| 1 | /* This file is part of the Linux Trace Toolkit viewer |
| 2 | * Copyright (C) 2009 Benjamin Poirier <benjamin.poirier@polymtl.ca> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License Version 2 as |
| 6 | * published by the Free Software Foundation; |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | * GNU General Public License for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public License |
| 14 | * along with this program; if not, write to the Free Software |
| 15 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
| 16 | * MA 02111-1307, USA. |
| 17 | */ |
| 18 | |
| 19 | // for INFINITY in math.h |
| 20 | #define _ISOC99_SOURCE |
| 21 | |
| 22 | #ifdef HAVE_CONFIG_H |
| 23 | #include <config.h> |
| 24 | #endif |
| 25 | |
| 26 | #include <math.h> |
| 27 | #include <stdio.h> |
| 28 | #include <stdlib.h> |
| 29 | |
| 30 | #include "sync_chain.h" |
| 31 | |
| 32 | #include "event_analysis_linreg.h" |
| 33 | |
| 34 | |
| 35 | #ifndef g_info |
| 36 | #define g_info(format...) g_log (G_LOG_DOMAIN, G_LOG_LEVEL_INFO, format) |
| 37 | #endif |
| 38 | |
| 39 | |
| 40 | // Functions common to all analysis modules |
| 41 | static void initAnalysisLinReg(SyncState* const syncState); |
| 42 | static void destroyAnalysisLinReg(SyncState* const syncState); |
| 43 | |
| 44 | static void analyzeExchangeLinReg(SyncState* const syncState, Packet* const packet); |
| 45 | static GArray* finalizeAnalysisLinReg(SyncState* const syncState); |
| 46 | static void printAnalysisStatsLinReg(SyncState* const syncState); |
| 47 | |
| 48 | // Functions specific to this module |
| 49 | static void registerAnalysisLinReg() __attribute__((constructor (101))); |
| 50 | |
| 51 | static void finalizeLSA(SyncState* const syncState); |
| 52 | static void doGraphProcessing(SyncState* const syncState); |
| 53 | static GArray* calculateFactors(SyncState* const syncState); |
| 54 | static void shortestPath(Fit* const* const fitArray, const unsigned int |
| 55 | traceNum, const unsigned int traceNb, double* const distances, |
| 56 | unsigned int* const previousVertex); |
| 57 | static double sumDistances(const double* const distances, const unsigned int |
| 58 | traceNb); |
| 59 | static void reduceFactors(Fit* const* const fitArray, const unsigned int* const |
| 60 | previousVertex, const unsigned int traceNum, double* const drift, |
| 61 | double* const offset, double* const stDev); |
| 62 | |
| 63 | // Graph-related Glib functions |
| 64 | static void gfGraphDestroy(gpointer data, gpointer user_data); |
| 65 | static gint gcfGraphTraceCompare(gconstpointer a, gconstpointer b); |
| 66 | |
| 67 | |
| 68 | static AnalysisModule analysisModuleLinReg= { |
| 69 | .name= "linreg", |
| 70 | .initAnalysis= &initAnalysisLinReg, |
| 71 | .destroyAnalysis= &destroyAnalysisLinReg, |
| 72 | .analyzePacket= NULL, |
| 73 | .analyzeExchange= &analyzeExchangeLinReg, |
| 74 | .finalizeAnalysis= &finalizeAnalysisLinReg, |
| 75 | .printAnalysisStats= &printAnalysisStatsLinReg, |
| 76 | }; |
| 77 | |
| 78 | |
| 79 | /* |
