Code

7207dea04bdab2a0414360197209bd7d4a253165
[postrr.git] / 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  */
28 /*
29  * A PostgreSQL data-type providing a timeslice implementing round-robin
30  * features.
31  */
33 #include "postrr.h"
34 #include "utils/pg_spi.h"
36 #include <string.h>
38 #include <postgres.h>
39 #include <fmgr.h>
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 */
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
57 /*
58  * data type
59  */
61 struct rrtimeslice {
62         Timestamp tstamp;
63         int32  tsid;
64         uint32 seq;
65 };
67 /*
68  * internal helper functions
69  */
71 static int32
72 rrtimeslice_set_spec(int32 len, int32 num)
73 {
74         int spi_rc;
76         char  query[256];
77         int32 typmod = 0;
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                                 ));
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                                 ));
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';
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);
108         snprintf(query, sizeof(query),
109                         "SELECT nextval('postrr.tsid'::regclass)");
110         query[sizeof(query) - 1] = '\0';
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);
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';
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                                 ));
129         SPI_finish();
130         return typmod;
131 } /* rrtimeslice_set_spec */
133 static int
134 rrtimeslice_get_spec(int32 typmod, int32 *len, int32 *num)
136         int spi_rc;
138         char query[256];
140         if (typmod <= 0)
141                 return -1;
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                                 ));
150         snprintf(query, sizeof(query),
151                         "SELECT tslen, tsnum FROM postrr.rrtimeslices "
152                                 "WHERE tsid = %d", typmod);
153         query[sizeof(query) - 1] = '\0';
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);
159         SPI_finish();
160         return 0;
161 } /* rrtimeslice_get_spec */
163 static int
164 rrtimeslice_apply_typmod(rrtimeslice_t *tslice, int32 typmod)
166         int64 tstamp;
167         int64 length;
168         int64 seq;
170         int32 len = 0;
171         int32 num = 0;
173         if (rrtimeslice_get_spec(typmod, &len, &num))
174                 return -1;
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                                 ));
184         tstamp = TSTAMP_TO_INT64(tslice->tstamp);
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;
192         tslice->tstamp = INT64_TO_TSTAMP(tstamp);
193         tslice->tsid   = typmod;
194         tslice->seq    = (uint32)seq;
195         return 0;
196 } /* rrtimeslice_apply_typmod */
198 /*
199  * prototypes for PostgreSQL functions
200  */
202 PG_FUNCTION_INFO_V1(rrtimeslice_validate);
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);
209 PG_FUNCTION_INFO_V1(rrtimeslice_to_rrtimeslice);
210 PG_FUNCTION_INFO_V1(rrtimeslice_to_timestamp);
212 PG_FUNCTION_INFO_V1(rrtimeslice_seq_eq);
213 PG_FUNCTION_INFO_V1(rrtimeslice_seq_ne);
214 PG_FUNCTION_INFO_V1(rrtimeslice_seq_lt);
215 PG_FUNCTION_INFO_V1(rrtimeslice_seq_gt);
216 PG_FUNCTION_INFO_V1(rrtimeslice_seq_le);
217 PG_FUNCTION_INFO_V1(rrtimeslice_seq_ge);
218 PG_FUNCTION_INFO_V1(rrtimeslice_seq_cmp);
219 PG_FUNCTION_INFO_V1(rrtimeslice_seq_hash);
221 /*
222  * public API
223  */
225 Datum
226 rrtimeslice_validate(PG_FUNCTION_ARGS)
228         char   type_info[1024];
229         char  *result;
230         size_t req_len;
231         size_t len;
233         if (PG_NARGS() != 1)
234                 ereport(ERROR, (
235                                         errmsg("rrtimeslice_validate() expect one argument"),
236                                         errhint("Usage rrtimeslice_validate(expected_size)")
237                                 ));
239         req_len = (size_t)PG_GETARG_UINT32(0);
240         len = sizeof(rrtimeslice_t);
242         if (req_len != len)
243                 ereport(ERROR, (
244                                         errmsg("length of the rrtimeslice type "
