos {
  45         struct trace_collection *tc;
  46         GArray *stream_saved_pos;       /* Contains struct stream_saved_pos */
  47 };
  48
  49 static int stream_read_event(struct ctf_file_stream *sin)
  50 {
  51         int ret;
  52
  53         ret = sin->pos.parent.event_cb(&sin->pos.parent, &sin->parent);
  54         if (ret == EOF)
  55                 return EOF;
  56         else if (ret) {
  57                 fprintf(stderr, "[error] Reading event failed.\n");
  58                 return ret;
  59         }
  60         return 0;
  61 }
  62
  63 /*
  64  * returns true if a < b, false otherwise.
  65  */
  66 int stream_compare(void *a, void *b)
  67 {
  68         struct ctf_file_stream *s_a = a, *s_b = b;
  69
  70         if (s_a->parent.timestamp < s_b->parent.timestamp)
  71                 return 1;
  72         else
  73                 return 0;
  74 }
  75
  76 void bt_iter_free_pos(struct bt_iter_pos *iter_pos)
  77 {
  78         if (!iter_pos)
  79                 return;
  80
  81         if (iter_pos->u.restore) {
  82                 if (iter_pos->u.restore->stream_saved_pos) {
  83                         g_array_free(
  84                                 iter_pos->u.restore->stream_saved_pos,
  85                                 TRUE);
  86                 }
  87                 g_free(iter_pos->u.restore);
  88         }
  89         g_free(iter_pos);
  90 }
  91
  92 /*
  93  * seek_file_stream_by_timestamp
  94  *
  95  * Browse a filestream by index, if an index contains the timestamp passed in
  96  * argument, seek inside the corresponding packet it until we find the event we
  97  * are looking for (either the exact timestamp or the event just after the
  98  * timestamp).
  99  *
 100  * Return 0 if the seek succeded and EOF if we didn't find any packet
 101  * containing the timestamp.
 102  */
 103 static int seek_file_stream_by_timestamp(struct ctf_file_stream *cfs,
 104                 uint64_t timestamp)
 105 {
 106         struct ctf_stream_pos *stream_pos;
 107         struct packet_index *index;
 108         int i, ret;
 109
 110         stream_pos = &cfs->pos;
 111         for (i = 0; i < stream_pos->packet_index->len; i++) {
 112                 index = &g_array_index(stream_pos->packet_index,
 113                                 struct packet_index, i);
 114                 if (index->timestamp_begin >= timestamp ||
 115                                 index->timestamp_end <= timestamp)
 116                         continue;
 117
 118                 stream_pos->cur_index = i;
 119                 stream_pos->move_pos_slow(stream_pos, index->offset, SEEK_SET);
 120                 while (cfs->parent.timestamp < timestamp) {
 121                         ret = stream_read_event(cfs);
 122                         if (ret < 0)
 123                                 break;
 124                 }
 125                 return 0;
 126         }
 127         return EOF;
 128 }
 129
 130 /*
 131  * seek_ctf_trace_by_timestamp : for each file stream, seek to the event with
 132  * the corresponding timestamp
 133  *
 134  * Return 0 on success.
