liquid_feedback_core: d11a5c013df9 lf_update_suggestion

liquid_feedback_core

view lf_update_suggestion_order.c @ 363:d11a5c013df9

Removed unused variable in "lf_update_suggestion_order"

author	jbe
date	Sun Mar 17 12:19:36 2013 +0100 (2013-03-17)
parents	6b59cf46f772
children	90ac85d184f8

line source

1 #include <stdlib.h>

2 #include <stdio.h>

3 #include <string.h>

4 #include <libpq-fe.h>

5 #include <search.h>

7 static char *escapeLiteral(PGconn *conn, const char *str, size_t len) {

8 // provides compatibility for PostgreSQL versions prior 9.0

9 // in future: return PQescapeLiteral(conn, str, len);

10 char *res;

11 size_t res_len;

12 res = malloc(2*len+3);

13 if (!res) return NULL;

14 res[0] = '\'';

15 res_len = PQescapeStringConn(conn, res+1, str, len, NULL);

16 res[res_len+1] = '\'';

17 res[res_len+2] = 0;

18 return res;

19 }

21 static void freemem(void *ptr) {

22 // to be used for "escapeLiteral" function

23 // provides compatibility for PostgreSQL versions prior 9.0

24 // in future: PQfreemem(ptr);

25 free(ptr);

26 }

28 #define COL_MEMBER_ID 0

29 #define COL_WEIGHT 1

30 #define COL_PREFERENCE 2

31 #define COL_SUGGESTION_ID 3

33 struct candidate {

34 char *key;

35 double score_per_step;

36 int reaches_score;

37 double score;

38 int seat;

39 };

41 static int compare_candidate(struct candidate *c1, struct candidate *c2) {

42 return strcmp(c1->key, c2->key);

43 }

45 static int candidate_count;

46 static struct candidate *candidates;

48 static void register_candidate(char **candidate_key, VISIT visit, int level) {

49 if (visit == postorder || visit == leaf) {

50 struct candidate *candidate;

51 candidate = candidates + (candidate_count++);

52 candidate->key = *candidate_key;

53 candidate->seat = 0;

54 }

55 }

57 static struct candidate *candidate_by_key(char *candidate_key) {

58 struct candidate *candidate;

59 struct candidate compare;

60 compare.key = candidate_key;

61 candidate = bsearch(&compare, candidates, candidate_count, sizeof(struct candidate), (void *)compare_candidate);

62 if (!candidate) {

63 fprintf(stderr, "Candidate not found (should not happen).\n");

64 abort();

65 }

66 return candidate;

67 }

69 struct ballot_section {

70 int count;

71 struct candidate **candidates;

72 };

74 struct ballot {

75 int weight;

76 struct ballot_section sections[4];

77 };

79 static struct candidate *loser(int round_number, struct ballot *ballots, int ballot_count) {

80 int i, j, k;

81 int remaining;

82 for (i=0; i<candidate_count; i++) {

83 candidates[i].score = 0.0;

84 }

85 remaining = candidate_count - round_number;

86 while (1) {

87 double scale;

88 if (remaining <= 1) break;

89 for (i=0; i<candidate_count; i++) {

90 candidates[i].score_per_step = 0.0;

91 candidates[i].reaches_score = 0;

92 }

93 for (i=0; i<ballot_count; i++) {

94 for (j=0; j<4; j++) {

95 int matches = 0;

96 for (k=0; k<ballots[i].sections[j].count; k++) {

97 struct candidate *candidate;

98 candidate = ballots[i].sections[j].candidates[k];

99 if (candidate->score < 1.0 && !candidate->seat) matches++;

100 }

101 if (matches) {

102 double score_inc;

103 score_inc = 1.0 / (double)matches;

104 for (k=0; k<ballots[i].sections[j].count; k++) {

105 struct candidate *candidate;

106 candidate = ballots[i].sections[j].candidates[k];

107 if (candidate->score < 1.0 && !candidate->seat) {

108 candidate->score_per_step += score_inc;

109 }

110 }

111 break;

112 }

113 }

114 }

115 scale = (double)candidate_count;

116 for (i=0; i<candidate_count; i++) {

117 double max_scale;

118 if (candidates[i].score_per_step > 0.0) {

119 max_scale = (1.0-candidates[i].score) / candidates[i].score_per_step;

120 if (max_scale <= scale) {

121 scale = max_scale;

122 candidates[i].reaches_score = 1;

123 }

124 }

125 }

126 for (i=0; i<candidate_count; i++) {

127 if (candidates[i].score_per_step > 0.0) {

128 if (candidates[i].reaches_score) {

129 candidates[i].score = 1.0;

130 remaining--;

131 } else {

132 candidates[i].score += scale * candidates[i].score_per_step;

133 if (candidates[i].score >= 1.0) remaining--;

