liquid_feedback_core

annotate lf_update_issue_order.c @ 402:29835e2525bd

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Improved comments/debug output in lf_update_issue_order.c
author jbe
date Sat Oct 12 18:58:51 2013 +0200 (2013-10-12)
parents ee922d286992
children 236cabef04d2
rev   line source
jbe@394 1 #include <stdlib.h>
jbe@394 2 #include <stdio.h>
jbe@394 3 #include <string.h>
jbe@394 4 #include <libpq-fe.h>
jbe@394 5 #include <search.h>
jbe@394 6
jbe@394 7 static int logging = 0;
jbe@394 8
jbe@394 9 static char *escapeLiteral(PGconn *conn, const char *str, size_t len) {
jbe@394 10 // provides compatibility for PostgreSQL versions prior 9.0
jbe@394 11 // in future: return PQescapeLiteral(conn, str, len);
jbe@394 12 char *res;
jbe@394 13 size_t res_len;
jbe@394 14 res = malloc(2*len+3);
jbe@394 15 if (!res) return NULL;
jbe@394 16 res[0] = '\'';
jbe@394 17 res_len = PQescapeStringConn(conn, res+1, str, len, NULL);
jbe@394 18 res[res_len+1] = '\'';
jbe@394 19 res[res_len+2] = 0;
jbe@394 20 return res;
jbe@394 21 }
jbe@394 22
jbe@394 23 static void freemem(void *ptr) {
jbe@394 24 // to be used for "escapeLiteral" function
jbe@394 25 // provides compatibility for PostgreSQL versions prior 9.0
jbe@394 26 // in future: PQfreemem(ptr);
jbe@394 27 free(ptr);
jbe@394 28 }
jbe@394 29
jbe@394 30 // column numbers when querying "issue_supporter_in_admission_state" view in function main():
jbe@394 31 #define COL_MEMBER_ID 0
jbe@394 32 #define COL_WEIGHT 1
jbe@394 33 #define COL_ISSUE_ID 2
jbe@394 34
jbe@394 35 // data structure for a candidate (in this case a suggestion) to the proportional runoff system:
jbe@394 36 struct candidate {
jbe@394 37 char *key; // identifier of the candidate, which is the "suggestion_id" string
jbe@394 38 double score_per_step; // added score per step
jbe@394 39 double score; // current score of candidate; a score of 1.0 is needed to survive a round
jbe@394 40 int seat; // equals 0 for unseated candidates, or contains rank number
jbe@394 41 };
jbe@394 42
jbe@394 43 // compare two integers stored as strings (invocation like strcmp):
jbe@394 44 static int compare_id(char *id1, char *id2) {
jbe@394 45 int ldiff;
jbe@394 46 ldiff = strlen(id1) - strlen(id2);
jbe@394 47 if (ldiff) return ldiff;
jbe@394 48 else return strcmp(id1, id2);
jbe@394 49 }
jbe@394 50
jbe@394 51 // compare two candidates by their key (invocation like strcmp):
jbe@394 52 static int compare_candidate(struct candidate *c1, struct candidate *c2) {
jbe@394 53 return compare_id(c1->key, c2->key);
jbe@394 54 }
jbe@394 55
jbe@394 56 // candidates are stored as global variables due to the constrained twalk() interface:
jbe@394 57 static int candidate_count;
jbe@394 58 static struct candidate *candidates;
jbe@394 59
jbe@394 60 // function to be passed to twalk() to store candidates ordered in candidates[] array:
jbe@394 61 static void register_candidate(char **candidate_key, VISIT visit, int level) {
jbe@394 62 if (visit == postorder || visit == leaf) {
jbe@394 63 struct candidate *candidate;
jbe@394 64 candidate = candidates + (candidate_count++);
jbe@394 65 candidate->key = *candidate_key;
jbe@394 66 candidate->seat = 0;
jbe@394 67 if (logging) printf("Candidate #%i is suggestion #%s.\n", candidate_count, candidate->key);
jbe@394 68 }
jbe@394 69 }
jbe@394 70
jbe@394 71 // performs a binary search in candidates[] array to lookup a candidate by its key (which is the suggestion_id):
jbe@394 72 static struct candidate *candidate_by_key(char *candidate_key) {
jbe@394 73 struct candidate *candidate;