| 80 | * Analysis module registering function |
| 81 | */ |
| 82 | static void registerAnalysisLinReg() |
| 83 | { |
| 84 | g_queue_push_tail(&analysisModules, &analysisModuleLinReg); |
| 85 | } |
| 86 | |
| 87 | |
| 88 | /* |
| 89 | * Analysis init function |
| 90 | * |
| 91 | * This function is called at the beginning of a synchronization run for a set |
| 92 | * of traces. |
| 93 | * |
| 94 | * Allocate some of the analysis specific data structures |
| 95 | * |
| 96 | * Args: |
| 97 | * syncState container for synchronization data. |
| 98 | * This function allocates these analysisData members: |
| 99 | * fitArray |
| 100 | * stDev |
| 101 | */ |
| 102 | static void initAnalysisLinReg(SyncState* const syncState) |
| 103 | { |
| 104 | unsigned int i; |
| 105 | AnalysisDataLinReg* analysisData; |
| 106 | |
| 107 | analysisData= malloc(sizeof(AnalysisDataLinReg)); |
| 108 | syncState->analysisData= analysisData; |
| 109 | |
| 110 | analysisData->fitArray= malloc(syncState->traceNb * sizeof(Fit*)); |
| 111 | for (i= 0; i < syncState->traceNb; i++) |
| 112 | { |
| 113 | analysisData->fitArray[i]= calloc(syncState->traceNb, sizeof(Fit)); |
| 114 | } |
| 115 | |
| 116 | if (syncState->stats) |
| 117 | { |
| 118 | analysisData->stDev= malloc(sizeof(double) * syncState->traceNb); |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | |
| 123 | /* |
| 124 | * Analysis destroy function |
| 125 | * |
| 126 | * Free the analysis specific data structures |
| 127 | * |
| 128 | * Args: |
| 129 | * syncState container for synchronization data. |
| 130 | * This function deallocates these analysisData members: |
| 131 | * fitArray |
| 132 | * graphList |
| 133 | * stDev |
| 134 | */ |
| 135 | static void destroyAnalysisLinReg(SyncState* const syncState) |
| 136 | { |
| 137 | unsigned int i; |
| 138 | AnalysisDataLinReg* analysisData; |
| 139 | |
| 140 | analysisData= (AnalysisDataLinReg*) syncState->analysisData; |
| 141 | |
| 142 | if (analysisData == NULL) |
| 143 | { |
| 144 | return; |
| 145 | } |
| 146 | |
| 147 | for (i= 0; i < syncState->traceNb; i++) |
| 148 | { |
| 149 | free(analysisData->fitArray[i]); |
| 150 | } |
| 151 | free(analysisData->fitArray); |
| 152 | |
| 153 | g_queue_foreach(analysisData->graphList, &gfGraphDestroy, NULL); |
| 154 | g_queue_free(analysisData->graphList); |
| 155 | |
| 156 | if (syncState->stats) |
| 157 | { |
| 158 | free(analysisData->stDev); |
| 159 | } |
| 160 | |
| 161 | free(syncState->analysisData); |
| 162 | syncState->analysisData= NULL; |
| 163 | } |
| 164 | |
| 165 | |
| 166 | /* |
| 167 | * Perform analysis on a series of event pairs. |
| 168 | * |
| 169 | * If one event pair is a packet, an exchange is composed of at least two |
| 170 | * packets, one in each direction. There should be a non-negative minimum |
| 171 | * "round trip time" (RTT) between the first and last event of the exchange. |
| 172 | * This RTT should be as small as possible so these packets should be closely |
| 173 | * related in time like a data packet and an acknowledgement packet. If the |