245                                                 "does not match the expected length"),
246                                         errhint("Please report a bug against PostRR")
247                                 ));
249         snprintf(type_info, sizeof(type_info),
250                         "rrtimeslice validated successfully; type length = %zu", len);
251         type_info[sizeof(type_info) - 1] = '\0';
253         result = pstrdup(type_info);
254         PG_RETURN_CSTRING(result);
255 } /* rrtimeslice_validate */
257 Datum
258 rrtimeslice_in(PG_FUNCTION_ARGS)
260         rrtimeslice_t *tslice;
262         Timestamp tstamp = 0;
263         int32 typmod;
265         struct pg_tm tm;
266         fsec_t fsec = 0;
267         int tz = 0;
269         char *time_str;
270         int   pg_dt_err;
271         char  buf[MAXDATELEN + MAXDATEFIELDS];
272         char *field[MAXDATEFIELDS];
273         int   ftype[MAXDATEFIELDS];
274         int   num_fields = 0;
275         int   dtype = 0;
277         if (PG_NARGS() != 3)
278                 ereport(ERROR, (
279                                         errmsg("rrtimeslice_in() expects three arguments"),
280                                         errhint("Usage: rrtimeslice_in(col_name, oid, typmod)")
281                                 ));
283         tslice   = (rrtimeslice_t *)palloc0(sizeof(*tslice));
284         time_str = PG_GETARG_CSTRING(0);
285         typmod   = PG_GETARG_INT32(2);
287         pg_dt_err = ParseDateTime(time_str, buf, sizeof(buf),
288                         field, ftype, MAXDATEFIELDS, &num_fields);
290         if (! pg_dt_err)
291                 pg_dt_err = DecodeDateTime(field, ftype, num_fields,
292                                 &dtype, &tm, &fsec, &tz);
293         if (pg_dt_err)
294                 DateTimeParseError(pg_dt_err, time_str, "rrtimeslice");
296         switch (dtype) {
297                 case DTK_DATE:
298                         if (tm2timestamp(&tm, fsec, NULL, &tstamp))
299                                 ereport(ERROR, (
300                                                         errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
301                                                         errmsg("timestamp out of range: %s", time_str)
302                                                 ));
303                         break;
305                 case DTK_EPOCH:
306                         tstamp = SetEpochTimestamp();
307                         break;
309                 default:
310                         ereport(ERROR, (
311                                                 errmsg("unexpected dtype %d while "
312                                                         "parsing rrtimeslice: %s", dtype, time_str)
313                                         ));
314         }
316         tslice->tstamp = tstamp;
318         /* most likely, this won't happen â€¦ coerce_type
319          * (src/backend/parser/parse_coerce.c) does not pass that information to
320          * the input function but rather lets a length conversion cast do that
321          * work */
322         if (typmod > 0)
323                 rrtimeslice_apply_typmod(tslice, typmod);
325         PG_RETURN_RRTIMESLICE_P(tslice);
326 } /* rrtimeslice_in */
328 Datum
329 rrtimeslice_out(PG_FUNCTION_ARGS)
331         rrtimeslice_t *tslice;
333         Interval interval;
335         struct pg_tm tm;
336         fsec_t fsec = 0;
337         char *tz = NULL;
339         char  ts_str[MAXDATELEN + 1];
340         char  buf_ts[MAXDATELEN + 1];
341         char  buf_l[MAXDATELEN + 1];
342         char *result;
344         int32 len = 0;
345         int32 num = 0;
347         if (PG_NARGS() != 1)
348                 ereport(ERROR, (
349                                         errmsg("rrtimeslice_out() expects one argument"),
350                                         errhint("Usage: rrtimeslice_out(rrtimeslice)")
351                                 ));
353         tslice = PG_GETARG_RRTIMESLICE_P(0);
355         if (TIMESTAMP_NOT_FINITE(tslice->tstamp)
356                         || (timestamp2tm(tslice->tstamp, NULL, &tm, &fsec, NULL, NULL) != 0))
357                 ereport(ERROR, (
