def __init__(self, graph: SyncedGraph, lib: EffectFunctionLibrary):

        self.graph = graph

        self.lib = lib

        self.faders: List[Fader] = []

        self.graph.addHandler(self._compile)

        self.lastLoopSucceeded = False

    @COMPILE.time()

    def _compile(self) -> None:

        """rebuild our data from the graph"""

        self.faders = []

        for fader in self.graph.subjects(RDF.type, L9['Fader']):

            try:

                self.faders.append(self._compileFader(fader))

            except ValueError:

                pass

        # this could go in a second, smaller addHandler call to avoid rebuilding Fader objs constantly

        for f in self.faders:

            try:

                setting = typedValue(Node, self.graph, f.uri, L9['setting'])

            except ValueError:

                f.value = None

            else:

                f.value = typedValue(float, self.graph, setting, L9['value'])

    def _compileFader(self, fader: URIRef) -> Fader:

        effect = typedValue(EffectUri, self.graph, fader, L9['effect'])

        setting = typedValue(Node, self.graph, fader, L9['setting'])

        setAttr = typedValue(EffectAttr, self.graph, setting, L9['effectAttr'])

        return (Fader(self.graph, self.lib, cast(URIRef, fader), effect, setAttr))

    @COMPUTE_ALL_FADERS.time()

    def computeOutput(self) -> DeviceSettings:

        faderEffectOutputs: List[DeviceSettings] = []

        now = UnixTime(time.time())

        for f in self.faders:

            try:

                if f.value is None:

                    log.warning(f'{f.value=}; should be set during _compile. Skipping {f.uri}')

                    continue

                effectSettings = EffectSettings(self.graph, [(f.effect, f.setEffectAttr, f.value)])

                ds = f.ee.compute(now, effectSettings)

                faderEffectOutputs.append(ds)

            except Exception:

                log.warning(f'on fader {f}')

        merged = DeviceSettings.merge(self.graph, faderEffectOutputs)

        # please remove (after fixing stats display to show it)

        log.debug("computed %s faders in %.1fms", len(self.faders), (time.time()-now)*1000)

        return merged