cp sql/ from GNU Taler exchange

include/sql/exchange_do_recoup_to_reserve.sql

@@ -0,0 +1,153 @@
+--
+-- This file is part of TALER
+-- Copyright (C) 2014--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/>
+--
+
+-- When parameter names have changed, we can not REPLACE
+-- but need to drop first
+DROP FUNCTION IF EXISTS exchange_do_recoup_to_reserve;
+
+CREATE FUNCTION exchange_do_recoup_to_reserve(
+  IN in_reserve_pub BYTEA,
+  IN in_withdraw_id INT8,
+  IN in_coin_blind BYTEA,
+  IN in_coin_pub BYTEA,
+  IN in_known_coin_id INT8,
+  IN in_coin_sig BYTEA,
+  IN in_reserve_gc INT8,
+  IN in_reserve_expiration INT8,
+  IN in_recoup_timestamp INT8,
+  OUT out_recoup_ok BOOLEAN,
+  OUT out_internal_failure BOOLEAN,
+  OUT out_recoup_timestamp INT8)
+LANGUAGE plpgsql
+AS $$
+DECLARE
+  tmp taler_amount; -- amount recouped
+  balance taler_amount; -- current balance of the reserve
+  new_balance taler_amount; -- new balance of the reserve
+  reserve RECORD;
+  rval RECORD;
+BEGIN
+-- Shards: SELECT known_coins (by coin_pub)
+--         SELECT recoup      (by coin_pub)
+--         UPDATE known_coins (by coin_pub)
+--         UPDATE reserves (by reserve_pub)
+--         INSERT recoup      (by coin_pub)
+
+out_internal_failure=FALSE;
+
+
+-- Check remaining balance of the coin.
+SELECT
+   remaining
+ INTO
+   rval
+FROM exchange.known_coins
+  WHERE coin_pub=in_coin_pub;
+
+IF NOT FOUND
+THEN
+  out_internal_failure=TRUE;
+  out_recoup_ok=FALSE;
+  RETURN;
+END IF;
+
+tmp := rval.remaining;
+
+IF tmp.val + tmp.frac = 0
+THEN
+  -- Check for idempotency
+  SELECT
+    recoup_timestamp
+  INTO
+    out_recoup_timestamp
+    FROM exchange.recoup
+    WHERE coin_pub=in_coin_pub;
+
+  out_recoup_ok=FOUND;
+  RETURN;
+END IF;
+
+
+-- Update balance of the coin.
+UPDATE known_coins
+  SET
+     remaining.val = 0
+    ,remaining.frac = 0
+  WHERE coin_pub=in_coin_pub;
+
+-- Get current balance
+SELECT current_balance
+  INTO reserve
+  FROM reserves
+ WHERE reserve_pub=in_reserve_pub;
+
+balance = reserve.current_balance;
+new_balance.frac=balance.frac+tmp.frac
+   - CASE
+     WHEN balance.frac+tmp.frac >= 100000000
+     THEN 100000000
+     ELSE 0
+     END;
+
+new_balance.val=balance.val+tmp.val
+   + CASE
+     WHEN balance.frac+tmp.frac >= 100000000
+     THEN 1
+     ELSE 0
+     END;
+
+-- Credit the reserve and update reserve timers.
+UPDATE reserves
+  SET
+    current_balance = new_balance,
+    gc_date=GREATEST(gc_date, in_reserve_gc),
+    expiration_date=GREATEST(expiration_date, in_reserve_expiration)
+  WHERE reserve_pub=in_reserve_pub;
+
+
+IF NOT FOUND
+THEN
+  RAISE NOTICE 'failed to increase reserve balance from recoup';
+  out_recoup_ok=TRUE;
+  out_internal_failure=TRUE;
+  RETURN;
+END IF;
+
+
+INSERT INTO exchange.recoup
+  (coin_pub
+  ,coin_sig
+  ,coin_blind
+  ,amount
+  ,recoup_timestamp
+  ,withdraw_id
+  )
+VALUES
+  (in_coin_pub
+  ,in_coin_sig
+  ,in_coin_blind
+  ,tmp
+  ,in_recoup_timestamp
+  ,in_withdraw_id);
+
+-- Normal end, everything is fine.
+out_recoup_ok=TRUE;
+out_recoup_timestamp=in_recoup_timestamp;
+
+END $$;
+
+-- COMMENT ON FUNCTION exchange_do_recoup_to_reserve(INT8, INT4, BYTEA, BOOLEAN, BOOLEAN)
+--  IS 'Executes a recoup of a coin that was withdrawn from a reserve';