Fixups for single-op-per-fingerprint view rendering.

Change-Id: Ie496d4529b65a3819c6042f43d7cf99e0e1ac60b

storage/metric/freelist.go

@@ -15,6 +15,7 @@ package metric
 
 import (
 	"time"
+
 	"github.com/prometheus/prometheus/utility"
 
 	clientmodel "github.com/prometheus/client_golang/model"
@@ -93,6 +94,7 @@ func (l *valueAtTimeList) Get(fp *clientmodel.Fingerprint, time clientmodel.Time
 	}
 	op.fp = *fp
 	op.current = time
+	op.consumed = false
 	return op
 }
 

storage/metric/tiered.go

@@ -434,6 +434,7 @@ func (t *TieredStorage) renderView(viewJob viewJob) {
 
 		memValues := t.memoryArena.CloneSamples(fp)
 
+		for !op.Consumed() {
 			// Abort the view rendering if the caller (MakeView) has timed out.
 			if len(viewJob.abort) > 0 {
 				return
@@ -504,7 +505,7 @@ func (t *TieredStorage) renderView(viewJob viewJob) {
 
 			// There's no data at all for this fingerprint, so stop processing.
 			if len(currentChunk) == 0 {
-			continue
+				break
 			}
 
 			currentChunk = currentChunk.TruncateBefore(targetTime)
@@ -514,12 +515,18 @@ func (t *TieredStorage) renderView(viewJob viewJob) {
 				targetTime = lastChunkTime
 			}
 
+			if op.CurrentTime().After(targetTime) {
+				break
+			}
+
 			// Extract all needed data from the current chunk and append the
 			// extracted samples to the materialized view.
 			for !op.Consumed() && !op.CurrentTime().After(targetTime) {
 				view.appendSamples(fp, op.ExtractSamples(Values(currentChunk)))
 			}
 		}
+		giveBackOp(op)
+	}
 	extractionTimer.Stop()
 
 	viewJob.output <- view