Postgres 19 beta 3

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#include "postgres.h"
#include "fmgr.h"
#include "varatt.h"
#include <stdlib.h>

PG_MODULE_MAGIC;

PG_FUNCTION_INFO_V1(random_bytea);

Datum
random_bytea(PG_FUNCTION_ARGS)
{
    int32     numbytes;
    bytea *   randbytea;
    char *    cur_data_ptr;
    long int  lastrand;
    long int  remaining;

    numbytes = PG_GETARG_INT32(0);
    randbytea = palloc(VARHDRSZ + numbytes);
    SET_VARSIZE(randbytea, VARHDRSZ + numbytes);
    cur_data_ptr = VARDATA(randbytea);
    remaining = 0;
    while ( (numbytes--) > 0) {
         remaining = remaining >> 8;
         lastrand = lastrand >> 8;
         if (remaining < 256) {
            lastrand = random();
            remaining = RAND_MAX;
         }
         *(cur_data_ptr++) = (unsigned char) lastrand;
    }

    PG_RETURN_BYTEA_P(randbytea);
}

built fiddle.1.so


create or replace function random_bytea(integer) returns bytea
	as 'fiddle.1','random_bytea'
	language c strict;

CREATE FUNCTION


select
  length(randombytes),
  encode(substring(randombytes for 8),'hex')
from (select random_bytea(1024*1024*16) as randombytes) z;


length
encode


16777216
c45e0b09a8050b6d



SELECT 1