| 174 | * events analyzed are such that the minimum RTT can be zero, there's nothing |
| 175 | * gained in analyzing exchanges beyond what can already be figured out by |
| 176 | * analyzing packets. |
| 177 | * |
| 178 | * An exchange can also consist of more than two packets, in case one packet |
| 179 | * single handedly acknowledges many data packets. |
| 180 | * |
| 181 | * Args: |
| 182 | * syncState container for synchronization data |
| 183 | * packet structure containing the many events |
| 184 | */ |
| 185 | static void analyzeExchangeLinReg(SyncState* const syncState, Packet* const packet) |
| 186 | { |
| 187 | unsigned int ni, nj; |
| 188 | double dji, eji; |
| 189 | double timoy; |
| 190 | Fit* fit; |
| 191 | Packet* ackedPacket; |
| 192 | AnalysisDataLinReg* analysisData; |
| 193 | |
| 194 | g_debug("Synchronization calculation, "); |
| 195 | g_debug("%d acked packets - using last one, ", |
| 196 | g_queue_get_length(packet->acks)); |
| 197 | |
| 198 | analysisData= (AnalysisDataLinReg*) syncState->analysisData; |
| 199 | ackedPacket= g_queue_peek_tail(packet->acks); |
| 200 | |
| 201 | // Calculate the intermediate values for the |
| 202 | // least-squares analysis |
| 203 | dji= ((double) ackedPacket->inE->tsc - (double) ackedPacket->outE->tsc + |
| 204 | (double) packet->outE->tsc - (double) packet->inE->tsc) / 2; |
| 205 | eji= fabs((double) ackedPacket->inE->tsc - (double) ackedPacket->outE->tsc |
| 206 | - (double) packet->outE->tsc + (double) packet->inE->tsc) / 2; |
| 207 | timoy= ((double) ackedPacket->outE->tsc + (double) packet->inE->tsc) / 2; |
| 208 | ni= ackedPacket->outE->traceNum; |
| 209 | nj= ackedPacket->inE->traceNum; |
| 210 | fit= &analysisData->fitArray[nj][ni]; |
| 211 | |
| 212 | fit->n++; |
| 213 | fit->st+= timoy; |
| 214 | fit->st2+= pow(timoy, 2); |
| 215 | fit->sd+= dji; |
| 216 | fit->sd2+= pow(dji, 2); |
| 217 | fit->std+= timoy * dji; |
| 218 | |
| 219 | g_debug("intermediate values: dji= %f ti moy= %f " |
| 220 | "ni= %u nj= %u fit: n= %u st= %f st2= %f sd= %f " |
| 221 | "sd2= %f std= %f, ", dji, timoy, ni, nj, fit->n, |
| 222 | fit->st, fit->st2, fit->sd, fit->sd2, fit->std); |
| 223 | } |
| 224 | |
| 225 | |
| 226 | /* |
| 227 | * Finalize the factor calculations |
| 228 | * |
| 229 | * The least squares analysis is finalized and finds the factors directly |
| 230 | * between each pair of traces that had events together. The traces are |
| 231 | * aranged in a graph, a reference trace is chosen and the factors between |
| 232 | * this reference and every other trace is calculated. Sometimes it is |
| 233 | * necessary to use many graphs when there are "islands" of independent |
| 234 | * traces. |
| 235 | * |
| 236 | * Args: |
| 237 | * syncState container for synchronization data. |
| 238 | * |
| 239 | * Returns: |
| 240 | * Factors[traceNb] synchronization factors for each trace |
| 241 | */ |
| 242 | static GArray* finalizeAnalysisLinReg(SyncState* const syncState) |
| 243 | { |
| 244 | GArray* factors; |
