def __do_fetch()

in src/buildstream/source.py [0:0]

• 43 lines of code
• 10 McCabe index (conditional complexity)

    def __do_fetch(self, **kwargs):
        project = self._get_project()
        context = self._get_context()

        # Silence the STATUS messages which might happen as a result
        # of checking the source fetchers.
        with context.messenger.silence():
            source_fetchers = self.get_source_fetchers()

        # Use the source fetchers if they are provided
        #
        if source_fetchers:

            # Use a contorted loop here, this is to allow us to
            # silence the messages which can result from consuming
            # the items of source_fetchers, if it happens to be a generator.
            #
            source_fetchers = iter(source_fetchers)

            while True:

                with context.messenger.silence():
                    try:
                        fetcher = next(source_fetchers)
                    except StopIteration:
                        # as per PEP479, we are not allowed to let StopIteration
                        # thrown from a context manager.
                        # Catching it here and breaking instead.
                        break

                alias = fetcher._get_alias()
                last_error = None
                for mirror in project.get_alias_uris(alias, first_pass=self.__first_pass, tracking=False):
                    try:
                        fetcher.fetch(mirror)
                    # FIXME: Need to consider temporary vs. permanent failures,
                    #        and how this works with retries.
                    except BstError as e:
                        last_error = e
                        continue

                    # No error, we're done with this fetcher
                    break

                else:
                    # No break occurred, raise the last detected error
                    raise last_error

        # Default codepath is to reinstantiate the Source
        #
        else:
            alias = self._get_alias()
            if self.__first_pass:
                mirrors = project.first_pass_config.mirrors
            else:
                mirrors = project.config.mirrors
            if not mirrors or not alias:
                self.fetch(**kwargs)
                return

            last_error = None
            for mirror in project.get_alias_uris(alias, first_pass=self.__first_pass, tracking=False):

                new_source = self.__clone_for_uri(mirror)
                try:
                    new_source.fetch(**kwargs)
                # FIXME: Need to consider temporary vs. permanent failures,
                #        and how this works with retries.
                except BstError as e:
                    last_error = e
                    continue

                # No error, we're done here
                return

            # Re raise the last detected error
            raise last_error