src/rrtimeslice.c

   1 /*
   2  * PostRR - src/rrtimeslice.c
   3  * Copyright (C) 2012 Sebastian 'tokkee' Harl <sh@tokkee.org>
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  16  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  17  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  18  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
  19  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 /*
  29  * A PostgreSQL data-type providing a timeslice implementing round-robin
  30  * features.
  31  */
  32
  33 #include "postrr.h"
  34 #include "utils/pg_spi.h"
  35
  36 #include <string.h>
  37
  38 #include <postgres.h>
  39 #include <fmgr.h>
  40
  41 /* Postgres utilities */
  42 #include <access/hash.h>
  43 #include <executor/spi.h>
  44 #include <utils/array.h>
  45 #include <utils/datetime.h>
  46 #include <utils/timestamp.h>
  47 #include <miscadmin.h> /* DateStyle, IntervalStyle */
  48
  49 #ifdef HAVE_INT64_TIMESTAMP
  50 #       define TSTAMP_TO_INT64(t) (t)
  51 #       define INT64_TO_TSTAMP(i) (i)
  52 #else /* ! HAVE_INT64_TIMESTAMP */
  53 #       define TSTAMP_TO_INT64(t) (int64)((t) * (double)USECS_PER_SEC)
  54 #       define INT64_TO_TSTAMP(i) ((double)(i) / (double)USECS_PER_SEC)
  55 #endif
  56
  57 /*
  58  * data type
  59  */
  60
  61 struct rrtimeslice {
  62         Timestamp tstamp;
  63         int32  tsid;
  64         uint32 seq;
  65 };
  66
  67 /*
  68  * internal helper functions
  69  */
  70
  71 static int32
  72 rrtimeslice_set_spec(int32 len, int32 num)
  73 {
  74         int spi_rc;
  75
  76         char  query[256];
  77         int32 typmod = 0;
  78
  79         if ((len <= 0) || (num <= 0))
  80                 ereport(ERROR, (
  81                                         errcode(ERRCODE_INVALID_PARAMETER_VALUE),
  82                                         errmsg("rrtimeslice(%i, %i) "
  83                                                 "length/num may not be less than zero",
  84                                                 len, num)
  85                                 ));
  86
  87         if ((spi_rc = SPI_connect()) != SPI_OK_CONNECT)
  88                 ereport(ERROR, (
  89                                         errmsg("failed to store rrtimeslice spec: "
  90                                                 "could not connect to SPI manager: %s",
  91                                                 SPI_result_code_string(spi_rc))
  92                                 ));
  93
  94         snprintf(query, sizeof(query),
  95                         "SELECT tsid FROM postrr.rrtimeslices "
  96                                 "WHERE tslen = %d AND tsnum = %d "
  97                                 "LIMIT 1", len, num);
  98         query[sizeof(query) - 1] = '\0';
  99
 100         spi_rc = pg_spi_get_int(query, 1, &typmod);
 101         if (spi_rc == PG_SPI_OK) {
 102                 SPI_finish();
 103                 return typmod;
 104         }
 105         else if (spi_rc != PG_SPI_ERROR_NO_VALUES)
 106                 pg_spi_ereport(ERROR, "store rrtimeslice spec", spi_rc);
 107
 108         snprintf(query, sizeof(query),
 109                         "SELECT nextval('postrr.tsid'::regclass)");
 110         query[sizeof(query) - 1] = '\0';
 111
 112         spi_rc = pg_spi_get_int(query, 1, &typmod);
 113         if ((spi_rc != PG_SPI_OK) || (typmod <= 0))
 114                 pg_spi_ereport(ERROR, "retrieve nextval(postrr.tsid)", spi_rc);
 115
 116         snprintf(query, sizeof(query),
 117                         "INSERT INTO postrr.rrtimeslices(tsid, tslen, tsnum) "
 118                         "VALUES (%d, %d, %d)", typmod, len, num);
 119         query[sizeof(query) - 1] = '\0';
 120
 121         spi_rc = SPI_exec(query, /* max num rows = */ 1);
 122         if (spi_rc != SPI_OK_INSERT)
 123                 ereport(ERROR, (
 124                                         errmsg("failed to store rrtimeslice spec: "
 125                                                 "failed to execute query: %s",
 126                                                 SPI_result_code_string(spi_rc))
 127                                 ));