 135  * If the timestamp is not part of any file stream, return EOF to inform the
 136  * user the timestamp is out of the scope
 137  */
 138 static int seek_ctf_trace_by_timestamp(struct ctf_trace *tin,
 139                 uint64_t timestamp, struct ptr_heap *stream_heap)
 140 {
 141         int i, j, ret;
 142         int found = EOF;
 143
 144         /* for each stream_class */
 145         for (i = 0; i < tin->streams->len; i++) {
 146                 struct ctf_stream_class *stream_class;
 147
 148                 stream_class = g_ptr_array_index(tin->streams, i);
 149                 /* for each file_stream */
 150                 for (j = 0; j < stream_class->streams->len; j++) {
 151                         struct ctf_stream *stream;
 152                         struct ctf_file_stream *cfs;
 153
 154                         stream = g_ptr_array_index(stream_class->streams, j);
 155                         cfs = container_of(stream, struct ctf_file_stream,
 156                                         parent);
 157                         ret = seek_file_stream_by_timestamp(cfs, timestamp);
 158                         if (ret == 0) {
 159                                 /* Add to heap */
 160                                 ret = heap_insert(stream_heap, cfs);
 161                                 if (ret)
 162                                         goto error;
 163                                 found = 0;
 164                         }
 165                 }
 166         }
 167
 168         return found;
 169
 170 error:
 171         return -2;
 172 }
 173
 174 int bt_iter_set_pos(struct bt_iter *iter, const struct bt_iter_pos *iter_pos)
 175 {
 176         struct trace_collection *tc;
 177         int i, ret;
 178
 179         switch (iter_pos->type) {
 180         case BT_SEEK_RESTORE:
 181                 if (!iter_pos->u.restore)
 182                         goto error_arg;
 183
 184                 heap_free(iter->stream_heap);
 185                 ret = heap_init(iter->stream_heap, 0, stream_compare);
 186                 if (ret < 0)
 187                         goto error;
 188
 189                 for (i = 0; i < iter_pos->u.restore->stream_saved_pos->len;
 190                                 i++) {
 191                         struct stream_saved_pos *saved_pos;
 192                         struct ctf_stream_pos *stream_pos;
 193                         struct packet_index *index;
 194                         struct ctf_stream *stream;
 195
 196                         saved_pos = &g_array_index(
 197                                         iter_pos->u.restore->stream_saved_pos,
 198                                         struct stream_saved_pos, i);
 199                         stream = &saved_pos->file_stream->parent;
 200                         stream_pos = &saved_pos->file_stream->pos;
 201                         index = &g_array_index(stream_pos->packet_index,
 202                                         struct packet_index,
 203                                         saved_pos->cur_index);
 204
 205                         stream_pos->cur_index = saved_pos->cur_index;
 206                         stream_pos->move_pos_slow(stream_pos, index->offset,
 207                                         SEEK_SET);
 208
 209                         /*
 210                          * the timestamp needs to be restored after
 211                          * move_pos_slow, because this function resets
 212                          * the timestamp to the beginning of the packet
 213                          */
 214                         stream->timestamp = saved_pos->current_timestamp;
 215                         stream_pos->offset = saved_pos->offset;
 216                         stream_pos->last_offset = saved_pos->offset;
 217
 218                         stream->prev_timestamp = 0;
 219                         stream->prev_timestamp_end = 0;
 220                         stream->consumed = 0;
 221
 222                         printf_debug("restored to cur_index = %zd and "
 223                                 "offset = %zd, timestamp = %" PRIu64 "\n",
 224                                 stream_pos->cur_index,
 225                                 stream_pos->offset, stream->timestamp);
 226
 227                         stream_read_event(saved_pos->file_stream);
 228
 229                         /* Add to heap */
 230                         ret = heap_insert(iter->stream_heap,
 231                                         saved_pos->file_stream);
 232                         if (ret)
 233                                 goto error;
 234                 }
 235         case BT_SEEK_TIME:
 236                 tc = iter->ctx->tc;
 237
 238                 if (!iter_pos->u.seek_time)
 239                         goto error_arg;
 240
 241                 heap_free(iter->stream_heap);
 242                 ret = heap_init(iter->stream_heap, 0, stream_compare);
 243                 if (ret < 0)
 244                         goto error;
 245
 246                 /* for each trace in the trace_collection */
 247                 for (i = 0; i < tc->array->len; i++) {
 248                         struct ctf_trace *tin;
 249                         struct trace_descriptor *td_read;
 250
 251                         td_read = g_ptr_array_index(tc->array, i);