134 }

135 if (remaining <= 1) break;

136 }

137 }

138 }

139 for (i=candidate_count-1; i>=0; i--) {

140 if (candidates[i].score < 1.0 && !candidates[i].seat) return candidates+i;

141 }

142 fprintf(stderr, "No remaining candidate (should not happen).");

143 abort();

144 }

145

146 static int write_ranks(PGconn *db, char *escaped_initiative_id, int final) {

147 PGresult *res;

148 char *cmd;

149 int i;

150 if (final) {

151 if (asprintf(&cmd, "BEGIN; UPDATE \"initiative\" SET \"final_suggestion_order_calculated\" = TRUE WHERE \"id\" = %s; UPDATE \"suggestion\" SET \"proportional_order\" = NULL WHERE \"initiative_id\" = %s", escaped_initiative_id, escaped_initiative_id) < 0) {

152 fprintf(stderr, "Could not prepare query string in memory.\n");

153 abort();

154 }

155 } else {

156 if (asprintf(&cmd, "BEGIN; UPDATE \"suggestion\" SET \"proportional_order\" = NULL WHERE \"initiative_id\" = %s", escaped_initiative_id) < 0) {

157 fprintf(stderr, "Could not prepare query string in memory.\n");

158 abort();

159 }

160 }

161 res = PQexec(db, cmd);

162 free(cmd);

163 if (!res) {

164 fprintf(stderr, "Error in pqlib while sending SQL command to initiate suggestion update.\n");

165 return 1;

166 } else if (

167 PQresultStatus(res) != PGRES_COMMAND_OK &&

168 PQresultStatus(res) != PGRES_TUPLES_OK

169 ) {

170 fprintf(stderr, "Error while executing SQL command to initiate suggestion update:\n%s", PQresultErrorMessage(res));

171 PQclear(res);

172 return 1;

173 } else {

174 PQclear(res);

175 }

176 for (i=0; i<candidate_count; i++) {

177 char *escaped_suggestion_id;

178 escaped_suggestion_id = escapeLiteral(db, candidates[i].key, strlen(candidates[i].key));

179 if (!escaped_suggestion_id) {

180 fprintf(stderr, "Could not escape literal in memory.\n");

181 abort();

182 }

183 if (asprintf(&cmd, "UPDATE \"suggestion\" SET \"proportional_order\" = %i WHERE \"id\" = %s", candidates[i].seat, escaped_suggestion_id) < 0) {

184 fprintf(stderr, "Could not prepare query string in memory.\n");

185 abort();

186 }

187 freemem(escaped_suggestion_id);

188 res = PQexec(db, cmd);

189 free(cmd);

190 if (!res) {

191 fprintf(stderr, "Error in pqlib while sending SQL command to update suggestion order.\n");

192 } else if (

193 PQresultStatus(res) != PGRES_COMMAND_OK &&

194 PQresultStatus(res) != PGRES_TUPLES_OK

195 ) {

196 fprintf(stderr, "Error while executing SQL command to update suggestion order:\n%s", PQresultErrorMessage(res));

197 PQclear(res);

198 } else {

199 PQclear(res);

200 continue;

201 }

202 res = PQexec(db, "ROLLBACK");

203 if (res) PQclear(res);

204 return 1;

205 }

206 res = PQexec(db, "COMMIT");

207 if (!res) {

208 fprintf(stderr, "Error in pqlib while sending SQL command to commit transaction.\n");

209 return 1;

210 } else if (

211 PQresultStatus(res) != PGRES_COMMAND_OK &&

212 PQresultStatus(res) != PGRES_TUPLES_OK

213 ) {

214 fprintf(stderr, "Error while executing SQL command to commit transaction:\n%s", PQresultErrorMessage(res));

215 PQclear(res);

216 return 1;

217 } else {

218 PQclear(res);

219 return 0;

220 }

221 }

222

223 static int process_initiative(PGconn *db, PGresult *res, char *escaped_initiative_id, int final) {

224 int err;

225 int ballot_count = 0;

226 struct ballot *ballots;

227 int i;

228 {

229 void *candidate_tree = NULL;

230 int tuple_count;

231 char *old_member_id = NULL;

232 struct ballot *ballot;

233 int candidates_in_sections[4] = {0, };

234 tuple_count = PQntuples(res);

235 if (!tuple_count) {

236 if (final) {

237 printf("No suggestions found, but marking initiative as finally calculated.\n");

238 err = write_ranks(db, escaped_initiative_id, final);

239 printf("Done.\n");

240 return err;

241 } else {

242 printf("Nothing to do.\n");

243 return 0;

244 }

245 }

246 candidate_count = 0;

247 for (i=0; i<=tuple_count; i++) {

248 char *member_id, *suggestion_id;

249 if (i<tuple_count) {

250 member_id = PQgetvalue(res, i, COL_MEMBER_ID);