jbe@394 74 struct candidate compare;
jbe@394 75 compare.key = candidate_key;
jbe@394 76 candidate = bsearch(&compare, candidates, candidate_count, sizeof(struct candidate), (void *)compare_candidate);
jbe@394 77 if (!candidate) {
jbe@394 78 fprintf(stderr, "Candidate not found (should not happen).\n");
jbe@394 79 abort();
jbe@394 80 }
jbe@394 81 return candidate;
jbe@394 82 }
jbe@394 83
jbe@402 84 // ballot of the proportional runoff system, containing only one preference section:
jbe@394 85 struct ballot {
jbe@394 86 int weight; // if weight is greater than 1, then the ballot is counted multiple times
jbe@402 87 int count; // number of candidates
jbe@402 88 struct candidate **candidates; // all candidates equally preferred
jbe@394 89 };
jbe@394 90
jbe@399 91 // open issue to be assigned an "order_in_open_states":
jbe@399 92 struct open_issue {
jbe@399 93 char *issue_id;
jbe@399 94 int minimum_position;
jbe@399 95 int position;
jbe@399 96 };
jbe@399 97
jbe@394 98 // determine candidate, which is assigned the next seat (starting with the worst rank):
jbe@394 99 static struct candidate *loser(int round_number, struct ballot *ballots, int ballot_count) {
jbe@394 100 int i, j; // index variables for loops
jbe@394 101 int remaining; // remaining candidates to be seated
jbe@394 102 // reset scores of all candidates:
jbe@394 103 for (i=0; i<candidate_count; i++) {
jbe@394 104 candidates[i].score = 0.0;
jbe@394 105 }
jbe@394 106 // calculate remaining candidates to be seated:
jbe@394 107 remaining = candidate_count - round_number;
jbe@394 108 // repeat following loop, as long as there is more than one remaining candidate:
jbe@394 109 while (remaining > 1) {
jbe@394 110 if (logging) printf("There are %i remaining candidates.\n", remaining);
jbe@394 111 double scale; // factor to be later multiplied with score_per_step:
jbe@394 112 // reset score_per_step for all candidates:
jbe@394 113 for (i=0; i<candidate_count; i++) {
jbe@394 114 candidates[i].score_per_step = 0.0;
jbe@394 115 }
jbe@394 116 // calculate score_per_step for all candidates:
jbe@394 117 for (i=0; i<ballot_count; i++) {
jbe@394 118 int matches = 0;
jbe@394 119 for (j=0; j<ballots[i].count; j++) {
jbe@394 120 struct candidate *candidate;
jbe@394 121 candidate = ballots[i].candidates[j];
jbe@394 122 if (candidate->score < 1.0 && !candidate->seat) matches++;
jbe@394 123 }
jbe@394 124 if (matches) {
jbe@394 125 double score_inc;
jbe@394 126 score_inc = (double)ballots[i].weight / (double)matches;
jbe@394 127 for (j=0; j<ballots[i].count; j++) {
jbe@394 128 struct candidate *candidate;
jbe@394 129 candidate = ballots[i].candidates[j];
jbe@394 130 if (candidate->score < 1.0 && !candidate->seat) {
jbe@394 131 candidate->score_per_step += score_inc;
jbe@394 132 }
jbe@394 133 }
jbe@394 134 }
jbe@394 135 }
jbe@394 136 // calculate scale factor:
jbe@394 137 scale = (double)0.0; // 0.0 is used to indicate that there is no value yet
jbe@394 138 for (i=0; i<candidate_count; i++) {
jbe@394 139 double max_scale;
jbe@394 140 if (candidates[i].score_per_step > 0.0) {
jbe@394 141 max_scale = (1.0-candidates[i].score) / candidates[i].score_per_step;
jbe@394 142 if (scale == 0.0 || max_scale <= scale) {
jbe@394 143 scale = max_scale;
jbe@394 144 }
jbe@394 145 }
jbe@394 146 }
jbe@394 147 // add scale*score_per_step to each candidates score:
jbe@394 148 for (i=0; i<candidate_count; i++) {
jbe@394 149 int log_candidate = 0;
jbe@394 150 if (logging && candidates[i].score < 1.0 && !candidates[i].seat) log_candidate = 1;