 252                         tin = container_of(td_read, struct ctf_trace, parent);
 253
 254                         ret = seek_ctf_trace_by_timestamp(tin,
 255                                         iter_pos->u.seek_time,
 256                                         iter->stream_heap);
 257                         if (ret < 0)
 258                                 goto error;
 259                 }
 260                 return 0;
 261         default:
 262                 /* not implemented */
 263                 goto error_arg;
 264         }
 265
 266         return 0;
 267
 268 error_arg:
 269         ret = -EINVAL;
 270 error:
 271         heap_free(iter->stream_heap);
 272         if (heap_init(iter->stream_heap, 0, stream_compare) < 0) {
 273                 heap_free(iter->stream_heap);
 274                 g_free(iter->stream_heap);
 275                 iter->stream_heap = NULL;
 276                 ret = -ENOMEM;
 277         }
 278         return ret;
 279 }
 280
 281 struct bt_iter_pos *bt_iter_get_pos(struct bt_iter *iter)
 282 {
 283         struct bt_iter_pos *pos;
 284         struct trace_collection *tc = iter->ctx->tc;
 285         int i, stream_class_id, stream_id;
 286
 287         pos = g_new0(struct bt_iter_pos, 1);
 288         pos->u.restore = g_new0(struct bt_saved_pos, 1);
 289         pos->u.restore->tc = tc;
 290         pos->u.restore->stream_saved_pos = g_array_new(FALSE, TRUE,
 291                         sizeof(struct stream_saved_pos));
 292         if (!pos->u.restore->stream_saved_pos)
 293                 goto error;
 294
 295         for (i = 0; i < tc->array->len; i++) {
 296                 struct ctf_trace *tin;
 297                 struct trace_descriptor *td_read;
 298
 299                 td_read = g_ptr_array_index(tc->array, i);
 300                 tin = container_of(td_read, struct ctf_trace, parent);
 301
 302                 for (stream_class_id = 0; stream_class_id < tin->streams->len;
 303                                 stream_class_id++) {
 304                         struct ctf_stream_class *stream_class;
 305
 306                         stream_class = g_ptr_array_index(tin->streams,
 307                                         stream_class_id);
 308                         for (stream_id = 0;
 309                                         stream_id < stream_class->streams->len;
 310                                         stream_id++) {
 311                                 struct ctf_stream *stream;
 312                                 struct ctf_file_stream *cfs;
 313                                 struct stream_saved_pos saved_pos;
 314
 315                                 stream = g_ptr_array_index(
 316                                                 stream_class->streams,
 317                                                 stream_id);
 318                                 cfs = container_of(stream,
 319                                                 struct ctf_file_stream,
 320                                                 parent);
 321
 322                                 saved_pos.file_stream = cfs;
 323                                 saved_pos.cur_index = cfs->pos.cur_index;
 324
 325                                 /*
 326                                  * It is possible that an event was read during
 327                                  * the last restore, never consumed and its
 328                                  * position saved again.  For this case, we
 329                                  * need to check if the event really was
 330                                  * consumed by the caller otherwise it is lost.
 331                                  */
 332                                 if (stream->consumed)
 333                                         saved_pos.offset = cfs->pos.offset;
 334                                 else
 335                                         saved_pos.offset = cfs->pos.last_offset;
 336
 337                                 saved_pos.current_timestamp = stream->timestamp;
 338
 339                                 g_array_append_val(
 340                                         pos->u.restore->stream_saved_pos,
 341                                         saved_pos);
 342
 343                                 printf_debug("stream : %" PRIu64 ", cur_index : %zd, "
 344                                         "offset : %zd, "
 345                                         "timestamp = %" PRIu64 "\n",
 346                                         stream->stream_id, saved_pos.cur_index,
 347                                         saved_pos.offset,
 348                                         saved_pos.current_timestamp);
 349                         }
 350                 }
 351         }
 352
 353         return pos;
 354
 355 error:
 356         return NULL;
 357 }
 358
 359 struct bt_iter_pos *bt_iter_create_time_pos(struct bt_iter *iter,
 360                 uint64_t timestamp)
 361 {
 362         struct bt_iter_pos *pos;
 363
 364         pos = g_new0(struct bt_iter_pos, 1);
 365         pos->type = BT_SEEK_TIME;
 366         pos->u.seek_time = timestamp;
 367         return pos;
 368 }
 369
 370 /*
 371  * babeltrace_filestream_seek: seek a filestream to given position.
 372  *
 373  * The stream_id parameter is only useful for BT_SEEK_RESTORE.
