cp sql/ from GNU Taler exchange

include/sql/exchange_do_set_aml_lock.sql

@@ -0,0 +1,46 @@
+--
+-- This file is part of TALER
+-- Copyright (C) 2024 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_set_aml_lock;
+CREATE FUNCTION exchange_do_set_aml_lock (
+  IN in_h_payto BYTEA,
+  IN in_now INT8,
+  IN in_expiration INT8,
+  OUT out_aml_program_lock_timeout INT8) -- set if we have an existing lock
+LANGUAGE plpgsql
+AS $$
+BEGIN
+
+UPDATE kyc_targets
+   SET aml_program_lock_timeout=in_expiration
+ WHERE h_normalized_payto=in_h_payto
+   AND ( (aml_program_lock_timeout IS NULL)
+      OR (aml_program_lock_timeout < in_now) );
+IF NOT FOUND
+THEN
+  SELECT aml_program_lock_timeout
+    INTO out_aml_program_lock_timeout
+    FROM kyc_targets
+   WHERE h_normalized_payto=in_h_payto;
+ELSE
+  out_aml_program_lock_timeout = 0;
+END IF;
+
+END $$;
+
+
+COMMENT ON FUNCTION exchange_do_set_aml_lock(BYTEA, INT8, INT8)
+  IS 'Tries to lock an account for running an AML program. Returns the timeout of the existing lock, 0 if there is no existing lock, and NULL if we do not know the account.';