/*
   This file is part of TALER
   Copyright (C) 2022 Taler Systems SA

   TALER is free software; you can redistribute it and/or modify it under the
   terms of the GNU General Public License as published by the Free Software
   Foundation; either version 3, or (at your option) any later version.

   TALER is distributed in the hope that it will be useful, but WITHOUT ANY
   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
   A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

   You should have received a copy of the GNU General Public License along with
   TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
 */
/**
 * @file exchangedb/compute_shard.c
 * @brief Implementation of the compute_shard function for Postgres
 * @author Christian Grothoff
 */
#include "exchange-database/compute_shard.h"
#include "helper.h"


uint64_t
TALER_EXCHANGEDB_compute_shard (const struct TALER_MerchantPublicKeyP *
                                merchant_pub)
{
  uint32_t res;

  GNUNET_assert (GNUNET_YES ==
                 GNUNET_CRYPTO_hkdf_gnunet (
                   &res,
                   sizeof (res),
                   merchant_pub,
                   sizeof (*merchant_pub),
                   "VOID",
                   4));
  /* interpret hash result as NBO for platform independence,
     convert to HBO and map to [0..2^31-1] range */
  res = ntohl (res);
  if (res > INT32_MAX)
    res += INT32_MIN;
  GNUNET_assert (res <= INT32_MAX);
  return (uint64_t) res;
}