 128
 129         SPI_finish();
 130         return typmod;
 131 } /* rrtimeslice_set_spec */
 132
 133 static int
 134 rrtimeslice_get_spec(int32 typmod, int32 *len, int32 *num)
 135 {
 136         int spi_rc;
 137
 138         char query[256];
 139
 140         if (typmod <= 0)
 141                 return -1;
 142
 143         if ((spi_rc = SPI_connect()) != SPI_OK_CONNECT)
 144                 ereport(ERROR, (
 145                                         errmsg("failed to determine rrtimeslice spec: "
 146                                                 "could not connect to SPI manager: %s",
 147                                                 SPI_result_code_string(spi_rc))
 148                                 ));
 149
 150         snprintf(query, sizeof(query),
 151                         "SELECT tslen, tsnum FROM postrr.rrtimeslices "
 152                                 "WHERE tsid = %d", typmod);
 153         query[sizeof(query) - 1] = '\0';
 154
 155         spi_rc = pg_spi_get_int(query, 2, len, num);
 156         if (spi_rc != PG_SPI_OK)
 157                 pg_spi_ereport(ERROR, "determine rrtimeslice spec", spi_rc);
 158
 159         SPI_finish();
 160         return 0;
 161 } /* rrtimeslice_get_spec */
 162
 163 static int
 164 rrtimeslice_apply_typmod(rrtimeslice_t *tslice, int32 typmod)
 165 {
 166         int64 tstamp;
 167         int64 length;
 168         int64 seq;
 169
 170         int32 len = 0;
 171         int32 num = 0;
 172
 173         if (rrtimeslice_get_spec(typmod, &len, &num))
 174                 return -1;
 175
 176         if ((len <= 0) || (num <= 0))
 177                 ereport(ERROR, (
 178                                         errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 179                                         errmsg("rrtimeslice(%i, %i) "
 180                                                 "length/num may not be less than zero",
 181                                                 len, num)
 182                                 ));
 183
 184         tstamp = TSTAMP_TO_INT64(tslice->tstamp);
 185
 186         length = len * USECS_PER_SEC;
 187         if (tstamp % length != 0)
 188                 tstamp = tstamp - (tstamp % length) + length;
 189         seq    = tstamp % (length * num) / length;
 190         seq    = seq % num;
 191
 192         tslice->tstamp = INT64_TO_TSTAMP(tstamp);
 193         tslice->tsid   = typmod;
 194         tslice->seq    = (uint32)seq;
 195         return 0;
 196 } /* rrtimeslice_apply_typmod */
 197
 198 /*
 199  * prototypes for PostgreSQL functions
 200  */
 201
 202 PG_FUNCTION_INFO_V1(rrtimeslice_validate);
 203
 204 PG_FUNCTION_INFO_V1(rrtimeslice_in);
 205 PG_FUNCTION_INFO_V1(rrtimeslice_out);
 206 PG_FUNCTION_INFO_V1(rrtimeslice_typmodin);
 207 PG_FUNCTION_INFO_V1(rrtimeslice_typmodout);
 208
 209 PG_FUNCTION_INFO_V1(rrtimeslice_to_rrtimeslice);
 210
 211 PG_FUNCTION_INFO_V1(rrtimeslice_eq);
 212 PG_FUNCTION_INFO_V1(rrtimeslice_ne);
 213 PG_FUNCTION_INFO_V1(rrtimeslice_lt);
 214 PG_FUNCTION_INFO_V1(rrtimeslice_gt);
 215 PG_FUNCTION_INFO_V1(rrtimeslice_le);
 216 PG_FUNCTION_INFO_V1(rrtimeslice_ge);
 217 PG_FUNCTION_INFO_V1(rrtimeslice_cmp);
 218 PG_FUNCTION_INFO_V1(rrtimeslice_hash);
 219
 220 /*
 221  * public API
 222  */
 223
 224 Datum
 225 rrtimeslice_validate(PG_FUNCTION_ARGS)
 226 {
 227         char   type_info[1024];
 228         char  *result;
 229         size_t req_len;
 230         size_t len;
 231
 232         if (PG_NARGS() != 1)
 233                 ereport(ERROR, (
 234                                         errmsg("rrtimeslice_validate() expect one argument"),
 235                                         errhint("Usage rrtimeslice_validate(expected_size)")
 236                                 ));
 237
 238         req_len = (size_t)PG_GETARG_UINT32(0);
 239         len = sizeof(rrtimeslice_t);
 240
 241         if (req_len != len)
 242                 ereport(ERROR, (
 243                                         errmsg("length of the rrtimeslice type "
 244                                                 "does not match the expected length"),
 245                                         errhint("Please report a bug against PostRR")
