liquid_feedback_core: e22a4d2aea2d lf_update_suggestion

liquid_feedback_core

view lf_update_suggestion_order.c @ 358:e22a4d2aea2d

Write ranks to database in "lf_update_suggestion_order"

author	jbe
date	Sun Mar 17 10:40:00 2013 +0100 (2013-03-17)
parents	4698b68e0942
children	c37c0b4f2027

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) {

147 PGresult *res;

148 char *cmd;

149 int i;

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

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

152 abort();

153 }

154 res = PQexec(db, cmd);

155 free(cmd);

156 if (!res) {

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

158 return 1;

159 } else if (

160 PQresultStatus(res) != PGRES_COMMAND_OK &&

161 PQresultStatus(res) != PGRES_TUPLES_OK

162 ) {

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

164 PQclear(res);

165 return 1;

166 } else {

167 PQclear(res);

168 }

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

170 char *escaped_suggestion_id;

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

172 if (!escaped_suggestion_id) {

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

174 abort();

175 }

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

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

178 abort();

179 }

180 freemem(escaped_suggestion_id);

181 res = PQexec(db, cmd);

182 free(cmd);

183 if (!res) {

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

185 } else if (

186 PQresultStatus(res) != PGRES_COMMAND_OK &&

187 PQresultStatus(res) != PGRES_TUPLES_OK

188 ) {

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

190 PQclear(res);

191 } else {

192 PQclear(res);

193 continue;

194 }

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

196 if (res) PQclear(res);

197 return 1;

198 }

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

200 if (!res) {

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

202 return 1;

203 } else if (

204 PQresultStatus(res) != PGRES_COMMAND_OK &&

205 PQresultStatus(res) != PGRES_TUPLES_OK

206 ) {

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

208 PQclear(res);

209 return 1;

210 } else {

211 PQclear(res);

212 return 0;

213 }

214 }

215

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

217 int err;

218 int ballot_count = 0;

219 struct ballot *ballots;

220 int i;

221 {

222 void *candidate_tree = NULL;

223 int tuple_count;

224 char *old_member_id = NULL;

225 struct ballot *ballot;

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

227 candidate_count = 0;

228 tuple_count = PQntuples(res);

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

230 char *member_id, *suggestion_id;

231 if (i<tuple_count) {

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

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

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

235 candidate_count++;

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

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

238 abort();

239 }

240 }

241 }

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

243 ballot_count++;

244 }

245 old_member_id = member_id;

246 }

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

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

249 if (!candidates) {

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

251 abort();

252 }

253 candidate_count = 0;

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

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

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

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

258 if (!ballots) {

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

260 abort();

261 }

262 ballot = ballots;

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

264 char *member_id, *suggestion_id;

265 int weight, preference;

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

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

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

269 if (weight <= 0) {

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

271 free(ballots);

272 free(candidates);

273 return 1;

274 }

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

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

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

278 free(ballots);

279 free(candidates);

280 return 1;

281 }

282 preference--;

283 ballot->weight = weight;

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

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

286 old_member_id = member_id;

287 }

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

289 int j;

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

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

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

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

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

295 abort();

296 }

297 }

298 }

299 }

300 ballot = ballots;

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

302 char *member_id, *suggestion_id;

303 int preference;

304 if (i<tuple_count) {

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

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

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

308 preference--;

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

310 }

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

312 ballot++;

313 candidates_in_sections[0] = 0;

314 candidates_in_sections[1] = 0;

315 candidates_in_sections[2] = 0;

316 candidates_in_sections[3] = 0;

317 }

318 old_member_id = member_id;

319 }

320 }

321

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

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

324 candidate->seat = candidate_count - i;

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

326 }

327

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

329 int j;

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

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

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

333 }

334 }

335 }

336 free(ballots);

337

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

339 err = write_ranks(db, escaped_initiative_id);

340 printf("Done.\n");

341

342 free(candidates);

343

344 return err;

345 }

346

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

348

349 // variable declarations:

350 int err = 0;

351 int i, count;

352 char *conninfo;

353 PGconn *db;

354 PGresult *res;

355

356 // parse command line:

357 if (argc == 0) return 1;

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

359 FILE *out;

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

361 fprintf(stdout, "\n");

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

363 fprintf(stdout, "\n");

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

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

366 fprintf(stdout, "\n");

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

368 fprintf(stdout, "\n");

369 return argc == 1 ? 1 : 0;

370 }

371 {

372 size_t len = 0;

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

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

375 if (!conninfo) {

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

377 abort();

378 }

379 conninfo[0] = 0;

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

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

382 strcat(conninfo, argv[i]);

383 }

384 }

385

386 // connect to database:

387 db = PQconnectdb(conninfo);

388 if (!db) {

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

390 return 1;

391 }

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

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

394 return 1;

395 }

396

397 // check initiatives:

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

399 if (!res) {

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

401 err = 1;

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

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

404 err = 1;

405 PQclear(res);

406 } else {

407 count = PQntuples(res);

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

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

410 char *initiative_id, *escaped_initiative_id;

411 char *cmd;

412 PGresult *res2;

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

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

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

416 if (!escaped_initiative_id) {

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

418 abort();

419 }

420 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) {

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

422 abort();

423 }

424 res2 = PQexec(db, cmd);

425 free(cmd);

426 if (!res2) {

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

428 err = 1;

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

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

431 err = 1;

432 PQclear(res2);

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

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

435 err = 1;

436 PQclear(res2);

437 } else {

438 if (PQntuples(res2) == 0) {

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

440 } else {

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

442 }

443 PQclear(res2);

444 }

445 freemem(escaped_initiative_id);

446 }

447 PQclear(res);

448 }

449

450 // cleanup and exit

451 PQfinish(db);

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

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

454 return err;

455

456 }