358                                         errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
359                                         errmsg("invalid (non-finite) timestamp")
360                                 ));
361         else
362                 EncodeDateTime(&tm, fsec, NULL, &tz, DateStyle, buf_ts);
364         if (! rrtimeslice_get_spec(tslice->tsid, &len, &num)) {
365                 memset(&interval, 0, sizeof(interval));
366                 interval.time = len * USECS_PER_SEC;
367                 fsec = 0;
369                 if (interval2tm(interval, &tm, &fsec))
370                         ereport(ERROR, (
371                                                 errmsg("could not convert interval to tm")
372                                         ));
373         }
374         else {
375                 strncpy(buf_l, "ERR", sizeof(buf_l));
376                 buf_l[sizeof(buf_l) - 1] = '\0';
377         }
379         EncodeInterval(&tm, fsec, IntervalStyle, buf_l);
381         snprintf(ts_str, sizeof(ts_str), "%s -%s (#%i)",
382                         buf_ts, buf_l, tslice->seq);
384         result = pstrdup(ts_str);
385         PG_RETURN_CSTRING(result);
386 } /* rrtimeslice_out */
388 Datum
389 rrtimeslice_typmodin(PG_FUNCTION_ARGS)
391         ArrayType *tm_array;
393         int32 *spec;
394         int    spec_elems = 0;
395         int32  typmod;
397         if (PG_NARGS() != 1)
398                 ereport(ERROR, (
399                                         errmsg("rrtimeslice_typmodin() expects one argument"),
400                                         errhint("Usage: rrtimeslice_typmodin(array)")
401                                 ));
403         tm_array = PG_GETARG_ARRAYTYPE_P(0);
405         spec = ArrayGetIntegerTypmods(tm_array, &spec_elems);
406         if (spec_elems != 2)
407                 ereport(ERROR, (
408                                         errcode(ERRCODE_INVALID_PARAMETER_VALUE),
409                                         errmsg("invalid rrtimeslice type modifier"),
410                                         errhint("Usage: rrtimeslice(<slice_len>, <num>)")
411                                 ));
413         typmod = rrtimeslice_set_spec(spec[0], spec[1]);
414         PG_RETURN_INT32(typmod);
415 } /* rrtimeslice_typmodin */
417 Datum
418 rrtimeslice_typmodout(PG_FUNCTION_ARGS)
420         int32 typmod;
421         char  tm_str[1024];
422         char *result;
424         int32 len = 0;
425         int32 num = 0;
427         if (PG_NARGS() != 1)
428                 ereport(ERROR, (
429                                         errmsg("rrtimeslice_typmodout() expects one argument"),
430                                         errhint("Usage: rrtimeslice_typmodout(typmod)")
431                                 ));
433         typmod = PG_GETARG_INT32(0);
434         if (rrtimeslice_get_spec(typmod, &len, &num))
435                 tm_str[0] = '\0';
436         else if ((len <= 0) || (num <= 0))
437                 snprintf(tm_str, sizeof(tm_str), "(#ERR, #ERR)");
438         else
439                 snprintf(tm_str, sizeof(tm_str), "(%d, %d)", len, num);
441         result = pstrdup(tm_str);
442         PG_RETURN_CSTRING(result);
443 } /* rrtimeslice_typmodout */
445 Datum
446 rrtimeslice_to_rrtimeslice(PG_FUNCTION_ARGS)
448         rrtimeslice_t *tslice;
449         int32 typmod;
451         if (PG_NARGS() != 3)
452                 ereport(ERROR, (
453                                         errmsg("rrtimeslice_to_rrtimeslice() "
454                                                 "expects three arguments"),
455                                         errhint("Usage: rrtimeslice_to_rrtimeslice"
456                                                 "(rrtimeslice, typmod, is_explicit)")
457                                 ));
459         tslice = PG_GETARG_RRTIMESLICE_P(0);
460         typmod = PG_GETARG_INT32(1);
462         if (typmod > 0) {
463                 if ((! tslice->tsid) && (! tslice->seq))
464                         rrtimeslice_apply_typmod(tslice, typmod);
465                 else
466                         ereport(ERROR, (
467                                                 errcode(ERRCODE_INVALID_PARAMETER_VALUE),
