From: Daira Hopwood Date: Mon, 28 Dec 2015 20:09:18 +0000 (+0000) Subject: Add support for ignore_count to HookMixin. X-Git-Url: https://git.rkrishnan.org/uri/frontends?a=commitdiff_plain;h=f32eb040b2ec1db91c4e2bbf6d1a86527604078b;p=tahoe-lafs%2Ftahoe-lafs.git Add support for ignore_count to HookMixin. Signed-off-by: Daira Hopwood --- diff --git a/src/allmydata/util/deferredutil.py b/src/allmydata/util/deferredutil.py index 989e85e8..dac399d7 100644 --- a/src/allmydata/util/deferredutil.py +++ b/src/allmydata/util/deferredutil.py @@ -5,6 +5,7 @@ from foolscap.api import eventually, fireEventually from twisted.internet import defer, reactor from allmydata.util import log +from allmydata.util.assertutil import _assert from allmydata.util.pollmixin import PollMixin @@ -77,28 +78,35 @@ class HookMixin: I am a helper mixin that maintains a collection of named hooks, primarily for use in tests. Each hook is set to an unfired Deferred using 'set_hook', and can then be fired exactly once at the appropriate time by '_call_hook'. + If 'ignore_count' is given, that number of calls to '_call_hook' will be + ignored before firing the hook. I assume a '_hooks' attribute that should set by the class constructor to a dict mapping each valid hook name to None. """ - def set_hook(self, name, d=None): + def set_hook(self, name, d=None, ignore_count=0): """ Called by the hook observer (e.g. by a test). If d is not given, an unfired Deferred is created and returned. The hook must not already be set. """ + self._log("set_hook %r, ignore_count=%r" % (name, ignore_count)) if d is None: d = defer.Deferred() - assert self._hooks[name] is None, self._hooks[name] - assert isinstance(d, defer.Deferred), d - self._hooks[name] = d + _assert(ignore_count >= 0, ignore_count=ignore_count) + _assert(name in self._hooks, name=name) + _assert(self._hooks[name] is None, name=name, hook=self._hooks[name]) + _assert(isinstance(d, defer.Deferred), d=d) + + self._hooks[name] = (d, ignore_count) return d def _call_hook(self, res, name): """ - Called to trigger the hook, with argument 'res'. This is a no-op if the - hook is unset. Otherwise, the hook will be unset, and then its Deferred - will be fired synchronously. + Called to trigger the hook, with argument 'res'. This is a no-op if + the hook is unset. If the hook's ignore_count is positive, it will be + decremented; if it was already zero, the hook will be unset, and then + its Deferred will be fired synchronously. The expected usage is "deferred.addBoth(self._call_hook, 'hookname')". This ensures that if 'res' is a failure, the hook will be errbacked, @@ -106,13 +114,22 @@ class HookMixin: 'res' is returned so that the current result or failure will be passed through. """ - d = self._hooks[name] - if d is None: - return defer.succeed(None) - self._hooks[name] = None - _with_log(d.callback, res) + hook = self._hooks[name] + if hook is None: + return None + + (d, ignore_count) = hook + self._log("call_hook %r, ignore_count=%r" % (name, ignore_count)) + if ignore_count > 0: + self._hooks[name] = (d, ignore_count - 1) + else: + self._hooks[name] = None + _with_log(d.callback, res) return res + def _log(self, msg): + log.msg(msg, level=log.NOISY) + def async_iterate(process, iterable, *extra_args, **kwargs): """