jbe@394 151 if (log_candidate) printf("Score for suggestion #%s = %.4f+%.4f*%.4f", candidates[i].key, candidates[i].score, scale, candidates[i].score_per_step);
jbe@394 152 if (candidates[i].score_per_step > 0.0) {
jbe@394 153 double max_scale;
jbe@394 154 max_scale = (1.0-candidates[i].score) / candidates[i].score_per_step;
jbe@394 155 if (max_scale == scale) {
jbe@394 156 // score of 1.0 should be reached, so we set score directly to avoid floating point errors:
jbe@394 157 candidates[i].score = 1.0;
jbe@394 158 remaining--;
jbe@394 159 } else {
jbe@394 160 candidates[i].score += scale * candidates[i].score_per_step;
jbe@394 161 if (candidates[i].score >= 1.0) remaining--;
jbe@394 162 }
jbe@394 163 }
jbe@394 164 if (log_candidate) {
jbe@394 165 if (candidates[i].score >= 1.0) printf("=1\n");
jbe@394 166 else printf("=%.4f\n", candidates[i].score);
jbe@394 167 }
jbe@394 168 // when there is only one candidate remaining, then break inner (and thus outer) loop:
jbe@394 169 if (remaining <= 1) {
jbe@394 170 break;
jbe@394 171 }
jbe@394 172 }
jbe@394 173 }
jbe@394 174 // return remaining candidate:
jbe@394 175 for (i=0; i<candidate_count; i++) {
jbe@394 176 if (candidates[i].score < 1.0 && !candidates[i].seat) return candidates+i;
jbe@394 177 }
jbe@394 178 // if there is no remaining candidate, then something went wrong:
jbe@394 179 fprintf(stderr, "No remaining candidate (should not happen).");
jbe@394 180 abort();
jbe@394 181 }
jbe@394 182
jbe@399 183 // calculate "order_in_open_states":
jbe@399 184 static void calculate_order_in_open_states(struct open_issue *open_issues, int open_issue_count) {
jbe@399 185 int i, j, fallback_j = 0, fallback_minimum_position;
jbe@399 186 for (i=1; i<=open_issue_count; i++) {
jbe@399 187 fallback_minimum_position = -1;
jbe@399 188 for (j=0; j<open_issue_count; j++) {
jbe@399 189 if (open_issues[j].position) continue;
jbe@399 190 if (open_issues[j].minimum_position <= i) break;
jbe@399 191 if (
jbe@399 192 fallback_minimum_position < 0 ||
jbe@399 193 open_issues[j].minimum_position < fallback_minimum_position
jbe@399 194 ) {
jbe@399 195 fallback_j = j;
jbe@399 196 fallback_minimum_position = open_issues[j].minimum_position;
jbe@399 197 }
jbe@399 198 }
jbe@399 199 if (j==open_issue_count) j = fallback_j;
jbe@399 200 open_issues[j].position = i;
jbe@399 201 }
jbe@399 202 }
jbe@399 203
jbe@399 204 // write results to database (calls calculate_open_issue_order):
jbe@394 205 static int write_ranks(PGconn *db, char *escaped_area_id) {
jbe@394 206 PGresult *res;
jbe@394 207 char *cmd;
jbe@394 208 int i;
jbe@398 209 if (asprintf(&cmd, "BEGIN; DELETE FROM \"issue_order\" USING \"issue\" WHERE \"issue_order\".\"id\" = \"issue\".\"id\" AND \"issue\".\"area_id\" = %s", escaped_area_id) < 0) {
jbe@394 210 fprintf(stderr, "Could not prepare query string in memory.\n");
jbe@394 211 abort();
jbe@394 212 }
jbe@394 213 res = PQexec(db, cmd);
jbe@394 214 free(cmd);
jbe@394 215 if (!res) {
jbe@398 216 fprintf(stderr, "Error in pqlib while sending SQL command to initiate issue order update.\n");
jbe@394 217 return 1;
jbe@394 218 } else if (
jbe@394 219 PQresultStatus(res) != PGRES_COMMAND_OK &&
jbe@394 220 PQresultStatus(res) != PGRES_TUPLES_OK
jbe@394 221 ) {
jbe@398 222 fprintf(stderr, "Error while executing SQL command to initiate issue order update:\n%s", PQresultErrorMessage(res));
jbe@394 223 PQclear(res);
jbe@394 224 return 1;
jbe@394 225 } else {
jbe@394 226 PQclear(res);
jbe@394 227 }
jbe@394 228 for (i=0; i<candidate_count; i++) {
jbe@394 229 char *escaped_issue_id;
jbe@394 230 escaped_issue_id = escapeLiteral(db, candidates[i].key, strlen(candidates[i].key));