 246                                 ));
 247
 248         snprintf(type_info, sizeof(type_info),
 249                         "rrtimeslice validated successfully; type length = %zu", len);
 250         type_info[sizeof(type_info) - 1] = '\0';
 251
 252         result = pstrdup(type_info);
 253         PG_RETURN_CSTRING(result);
 254 } /* rrtimeslice_validate */
 255
 256 Datum
 257 rrtimeslice_in(PG_FUNCTION_ARGS)
 258 {
 259         rrtimeslice_t *tslice;
 260
 261         Timestamp tstamp = 0;
 262         int32 typmod;
 263
 264         struct pg_tm tm;
 265         fsec_t fsec = 0;
 266         int tz = 0;
 267
 268         char *time_str;
 269         int   pg_dt_err;
 270         char  buf[MAXDATELEN + MAXDATEFIELDS];
 271         char *field[MAXDATEFIELDS];
 272         int   ftype[MAXDATEFIELDS];
 273         int   num_fields = 0;
 274         int   dtype = 0;
 275
 276         if (PG_NARGS() != 3)
 277                 ereport(ERROR, (
 278                                         errmsg("rrtimeslice_in() expects three arguments"),
 279                                         errhint("Usage: rrtimeslice_in(col_name, oid, typmod)")
 280                                 ));
 281
 282         tslice   = (rrtimeslice_t *)palloc0(sizeof(*tslice));
 283         time_str = PG_GETARG_CSTRING(0);
 284         typmod   = PG_GETARG_INT32(2);
 285
 286         pg_dt_err = ParseDateTime(time_str, buf, sizeof(buf),
 287                         field, ftype, MAXDATEFIELDS, &num_fields);
 288
 289         if (! pg_dt_err)
 290                 pg_dt_err = DecodeDateTime(field, ftype, num_fields,
 291                                 &dtype, &tm, &fsec, &tz);
 292         if (pg_dt_err)
 293                 DateTimeParseError(pg_dt_err, time_str, "rrtimeslice");
 294
 295         switch (dtype) {
 296                 case DTK_DATE:
 297                         if (tm2timestamp(&tm, fsec, NULL, &tstamp))
 298                                 ereport(ERROR, (
 299                                                         errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 300                                                         errmsg("timestamp out of range: %s", time_str)
 301                                                 ));
 302                         break;
 303
 304                 case DTK_EPOCH:
 305                         tstamp = SetEpochTimestamp();
 306                         break;
 307
 308                 default:
 309                         ereport(ERROR, (
 310                                                 errmsg("unexpected dtype %d while "
 311                                                         "parsing rrtimeslice: %s", dtype, time_str)
 312                                         ));
 313         }
 314
 315         tslice->tstamp = tstamp;
 316
 317         /* most likely, this won't happen … coerce_type
 318          * (src/backend/parser/parse_coerce.c) does not pass that information to
 319          * the input function but rather lets a length conversion cast do that
 320          * work */
 321         if (typmod > 0)
 322                 rrtimeslice_apply_typmod(tslice, typmod);
 323
 324         PG_RETURN_RRTIMESLICE_P(tslice);
 325 } /* rrtimeslice_in */
 326
 327 Datum
 328 rrtimeslice_out(PG_FUNCTION_ARGS)
 329 {
 330         rrtimeslice_t *tslice;
 331
 332         Interval interval;
 333
 334         struct pg_tm tm;
 335         fsec_t fsec = 0;
 336         char *tz = NULL;
 337
 338         char  ts_str[MAXDATELEN + 1];
 339         char  buf_ts[MAXDATELEN + 1];
 340         char  buf_l[MAXDATELEN + 1];
 341         char *result;
 342
 343         int32 len = 0;
 344         int32 num = 0;
 345
 346         if (PG_NARGS() != 1)
 347                 ereport(ERROR, (
 348                                         errmsg("rrtimeslice_out() expects one argument"),
 349                                         errhint("Usage: rrtimeslice_out(rrtimeslice)")
 350                                 ));
 351
 352         tslice = PG_GETARG_RRTIMESLICE_P(0);
 353
 354         if (TIMESTAMP_NOT_FINITE(tslice->tstamp)