| 245 | |
| 246 | // Finalize the processing |
| 247 | finalizeLSA(syncState); |
| 248 | |
| 249 | // Find a reference node and structure nodes in a graph |
| 250 | doGraphProcessing(syncState); |
| 251 | |
| 252 | /* Calculate the resulting offset and drift between each trace and its |
| 253 | * reference |
| 254 | */ |
| 255 | factors= calculateFactors(syncState); |
| 256 | |
| 257 | return factors; |
| 258 | } |
| 259 | |
| 260 | |
| 261 | /* |
| 262 | * Print statistics related to analysis. Must be called after |
| 263 | * finalizeAnalysis. |
| 264 | * |
| 265 | * Args: |
| 266 | * syncState container for synchronization data. |
| 267 | */ |
| 268 | static void printAnalysisStatsLinReg(SyncState* const syncState) |
| 269 | { |
| 270 | unsigned int i, j; |
| 271 | AnalysisDataLinReg* analysisData; |
| 272 | |
| 273 | if (!syncState->stats) |
| 274 | { |
| 275 | return; |
| 276 | } |
| 277 | |
| 278 | analysisData= (AnalysisDataLinReg*) syncState->analysisData; |
| 279 | |
| 280 | printf("Linear regression analysis stats:\n"); |
| 281 | |
| 282 | printf("\tIndividual synchronization factors:\n"); |
| 283 | |
| 284 | for (j= 0; j < syncState->traceNb; j++) |
| 285 | { |
| 286 | for (i= 0; i < j; i++) |
| 287 | { |
| 288 | Fit* fit; |
| 289 | |
| 290 | fit= &analysisData->fitArray[j][i]; |
| 291 | printf("\t\t%3d - %-3d: ", i, j); |
| 292 | printf("a0= % 7g a1= 1 %c %7g accuracy %7g\n", fit->d0, fit->x < |
| 293 | 0. ? '-' : '+', fabs(fit->x), fit->e); |
| 294 | |
| 295 | fit= &analysisData->fitArray[i][j]; |
| 296 | printf("\t\t%3d - %-3d: ", j, i); |
| 297 | printf("a0= % 7g a1= 1 %c %7g accuracy %7g\n", fit->d0, fit->x < |
| 298 | 0. ? '-' : '+', fabs(fit->x), fit->e); |
| 299 | } |
| 300 | } |
| 301 | |
| 302 | printf("\tTree:\n"); |
| 303 | for (i= 0; i < syncState->traceNb; i++) |
| 304 | { |
| 305 | GList* result; |
| 306 | |
| 307 | result= g_queue_find_custom(analysisData->graphList, &i, |
| 308 | &gcfGraphTraceCompare); |
| 309 | if (result != NULL) |
| 310 | { |
| 311 | Graph* graph; |
| 312 | |
| 313 | graph= (Graph*) result->data; |
| 314 | |
| 315 | printf("\t\ttrace %u reference %u previous vertex ", i, |
| 316 | graph->reference); |
| 317 | |
| 318 | if (i == graph->reference) |
| 319 | { |
| 320 | printf("- "); |
| 321 | } |
| 322 | else |
| 323 | { |
| 324 | printf("%u ", graph->previousVertex[i]); |
| 325 | } |
| 326 | |
| 327 | printf("stdev= %g\n", analysisData->stDev[i]); |
| 328 | } |
| 329 | else |
| 330 | { |
| 331 | g_error("Trace %d not part of a graph\n", i); |
| 332 | } |
| 333 | } |
| 334 | } |
| 335 | |
| 336 | |
| 337 | /* |
| 338 | * Finalize the least-squares analysis. The intermediate values in the fit |
| 339 | * array are used to calculate the drift and the offset between each pair of |
| 340 | * nodes based on their exchanges. |
| 341 | * |
| 342 | * Args: |
| 343 | * syncState: container for synchronization data. |
| 344 | */ |
| 345 | static void finalizeLSA(SyncState* const syncState) |
| 346 | { |
| 347 | unsigned int i, j; |