251 suggestion_id = PQgetvalue(res, i, COL_SUGGESTION_ID);

252 if (!candidate_tree || !tfind(suggestion_id, &candidate_tree, (void *)strcmp)) {

253 candidate_count++;

254 if (!tsearch(suggestion_id, &candidate_tree, (void *)strcmp)) {

255 fprintf(stderr, "Insufficient memory while inserting into candidate tree.\n");

256 abort();

257 }

258 }

259 }

260 if (i==tuple_count || (old_member_id && strcmp(old_member_id, member_id))) {

261 ballot_count++;

262 }

263 old_member_id = member_id;

264 }

265 printf("Candidate count: %i\n", candidate_count);

266 candidates = malloc(candidate_count * sizeof(struct candidate));

267 if (!candidates) {

268 fprintf(stderr, "Insufficient memory while creating candidate list.\n");

269 abort();

270 }

271 candidate_count = 0;

272 twalk(candidate_tree, (void *)register_candidate);

273 while (candidate_tree) tdelete(*(void **)candidate_tree, &candidate_tree, (void *)strcmp);

274 printf("Ballot count: %i\n", ballot_count);

275 ballots = calloc(ballot_count, sizeof(struct ballot));

276 if (!ballots) {

277 fprintf(stderr, "Insufficient memory while creating ballot list.\n");

278 abort();

279 }

280 ballot = ballots;

281 for (i=0; i<tuple_count; i++) {

282 char *member_id;

283 int weight, preference;

284 member_id = PQgetvalue(res, i, COL_MEMBER_ID);

285 weight = (int)strtol(PQgetvalue(res, i, COL_WEIGHT), (char **)NULL, 10);

286 if (weight <= 0) {

287 fprintf(stderr, "Unexpected weight value.\n");

288 free(ballots);

289 free(candidates);

290 return 1;

291 }

292 preference = (int)strtol(PQgetvalue(res, i, COL_PREFERENCE), (char **)NULL, 10);

293 if (preference < 1 || preference > 4) {

294 fprintf(stderr, "Unexpected preference value.\n");

295 free(ballots);

296 free(candidates);

297 return 1;

298 }

299 preference--;

300 ballot->weight = weight;

301 ballot->sections[preference].count++;

302 if (old_member_id && strcmp(old_member_id, member_id)) ballot++;

303 old_member_id = member_id;

304 }

305 for (i=0; i<ballot_count; i++) {

306 int j;

307 for (j=0; j<4; j++) {

308 if (ballots[i].sections[j].count) {

309 ballots[i].sections[j].candidates = malloc(ballots[i].sections[j].count * sizeof(struct candidate *));

310 if (!ballots[i].sections[j].candidates) {

311 fprintf(stderr, "Insufficient memory while creating ballot section.\n");

312 abort();

313 }

314 }

315 }

316 }

317 ballot = ballots;

318 for (i=0; i<=tuple_count; i++) {

319 char *member_id, *suggestion_id;

320 int preference;

321 if (i<tuple_count) {

322 member_id = PQgetvalue(res, i, COL_MEMBER_ID);

323 suggestion_id = PQgetvalue(res, i, COL_SUGGESTION_ID);

324 preference = (int)strtol(PQgetvalue(res, i, COL_PREFERENCE), (char **)NULL, 10);

325 preference--;

326 ballot->sections[preference].candidates[candidates_in_sections[preference]++] = candidate_by_key(suggestion_id);

327 }

328 if (i==tuple_count || (old_member_id && strcmp(old_member_id, member_id))) {

329 ballot++;

330 candidates_in_sections[0] = 0;

331 candidates_in_sections[1] = 0;

332 candidates_in_sections[2] = 0;

333 candidates_in_sections[3] = 0;

334 }

335 old_member_id = member_id;

336 }

337 }

338

339 for (i=0; i<candidate_count; i++) {

340 struct candidate *candidate = loser(i, ballots, ballot_count);

341 candidate->seat = candidate_count - i;

342 printf("Assigning rank #%i to suggestion #%s.\n", candidate_count - i, candidate->key);

343 }

344

345 for (i=0; i<ballot_count; i++) {

346 int j;

347 for (j=0; j<4; j++) {

348 if (ballots[i].sections[j].count) {

349 free(ballots[i].sections[j].candidates);

350 }

351 }

352 }

353 free(ballots);

354

355 if (final) {

356 printf("Writing final ranks to database.\n");

357 } else {

358 printf("Writing ranks to database.\n");

359 }

360 err = write_ranks(db, escaped_initiative_id, final);

361 printf("Done.\n");

362

363 free(candidates);

364

365 return err;

366 }

367

368 int main(int argc, char **argv) {

369

370 // variable declarations:

371 int err = 0;

372 int i, count;

