lowestPrecedenceStateShouldBeDropped() — netty Function Reference

Source Code

codec-http2/src/test/java/io/netty/handler/codec/http2/WeightedFairQueueByteDistributorDependencyTreeTest.java lines 271–314

    @Test
    public void lowestPrecedenceStateShouldBeDropped() throws Http2Exception {
        setup(3);

        short weight3 = MAX_WEIGHT;
        short weight5 = (short) (weight3 - 1);
        short weight7 = (short) (weight5 - 1);
        short weight9 = (short) (weight7 - 1);
        setPriority(3, connection.connectionStream().id(), weight3, true);
        setPriority(5, connection.connectionStream().id(), weight5, true);
        setPriority(7, connection.connectionStream().id(), weight7, false);
        assertEquals(0, connection.numActiveStreams());
        verifyLowestPrecedenceStateShouldBeDropped1(weight3, weight5, weight7);

        // Attempt to create a new item in the dependency tree but the maximum amount of "state only" streams is meet
        // so a stream will have to be dropped. Currently the new stream is the lowest "precedence" so it is dropped.
        setPriority(9, 3, weight9, false);
        assertEquals(0, connection.numActiveStreams());
        verifyLowestPrecedenceStateShouldBeDropped1(weight3, weight5, weight7);

        // Set the priority for stream 9 such that its depth in the dependency tree is numerically lower than stream 3,
        // and therefore the dependency state associated with stream 3 will be dropped.
        setPriority(9, 5, weight9, true);
        verifyLowestPrecedenceStateShouldBeDropped2(weight9, weight5, weight7);

        // Test that stream which has been activated is lower priority than other streams that have not been activated.
        Http2Stream streamA = connection.local().createStream(5, false);
        streamA.close();
        verifyLowestPrecedenceStateShouldBeDropped2(weight9, weight5, weight7);

        // Stream 3 (hasn't been opened) should result in stream 5 being dropped.
        // dropping stream 5 will distribute its weight to children (only 9)
        setPriority(3, 9, weight3, false);
        verifyLowestPrecedenceStateShouldBeDropped3(weight3, weight7, weight5);

        // Stream 5's state has been discarded so we should be able to re-insert this state.
        setPriority(5, 0, weight5, false);
        verifyLowestPrecedenceStateShouldBeDropped4(weight5, weight7, weight5);

        // All streams are at the same level, so stream ID should be used to drop the numeric lowest valued stream.
        short weight11 = (short) (weight9 - 1);
        setPriority(11, 0, weight11, false);
        verifyLowestPrecedenceStateShouldBeDropped5(weight7, weight5, weight11);
    }