From 5100ae50a238e297901c67446cd47c2986c04676 Mon Sep 17 00:00:00 2001
From: Jean-Paul Calderone <exarkun@twistedmatrix.com>
Date: Wed, 29 Apr 2020 15:32:38 -0400
Subject: [PATCH] Stop iterating on a voucher redemption if one of the
iterations fails
---
src/_zkapauthorizer/controller.py | 92 ++++++++++++++++++-------------
1 file changed, 53 insertions(+), 39 deletions(-)
diff --git a/src/_zkapauthorizer/controller.py b/src/_zkapauthorizer/controller.py
index 6cc8f02..f40ffef 100644
--- a/src/_zkapauthorizer/controller.py
+++ b/src/_zkapauthorizer/controller.py
@@ -766,41 +766,6 @@ class PaymentController(object):
voucher=voucher.number,
)
- def _perform_redeem(self, voucher, counter, random_tokens):
- """
- Use the redeemer to redeem the given voucher and random tokens.
-
- This will not persist the voucher or random tokens but it will persist
- the result.
- """
- if not isinstance(voucher.state, model_Pending):
- raise ValueError(
- "Cannot redeem voucher in state {} instead of Pending.".format(
- voucher.state,
- ),
- )
-
- # Ask the redeemer to do the real task of redemption.
- self._log.info("Redeeming random tokens for a voucher ({voucher}).", voucher=voucher)
- d = bracket(
- lambda: setitem(
- self._active,
- voucher.number,
- model_Redeeming(
- started=self.store.now(),
- counter=voucher.state.counter,
- ),
- ),
- lambda: delitem(self._active, voucher.number),
- lambda: self.redeemer.redeemWithCounter(voucher, counter, random_tokens),
- )
- d.addCallbacks(
- partial(self._redeem_success, voucher.number, counter),
- partial(self._redeem_failure, voucher.number),
- )
- d.addErrback(partial(self._final_redeem_error, voucher.number))
- return d
-
def _get_random_tokens_for_voucher(self, voucher, counter, num_tokens):
"""
Generate or load random tokens for a redemption attempt of a voucher.
@@ -871,7 +836,51 @@ class PaymentController(object):
# An earlier iteration may have encountered a fatal error.
break
- yield self._perform_redeem(voucher_obj, counter, tokens)
+ succeeded = yield self._perform_redeem(voucher_obj, counter, tokens)
+ if not succeeded:
+ self._log.info(
+ "Temporarily suspending redemption of {voucher} after non-success result.",
+ voucher=voucher,
+ )
+ break
+
+ def _perform_redeem(self, voucher, counter, random_tokens):
+ """
+ Use the redeemer to redeem the given voucher and random tokens.
+
+ This will not persist the voucher or random tokens but it will persist
+ the result.
+
+ :return Deferred[bool]: A ``Deferred`` firing with ``True`` if and
+ only if redemption succeeds.
+ """
+ if not isinstance(voucher.state, model_Pending):
+ raise ValueError(
+ "Cannot redeem voucher in state {} instead of Pending.".format(
+ voucher.state,
+ ),
+ )
+
+ # Ask the redeemer to do the real task of redemption.
+ self._log.info("Redeeming random tokens for a voucher ({voucher}).", voucher=voucher)
+ d = bracket(
+ lambda: setitem(
+ self._active,
+ voucher.number,
+ model_Redeeming(
+ started=self.store.now(),
+ counter=voucher.state.counter,
+ ),
+ ),
+ lambda: delitem(self._active, voucher.number),
+ lambda: self.redeemer.redeemWithCounter(voucher, counter, random_tokens),
+ )
+ d.addCallbacks(
+ partial(self._redeem_success, voucher.number, counter),
+ partial(self._redeem_failure, voucher.number),
+ )
+ d.addErrback(partial(self._final_redeem_error, voucher.number))
+ return d
def _redeem_success(self, voucher, counter, result):
"""
@@ -889,6 +898,7 @@ class PaymentController(object):
result.unblinded_tokens,
completed=(counter + 1 == self.num_redemption_groups),
)
+ return True
def _redeem_failure(self, voucher, reason):
if reason.check(AlreadySpent):
@@ -913,11 +923,15 @@ class PaymentController(object):
finished=self.store.now(),
details=reason.getErrorMessage().decode("utf-8", "replace"),
)
- return None
+ return False
def _final_redeem_error(self, voucher, reason):
- self._log.failure("Redeeming random tokens for a voucher ({voucher}) encountered error.", reason, voucher=voucher)
- return None
+ self._log.failure(
+ "Redeeming random tokens for a voucher ({voucher}) encountered error.",
+ reason,
+ voucher=voucher,
+ )
+ return False
def get_voucher(self, number):
return self.incorporate_transient_state(
--
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