 355                         || (timestamp2tm(tslice->tstamp, NULL, &tm, &fsec, NULL, NULL) != 0))
 356                 ereport(ERROR, (
 357                                         errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 358                                         errmsg("invalid (non-finite) timestamp")
 359                                 ));
 360         else
 361                 EncodeDateTime(&tm, fsec, NULL, &tz, DateStyle, buf_ts);
 362
 363         if (! rrtimeslice_get_spec(tslice->tsid, &len, &num)) {
 364                 memset(&interval, 0, sizeof(interval));
 365                 interval.time = len * USECS_PER_SEC;
 366                 fsec = 0;
 367
 368                 if (interval2tm(interval, &tm, &fsec))
 369                         ereport(ERROR, (
 370                                                 errmsg("could not convert interval to tm")
 371                                         ));
 372         }
 373         else {
 374                 strncpy(buf_l, "ERR", sizeof(buf_l));
 375                 buf_l[sizeof(buf_l) - 1] = '\0';
 376         }
 377
 378         EncodeInterval(&tm, fsec, IntervalStyle, buf_l);
 379
 380         snprintf(ts_str, sizeof(ts_str), "%s -%s (#%i)",
 381                         buf_ts, buf_l, tslice->seq);
 382
 383         result = pstrdup(ts_str);
 384         PG_RETURN_CSTRING(result);
 385 } /* rrtimeslice_out */
 386
 387 Datum
 388 rrtimeslice_typmodin(PG_FUNCTION_ARGS)
 389 {
 390         ArrayType *tm_array;
 391
 392         int32 *spec;
 393         int    spec_elems = 0;
 394         int32  typmod;
 395
 396         if (PG_NARGS() != 1)
 397                 ereport(ERROR, (
 398                                         errmsg("rrtimeslice_typmodin() expects one argument"),
 399                                         errhint("Usage: rrtimeslice_typmodin(array)")
 400                                 ));
 401
 402         tm_array = PG_GETARG_ARRAYTYPE_P(0);
 403
 404         spec = ArrayGetIntegerTypmods(tm_array, &spec_elems);
 405         if (spec_elems != 2)
 406                 ereport(ERROR, (
 407                                         errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 408                                         errmsg("invalid rrtimeslice type modifier"),
 409                                         errhint("Usage: rrtimeslice(<slice_len>, <num>)")
 410                                 ));
 411
 412         typmod = rrtimeslice_set_spec(spec[0], spec[1]);
 413         PG_RETURN_INT32(typmod);
 414 } /* rrtimeslice_typmodin */
 415
 416 Datum
 417 rrtimeslice_typmodout(PG_FUNCTION_ARGS)
 418 {
 419         int32 typmod;
 420         char  tm_str[1024];
 421         char *result;
 422
 423         int32 len = 0;
 424         int32 num = 0;
 425
 426         if (PG_NARGS() != 1)
 427                 ereport(ERROR, (
 428                                         errmsg("rrtimeslice_typmodout() expects one argument"),
 429                                         errhint("Usage: rrtimeslice_typmodout(typmod)")
 430                                 ));
 431
 432         typmod = PG_GETARG_INT32(0);
 433         if (rrtimeslice_get_spec(typmod, &len, &num))
 434                 tm_str[0] = '\0';
 435         else if ((len <= 0) || (num <= 0))
 436                 snprintf(tm_str, sizeof(tm_str), "(#ERR, #ERR)");
 437         else
 438                 snprintf(tm_str, sizeof(tm_str), "(%d, %d)", len, num);
 439
 440         result = pstrdup(tm_str);
 441         PG_RETURN_CSTRING(result);
 442 } /* rrtimeslice_typmodout */
 443
 444 Datum
 445 rrtimeslice_to_rrtimeslice(PG_FUNCTION_ARGS)
 446 {
 447         rrtimeslice_t *tslice;
 448         int32 typmod;
 449
 450         if (PG_NARGS() != 3)
 451                 ereport(ERROR, (
 452                                         errmsg("rrtimeslice_to_rrtimeslice() "
 453                                                 "expects three arguments"),
 454                                         errhint("Usage: rrtimeslice_to_rrtimeslice"
 455                                                 "(rrtimeslice, typmod, is_explicit)")
 456                                 ));
 457
