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 }