cp sql/ from GNU Taler exchange

include/sql/exchange_do_reserve_purse.sql

@@ -0,0 +1,162 @@
+--
+-- 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/>
+--
+
+CREATE OR REPLACE FUNCTION exchange_do_reserve_purse(
+  IN in_purse_pub BYTEA,
+  IN in_merge_sig BYTEA,
+  IN in_merge_timestamp INT8,
+  IN in_reserve_expiration INT8,
+  IN in_reserve_gc INT8,
+  IN in_reserve_sig BYTEA,
+  IN in_reserve_quota BOOLEAN,
+  IN in_purse_fee taler_amount,
+  IN in_reserve_pub BYTEA,
+  IN in_wallet_h_payto BYTEA,
+  OUT out_no_funds BOOLEAN,
+  OUT out_no_reserve BOOLEAN,
+  OUT out_conflict BOOLEAN)
+LANGUAGE plpgsql
+AS $$
+BEGIN
+
+-- Store purse merge signature, checks for purse_pub uniqueness
+INSERT INTO purse_merges
+    (partner_serial_id
+    ,reserve_pub
+    ,purse_pub
+    ,merge_sig
+    ,merge_timestamp)
+  VALUES
+    (NULL
+    ,in_reserve_pub
+    ,in_purse_pub
+    ,in_merge_sig
+    ,in_merge_timestamp)
+  ON CONFLICT DO NOTHING;
+
+IF NOT FOUND
+THEN
+  -- Idempotency check: see if an identical record exists.
+  -- Note that by checking 'merge_sig', we implicitly check
+  -- identity over everything that the signature covers.
+  PERFORM
+  FROM purse_merges
+  WHERE purse_pub=in_purse_pub
+     AND merge_sig=in_merge_sig;
+  IF NOT FOUND
+  THEN
+     -- Purse was merged, but to some other reserve. Not allowed.
+     out_conflict=TRUE;
+     out_no_reserve=FALSE;
+     out_no_funds=FALSE;
+     RETURN;
+  END IF;
+
+  -- "success"
+  out_conflict=FALSE;
+  out_no_funds=FALSE;
+  out_no_reserve=FALSE;
+  RETURN;
+END IF;
+out_conflict=FALSE;
+
+PERFORM
+  FROM exchange.reserves
+ WHERE reserve_pub=in_reserve_pub;
+
+out_no_reserve = NOT FOUND;
+
+IF (in_reserve_quota)
+THEN
+  -- Increment active purses per reserve (and check this is allowed)
+  IF (out_no_reserve)
+  THEN
+    out_no_funds=TRUE;
+    RETURN;
+  END IF;
+  UPDATE exchange.reserves
+     SET purses_active=purses_active+1
+   WHERE reserve_pub=in_reserve_pub
+     AND purses_active < purses_allowed;
+  IF NOT FOUND
+  THEN
+    out_no_funds=TRUE;
+    RETURN;
+  END IF;
+ELSE
+  --  UPDATE reserves balance (and check if balance is enough to pay the fee)
+  IF (out_no_reserve)
+  THEN
+    IF ( (0 != in_purse_fee.val) OR
+         (0 != in_purse_fee.frac) )
+    THEN
+      out_no_funds=TRUE;
+      RETURN;
+    END IF;
+    INSERT INTO exchange.reserves
+      (reserve_pub
+      ,expiration_date
+      ,gc_date)
+    VALUES
+      (in_reserve_pub
+      ,in_reserve_expiration
+      ,in_reserve_gc);
+  ELSE
+    UPDATE exchange.reserves
+      SET
+        current_balance.frac=(current_balance).frac-in_purse_fee.frac
+         + CASE
+         WHEN (current_balance).frac < in_purse_fee.frac
+         THEN 100000000
+         ELSE 0
+         END,
+       current_balance.val=(current_balance).val-in_purse_fee.val
+         - CASE
+         WHEN (current_balance).frac < in_purse_fee.frac
+         THEN 1
+         ELSE 0
+         END
+      WHERE reserve_pub=in_reserve_pub
+        AND ( ((current_balance).val > in_purse_fee.val) OR
+              ( ((current_balance).frac >= in_purse_fee.frac) AND
+                ((current_balance).val >= in_purse_fee.val) ) );
+    IF NOT FOUND
+    THEN
+      out_no_funds=TRUE;
+      RETURN;
+    END IF;
+  END IF;
+END IF;
+
+out_no_funds=FALSE;
+
+
+-- Store account merge signature.
+INSERT INTO account_merges
+  (reserve_pub
+  ,reserve_sig
+  ,purse_pub
+  ,wallet_h_payto)
+  VALUES
+  (in_reserve_pub
+  ,in_reserve_sig
+  ,in_purse_pub
+  ,in_wallet_h_payto);
+
+END $$;
+
+COMMENT ON FUNCTION exchange_do_reserve_purse(BYTEA, BYTEA, INT8, INT8, INT8, BYTEA, BOOLEAN, taler_amount, BYTEA, BYTEA)
+  IS 'Create a purse for a reserve.';