Function TestChannelCacheCompactInactiveChannels

db/channel_cache_test.go:164–220

(t *testing.T)

}

func TestChannelCacheCompactInactiveChannels(t *testing.T) {

	base.SetUpTestLogging(t, base.LevelInfo, base.KeyCache)

	// Define cache with max channels 20, watermarks 50/90
	options := DefaultCacheOptions().ChannelCacheOptions
	options.MaxNumChannels = 20
	options.CompactHighWatermarkPercent = 90
	options.CompactLowWatermarkPercent = 50

	stats, err := base.NewSyncGatewayStats()
	require.NoError(t, err)
	dbstats, err := stats.NewDBStats("", false, false, false, nil, nil)
	require.NoError(t, err)
	testStats := dbstats.Cache()
	activeChannelStat := &base.SgwIntStat{}
	activeChannels := channels.NewActiveChannels(activeChannelStat)

	ctx := base.TestCtx(t)
	cache, err := newChannelCache(base.TestCtx(t), "testDb", options, testQueryHandlerFactory, activeChannels, testStats)
	require.NoError(t, err, "Background task error whilst creating channel cache")
	defer cache.Stop(ctx)

	// Add 16 channels to the cache.  Mark odd channels as active, even channels as inactive.
	// Shouldn't trigger compaction (hwm is not exceeded)
	for i := 1; i <= 18; i++ {
		channel := channels.NewID(fmt.Sprintf("chan_%d", i), base.DefaultCollectionID)
		cache.addChannelCache(ctx, channel)
		if i%2 == 1 {
			log.Printf("Marking channel %q as active", channel)
			activeChannels.IncrChannel(channel)
		}
	}
	// Validate cache size
	assert.Equal(t, 18, cache.channelCaches.Length())

	log.Printf("adding 19th element to cache...")
	// Add another channel to cache, should trigger compaction
	cache.addChannelCache(ctx, channels.NewID("chan_19", base.DefaultCollectionID))

	assert.True(t, waitForCompaction(cache), "Compaction didn't complete in expected time")

	// Validate cache size
	assert.Equal(t, 10, cache.channelCaches.Length())

	// Validate active channels have been retained in cache
	for i := 1; i <= 19; i++ {
		channel := channels.NewID(fmt.Sprintf("chan_%d", i), base.DefaultCollectionID)
		_, isCached := cache.channelCaches.Get(channel)
		if i%2 == 1 {
			assert.True(t, isCached, fmt.Sprintf("Channel %q was active, should be retained in cache", channel))
		} else {
			assert.False(t, isCached, fmt.Sprintf("Channel %q was inactive, should be evicted from cache", channel))
		}
	}

}