jbe@394 231 if (!escaped_issue_id) {
jbe@394 232 fprintf(stderr, "Could not escape literal in memory.\n");
jbe@394 233 abort();
jbe@394 234 }
jbe@399 235 if (asprintf(&cmd, "INSERT INTO \"issue_order\" (\"id\", \"order_in_admission_state\") VALUES (%s, %i)", escaped_issue_id, candidates[i].seat) < 0) {
jbe@394 236 fprintf(stderr, "Could not prepare query string in memory.\n");
jbe@394 237 abort();
jbe@394 238 }
jbe@394 239 freemem(escaped_issue_id);
jbe@394 240 res = PQexec(db, cmd);
jbe@394 241 free(cmd);
jbe@394 242 if (!res) {
jbe@398 243 fprintf(stderr, "Error in pqlib while sending SQL command to insert issue order.\n");
jbe@394 244 } else if (
jbe@394 245 PQresultStatus(res) != PGRES_COMMAND_OK &&
jbe@394 246 PQresultStatus(res) != PGRES_TUPLES_OK
jbe@394 247 ) {
jbe@398 248 fprintf(stderr, "Error while executing SQL command to insert issue order:\n%s", PQresultErrorMessage(res));
jbe@394 249 PQclear(res);
jbe@394 250 } else {
jbe@394 251 PQclear(res);
jbe@394 252 continue;
jbe@394 253 }
jbe@394 254 res = PQexec(db, "ROLLBACK");
jbe@394 255 if (res) PQclear(res);
jbe@394 256 return 1;
jbe@394 257 }
jbe@399 258 if (asprintf(&cmd, "SELECT \"issue_id\", \"minimum_position\" FROM \"open_issues_ordered_with_minimum_position\" WHERE \"area_id\" = %s", escaped_area_id) < 0) {
jbe@399 259 fprintf(stderr, "Could not prepare query string in memory.\n");
jbe@399 260 abort();
jbe@399 261 }
jbe@399 262 res = PQexec(db, cmd);
jbe@399 263 free(cmd);
jbe@399 264 if (!res) {
jbe@399 265 fprintf(stderr, "Error in pqlib while sending SQL command selecting ordered issues with minimum position.\n");
jbe@399 266 res = PQexec(db, "ROLLBACK");
jbe@399 267 if (res) PQclear(res);
jbe@399 268 return 1;
jbe@399 269 } else if (PQresultStatus(res) != PGRES_TUPLES_OK) {
jbe@399 270 fprintf(stderr, "Error while executing SQL command selecting ordered issues with minimum position:\n%s", PQresultErrorMessage(res));
jbe@399 271 PQclear(res);
jbe@399 272 res = PQexec(db, "ROLLBACK");
jbe@399 273 if (res) PQclear(res);
jbe@399 274 return 1;
jbe@399 275 } else if (PQnfields(res) < 2) {
jbe@399 276 fprintf(stderr, "Too few columns returned by SQL command selecting ordered issues with minimum position.\n");
jbe@399 277 PQclear(res);
jbe@399 278 res = PQexec(db, "ROLLBACK");
jbe@399 279 if (res) PQclear(res);
jbe@399 280 return 1;
jbe@399 281 } else {
jbe@399 282 int open_issue_count;
jbe@399 283 struct open_issue *open_issues;
jbe@399 284 open_issue_count = PQntuples(res);
jbe@399 285 open_issues = calloc(open_issue_count, sizeof(struct open_issue));
jbe@399 286 for (i=0; i<open_issue_count; i++) {
jbe@399 287 open_issues[i].issue_id = PQgetvalue(res, i, 0);
jbe@399 288 if (PQgetisnull(res, i, 1)) {
jbe@399 289 open_issues[i].minimum_position = 0;
jbe@399 290 } else {
jbe@399 291 open_issues[i].minimum_position = (int)strtol(PQgetvalue(res, i, 1), (char **)NULL, 10);
jbe@399 292 if (open_issues[i].minimum_position < 1) {
jbe@399 293 fprintf(stderr, "Unexpected minimum position value.\n");
jbe@399 294 PQclear(res);
jbe@399 295 free(open_issues);
jbe@399 296 res = PQexec(db, "ROLLBACK");
jbe@399 297 if (res) PQclear(res);
jbe@399 298 return 1;
jbe@399 299 }
jbe@399 300 }
jbe@399 301 }
jbe@399 302 PQclear(res);
jbe@399 303 calculate_order_in_open_states(open_issues, open_issue_count);
jbe@399 304 for (i=0; i<open_issue_count; i++) {
jbe@399 305 char *escaped_issue_id;
jbe@399 306 escaped_issue_id = escapeLiteral(db, open_issues[i].issue_id, strlen(open_issues[i].issue_id));
jbe@399 307 if (!escaped_issue_id) {