| 348 | AnalysisDataLinReg* analysisData; |
| 349 | |
| 350 | analysisData= (AnalysisDataLinReg*) syncState->analysisData; |
| 351 | |
| 352 | for (i= 0; i < syncState->traceNb; i++) |
| 353 | { |
| 354 | for (j= 0; j < syncState->traceNb; j++) |
| 355 | { |
| 356 | if (i != j) |
| 357 | { |
| 358 | Fit* fit; |
| 359 | double delta; |
| 360 | |
| 361 | fit= &analysisData->fitArray[i][j]; |
| 362 | |
| 363 | delta= fit->n * fit->st2 - pow(fit->st, 2); |
| 364 | fit->x= (fit->n * fit->std - fit->st * fit->sd) / delta; |
| 365 | fit->d0= (fit->st2 * fit->sd - fit->st * fit->std) / delta; |
| 366 | fit->e= sqrt((fit->sd2 - (fit->n * pow(fit->std, 2) + |
| 367 | pow(fit->sd, 2) * fit->st2 - 2 * fit->st * fit->sd |
| 368 | * fit->std) / delta) / (fit->n - 2)); |
| 369 | |
| 370 | g_debug("[i= %u j= %u]\n", i, j); |
| 371 | g_debug("n= %d st= %g st2= %g sd= %g sd2= %g std= %g\n", |
| 372 | fit->n, fit->st, fit->st2, fit->sd, fit->sd2, fit->std); |
| 373 | g_debug("xij= %g d0ij= %g e= %g\n", fit->x, fit->d0, fit->e); |
| 374 | g_debug("(xji= %g d0ji= %g)\n", -fit->x / (1 + fit->x), |
| 375 | -fit->d0 / (1 + fit->x)); |
| 376 | } |
| 377 | } |
| 378 | } |
| 379 | } |
| 380 | |
| 381 | |
| 382 | /* |
| 383 | * Structure nodes in graphs of nodes that had exchanges. Each graph has a |
| 384 | * reference node, the one that can reach the others with the smallest |
| 385 | * cummulative error. |
| 386 | * |
| 387 | * Args: |
| 388 | * syncState: container for synchronization data. |
| 389 | * This function allocates these analysisData members: |
| 390 | * graphList |
| 391 | */ |
| 392 | static void doGraphProcessing(SyncState* const syncState) |
| 393 | { |
| 394 | unsigned int i, j; |
| 395 | double* distances; |
| 396 | unsigned int* previousVertex; |
| 397 | AnalysisDataLinReg* analysisData; |
| 398 | |
| 399 | analysisData= (AnalysisDataLinReg*) syncState->analysisData; |
| 400 | |
| 401 | distances= malloc(syncState->traceNb * sizeof(double)); |
| 402 | previousVertex= malloc(syncState->traceNb * sizeof(unsigned int)); |
| 403 | analysisData->graphList= g_queue_new(); |
| 404 | |
| 405 | for (i= 0; i < syncState->traceNb; i++) |
| 406 | { |
| 407 | double errorSum; |
| 408 | GList* result; |
| 409 | |
| 410 | // Perform shortest path search |
| 411 | g_debug("shortest path trace %d\ndistances: ", i); |
| 412 | shortestPath(analysisData->fitArray, i, syncState->traceNb, distances, |
| 413 | previousVertex); |
| 414 | |
| 415 | for (j= 0; j < syncState->traceNb; j++) |
| 416 | { |
| 417 | g_debug("%g, ", distances[j]); |
| 418 | } |
| 419 | g_debug("\npreviousVertex: "); |
| 420 | for (j= 0; j < syncState->traceNb; j++) |
| 421 | { |
| 422 | g_debug("%u, ", previousVertex[j]); |
| 423 | } |
| 424 | g_debug("\n"); |
| 425 | |
| 426 | // Group in graphs nodes that have exchanges |
| 427 | errorSum= sumDistances(distances, syncState->traceNb); |
| 428 | result= g_queue_find_custom(analysisData->graphList, &i, |
| 429 | &gcfGraphTraceCompare); |
| 430 | if (result != NULL) |
| 431 | { |
| 432 | Graph* graph; |
| 433 | |