 374  */
 375 static int babeltrace_filestream_seek(struct ctf_file_stream *file_stream,
 376                 const struct bt_iter_pos *begin_pos,
 377                 unsigned long stream_id)
 378 {
 379         int ret = 0;
 380
 381         switch (begin_pos->type) {
 382         case BT_SEEK_CUR:
 383                 /*
 384                  * just insert into the heap we should already know
 385                  * the timestamps
 386                  */
 387                 break;
 388         case BT_SEEK_BEGIN:
 389                 file_stream->pos.move_pos_slow(&file_stream->pos, 0, SEEK_SET);
 390                 ret = stream_read_event(file_stream);
 391                 break;
 392         case BT_SEEK_TIME:
 393         case BT_SEEK_RESTORE:
 394         case BT_SEEK_END:
 395         default:
 396                 assert(0); /* Not yet defined */
 397         }
 398
 399         return ret;
 400 }
 401
 402 /*
 403  * bt_iter_seek: seek iterator to given position.
 404  */
 405 int bt_iter_seek(struct bt_iter *iter,
 406                 const struct bt_iter_pos *begin_pos)
 407 {
 408         int i, stream_id;
 409         int ret = 0;
 410         struct trace_collection *tc = iter->ctx->tc;
 411
 412         for (i = 0; i < tc->array->len; i++) {
 413                 struct ctf_trace *tin;
 414                 struct trace_descriptor *td_read;
 415
 416                 td_read = g_ptr_array_index(tc->array, i);
 417                 tin = container_of(td_read, struct ctf_trace, parent);
 418
 419                 /* Populate heap with each stream */
 420                 for (stream_id = 0; stream_id < tin->streams->len;
 421                                 stream_id++) {
 422                         struct ctf_stream_class *stream;
 423                         int filenr;
 424
 425                         stream = g_ptr_array_index(tin->streams, stream_id);
 426                         for (filenr = 0; filenr < stream->streams->len;
 427                                         filenr++) {
 428                                 struct ctf_file_stream *file_stream;
 429
 430                                 file_stream = g_ptr_array_index(stream->streams,
 431                                                 filenr);
 432                                 ret = babeltrace_filestream_seek(file_stream, begin_pos,
 433                                                 stream_id);
 434                                 if (ret < 0)
 435                                         goto end;
 436                         }
 437                 }
 438         }
 439 end:
 440         return ret;
 441 }
 442
 443 struct bt_iter *bt_iter_create(struct bt_context *ctx,
 444                 struct bt_iter_pos *begin_pos,
 445                 struct bt_iter_pos *end_pos)
 446 {
 447         int i, stream_id;
 448         int ret = 0;
 449         struct bt_iter *iter;
 450
 451         iter = g_new0(struct bt_iter, 1);
 452         iter->stream_heap = g_new(struct ptr_heap, 1);
 453         iter->end_pos = end_pos;
 454         iter->callbacks = g_array_new(0, 1, sizeof(struct bt_stream_callbacks));
 455         iter->recalculate_dep_graph = 0;
 456         iter->main_callbacks.callback = NULL;
 457         iter->dep_gc = g_ptr_array_new();
 458         bt_context_get(ctx);
 459         iter->ctx = ctx;
 460
 461         ret = heap_init(iter->stream_heap, 0, stream_compare);
 462         if (ret < 0)
 463                 goto error_heap_init;
 464
 465         for (i = 0; i < ctx->tc->array->len; i++) {
 466                 struct ctf_trace *tin;
 467                 struct trace_descriptor *td_read;
 468
 469                 td_read = g_ptr_array_index(ctx->tc->array, i);
 470                 tin = container_of(td_read, struct ctf_trace, parent);
 471
 472                 /* Populate heap with each stream */
 473                 for (stream_id = 0; stream_id < tin->streams->len;
 474                                 stream_id++) {
 475                         struct ctf_stream_class *stream;
 476                         int filenr;
 477
 478                         stream = g_ptr_array_index(tin->streams, stream_id);
 479                         if (!stream)
 480                                 continue;
 481                         for (filenr = 0; filenr < stream->streams->len;
 482                                         filenr++) {
 483                                 struct ctf_file_stream *file_stream;
 484