jbe@399 308 fprintf(stderr, "Could not escape literal in memory.\n");
jbe@399 309 abort();
jbe@399 310 }
jbe@399 311 if (asprintf(&cmd, "UPDATE \"issue_order\" SET \"order_in_open_states\" = %i WHERE \"id\" = %s)", open_issues[i].position, escaped_issue_id) < 0) {
jbe@399 312 fprintf(stderr, "Could not prepare query string in memory.\n");
jbe@399 313 abort();
jbe@399 314 }
jbe@399 315 freemem(escaped_issue_id);
jbe@399 316 res = PQexec(db, cmd);
jbe@399 317 free(cmd);
jbe@399 318 if (!res) {
jbe@399 319 fprintf(stderr, "Error in pqlib while sending SQL command to update issue order.\n");
jbe@399 320 } else if (
jbe@399 321 PQresultStatus(res) != PGRES_COMMAND_OK &&
jbe@399 322 PQresultStatus(res) != PGRES_TUPLES_OK
jbe@399 323 ) {
jbe@399 324 fprintf(stderr, "Error while executing SQL command to update issue order:\n%s", PQresultErrorMessage(res));
jbe@399 325 PQclear(res);
jbe@399 326 } else {
jbe@399 327 PQclear(res);
jbe@399 328 continue;
jbe@399 329 }
jbe@399 330 free(open_issues);
jbe@399 331 res = PQexec(db, "ROLLBACK");
jbe@399 332 if (res) PQclear(res);
jbe@399 333 return 1;
jbe@399 334 }
jbe@399 335 free(open_issues);
jbe@399 336 }
jbe@394 337 res = PQexec(db, "COMMIT");
jbe@394 338 if (!res) {
jbe@394 339 fprintf(stderr, "Error in pqlib while sending SQL command to commit transaction.\n");
jbe@394 340 return 1;
jbe@394 341 } else if (
jbe@394 342 PQresultStatus(res) != PGRES_COMMAND_OK &&
jbe@394 343 PQresultStatus(res) != PGRES_TUPLES_OK
jbe@394 344 ) {
jbe@394 345 fprintf(stderr, "Error while executing SQL command to commit transaction:\n%s", PQresultErrorMessage(res));
jbe@394 346 PQclear(res);
jbe@394 347 return 1;
jbe@394 348 } else {
jbe@394 349 PQclear(res);
jbe@394 350 }
jbe@399 351 return 0;
jbe@394 352 }
jbe@394 353
jbe@394 354 // calculate ordering of issues in admission state for an area and call write_ranks() to write it to database:
jbe@394 355 static int process_area(PGconn *db, PGresult *res, char *escaped_area_id) {
jbe@394 356 int err; // variable to store an error condition (0 = success)
jbe@394 357 int ballot_count = 1; // number of ballots, must be initiatized to 1, due to loop below
jbe@394 358 struct ballot *ballots; // data structure containing the ballots
jbe@394 359 int i; // index variable for loops
jbe@394 360 // create candidates[] and ballots[] arrays:
jbe@394 361 {
jbe@394 362 void *candidate_tree = NULL; // temporary structure to create a sorted unique list of all candidate keys
jbe@394 363 int tuple_count; // number of tuples returned from the database
jbe@394 364 char *old_member_id = NULL; // old member_id to be able to detect a new ballot in loops
jbe@394 365 struct ballot *ballot; // pointer to current ballot
jbe@394 366 int candidates_in_ballot = 0; // number of candidates in ballot
jbe@394 367 // reset candidate count:
jbe@394 368 candidate_count = 0;
jbe@394 369 // determine number of tuples:
jbe@394 370 tuple_count = PQntuples(res);
jbe@394 371 // trivial case, when there are no tuples:
jbe@394 372 if (!tuple_count) {
jbe@395 373 // write results to database:
jbe@402 374 if (logging) printf("No supporters for any issue. Writing ranks to database.\n");
jbe@395 375 err = write_ranks(db, escaped_area_id);
jbe@395 376 if (logging) printf("Done.\n");
jbe@394 377 return 0;
jbe@394 378 }
jbe@394 379 // calculate ballot_count and generate set of candidate keys (suggestion_id is used as key):
jbe@394 380 for (i=0; i<tuple_count; i++) {
jbe@394 381 char *member_id, *issue_id;
jbe@394 382 member_id = PQgetvalue(res, i, COL_MEMBER_ID);