| 434 | g_debug("found graph\n"); |
| 435 | graph= (Graph*) result->data; |
| 436 | if (errorSum < graph->errorSum) |
| 437 | { |
| 438 | g_debug("adding to graph\n"); |
| 439 | graph->errorSum= errorSum; |
| 440 | free(graph->previousVertex); |
| 441 | graph->previousVertex= previousVertex; |
| 442 | graph->reference= i; |
| 443 | previousVertex= malloc(syncState->traceNb * sizeof(unsigned |
| 444 | int)); |
| 445 | } |
| 446 | } |
| 447 | else |
| 448 | { |
| 449 | Graph* newGraph; |
| 450 | |
| 451 | g_debug("creating new graph\n"); |
| 452 | newGraph= malloc(sizeof(Graph)); |
| 453 | newGraph->errorSum= errorSum; |
| 454 | newGraph->previousVertex= previousVertex; |
| 455 | newGraph->reference= i; |
| 456 | previousVertex= malloc(syncState->traceNb * sizeof(unsigned int)); |
| 457 | |
| 458 | g_queue_push_tail(analysisData->graphList, newGraph); |
| 459 | } |
| 460 | } |
| 461 | |
| 462 | free(previousVertex); |
| 463 | free(distances); |
| 464 | } |
| 465 | |
| 466 | |
| 467 | /* |
| 468 | * Calculate the resulting offset and drift between each trace and its |
| 469 | * reference. |
| 470 | * |
| 471 | * Args: |
| 472 | * syncState: container for synchronization data. |
| 473 | * |
| 474 | * Returns: |
| 475 | * Factors[traceNb] synchronization factors for each trace |
| 476 | */ |
| 477 | static GArray* calculateFactors(SyncState* const syncState) |
| 478 | { |
| 479 | unsigned int i; |
| 480 | AnalysisDataLinReg* analysisData; |
| 481 | GArray* factors; |
| 482 | |
| 483 | analysisData= (AnalysisDataLinReg*) syncState->analysisData; |
| 484 | factors= g_array_sized_new(FALSE, FALSE, sizeof(Factors), |
| 485 | syncState->traceNb); |
| 486 | |
| 487 | // Calculate the resulting offset and drift between each trace and its |
| 488 | // reference |
| 489 | for (i= 0; i < syncState->traceNb; i++) |
| 490 | { |
| 491 | GList* result; |
| 492 | |
| 493 | result= g_queue_find_custom(analysisData->graphList, &i, |
| 494 | &gcfGraphTraceCompare); |
| 495 | if (result != NULL) |
| 496 | { |
| 497 | Graph* graph; |
| 498 | double stDev; |
| 499 | Factors* traceFactors; |
| 500 | |
| 501 | graph= (Graph*) result->data; |
| 502 | traceFactors= &g_array_index(factors, Factors, i); |
| 503 | |
| 504 | reduceFactors(analysisData->fitArray, graph->previousVertex, i, |
| 505 | &traceFactors->drift, &traceFactors->offset, &stDev); |
| 506 | |
| 507 | if (syncState->stats) |
| 508 | { |
| 509 | analysisData->stDev[i]= stDev; |
| 510 | } |
| 511 | } |
| 512 | else |
| 513 | { |
| 514 | g_error("Trace %d not part of a graph\n", i); |
| 515 | } |
| 516 | } |
| 517 | |
| 518 | return factors; |
| 519 | } |
| 520 | |
| 521 | |
| 522 | /* |
| 523 | * Single-source shortest path search to find the path with the lowest error to |
| 524 | * convert one node's time to another. |
| 525 | * Uses Dijkstra's algorithm |
| 526 | * |
| 527 | * Args: |
| 528 | * fitArray: array with the regression parameters |
| 529 | * traceNum: reference node |
| 530 | * traceNb: number of traces = number of nodes |