 485                                 file_stream = g_ptr_array_index(stream->streams,
 486                                                 filenr);
 487
 488                                 if (begin_pos) {
 489                                     ret = babeltrace_filestream_seek(file_stream, begin_pos,
 490                                                         stream_id);
 491                                     if (ret == EOF) {
 492                                            ret = 0;
 493                                            continue;
 494                                     } else if (ret) {
 495                                            goto error;
 496                                     }
 497                                 }
 498                                 /* Add to heap */
 499                                 ret = heap_insert(iter->stream_heap, file_stream);
 500                                 if (ret)
 501                                         goto error;
 502                         }
 503                 }
 504         }
 505
 506         return iter;
 507
 508 error:
 509         heap_free(iter->stream_heap);
 510 error_heap_init:
 511         g_free(iter->stream_heap);
 512         g_free(iter);
 513         return NULL;
 514 }
 515
 516 void bt_iter_destroy(struct bt_iter *iter)
 517 {
 518         struct bt_stream_callbacks *bt_stream_cb;
 519         struct bt_callback_chain *bt_chain;
 520         int i, j;
 521
 522         if (iter->stream_heap) {
 523                 heap_free(iter->stream_heap);
 524                 g_free(iter->stream_heap);
 525         }
 526
 527         /* free all events callbacks */
 528         if (iter->main_callbacks.callback)
 529                 g_array_free(iter->main_callbacks.callback, TRUE);
 530
 531         /* free per-event callbacks */
 532         for (i = 0; i < iter->callbacks->len; i++) {
 533                 bt_stream_cb = &g_array_index(iter->callbacks,
 534                                 struct bt_stream_callbacks, i);
 535                 if (!bt_stream_cb || !bt_stream_cb->per_id_callbacks)
 536                         continue;
 537                 for (j = 0; j < bt_stream_cb->per_id_callbacks->len; j++) {
 538                         bt_chain = &g_array_index(bt_stream_cb->per_id_callbacks,
 539                                         struct bt_callback_chain, j);
 540                         if (bt_chain->callback) {
 541                                 g_array_free(bt_chain->callback, TRUE);
 542                         }
 543                 }
 544                 g_array_free(bt_stream_cb->per_id_callbacks, TRUE);
 545         }
 546
 547         bt_context_put(iter->ctx);
 548
 549         g_free(iter);
 550 }
 551
 552 int bt_iter_next(struct bt_iter *iter)
 553 {
 554         struct ctf_file_stream *file_stream, *removed;
 555         int ret;
 556
 557         file_stream = heap_maximum(iter->stream_heap);
 558         if (!file_stream) {
 559                 /* end of file for all streams */
 560                 ret = 0;
 561                 goto end;
 562         }
 563
 564         ret = stream_read_event(file_stream);
 565         if (ret == EOF) {
 566                 removed = heap_remove(iter->stream_heap);
 567                 assert(removed == file_stream);
 568                 ret = 0;
 569                 goto end;
 570         } else if (ret) {
 571                 goto end;
 572         }
 573         /* Reinsert the file stream into the heap, and rebalance. */
 574         removed = heap_replace_max(iter->stream_heap, file_stream);
 575         assert(removed == file_stream);
 576
 577 end:
 578         return ret;
 579 }
 580
 581 struct bt_ctf_event *bt_iter_read_ctf_event(struct bt_iter *iter)
 582 {
 583         struct ctf_file_stream *file_stream;
 584         struct bt_ctf_event *ret = &iter->current_ctf_event;
 585
 586         file_stream = heap_maximum(iter->stream_heap);
 587         if (!file_stream) {
 588                 /* end of file for all streams */
 589                 goto stop;
 590         }
 591         ret->stream = &file_stream->parent;
 592         ret->event = g_ptr_array_index(ret->stream->events_by_id,
 593                         ret->stream->event_id);
 594
 595         if (ret->stream->stream_id > iter->callbacks->len)
 596                 goto end;
 597
 598         process_callbacks(iter, ret->stream);
 599
 600 end:
 601         return ret;
 602 stop:
 603         return NULL;
 604 }