# -*- mode: python; coding: utf-8 -*- # :Progetto: vcpx -- Updatable VC working directory # :Creato: mer 09 giu 2004 13:55:35 CEST # :Autore: Lele Gaifax # :Licenza: GNU General Public License # """ Updatable sources are the simplest abstract wrappers around a working directory under some kind of version control system. """ __docformat__ = 'reStructuredText' from vcpx import TailorBug, TailorException from vcpx.workdir import WorkingDir CONFLICTS_PROMPT = """ The changeset %s caused conflicts on the following files: * %s This is quite unusual, and most probably it means someone else has changed the working dir, beyond tailor control, or maybe a tailor bug is showing up. Either abort the session with Ctrl-C, or manually correct the situation with a Ctrl-Z, explore and correct, and coming back from the shell with 'fg'. What would you like to do? """ class GetUpstreamChangesetsFailure(TailorException): "Failure getting upstream changes" class ChangesetApplicationFailure(TailorException): "Failure applying upstream changes" class InvocationError(TailorException): "Bad invocation, use --help for details" class UpdatableSourceWorkingDir(WorkingDir): """ This is an abstract working dir able to follow an upstream source of ``changesets``. It has three main functionalities: getPendingChangesets to query the upstream server about new changesets applyPendingChangesets to apply them to the working directory checkoutUpstreamRevision to extract a new copy of the sources, actually initializing the mechanism. Subclasses MUST override at least the _underscoredMethods. """ def applyPendingChangesets(self, applyable=None, replayable=None, replay=None, applied=None): """ Apply the collected upstream changes. Loop over the collected changesets, doing whatever is needed to apply each one to the working dir and if the changes do not raise conflicts call the `replay` function to mirror the changes on the target. Return a tuple of two elements: - the last applied changeset, if any - the sequence (potentially empty!) of conflicts. """ from time import sleep c = None last = None conflicts = [] try: i = 0 for c in self.state_file: i += 1 self.log.info('Changeset #%d', i) # Give the opportunity to subclasses to stop the application # of the queue, before the application of the patch by the # source backend. if not self._willApplyChangeset(c, applyable): self.log.debug('Stopping application at revision %r', c.revision) break # Sometime is better to wait a little while before each # changeset, to avoid upstream server stress. if self.repository.delay_before_apply: sleep(self.repository.delay_before_apply) try: res = self._applyChangeset(c) except ChangesetApplicationFailure, e: self.log.critical("Couldn't apply changeset") self.log.debug("Reason: %s", str(e)) self.log.debug("Changeset: %s", c) raise except KeyboardInterrupt: self.log.warning("INTERRUPTED BY THE USER!") break except: self.log.exception("Couldn't apply changeset\n%s", c) raise if res: # We have a conflict. Give the user a chance of fixing # the situation, or abort with Ctrl-C, or whatever the # subclasses decide. try: self._handleConflict(c, conflicts, res) except KeyboardInterrupt: self.log.warning("INTERRUPTED BY THE USER!") break # Give the opportunity to subclasses to skip the commit on # the target backend. if self._didApplyChangeset(c, replayable): if replay: try: replay(c) except ChangesetApplicationFailure, e: self.log.critical("Couldn't replay changeset") self.log.debug("Reason: %s", str(e)) self.log.debug("Changeset: %s", c) raise except: self.log.exception("Couldn't replay changeset\n%s", c) raise # Remember it for the finally clause and notify the state # file so that it gets removed from the queue last = c self.state_file.applied() # Another hook (last==c here) if applied: applied(last) finally: # For whatever reason we exit the loop, save the last state self.state_file.finalize() return last, conflicts def _willApplyChangeset(self, changeset, applyable=None): """ This gets called just before applying each changeset. The whole process will be stopped if this returns False. Subclasses may use this to stop the process on some conditions, or to do whatever before application. """ if applyable: return applyable(changeset) else: return True def _didApplyChangeset(self, changeset, replayable=None): """ This gets called right after changeset application. The final commit on the target system won't be carried out if this returns False. Subclasses may use this to alter the changeset in any way, before committing its changes to the target system. """ if replayable: return replayable(changeset) else: return True def _handleConflict(self, changeset, conflicts, conflict): """ Handle the conflict raised by the application of the upstream changeset. This implementation just append a (changeset, conflict) to the list of all conflicts, and present a prompt to the user that may abort with Ctrl-C (that in turn generates a KeyboardInterrupt). """ conflicts.append((changeset, conflict)) raw_input(CONFLICTS_PROMPT % (str(changeset), '\n * '.join(conflict))) def getPendingChangesets(self, sincerev=None): """ Load the pending changesets from the state file, or query the upstream repository if there's none. Return an iterator over pending changesets. """ if not self.state_file.pending(): last = self.state_file.lastAppliedChangeset() if last: revision = last.revision else: revision = sincerev changesets = self._getUpstreamChangesets(revision) self.state_file.setPendingChangesets(changesets) return self.state_file def _getUpstreamChangesets(self, sincerev): """ Query the upstream repository about what happened on the sources since last sync, returning a sequence of Changesets instances. This method must be overridden by subclasses. """ raise TailorBug("%s should override this method!" % self.__class__) def _applyChangeset(self, changeset): """ Do the actual work of applying the changeset to the working copy. Subclasses should reimplement this method performing the necessary steps to *merge* given `changeset`, returning a list with the conflicts, if any. """ raise TailorBug("%s should override this method!" % self.__class__) def checkoutUpstreamRevision(self, revision): """ Extract a working copy of the given revision from a repository. Return the last applied changeset. """ last = self._checkoutUpstreamRevision(revision) # Notify the state file about latest applied changeset self.state_file.applied(last) self.state_file.finalize() return last def _checkoutUpstreamRevision(self, revision): """ Concretely do the checkout of the upstream revision. """ raise TailorBug("%s should override this method!" % self.__class__) def prepareSourceRepository(self): """ Do whatever is needed to setup or connect to the source repository. """ self._prepareSourceRepository() def _prepareSourceRepository(self): """ Possibly connect to the source repository, when overriden by subclasses. """