Add Cache and Aggregator to MetricRouter (#21)

* Add Cache and Aggregator to MetricRouter

* Close done channel in MetricCache

internal/metricRouter/metricRouter.go

@@ -23,23 +23,28 @@ type metricRouterTagConfig struct {
 
 // Metric router configuration
 type metricRouterConfig struct {
-	AddTags       []metricRouterTagConfig `json:"add_tags"`           // List of tags that are added when the condition is met
-	DelTags       []metricRouterTagConfig `json:"delete_tags"`        // List of tags that are removed when the condition is met
-	IntervalStamp bool                    `json:"interval_timestamp"` // Update timestamp periodically by ticker each interval?
+	AddTags           []metricRouterTagConfig          `json:"add_tags"`            // List of tags that are added when the condition is met
+	DelTags           []metricRouterTagConfig          `json:"delete_tags"`         // List of tags that are removed when the condition is met
+	IntervalAgg       []metricAggregatorIntervalConfig `json:"interval_aggregates"` // List of aggregation function processed at the end of an interval
+	IntervalStamp     bool                             `json:"interval_timestamp"`  // Update timestamp periodically by ticker each interval?
+	NumCacheIntervals int                              `json:"num_cache_intervals"` // Number of intervals of cached metrics for evaluation
 }
 
 // Metric router data structure
 type metricRouter struct {
-	hostname   string              // Hostname used in tags
-	coll_input chan lp.CCMetric    // Input channel from CollectorManager
-	recv_input chan lp.CCMetric    // Input channel from ReceiveManager
-	outputs    []chan lp.CCMetric  // List of all output channels
-	done       chan bool           // channel to finish / stop metric router
-	wg         *sync.WaitGroup     // wait group for all goroutines in cc-metric-collector
-	timestamp  time.Time           // timestamp periodically updated by ticker each interval
-	timerdone  chan bool           // channel to finish / stop timestamp updater
-	ticker     mct.MultiChanTicker // periodically ticking once each interval
-	config     metricRouterConfig  // json encoded config for metric router
+	hostname    string              // Hostname used in tags
+	coll_input  chan lp.CCMetric    // Input channel from CollectorManager
+	recv_input  chan lp.CCMetric    // Input channel from ReceiveManager
+	cache_input chan lp.CCMetric    // Input channel from MetricCache
+	outputs     []chan lp.CCMetric  // List of all output channels
+	done        chan bool           // channel to finish / stop metric router
+	wg          *sync.WaitGroup     // wait group for all goroutines in cc-metric-collector
+	timestamp   time.Time           // timestamp periodically updated by ticker each interval
+	timerdone   chan bool           // channel to finish / stop timestamp updater
+	ticker      mct.MultiChanTicker // periodically ticking once each interval
+	config      metricRouterConfig  // json encoded config for metric router
+	cache       MetricCache         // pointer to MetricCache
+	cachewg     sync.WaitGroup      // wait group for MetricCache
 }
 
 // MetricRouter access functions
@@ -61,6 +66,7 @@ type MetricRouter interface {
 func (r *metricRouter) Init(ticker mct.MultiChanTicker, wg *sync.WaitGroup, routerConfigFile string) error {
 	r.outputs = make([]chan lp.CCMetric, 0)
 	r.done = make(chan bool)
+	r.cache_input = make(chan lp.CCMetric)
 	r.wg = wg
 	r.ticker = ticker
 
@@ -86,6 +92,18 @@ func (r *metricRouter) Init(ticker mct.MultiChanTicker, wg *sync.WaitGroup, rout
 		cclog.ComponentError("MetricRouter", err.Error())
 		return err
 	}
+	numIntervals := r.config.NumCacheIntervals
+	if numIntervals <= 0 {
+		numIntervals = 1
+	}
+	r.cache, err = NewCache(r.cache_input, r.ticker, &r.cachewg, numIntervals)
+	if err != nil {
+		cclog.ComponentError("MetricRouter", "MetricCache initialization failed:", err.Error())
+		return err
+	}
+	for _, agg := range r.config.IntervalAgg {
+		r.cache.AddAggregation(agg.Name, agg.Function, agg.Condition, agg.Tags, agg.Meta)
+	}
 	return nil
 }
 
@@ -211,6 +229,9 @@ func (r *metricRouter) Start() {
 		}
 	}
 
+	// Start Metric Cache
+	r.cache.Start()
+
 	r.wg.Add(1)
 	go func() {
 		defer r.wg.Done()
@@ -227,6 +248,7 @@ func (r *metricRouter) Start() {
 					p.SetTime(r.timestamp)
 				}
 				forward(p)
+				r.cache.Add(p)
 
 			case p := <-r.recv_input:
 				// receive from receive manager
@@ -234,6 +256,11 @@ func (r *metricRouter) Start() {
 					p.SetTime(r.timestamp)
 				}
 				forward(p)
+
+			case p := <-r.cache_input:
+				// receive from metric collector
+				p.AddTag("hostname", r.hostname)
+				forward(p)
 			}
 		}
 	}()
@@ -267,6 +294,8 @@ func (r *metricRouter) Close() {
 		// wait for close of channel r.timerdone
 		<-r.timerdone
 	}
+	r.cache.Close()
+	r.cachewg.Wait()
 }
 
 // New creates a new initialized metric router