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email-tracker/external/duckdb/extension/tpch/dbgen/rnd.cpp
2025-10-24 19:21:19 -05:00

144 lines
3.5 KiB
C++

/*
* Copyright owned by the Transaction Processing Performance Council.
*
* A copy of the license is included under extension/tpch/dbgen/LICENSE
* in this repository.
*
* You may not use this file except in compliance with the License.
*
* THE TPC SOFTWARE IS AVAILABLE WITHOUT CHARGE FROM TPC.
*//*
* RANDOM.C -- Implements Park & Miller's "Minimum Standard" RNG
*
* (Reference: CACM, Oct 1988, pp 1192-1201)
*
* NextRand: Computes next random integer
* UnifInt: Yields an long uniformly distributed between given bounds
* UnifReal: ields a real uniformly distributed between given bounds
* Exponential: Yields a real exponentially distributed with given mean
*
*/
#include "dbgen/config.h"
#include <math.h>
#include <stdio.h>
#include <stdint.h>
#include "dbgen/dss.h"
#include "dbgen/rnd.h"
const char *tpch_env_config PROTO((const char *tag, const char *dflt));
void NthElement(DSS_HUGE, DSS_HUGE *);
void dss_random(DSS_HUGE *tgt, DSS_HUGE lower, DSS_HUGE upper, seed_t *seed) {
*tgt = UnifInt(lower, upper, seed);
seed->usage += 1;
return;
}
void row_start(int t, DBGenContext *ctx) {
(void)t;
int i;
for (i = 0; i <= MAX_STREAM; i++)
ctx->Seed[i].usage = 0;
return;
}
void row_stop_h(int t, DBGenContext *ctx) {
int i;
/* need to allow for handling the master and detail together */
if (t == ORDER_LINE)
t = ORDER;
if (t == PART_PSUPP)
t = PART;
for (i = 0; i <= MAX_STREAM; i++)
if ((ctx->Seed[i].table == t) || (ctx->Seed[i].table == ctx->tdefs[t].child)) {
if (set_seeds && (ctx->Seed[i].usage > ctx->Seed[i].boundary)) {
fprintf(stderr, "\nSEED CHANGE: seed[%d].usage = " HUGE_FORMAT "\n", i, ctx->Seed[i].usage);
ctx->Seed[i].boundary = ctx->Seed[i].usage;
} else {
NthElement((ctx->Seed[i].boundary - ctx->Seed[i].usage), &ctx->Seed[i].value);
#ifdef RNG_TEST
ctx->Seed[i].nCalls += ctx->Seed[i].boundary - ctx->Seed[i].usage;
#endif
}
}
return;
}
void dump_seeds(int tbl, seed_t *seeds) {
int i;
for (i = 0; i <= MAX_STREAM; i++)
if (seeds[i].table == tbl)
#ifdef RNG_TEST
printf("%d(" HUGE_FORMAT "):\t" HUGE_FORMAT "\n", i, seeds[i].nCalls, seeds[i].value);
#else
printf("%d:\t" HUGE_FORMAT "\n", i, seeds[i].value);
#endif
return;
}
/******************************************************************
NextRand: Computes next random integer
*******************************************************************/
/*
* long NextRand( long nSeed )
*/
DSS_HUGE
NextRand(DSS_HUGE nSeed)
/*
* nSeed is the previous random number; the returned value is the
* next random number. The routine generates all numbers in the
* range 1 .. nM-1.
*/
{
nSeed = (nSeed * 16807) % 2147483647;
return (nSeed);
}
/******************************************************************
UnifInt: Yields an long uniformly distributed between given bounds
*******************************************************************/
/*
* long UnifInt( long nLow, long nHigh, seed_t *seed )
*/
DSS_HUGE
UnifInt(DSS_HUGE nLow, DSS_HUGE nHigh, seed_t *seed)
/*
* Returns an integer uniformly distributed between nLow and nHigh,
* including * the endpoints. Seed points to the random number stream.
*/
{
double dRange;
DSS_HUGE nTemp;
int32_t nLow32 = (int32_t)nLow, nHigh32 = (int32_t)nHigh;
if ((nHigh == MAX_LONG) && (nLow == 0)) {
dRange = (double)((DSS_HUGE)(nHigh32 - nLow32) + 1);
} else {
dRange = (double)(nHigh - nLow + 1);
}
seed->value = NextRand(seed->value);
#ifdef RNG_TEST
seed->nCalls += 1;
#endif
nTemp = (DSS_HUGE)(((double)seed->value / DBGenContext::dM) * (dRange));
return (nLow + nTemp);
}