468                                                 errmsg("invalid cast: cannot cast rrtimeslices "
469                                                         "with different typmod (yet)")
470                                         ));
471         }
473         PG_RETURN_RRTIMESLICE_P(tslice);
474 } /* rrtimeslice_to_rrtimeslice */
476 Datum
477 rrtimeslice_to_timestamp(PG_FUNCTION_ARGS)
479         rrtimeslice_t *tslice;
481         if (PG_NARGS() != 1)
482                 ereport(ERROR, (
483                                         errmsg("rrtimeslice_to_timestamp() "
484                                                 "expects one argument"),
485                                         errhint("Usage: rrtimeslice_to_timestamp"
486                                                 "(rrtimeslice)")
487                                 ));
489         tslice = PG_GETARG_RRTIMESLICE_P(0);
490         PG_RETURN_TIMESTAMP(tslice->tstamp);
491 } /* rrtimeslice_to_timestamp */
493 int
494 rrtimeslice_seq_cmp_internal(rrtimeslice_t *ts1, rrtimeslice_t *ts2)
496         if ((! ts1) && (! ts2))
497                 return 0;
498         else if (! ts1)
499                 return -1;
500         else if (! ts2)
501                 return 1;
503         if (ts1->tsid && (! ts2->tsid))
504                 rrtimeslice_apply_typmod(ts2, ts1->tsid);
505         else if ((! ts1->tsid) && ts2->tsid)
506                 rrtimeslice_apply_typmod(ts1, ts2->tsid);
508         if (ts1->tsid != ts2->tsid) /* XXX: compare len/num */
509                 ereport(ERROR, (
510                                         errcode(ERRCODE_INVALID_PARAMETER_VALUE),
511                                         errmsg("invalid comparison: cannot compare "
512                                                 "rrtimeslices with different typmods (yet)")
513                                 ));
515         if (ts1->seq < ts2->seq)
516                 return -1;
517         else if (ts1->seq == ts2->seq)
518                 return 0;
519         else
520                 return 1;
521 } /* rrtimeslice_seq_cmp_internal */
523 Datum
524 rrtimeslice_seq_eq(PG_FUNCTION_ARGS)
526         rrtimeslice_t *ts1 = PG_GETARG_RRTIMESLICE_P(0);
527         rrtimeslice_t *ts2 = PG_GETARG_RRTIMESLICE_P(1);
529         PG_RETURN_BOOL(rrtimeslice_seq_cmp_internal(ts1, ts2) == 0);
530 } /* rrtimeslice_seq_eq */
532 Datum
533 rrtimeslice_seq_ne(PG_FUNCTION_ARGS)
535         rrtimeslice_t *ts1 = PG_GETARG_RRTIMESLICE_P(0);
536         rrtimeslice_t *ts2 = PG_GETARG_RRTIMESLICE_P(1);
538         PG_RETURN_BOOL(rrtimeslice_seq_cmp_internal(ts1, ts2) != 0);
539 } /* rrtimeslice_seq_ne */
541 Datum
542 rrtimeslice_seq_lt(PG_FUNCTION_ARGS)
544         rrtimeslice_t *ts1 = PG_GETARG_RRTIMESLICE_P(0);
545         rrtimeslice_t *ts2 = PG_GETARG_RRTIMESLICE_P(1);
547         PG_RETURN_BOOL(rrtimeslice_seq_cmp_internal(ts1, ts2) < 0);
548 } /* rrtimeslice_seq_lt */
550 Datum
551 rrtimeslice_seq_le(PG_FUNCTION_ARGS)
553         rrtimeslice_t *ts1 = PG_GETARG_RRTIMESLICE_P(0);
554         rrtimeslice_t *ts2 = PG_GETARG_RRTIMESLICE_P(1);
556         PG_RETURN_BOOL(rrtimeslice_seq_cmp_internal(ts1, ts2) <= 0);
557 } /* rrtimeslice_seq_le */
559 Datum
560 rrtimeslice_seq_gt(PG_FUNCTION_ARGS)
562         rrtimeslice_t *ts1 = PG_GETARG_RRTIMESLICE_P(0);
563         rrtimeslice_t *ts2 = PG_GETARG_RRTIMESLICE_P(1);
565         PG_RETURN_BOOL(rrtimeslice_seq_cmp_internal(ts1, ts2) > 0);
566 } /* rrtimeslice_seq_gt */
568 Datum
569 rrtimeslice_seq_ge(PG_FUNCTION_ARGS)
571         rrtimeslice_t *ts1 = PG_GETARG_RRTIMESLICE_P(0);
572         rrtimeslice_t *ts2 = PG_GETARG_RRTIMESLICE_P(1);
574         PG_RETURN_BOOL(rrtimeslice_seq_cmp_internal(ts1, ts2) >= 0);
575 } /* rrtimeslice_seq_ge */
577 Datum
578 rrtimeslice_seq_cmp(PG_FUNCTION_ARGS)
580         rrtimeslice_t *ts1 = PG_GETARG_RRTIMESLICE_P(0);
581         rrtimeslice_t *ts2 = PG_GETARG_RRTIMESLICE_P(1);
583         PG_RETURN_INT32(rrtimeslice_seq_cmp_internal(ts1, ts2));
584 } /* rrtimeslice_seq_ge */
586 Datum
587 rrtimeslice_seq_hash(PG_FUNCTION_ARGS)
589         rrtimeslice_t *ts = PG_GETARG_RRTIMESLICE_P(0);
590         return hash_uint32(ts->seq);
591 } /* rrtimeslice_seq_hash */
593 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */