Cleanups and adds performance regression.

main.go

@@ -99,7 +99,7 @@ func main() {
 
 	go func() {
 		ticker := time.Tick(time.Second)
-		for i := 0; i < 5; i++ {
+		for i := 0; i < 120; i++ {
 			<-ticker
 			if i%10 == 0 {
 				fmt.Printf(".")
@@ -109,7 +109,7 @@ func main() {
 		//f := model.NewFingerprintFromRowKey("9776005627788788740-g-131-0")
 		f := model.NewFingerprintFromRowKey("09923616460706181007-g-131-0")
 		v := metric.NewViewRequestBuilder()
-		v.GetMetricAtTime(f, time.Now().Add(-30*time.Second))
+		v.GetMetricAtTime(f, time.Now().Add(-120*time.Second))
 
 		view, err := ts.MakeView(v, time.Minute)
 		fmt.Println(view, err)

storage/metric/leveldb.go

@@ -28,6 +28,7 @@ import (
 	"io"
 	"log"
 	"sort"
+	"sync"
 	"time"
 )
 
@@ -223,25 +224,25 @@ func (l *LevelDBMetricPersistence) AppendSamples(samples model.Samples) (err err
 	}
 
 	// Begin the sorting of grouped samples.
-
-	sortingSemaphore := make(chan bool, sortConcurrency)
-	doneSorting := make(chan bool, len(fingerprintToSamples))
+	var (
+		sortingSemaphore = make(chan bool, sortConcurrency)
+		doneSorting      = sync.WaitGroup{}
+	)
 	for i := 0; i < sortConcurrency; i++ {
 		sortingSemaphore <- true
 	}
 
 	for _, samples := range fingerprintToSamples {
+		doneSorting.Add(1)
 		go func(samples model.Samples) {
 			<-sortingSemaphore
 			sort.Sort(samples)
 			sortingSemaphore <- true
-			doneSorting <- true
+			doneSorting.Done()
 		}(samples)
 	}
 
-	for i := 0; i < len(fingerprintToSamples); i++ {
-		<-doneSorting
-	}
+	doneSorting.Wait()
 
 	var (
 		absentFingerprints = map[model.Fingerprint]model.Samples{}

storage/metric/operation.go

@@ -101,7 +101,7 @@ func (s getMetricRangeOperations) Swap(i, j int) {
 	s[i], s[j] = s[j], s[i]
 }
 
-// Sorts getMetricRangeOperation according duration in descending order.
+// Sorts getMetricRangeOperation according to duration in descending order.
 type rangeDurationSorter struct {
 	getMetricRangeOperations
 }
@@ -176,15 +176,13 @@ func collectIntervals(ops ops) (intervals map[time.Duration]getValuesAtIntervalO
 	intervals = make(map[time.Duration]getValuesAtIntervalOps)
 
 	for _, operation := range ops {
-		intervalOp, ok := operation.(getValuesAtIntervalOp)
-		if !ok {
-			continue
+		switch t := operation.(type) {
+		case getValuesAtIntervalOp:
+			operations, _ := intervals[t.interval]
+
+			operations = append(operations, t)
+			intervals[t.interval] = operations
 		}
-
-		operations, _ := intervals[intervalOp.interval]
-
-		operations = append(operations, intervalOp)
-		intervals[intervalOp.interval] = operations
 	}
 
 	for _, operations := range intervals {
@@ -197,9 +195,9 @@ func collectIntervals(ops ops) (intervals map[time.Duration]getValuesAtIntervalO
 // Selects and returns all operations that are getValuesAlongRangeOp operations.
 func collectRanges(ops ops) (ranges getMetricRangeOperations) {
 	for _, operation := range ops {
-		op, ok := operation.(getValuesAlongRangeOp)
-		if ok {
-			ranges = append(ranges, op)
+		switch t := operation.(type) {
+		case getValuesAlongRangeOp:
+			ranges = append(ranges, t)
 		}
 	}
 
@@ -208,6 +206,11 @@ func collectRanges(ops ops) (ranges getMetricRangeOperations) {
 	return
 }
 
+// optimizeForward iteratively scans operations and peeks ahead to subsequent
+// ones to find candidates that can either be removed or truncated through
+// simplification.  For instance, if a range query happens to overlap a get-a-
+// value-at-a-certain-point-request, the range query should flatten and subsume
+// the other.
 func optimizeForward(pending ops) (out ops) {
 	if len(pending) == 0 {
 		return
@@ -219,79 +222,75 @@ func optimizeForward(pending ops) (out ops) {
 
 	pending = pending[1:len(pending)]
 