373 char *conninfo;

374 PGconn *db;

375 PGresult *res;

376

377 // parse command line:

378 if (argc == 0) return 1;

379 if (argc == 1 || !strcmp(argv[1], "-h") || !strcmp(argv[1], "--help")) {

380 FILE *out;

381 out = argc == 1 ? stderr : stdout;

382 fprintf(out, "\n");

383 fprintf(out, "Usage: %s <conninfo>\n", argv[0]);

384 fprintf(out, "\n");

385 fprintf(out, "<conninfo> is specified by PostgreSQL's libpq,\n");

386 fprintf(out, "see http://www.postgresql.org/docs/9.1/static/libpq-connect.html\n");

387 fprintf(out, "\n");

388 fprintf(out, "Example: %s dbname=liquid_feedback\n", argv[0]);

389 fprintf(out, "\n");

390 return argc == 1 ? 1 : 0;

391 }

392 {

393 size_t len = 0;

394 for (i=1; i<argc; i++) len += strlen(argv[i]) + 1;

395 conninfo = malloc(len * sizeof(char));

396 if (!conninfo) {

397 fprintf(stderr, "Error: Could not allocate memory for conninfo string.\n");

398 abort();

399 }

400 conninfo[0] = 0;

401 for (i=1; i<argc; i++) {

402 if (i>1) strcat(conninfo, " ");

403 strcat(conninfo, argv[i]);

404 }

405 }

406

407 // connect to database:

408 db = PQconnectdb(conninfo);

409 if (!db) {

410 fprintf(stderr, "Error: Could not create database handle.\n");

411 return 1;

412 }

413 if (PQstatus(db) != CONNECTION_OK) {

414 fprintf(stderr, "Could not open connection:\n%s", PQerrorMessage(db));

415 return 1;

416 }

417

418 // check initiatives:

419 res = PQexec(db, "SELECT \"initiative_id\", \"final\" FROM \"initiative_suggestion_order_calculation\"");

420 if (!res) {

421 fprintf(stderr, "Error in pqlib while sending SQL command selecting initiatives to process.\n");

422 err = 1;

423 } else if (PQresultStatus(res) != PGRES_TUPLES_OK) {

424 fprintf(stderr, "Error while executing SQL command selecting initiatives to process:\n%s", PQresultErrorMessage(res));

425 err = 1;

426 PQclear(res);

427 } else if (PQnfields(res) < 2) {

428 fprintf(stderr, "Too few columns returned by SQL command selecting initiatives to process.\n");

429 err = 1;

430 PQclear(res);

431 } else {

432 count = PQntuples(res);

433 printf("Number of initiatives to process: %i\n", count);

434 for (i=0; i<count; i++) {

435 char *initiative_id, *escaped_initiative_id;

436 int final;

437 char *cmd;

438 PGresult *res2;

439 initiative_id = PQgetvalue(res, i, 0);

440 final = (PQgetvalue(res, i, 1)[0] == 't') ? 1 : 0;

441 printf("Processing initiative_id: %s\n", initiative_id);

442 escaped_initiative_id = escapeLiteral(db, initiative_id, strlen(initiative_id));

443 if (!escaped_initiative_id) {

444 fprintf(stderr, "Could not escape literal in memory.\n");

445 abort();

446 }

447 if (asprintf(&cmd, "SELECT \"member_id\", \"weight\", \"preference\", \"suggestion_id\" FROM \"individual_suggestion_ranking\" WHERE \"initiative_id\" = %s ORDER BY \"member_id\", \"preference\"", escaped_initiative_id) < 0) {

448 fprintf(stderr, "Could not prepare query string in memory.\n");

449 abort();

450 }

451 res2 = PQexec(db, cmd);

452 free(cmd);

453 if (!res2) {

454 fprintf(stderr, "Error in pqlib while sending SQL command selecting individual suggestion rankings.\n");

455 err = 1;

456 } else if (PQresultStatus(res2) != PGRES_TUPLES_OK) {

457 fprintf(stderr, "Error while executing SQL command selecting individual suggestion rankings:\n%s", PQresultErrorMessage(res));

458 err = 1;

459 PQclear(res2);

460 } else if (PQnfields(res2) < 4) {

461 fprintf(stderr, "Too few columns returned by SQL command selecting individual suggestion rankings.\n");

462 err = 1;

463 PQclear(res2);

464 } else {

465 if (process_initiative(db, res2, escaped_initiative_id, final)) err = 1;

466 PQclear(res2);

467 }

468 freemem(escaped_initiative_id);

469 }

470 PQclear(res);

471 }

472

473 // cleanup and exit

474 PQfinish(db);

475 if (!err) printf("Successfully terminated.\n");

476 else fprintf(stderr, "Exiting with error code #%i.\n", err);

477 return err;

478

479 }