jbe@394 383 issue_id = PQgetvalue(res, i, COL_ISSUE_ID);
jbe@394 384 if (!candidate_tree || !tfind(issue_id, &candidate_tree, (void *)compare_id)) {
jbe@394 385 candidate_count++;
jbe@394 386 if (!tsearch(issue_id, &candidate_tree, (void *)compare_id)) {
jbe@394 387 fprintf(stderr, "Insufficient memory while inserting into candidate tree.\n");
jbe@394 388 abort();
jbe@394 389 }
jbe@394 390 }
jbe@394 391 if (old_member_id && strcmp(old_member_id, member_id)) ballot_count++;
jbe@394 392 old_member_id = member_id;
jbe@394 393 }
jbe@394 394 // allocate memory for candidates[] array:
jbe@394 395 candidates = malloc(candidate_count * sizeof(struct candidate));
jbe@394 396 if (!candidates) {
jbe@394 397 fprintf(stderr, "Insufficient memory while creating candidate list.\n");
jbe@394 398 abort();
jbe@394 399 }
jbe@394 400 // transform tree of candidate keys into sorted array:
jbe@394 401 candidate_count = 0; // needed by register_candidate()
jbe@394 402 twalk(candidate_tree, (void *)register_candidate);
jbe@394 403 // free memory of tree structure (tdestroy() is not available on all platforms):
jbe@394 404 while (candidate_tree) tdelete(*(void **)candidate_tree, &candidate_tree, (void *)compare_id);
jbe@394 405 // allocate memory for ballots[] array:
jbe@394 406 ballots = calloc(ballot_count, sizeof(struct ballot));
jbe@394 407 if (!ballots) {
jbe@394 408 fprintf(stderr, "Insufficient memory while creating ballot list.\n");
jbe@394 409 abort();
jbe@394 410 }
jbe@394 411 // set ballot weights, determine ballot section sizes, and verify preference values:
jbe@394 412 ballot = ballots;
jbe@394 413 old_member_id = NULL;
jbe@394 414 for (i=0; i<tuple_count; i++) {
jbe@394 415 char *member_id;
jbe@394 416 int weight;
jbe@394 417 member_id = PQgetvalue(res, i, COL_MEMBER_ID);
jbe@394 418 weight = (int)strtol(PQgetvalue(res, i, COL_WEIGHT), (char **)NULL, 10);
jbe@394 419 if (weight <= 0) {
jbe@394 420 fprintf(stderr, "Unexpected weight value.\n");
jbe@394 421 free(ballots);
jbe@394 422 free(candidates);
jbe@394 423 return 1;
jbe@394 424 }
jbe@394 425 if (old_member_id && strcmp(old_member_id, member_id)) ballot++;
jbe@394 426 ballot->weight = weight;
jbe@394 427 ballot->count++;
jbe@394 428 old_member_id = member_id;
jbe@394 429 }
jbe@394 430 // allocate memory for ballot sections:
jbe@394 431 for (i=0; i<ballot_count; i++) {
jbe@394 432 if (ballots[i].count) {
jbe@394 433 ballots[i].candidates = malloc(ballots[i].count * sizeof(struct candidate *));
jbe@394 434 if (!ballots[i].candidates) {
jbe@394 435 fprintf(stderr, "Insufficient memory while creating ballot section.\n");
jbe@394 436 abort();
jbe@394 437 }
jbe@394 438 }
jbe@394 439 }
jbe@394 440 // fill ballot sections with candidate references:
jbe@394 441 old_member_id = NULL;
jbe@394 442 ballot = ballots;
jbe@394 443 for (i=0; i<tuple_count; i++) {
jbe@394 444 char *member_id, *issue_id;
jbe@394 445 member_id = PQgetvalue(res, i, COL_MEMBER_ID);
jbe@394 446 issue_id = PQgetvalue(res, i, COL_ISSUE_ID);
jbe@394 447 if (old_member_id && strcmp(old_member_id, member_id)) {
jbe@394 448 ballot++;
jbe@394 449 candidates_in_ballot = 0;
jbe@394 450 }
jbe@394 451 ballot->candidates[candidates_in_ballot++] = candidate_by_key(issue_id);
jbe@394 452 old_member_id = member_id;
jbe@394 453 }
jbe@394 454 // print ballots, if logging is enabled:
jbe@394 455 if (logging) {
jbe@394 456 for (i=0; i<ballot_count; i++) {
jbe@394 457 int j;
jbe@394 458 printf("Ballot #%i: ", i+1);
jbe@394 459 for (j=0; j<ballots[i].count; j++) {
jbe@394 460 if (!j) printf("issues ");
jbe@394 461 else printf(", ");