| 531 | * distances: array of computed distance from source node to node i, |
| 532 | * INFINITY if i is unreachable, preallocated to the number of |
| 533 | * nodes |
| 534 | * previousVertex: previous vertex from a node i on the way to the source, |
| 535 | * UINT_MAX if i is not on the way or is the source, |
| 536 | * preallocated to the number of nodes |
| 537 | */ |
| 538 | static void shortestPath(Fit* const* const fitArray, const unsigned int |
| 539 | traceNum, const unsigned int traceNb, double* const distances, unsigned |
| 540 | int* const previousVertex) |
| 541 | { |
| 542 | bool* visited; |
| 543 | unsigned int i, j; |
| 544 | |
| 545 | visited= malloc(traceNb * sizeof(bool)); |
| 546 | |
| 547 | for (i= 0; i < traceNb; i++) |
| 548 | { |
| 549 | const Fit* fit; |
| 550 | |
| 551 | visited[i]= false; |
| 552 | |
| 553 | fit= &fitArray[traceNum][i]; |
| 554 | g_debug("fitArray[traceNum= %u][i= %u]->n = %u\n", traceNum, i, fit->n); |
| 555 | if (fit->n > 0) |
| 556 | { |
| 557 | distances[i]= fit->e; |
| 558 | previousVertex[i]= traceNum; |
| 559 | } |
| 560 | else |
| 561 | { |
| 562 | distances[i]= INFINITY; |
| 563 | previousVertex[i]= UINT_MAX; |
| 564 | } |
| 565 | } |
| 566 | visited[traceNum]= true; |
| 567 | |
| 568 | for (j= 0; j < traceNb; j++) |
| 569 | { |
| 570 | g_debug("(%d, %u, %g), ", visited[j], previousVertex[j], distances[j]); |
| 571 | } |
| 572 | g_debug("\n"); |
| 573 | |
| 574 | for (i= 0; i < traceNb - 2; i++) |
| 575 | { |
| 576 | unsigned int v; |
| 577 | double dvMin; |
| 578 | |
| 579 | dvMin= INFINITY; |
| 580 | for (j= 0; j < traceNb; j++) |
| 581 | { |
| 582 | if (visited[j] == false && distances[j] < dvMin) |
| 583 | { |
| 584 | v= j; |
| 585 | dvMin= distances[j]; |
| 586 | } |
| 587 | } |
| 588 | |
| 589 | g_debug("v= %u dvMin= %g\n", v, dvMin); |
| 590 | |
| 591 | if (dvMin != INFINITY) |
| 592 | { |
| 593 | visited[v]= true; |
| 594 | |
| 595 | for (j= 0; j < traceNb; j++) |
| 596 | { |
| 597 | const Fit* fit; |
| 598 | |
| 599 | fit= &fitArray[v][j]; |
| 600 | if (visited[j] == false && fit->n > 0 && distances[v] + fit->e |
| 601 | < distances[j]) |
| 602 | { |
| 603 | distances[j]= distances[v] + fit->e; |
| 604 | previousVertex[j]= v; |
| 605 | } |
| 606 | } |
| 607 | } |
| 608 | else |
| 609 | { |
| 610 | break; |
| 611 | } |
| 612 | |
| 613 | for (j= 0; j < traceNb; j++) |
| 614 | { |
| 615 | g_debug("(%d, %u, %g), ", visited[j], previousVertex[j], distances[j]); |
| 616 | } |
| 617 | g_debug("\n"); |
| 618 | } |
| 619 | |
| 620 | free(visited); |
| 621 | } |
| 622 | |
| 623 | |
| 624 | /* |
| 625 | * Cummulate the distances between a reference node and the other nodes |
| 626 | * reachable from it in a graph. |
| 627 | * |
| 628 | * Args: |
| 629 | * distances: array of shortest path distances, with UINT_MAX for |
| 630 | * unreachable nodes |
| 631 | * traceNb: number of nodes = number of traces |
| 632 | */ |
| 633 | static double sumDistances(const double* const distances, const unsigned int traceNb) |
| 634 | { |
| 635 | unsigned int i; |
