refactor procedures.sql

1 files changed, 216 insertions, 0 deletions

diff --git a/src/exchangedb/exchange_do_purse_merge.sql b/src/exchangedb/exchange_do_purse_merge.sql
new file mode 100644
index 000000000..2e799c9f2
--- /dev/null
+++ b/src/exchangedb/exchange_do_purse_merge.sql
@@ -0,0 +1,216 @@
+--
+-- 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_purse_merge(
+  IN in_purse_pub BYTEA,
+  IN in_merge_sig BYTEA,
+  IN in_merge_timestamp INT8,
+  IN in_reserve_sig BYTEA,
+  IN in_partner_url VARCHAR,
+  IN in_reserve_pub BYTEA,
+  IN in_wallet_h_payto BYTEA,
+  IN in_expiration_date INT8,
+  OUT out_no_partner BOOLEAN,
+  OUT out_no_balance BOOLEAN,
+  OUT out_conflict BOOLEAN)
+LANGUAGE plpgsql
+AS $$
+DECLARE
+  my_amount_val INT8;
+DECLARE
+  my_amount_frac INT4;
+DECLARE
+  my_purse_fee_val INT8;
+DECLARE
+  my_purse_fee_frac INT4;
+DECLARE
+  my_partner_serial_id INT8;
+DECLARE
+  my_in_reserve_quota BOOLEAN;
+BEGIN
+
+IF in_partner_url IS NULL
+THEN
+  my_partner_serial_id=NULL;
+ELSE
+  SELECT
+    partner_serial_id
+  INTO
+    my_partner_serial_id
+  FROM exchange.partners
+  WHERE partner_base_url=in_partner_url
+    AND start_date <= in_merge_timestamp
+    AND end_date > in_merge_timestamp;
+  IF NOT FOUND
+  THEN
+    out_no_partner=TRUE;
+    out_conflict=FALSE;
+    RETURN;
+  END IF;
+END IF;
+
+out_no_partner=FALSE;
+
+
+-- Check purse is 'full'.
+SELECT amount_with_fee_val
+      ,amount_with_fee_frac
+      ,purse_fee_val
+      ,purse_fee_frac
+      ,in_reserve_quota
+  INTO my_amount_val
+      ,my_amount_frac
+      ,my_purse_fee_val
+      ,my_purse_fee_frac
+      ,my_in_reserve_quota
+  FROM exchange.purse_requests
+  WHERE purse_pub=in_purse_pub
+    AND balance_val >= amount_with_fee_val
+    AND ( (balance_frac >= amount_with_fee_frac) OR
+          (balance_val > amount_with_fee_val) );
+IF NOT FOUND
+THEN
+  out_no_balance=TRUE;
+  out_conflict=FALSE;
+  RETURN;
+END IF;
+out_no_balance=FALSE;
+
+-- Store purse merge signature, checks for purse_pub uniqueness
+INSERT INTO exchange.purse_merges
+    (partner_serial_id
+    ,reserve_pub
+    ,purse_pub
+    ,merge_sig
+    ,merge_timestamp)
+  VALUES
+    (my_partner_serial_id
+    ,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 exchange.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;
+     RETURN;
+  END IF;
+
+  -- "success"
+  out_conflict=FALSE;
+  RETURN;
+END IF;
+out_conflict=FALSE;
+
+
+-- Initialize reserve, if not yet exists.
+INSERT INTO reserves
+  (reserve_pub
+  ,expiration_date
+  ,gc_date)
+  VALUES
+  (in_reserve_pub
+  ,in_expiration_date
+  ,in_expiration_date)
+  ON CONFLICT DO NOTHING;
+
+-- Remember how this purse was finished.
+INSERT INTO purse_decision
+  (purse_pub
+  ,action_timestamp
+  ,refunded)
+VALUES
+  (in_purse_pub
+  ,in_merge_timestamp
+  ,FALSE);
+
+IF (my_in_reserve_quota)
+THEN
+  UPDATE reserves
+    SET purses_active=purses_active-1
+  WHERE reserve_pub IN
+    (SELECT reserve_pub
+       FROM exchange.purse_merges
+      WHERE purse_pub=my_purse_pub
+     LIMIT 1);
+END IF;
+
+-- Store account merge signature.
+INSERT INTO exchange.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);
+
+-- If we need a wad transfer, mark purse ready for it.
+IF (0 != my_partner_serial_id)
+THEN
+  -- The taler-exchange-router will take care of this.
+  UPDATE purse_actions
+     SET action_date=0 --- "immediately"
+        ,partner_serial_id=my_partner_serial_id
+   WHERE purse_pub=in_purse_pub;
+ELSE
+  -- This is a local reserve, update reserve balance immediately.
+
+  -- Refund the purse fee, by adding it to the purse value:
+  my_amount_val = my_amount_val + my_purse_fee_val;
+  my_amount_frac = my_amount_frac + my_purse_fee_frac;
+  -- normalize result
+  my_amount_val = my_amount_val + my_amount_frac / 100000000;
+  my_amount_frac = my_amount_frac % 100000000;
+
+  UPDATE exchange.reserves
+  SET
+    current_balance_frac=current_balance_frac+my_amount_frac
+       - CASE
+         WHEN current_balance_frac + my_amount_frac >= 100000000
+         THEN 100000000
+         ELSE 0
+         END,
+    current_balance_val=current_balance_val+my_amount_val
+       + CASE
+         WHEN current_balance_frac + my_amount_frac >= 100000000
+         THEN 1
+         ELSE 0
+         END
+  WHERE reserve_pub=in_reserve_pub;
+
+END IF;
+
+RETURN;
+
+END $$;
+
+COMMENT ON FUNCTION exchange_do_purse_merge(BYTEA, BYTEA, INT8, BYTEA, VARCHAR, BYTEA, BYTEA, INT8)
+  IS 'Checks that the partner exists, the purse has not been merged with a different reserve and that the purse is full. If so, persists the merge data and either merges the purse with the reserve or marks it as ready for the taler-exchange-router. Caller MUST abort the transaction on failures so as to not persist data by accident.';
+