jbe@394 462 printf("#%s", ballots[i].candidates[j]->key);
jbe@394 463 }
jbe@394 464 // if (!j) printf("empty"); // should not happen
jbe@394 465 printf(".\n");
jbe@394 466 }
jbe@394 467 }
jbe@394 468 }
jbe@394 469
jbe@394 470 // calculate ranks based on constructed data structures:
jbe@394 471 for (i=0; i<candidate_count; i++) {
jbe@394 472 struct candidate *candidate = loser(i, ballots, ballot_count);
jbe@394 473 candidate->seat = candidate_count - i;
jbe@394 474 if (logging) printf("Assigning rank #%i to issue #%s.\n", candidate_count-i, candidate->key);
jbe@394 475 }
jbe@394 476
jbe@394 477 // free ballots[] array:
jbe@394 478 for (i=0; i<ballot_count; i++) {
jbe@394 479 // if (ballots[i].count) { // count should not be zero
jbe@394 480 free(ballots[i].candidates);
jbe@394 481 // }
jbe@394 482 }
jbe@394 483 free(ballots);
jbe@394 484
jbe@394 485 // write results to database:
jbe@394 486 if (logging) printf("Writing ranks to database.\n");
jbe@394 487 err = write_ranks(db, escaped_area_id);
jbe@394 488 if (logging) printf("Done.\n");
jbe@394 489
jbe@394 490 // free candidates[] array:
jbe@394 491 free(candidates);
jbe@394 492
jbe@394 493 // return error code of write_ranks() call
jbe@394 494 return err;
jbe@394 495 }
jbe@394 496
jbe@394 497 int main(int argc, char **argv) {
jbe@394 498
jbe@394 499 // variable declarations:
jbe@394 500 int err = 0;
jbe@394 501 int i, count;
jbe@394 502 char *conninfo;
jbe@394 503 PGconn *db;
jbe@394 504 PGresult *res;
jbe@394 505
jbe@394 506 // parse command line:
jbe@394 507 if (argc == 0) return 1;
jbe@394 508 if (argc == 1 || !strcmp(argv[1], "-h") || !strcmp(argv[1], "--help")) {
jbe@394 509 FILE *out;
jbe@394 510 out = argc == 1 ? stderr : stdout;
jbe@394 511 fprintf(out, "\n");
jbe@394 512 fprintf(out, "Usage: %s [-v|--verbose] <conninfo>\n", argv[0]);
jbe@394 513 fprintf(out, "\n");
jbe@394 514 fprintf(out, "<conninfo> is specified by PostgreSQL's libpq,\n");
jbe@394 515 fprintf(out, "see http://www.postgresql.org/docs/9.1/static/libpq-connect.html\n");
jbe@394 516 fprintf(out, "\n");
jbe@394 517 fprintf(out, "Example: %s dbname=liquid_feedback\n", argv[0]);
jbe@394 518 fprintf(out, "\n");
jbe@394 519 return argc == 1 ? 1 : 0;
jbe@394 520 }
jbe@394 521 {
jbe@394 522 size_t len = 0;
jbe@394 523 int argb = 1;
jbe@394 524 if (
jbe@394 525 argc >= 2 &&
jbe@394 526 (!strcmp(argv[1], "-v") || !strcmp(argv[1], "--verbose"))
jbe@394 527 ) {
jbe@394 528 argb = 2;
jbe@394 529 logging = 1;
jbe@394 530 }
jbe@394 531 for (i=argb; i<argc; i++) len += strlen(argv[i]) + 1;
jbe@394 532 conninfo = malloc(len * sizeof(char));
jbe@394 533 if (!conninfo) {
jbe@394 534 fprintf(stderr, "Error: Could not allocate memory for conninfo string.\n");
jbe@394 535 abort();
jbe@394 536 }
jbe@394 537 conninfo[0] = 0;
jbe@394 538 for (i=argb; i<argc; i++) {
jbe@394 539 if (i>argb) strcat(conninfo, " ");
jbe@394 540 strcat(conninfo, argv[i]);
jbe@394 541 }
jbe@394 542 }
jbe@394 543
jbe@394 544 // connect to database:
jbe@394 545 db = PQconnectdb(conninfo);
jbe@394 546 if (!db) {
jbe@394 547 fprintf(stderr, "Error: Could not create database handle.\n");
jbe@394 548 return 1;
jbe@394 549 }
jbe@394 550 if (PQstatus(db) != CONNECTION_OK) {
jbe@394 551 fprintf(stderr, "Could not open connection:\n%s", PQerrorMessage(db));
jbe@394 552 return 1;
jbe@394 553 }
jbe@394 554
jbe@394 555 // go through areas:
jbe@394 556 res = PQexec(db, "SELECT \"id\" FROM \"area\"");
jbe@394 557 if (!res) {
jbe@394 558 fprintf(stderr, "Error in pqlib while sending SQL command selecting areas to process.\n");
