diff options
Diffstat (limited to 'src/backend/utils/adt/float.c')
| -rw-r--r-- | src/backend/utils/adt/float.c | 20 |
1 files changed, 7 insertions, 13 deletions
diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c index 098bbb372bf..455e5d8cbea 100644 --- a/src/backend/utils/adt/float.c +++ b/src/backend/utils/adt/float.c @@ -21,6 +21,7 @@ #include "catalog/pg_type.h" #include "common/int.h" +#include "common/pg_prng.h" #include "common/shortest_dec.h" #include "libpq/pqformat.h" #include "miscadmin.h" @@ -65,7 +66,7 @@ float8 degree_c_one = 1.0; /* State for drandom() and setseed() */ static bool drandom_seed_set = false; -static unsigned short drandom_seed[3] = {0, 0, 0}; +static pg_prng_state drandom_seed; /* Local function prototypes */ static double sind_q1(double x); @@ -2762,22 +2763,20 @@ drandom(PG_FUNCTION_ARGS) * Should that fail for some reason, we fall back on a lower-quality * seed based on current time and PID. */ - if (!pg_strong_random(drandom_seed, sizeof(drandom_seed))) + if (unlikely(!pg_prng_strong_seed(&drandom_seed))) { TimestampTz now = GetCurrentTimestamp(); uint64 iseed; /* Mix the PID with the most predictable bits of the timestamp */ iseed = (uint64) now ^ ((uint64) MyProcPid << 32); - drandom_seed[0] = (unsigned short) iseed; - drandom_seed[1] = (unsigned short) (iseed >> 16); - drandom_seed[2] = (unsigned short) (iseed >> 32); + pg_prng_seed(&drandom_seed, iseed); } drandom_seed_set = true; } - /* pg_erand48 produces desired result range [0.0 - 1.0) */ - result = pg_erand48(drandom_seed); + /* pg_prng_double produces desired result range [0.0 - 1.0) */ + result = pg_prng_double(&drandom_seed); PG_RETURN_FLOAT8(result); } @@ -2790,7 +2789,6 @@ Datum setseed(PG_FUNCTION_ARGS) { float8 seed = PG_GETARG_FLOAT8(0); - uint64 iseed; if (seed < -1 || seed > 1 || isnan(seed)) ereport(ERROR, @@ -2798,11 +2796,7 @@ setseed(PG_FUNCTION_ARGS) errmsg("setseed parameter %g is out of allowed range [-1,1]", seed))); - /* Use sign bit + 47 fractional bits to fill drandom_seed[] */ - iseed = (int64) (seed * (float8) UINT64CONST(0x7FFFFFFFFFFF)); - drandom_seed[0] = (unsigned short) iseed; - drandom_seed[1] = (unsigned short) (iseed >> 16); - drandom_seed[2] = (unsigned short) (iseed >> 32); + pg_prng_fseed(&drandom_seed, seed); drandom_seed_set = true; PG_RETURN_VOID(); |