| 636 | double result; |
| 637 | |
| 638 | result= 0; |
| 639 | for (i= 0; i < traceNb; i++) |
| 640 | { |
| 641 | if (distances[i] != INFINITY) |
| 642 | { |
| 643 | result+= distances[i]; |
| 644 | } |
| 645 | } |
| 646 | |
| 647 | return result; |
| 648 | } |
| 649 | |
| 650 | |
| 651 | /* |
| 652 | * Cummulate the time correction factors between two nodes accross a graph |
| 653 | * |
| 654 | * With traceNum i, reference node r: |
| 655 | * tr= (1 + Xri) * ti + D0ri |
| 656 | * = drift * ti + offset |
| 657 | * |
| 658 | * Args: |
| 659 | * fitArray: array with the regression parameters |
| 660 | * previousVertex: previous vertex from a node i on the way to the source, |
| 661 | * UINT_MAX if i is not on the way or is the source, |
| 662 | * preallocated to the number of nodes |
| 663 | * traceNum: end node, the reference depends on previousVertex |
| 664 | * drift: drift factor |
| 665 | * offset: offset factor |
| 666 | */ |
| 667 | static void reduceFactors(Fit* const* const fitArray, const unsigned int* const |
| 668 | previousVertex, const unsigned int traceNum, double* const drift, double* |
| 669 | const offset, double* const stDev) |
| 670 | { |
| 671 | if (previousVertex[traceNum] == UINT_MAX) |
| 672 | { |
| 673 | *drift= 1.; |
| 674 | *offset= 0.; |
| 675 | *stDev= 0.; |
| 676 | } |
| 677 | else |
| 678 | { |
| 679 | const Fit* fit; |
| 680 | double cummDrift, cummOffset, cummStDev; |
| 681 | unsigned int pv; |
| 682 | |
| 683 | pv= previousVertex[traceNum]; |
| 684 | |
| 685 | fit= &fitArray[pv][traceNum]; |
| 686 | reduceFactors(fitArray, previousVertex, pv, &cummDrift, &cummOffset, |
| 687 | &cummStDev); |
| 688 | |
| 689 | *drift= cummDrift * (1 + fit->x); |
| 690 | *offset= cummDrift * fit->d0 + cummOffset; |
| 691 | *stDev= fit->x * cummStDev + fit->e; |
| 692 | } |
| 693 | } |
| 694 | |
| 695 | |
| 696 | /* |
| 697 | * A GFunc for g_queue_foreach() |
| 698 | * |
| 699 | * Args: |
| 700 | * data Graph*, graph to destroy |
| 701 | * user_data NULL |
| 702 | */ |
| 703 | static void gfGraphDestroy(gpointer data, gpointer user_data) |
| 704 | { |
| 705 | Graph* graph; |
| 706 | |
| 707 | graph= (Graph*) data; |
| 708 | |
| 709 | free(graph->previousVertex); |
| 710 | free(graph); |
| 711 | } |
| 712 | |
| 713 | |
| 714 | /* |
| 715 | * A GCompareFunc for g_queue_find_custom() |
| 716 | * |
| 717 | * Args: |
| 718 | * a: Graph* graph |
| 719 | * b: unsigned int* traceNum |
| 720 | * |
| 721 | * Returns: |
| 722 | * 0 if graph contains traceNum |
| 723 | */ |
| 724 | static gint gcfGraphTraceCompare(gconstpointer a, gconstpointer b) |
| 725 | { |
| 726 | Graph* graph; |
| 727 | unsigned int traceNum; |
| 728 | |
| 729 | graph= (Graph*) a; |
| 730 | traceNum= *(unsigned int *) b; |
| 731 | |
| 732 | if (graph->previousVertex[traceNum] != UINT_MAX) |
| 733 | { |
| 734 | return 0; |
| 735 | } |
| 736 | else if (graph->reference == traceNum) |
| 737 | { |
| 738 | return 0; |
| 739 | } |
| 740 | else |
| 741 | { |
| 742 | return 1; |
| 743 | } |
| 744 | } |
| 745 | |