jbe@394 559 err = 1;
jbe@394 560 } else if (PQresultStatus(res) != PGRES_TUPLES_OK) {
jbe@394 561 fprintf(stderr, "Error while executing SQL command selecting areas to process:\n%s", PQresultErrorMessage(res));
jbe@394 562 err = 1;
jbe@394 563 PQclear(res);
jbe@394 564 } else if (PQnfields(res) < 1) {
jbe@394 565 fprintf(stderr, "Too few columns returned by SQL command selecting areas to process.\n");
jbe@394 566 err = 1;
jbe@394 567 PQclear(res);
jbe@394 568 } else {
jbe@394 569 count = PQntuples(res);
jbe@394 570 if (logging) printf("Number of areas to process: %i\n", count);
jbe@394 571 for (i=0; i<count; i++) {
jbe@394 572 char *area_id, *escaped_area_id;
jbe@394 573 char *cmd;
jbe@394 574 PGresult *res2;
jbe@394 575 area_id = PQgetvalue(res, i, 0);
jbe@394 576 if (logging) printf("Processing area #%s:\n", area_id);
jbe@394 577 escaped_area_id = escapeLiteral(db, area_id, strlen(area_id));
jbe@394 578 if (!escaped_area_id) {
jbe@394 579 fprintf(stderr, "Could not escape literal in memory.\n");
jbe@394 580 abort();
jbe@394 581 }
jbe@394 582 if (asprintf(&cmd, "SELECT \"member_id\", \"weight\", \"issue_id\" FROM \"issue_supporter_in_admission_state\" WHERE \"area_id\" = %s ORDER BY \"member_id\"", escaped_area_id) < 0) {
jbe@394 583 fprintf(stderr, "Could not prepare query string in memory.\n");
jbe@394 584 abort();
jbe@394 585 }
jbe@394 586 res2 = PQexec(db, cmd);
jbe@394 587 free(cmd);
jbe@394 588 if (!res2) {
jbe@394 589 fprintf(stderr, "Error in pqlib while sending SQL command selecting issue supporter in admission state.\n");
jbe@394 590 err = 1;
jbe@394 591 } else if (PQresultStatus(res2) != PGRES_TUPLES_OK) {
jbe@394 592 fprintf(stderr, "Error while executing SQL command selecting issue supporter in admission state:\n%s", PQresultErrorMessage(res));
jbe@394 593 err = 1;
jbe@394 594 PQclear(res2);
jbe@394 595 } else if (PQnfields(res2) < 3) {
jbe@394 596 fprintf(stderr, "Too few columns returned by SQL command selecting issue supporter in admission state.\n");
jbe@394 597 err = 1;
jbe@394 598 PQclear(res2);
jbe@394 599 } else {
jbe@394 600 if (process_area(db, res2, escaped_area_id)) err = 1;
jbe@394 601 PQclear(res2);
jbe@394 602 }
jbe@394 603 freemem(escaped_area_id);
jbe@394 604 }
jbe@394 605 PQclear(res);
jbe@394 606 }
jbe@394 607
jbe@401 608 // clean-up entries of deleted issues
jbe@401 609 res = PQexec(db, "DELETE FROM \"issue_order\" USING \"issue_order\" AS \"issue_order2\" NATURAL LEFT JOIN \"issue\" WHERE \"issue_order\".\"id\" = \"issue_order2\".\"id\" AND \"issue\".\"id\" ISNULL");
jbe@401 610 if (!res) {
jbe@401 611 fprintf(stderr, "Error in pqlib while sending SQL command deleting ordering data of deleted issues.\n");
jbe@401 612 err = 1;
jbe@401 613 } else if (
jbe@401 614 PQresultStatus(res) != PGRES_COMMAND_OK &&
jbe@401 615 PQresultStatus(res) != PGRES_TUPLES_OK
jbe@401 616 ) {
jbe@401 617 fprintf(stderr, "Error while executing SQL command deleting ordering data of deleted issues:\n%s", PQresultErrorMessage(res));
jbe@401 618 err = 1;
jbe@401 619 PQclear(res);
jbe@401 620 } else {
jbe@401 621 if (logging) printf("Cleaned up ordering data of %s deleted issues.\n", PQcmdTuples(res));
jbe@401 622 PQclear(res);
jbe@401 623 }
jbe@401 624
jbe@394 625 // cleanup and exit:
jbe@394 626 PQfinish(db);
jbe@394 627 if (!err) {
jbe@394 628 if (logging) printf("Successfully terminated.\n");
jbe@394 629 } else {
jbe@394 630 fprintf(stderr, "Exiting with error code %i.\n", err);
jbe@394 631 }
jbe@394 632 return err;
jbe@394 633
jbe@394 634 }

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