cp sql/ from GNU Taler exchange

include/sql/exchange_do_recoup_to_coin.sql

@@ -0,0 +1,133 @@
+--
+-- 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/>
+--
+
+DROP FUNCTION IF EXISTS exchange_do_recoup_to_coin;
+CREATE FUNCTION exchange_do_recoup_to_coin(
+  IN in_old_coin_pub BYTEA,
+  IN in_refresh_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_recoup_timestamp INT8,
+  OUT out_recoup_ok BOOLEAN,
+  OUT out_internal_failure BOOLEAN,
+  OUT out_recoup_timestamp INT8)
+LANGUAGE plpgsql
+AS $$
+DECLARE
+  rval RECORD;
+DECLARE
+  tmp taler_amount; -- amount recouped
+BEGIN
+
+-- Shards: UPDATE known_coins (by coin_pub)
+--         SELECT recoup_refresh (by coin_pub)
+--         UPDATE known_coins (by coin_pub)
+--         INSERT recoup_refresh (by coin_pub)
+
+out_internal_failure=FALSE;
+
+-- Check remaining balance of the coin.
+SELECT
+   remaining
+ INTO
+   rval
+FROM exchange.known_coins
+  WHERE coin_pub=in_coin_pub;
+
+IF NOT FOUND
+THEN
+  out_internal_failure=TRUE;
+  out_recoup_ok=FALSE;
+  RETURN;
+END IF;
+
+tmp := rval.remaining;
+
+IF tmp.val + tmp.frac = 0
+THEN
+  -- Check for idempotency
+  SELECT
+      recoup_timestamp
+    INTO
+      out_recoup_timestamp
+    FROM recoup_refresh
+    WHERE coin_pub=in_coin_pub;
+  out_recoup_ok=FOUND;
+  RETURN;
+END IF;
+
+-- Update balance of the coin.
+UPDATE known_coins
+  SET
+     remaining.val = 0
+    ,remaining.frac = 0
+  WHERE coin_pub=in_coin_pub;
+
+-- Credit the old coin.
+UPDATE known_coins kc
+  SET
+    remaining.frac=(kc.remaining).frac+tmp.frac
+       - CASE
+         WHEN (kc.remaining).frac+tmp.frac >= 100000000
+         THEN 100000000
+         ELSE 0
+         END,
+    remaining.val=(kc.remaining).val+tmp.val
+       + CASE
+         WHEN (kc.remaining).frac+tmp.frac >= 100000000
+         THEN 1
+         ELSE 0
+         END
+  WHERE coin_pub=in_old_coin_pub;
+
+IF NOT FOUND
+THEN
+  RAISE NOTICE 'failed to increase old coin balance from recoup';
+  out_recoup_ok=TRUE;
+  out_internal_failure=TRUE;
+  RETURN;
+END IF;
+
+
+INSERT INTO recoup_refresh
+  (coin_pub
+  ,known_coin_id
+  ,coin_sig
+  ,coin_blind
+  ,amount
+  ,recoup_timestamp
+  ,refresh_id
+  )
+VALUES
+  (in_coin_pub
+  ,in_known_coin_id
+  ,in_coin_sig
+  ,in_coin_blind
+  ,tmp
+  ,in_recoup_timestamp
+  ,in_refresh_id);
+
+-- Normal end, everything is fine.
+out_recoup_ok=TRUE;
+out_recoup_timestamp=in_recoup_timestamp;
+
+END $$;
+
+
+-- COMMENT ON FUNCTION exchange_do_recoup_to_coin(INT8, INT4, BYTEA, BOOLEAN, BOOLEAN)
+--  IS 'Executes a recoup-refresh of a coin that was obtained from a refresh-reveal process';