 458         tslice = PG_GETARG_RRTIMESLICE_P(0);
 459         typmod = PG_GETARG_INT32(1);
 460
 461         if (typmod > 0) {
 462                 if ((! tslice->tsid) && (! tslice->seq))
 463                         rrtimeslice_apply_typmod(tslice, typmod);
 464                 else
 465                         ereport(ERROR, (
 466                                                 errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 467                                                 errmsg("invalid cast: cannot cast rrtimeslices "
 468                                                         "with different typmod (yet)")
 469                                         ));
 470         }
 471
 472         PG_RETURN_RRTIMESLICE_P(tslice);
 473 } /* rrtimeslice_to_rrtimeslice */
 474
 475 int
 476 rrtimeslice_cmp_internal(rrtimeslice_t *ts1, rrtimeslice_t *ts2)
 477 {
 478         if ((! ts1) && (! ts2))
 479                 return 0;
 480         else if (! ts1)
 481                 return -1;
 482         else if (! ts2)
 483                 return 1;
 484
 485         if (ts1->tsid && (! ts2->tsid))
 486                 rrtimeslice_apply_typmod(ts2, ts1->tsid);
 487         else if ((! ts1->tsid) && ts2->tsid)
 488                 rrtimeslice_apply_typmod(ts1, ts2->tsid);
 489
 490         if (ts1->tsid != ts2->tsid) /* XXX: compare len/num */
 491                 ereport(ERROR, (
 492                                         errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 493                                         errmsg("invalid comparison: cannot compare "
 494                                                 "rrtimeslices with different typmods (yet)")
 495                                 ));
 496
 497         if (ts1->seq == ts2->seq)
 498                 return 0;
 499
 500         return timestamp_cmp_internal(ts1->tstamp, ts2->tstamp);
 501 } /* rrtimeslice_cmp_internal */
 502
 503 Datum
 504 rrtimeslice_eq(PG_FUNCTION_ARGS)
 505 {
 506         rrtimeslice_t *ts1 = PG_GETARG_RRTIMESLICE_P(0);
 507         rrtimeslice_t *ts2 = PG_GETARG_RRTIMESLICE_P(1);
 508
 509         PG_RETURN_BOOL(rrtimeslice_cmp_internal(ts1, ts2) == 0);
 510 } /* rrtimeslice_eq */
 511
 512 Datum
 513 rrtimeslice_ne(PG_FUNCTION_ARGS)
 514 {
 515         rrtimeslice_t *ts1 = PG_GETARG_RRTIMESLICE_P(0);
 516         rrtimeslice_t *ts2 = PG_GETARG_RRTIMESLICE_P(1);
 517
 518         PG_RETURN_BOOL(rrtimeslice_cmp_internal(ts1, ts2) != 0);
 519 } /* rrtimeslice_ne */
 520
 521 Datum
 522 rrtimeslice_lt(PG_FUNCTION_ARGS)
 523 {
 524         rrtimeslice_t *ts1 = PG_GETARG_RRTIMESLICE_P(0);
 525         rrtimeslice_t *ts2 = PG_GETARG_RRTIMESLICE_P(1);
 526
 527         PG_RETURN_BOOL(rrtimeslice_cmp_internal(ts1, ts2) < 0);
 528 } /* rrtimeslice_lt */
 529
 530 Datum
 531 rrtimeslice_le(PG_FUNCTION_ARGS)
 532 {
 533         rrtimeslice_t *ts1 = PG_GETARG_RRTIMESLICE_P(0);
 534         rrtimeslice_t *ts2 = PG_GETARG_RRTIMESLICE_P(1);
 535
 536         PG_RETURN_BOOL(rrtimeslice_cmp_internal(ts1, ts2) <= 0);
 537 } /* rrtimeslice_le */
 538
 539 Datum
 540 rrtimeslice_gt(PG_FUNCTION_ARGS)
 541 {
 542         rrtimeslice_t *ts1 = PG_GETARG_RRTIMESLICE_P(0);
 543         rrtimeslice_t *ts2 = PG_GETARG_RRTIMESLICE_P(1);
 544
 545         PG_RETURN_BOOL(rrtimeslice_cmp_internal(ts1, ts2) > 0);
 546 } /* rrtimeslice_gt */
 547
 548 Datum
 549 rrtimeslice_ge(PG_FUNCTION_ARGS)
 550 {
 551         rrtimeslice_t *ts1 = PG_GETARG_RRTIMESLICE_P(0);
 552         rrtimeslice_t *ts2 = PG_GETARG_RRTIMESLICE_P(1);
 553
 554         PG_RETURN_BOOL(rrtimeslice_cmp_internal(ts1, ts2) >= 0);
 555 } /* rrtimeslice_ge */
 556
 557 Datum
 558 rrtimeslice_cmp(PG_FUNCTION_ARGS)
 559 {
 560         rrtimeslice_t *ts1 = PG_GETARG_RRTIMESLICE_P(0);
 561         rrtimeslice_t *ts2 = PG_GETARG_RRTIMESLICE_P(1);
 562
 563         PG_RETURN_INT32(rrtimeslice_cmp_internal(ts1, ts2));
 564 } /* rrtimeslice_ge */
 565
 566 Datum
 567 rrtimeslice_hash(PG_FUNCTION_ARGS)
 568 {
 569         rrtimeslice_t *ts = PG_GETARG_RRTIMESLICE_P(0);
 570         return hash_uint32(ts->seq);
 571 } /* rrtimeslice_hash */
 572
 573 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 574