-	if _, ok := firstOperation.(getValuesAtTimeOp); ok {
+	switch t := firstOperation.(type) {
+	case getValuesAtTimeOp:
 		out = ops{firstOperation}
 		tail := optimizeForward(pending)
 
 		return append(out, tail...)
-	}
 
-	// If the last value was a scan at a given frequency along an interval,
-	// several optimizations may exist.
-	if operation, ok := firstOperation.(getValuesAtIntervalOp); ok {
+	case getValuesAtIntervalOp:
+		// If the last value was a scan at a given frequency along an interval,
+		// several optimizations may exist.
 		for _, peekOperation := range pending {
-			if peekOperation.StartsAt().After(operation.Through()) {
+			if peekOperation.StartsAt().After(t.Through()) {
 				break
 			}
 
 			// If the type is not a range request, we can't do anything.
-			rangeOperation, ok := peekOperation.(getValuesAlongRangeOp)
-			if !ok {
-				continue
-			}
+			switch next := peekOperation.(type) {
+			case getValuesAlongRangeOp:
+				if !next.Through().After(t.Through()) {
+					var (
+						before = getValuesAtIntervalOp(t)
+						after  = getValuesAtIntervalOp(t)
+					)
 
-			if !rangeOperation.Through().After(operation.Through()) {
-				var (
-					before = getValuesAtIntervalOp(operation)
-					after  = getValuesAtIntervalOp(operation)
-				)
+					before.through = next.from
 
-				before.through = rangeOperation.from
+					// Truncate the get value at interval request if a range request cuts
+					// it off somewhere.
+					var (
+						from = next.from
+					)
 
-				// Truncate the get value at interval request if a range request cuts
-				// it off somewhere.
-				var (
-					t = rangeOperation.from
-				)
+					for {
+						from = from.Add(t.interval)
 
-				for {
-					t = t.Add(operation.interval)
-
-					if t.After(rangeOperation.through) {
-						after.from = t
-						break
+						if from.After(next.through) {
+							after.from = from
+							break
+						}
 					}
+
+					pending = append(ops{before, after}, pending...)
+					sort.Sort(pending)
+
+					return optimizeForward(pending)
 				}
-
-				pending = append(ops{before, after}, pending...)
-				sort.Sort(pending)
-
-				return optimizeForward(pending)
 			}
 		}
-	}
 
-	if operation, ok := firstOperation.(getValuesAlongRangeOp); ok {
+	case getValuesAlongRangeOp:
 		for _, peekOperation := range pending {
-			if peekOperation.StartsAt().After(operation.Through()) {
+			if peekOperation.StartsAt().After(t.Through()) {
 				break
 			}
 
+			switch next := peekOperation.(type) {
 			// All values at a specific time may be elided into the range query.
-			if _, ok := peekOperation.(getValuesAtTimeOp); ok {
+			case getValuesAtTimeOp:
 				pending = pending[1:len(pending)]
 				continue
-			}
-
-			// Range queries should be concatenated if they overlap.
-			if rangeOperation, ok := peekOperation.(getValuesAlongRangeOp); ok {
+			case getValuesAlongRangeOp:
+				// Range queries should be concatenated if they overlap.
 				pending = pending[1:len(pending)]
 
-				if rangeOperation.Through().After(operation.Through()) {
-					operation.through = rangeOperation.through
+				if next.Through().After(t.Through()) {
+					t.through = next.through
 
 					var (
-						head = ops{operation}
+						head = ops{t}
 						tail = pending
 					)
 
@@ -299,22 +298,20 @@ func optimizeForward(pending ops) (out ops) {
 
 					return optimizeForward(pending)
 				}
-			}
-
-			if intervalOperation, ok := peekOperation.(getValuesAtIntervalOp); ok {
+			case getValuesAtIntervalOp:
 				pending = pending[1:len(pending)]
 
-				if intervalOperation.through.After(operation.Through()) {
+				if next.through.After(t.Through()) {
 					var (
-						t = intervalOperation.from
+						t = next.from
 					)
 					for {
-						t = t.Add(intervalOperation.interval)
+						t = t.Add(next.interval)
 
-						if t.After(intervalOperation.through) {
-							intervalOperation.from = t
+						if t.After(next.through) {
+							next.from = t
 
-							pending = append(ops{intervalOperation}, pending...)
+							pending = append(ops{next}, pending...)
 
 							return optimizeForward(pending)
 						}
@@ -322,6 +319,7 @@ func optimizeForward(pending ops) (out ops) {
 				}
 			}
 		}
+
 	}
 
 	// Strictly needed?

storage/raw/leveldb/leveldb.go

@@ -28,7 +28,7 @@ var (
 	leveldbUseParanoidChecks = flag.Bool("leveldbUseParanoidChecks", true, "Whether LevelDB uses expensive checks (bool).")
 )
 
-// LevelDBPersistence is an disk-backed sorted key-value store.
+// LevelDBPersistence is a disk-backed sorted key-value store.
 type LevelDBPersistence struct {
 	cache        *levigo.Cache
 	filterPolicy *levigo.FilterPolicy