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 }