Remove Evict() API and call Close(). (#2382)

src/dbnode/storage/index/block.go

@@ -1004,7 +1004,7 @@ func (b *block) EvictMutableSegments() error {
 		return fmt.Errorf("unable to evict mutable segments, block must be sealed, found: %v", b.state)
 	}
 
-	b.mutableSegments.Evict()
+	b.mutableSegments.Close()
 
 	// Close any other mutable segments that was added.
 	multiErr := xerrors.NewMultiError()
@@ -1046,7 +1046,7 @@ func (b *block) EvictColdMutableSegments() error {
 	// Evict/remove all but the most recent cold mutable segment (That is the one we are actively writing to).
 	for i, coldSeg := range b.coldMutableSegments {
 		if i < len(b.coldMutableSegments)-1 {
-			coldSeg.Evict()
+			coldSeg.Close()
 			b.coldMutableSegments[i] = nil
 		}
 	}

src/dbnode/storage/index/mutable_segments.go

@@ -59,8 +59,7 @@ const (
 type mutableSegments struct {
 	sync.RWMutex
 
-	state              mutableSegmentsState
-	hasEvictedAnyTimes bool
+	state mutableSegmentsState
 
 	foregroundSegments []*readableSeg
 	backgroundSegments []*readableSeg
@@ -243,13 +242,6 @@ func (m *mutableSegments) NeedsEviction() bool {
 	return needsEviction
 }
 
-func (m *mutableSegments) Evict() {
-	m.Lock()
-	defer m.Unlock()
-	m.hasEvictedAnyTimes = true
-	m.cleanupCompactWithLock()
-}
-
 func (m *mutableSegments) NumSegmentsAndDocs() (int64, int64) {
 	var (
 		numSegments, numDocs int64
@@ -334,12 +326,7 @@ func (m *mutableSegments) maybeBackgroundCompactWithLock() {
 }
 
 func (m *mutableSegments) shouldEvictCompactedSegmentsWithLock() bool {
-	// NB(r): The frozen/compacted segments are derived segments of the
-	// active mutable segment, if we ever evict that segment then
-	// we don't need the frozen/compacted segments either and should
-	// shed them from memory.
-	return m.state == mutableSegmentsStateClosed ||
-		m.hasEvictedAnyTimes
+	return m.state == mutableSegmentsStateClosed
 }
 
 func (m *mutableSegments) cleanupBackgroundCompactWithLock() {
@@ -350,12 +337,12 @@ func (m *mutableSegments) cleanupBackgroundCompactWithLock() {
 	}
 
 	// Check if need to close all the compacted segments due to
-	// having evicted mutable segments or the block being closed.
+	// mutableSegments being closed.
 	if !m.shouldEvictCompactedSegmentsWithLock() {
 		return
 	}
 
-	// Evict compacted segments.
+	// Close compacted segments.
 	m.closeCompactedSegments(m.backgroundSegments)
 	m.backgroundSegments = nil
 
@@ -685,13 +672,13 @@ func (m *mutableSegments) foregroundCompactWithTask(
 }
 
 func (m *mutableSegments) cleanupForegroundCompactWithLock() {
-	// Check if we need to close all the compacted segments due to
-	// having evicted mutable segments or the block being closed.
+	// Check if need to close all the compacted segments due to
+	// mutableSegments being closed.
 	if !m.shouldEvictCompactedSegmentsWithLock() {
 		return
 	}
 
-	// Evict compacted segments.
+	// Close compacted segments.
 	m.closeCompactedSegments(m.foregroundSegments)
 	m.foregroundSegments = nil