Made suggested change.

Signed-off-by: Cody Littley <[email protected]>

Author: cody-littley

litt/disktable/control_loop.go

@@ -151,7 +151,7 @@ func (c *controlLoop) run() {
 
 // doGarbageCollection performs garbage collection on all segments, deleting old ones as necessary.
 func (c *controlLoop) doGarbageCollection() {
-	now := c.clock()
+	start := c.clock()
 	ttl := c.metadata.GetTTL()
 	if ttl.Nanoseconds() <= 0 {
 		// No TTL set, so nothing to do.
@@ -161,7 +161,7 @@ func (c *controlLoop) doGarbageCollection() {
 	defer func() {
 		if c.metrics != nil {
 			end := c.clock()
-			delta := end.Sub(now)
+			delta := end.Sub(start)
 			c.metrics.ReportGarbageCollectionLatency(c.name, delta)
 
 		}
@@ -176,7 +176,7 @@ func (c *controlLoop) doGarbageCollection() {
 		}
 
 		sealTime := seg.GetSealTime()
-		segmentAge := now.Sub(sealTime)
+		segmentAge := start.Sub(sealTime)
 		if segmentAge < ttl {
 			// Segment is not old enough to be deleted.
 			return

litt/disktable/disk_table.go

@@ -198,11 +198,11 @@ func NewDiskTable(
 		return nil, fmt.Errorf("failed to gather segment files: %w", err)
 	}
 
-	keyCount := uint64(0)
+	keyCount := int64(0)
 	for _, seg := range segments {
-		keyCount += uint64(seg.KeyCount())
+		keyCount += int64(seg.KeyCount())
 	}
-	table.keyCount.Store(int64(keyCount))
+	table.keyCount.Store(keyCount)
 
 	immutableSegmentSize := uint64(0)
 	for _, seg := range segments {

litt/disktable/keymap/level_db_keymap.go

@@ -29,6 +29,8 @@ type LevelDBKeymap struct {
 	syncWrites bool
 }
 
+var _ BuildKeymap = NewLevelDBKeymap
+
 // NewLevelDBKeymap creates a new LevelDBKeymap instance.
 func NewLevelDBKeymap(
 	logger logging.Logger,

litt/disktable/keymap/mem_keymap.go

@@ -25,6 +25,8 @@ type memKeymap struct {
 	lock                  sync.RWMutex
 }
 
+var _ BuildKeymap = NewMemKeymap
+
 // NewMemKeymap creates a new in-memory keymap.
 func NewMemKeymap(logger logging.Logger,
 	_ string,

litt/disktable/segment/metadata_file.go

@@ -38,7 +38,7 @@ const (
 	// - and 1 byte for sealed.
 	V1MetadataSize = 33
 
-	// V2MetadataSize is the size of the metadata file at version 3 (aka ValueSizeSegmentVersion).
+	// V2MetadataSize is the size of the metadata file at version 2 (aka ValueSizeSegmentVersion).
 	// This is a constant, so it's convenient to have it here.
 	// - 4 bytes for version
 	// - 4 bytes for the sharding factor

litt/disktable/segment/segment_scanner.go

@@ -51,10 +51,7 @@ func scanDirectories(logger logging.Logger, rootDirectories []string) (
 			var index uint32
 
 			switch extension {
-			case MetadataSwapExtension:
-				garbageFiles = append(garbageFiles, filePath)
-				continue
-			case KeyFileSwapExtension:
+			case MetadataSwapExtension, KeyFileSwapExtension:
 				garbageFiles = append(garbageFiles, filePath)
 				continue
 			case MetadataFileExtension:

litt/disktable/segment/segment_version.go

@@ -4,18 +4,16 @@ package segment
 // in segment files, this version should be incremented.
 type SegmentVersion uint32
 
-// IMPORTANT! Never remove old versions from this list, as doing so remaps the segment version numbers.
-
 const (
 	// OldHashFunctionSegmentVersion is the serialization version for the old hash function.
-	OldHashFunctionSegmentVersion SegmentVersion = iota
+	OldHashFunctionSegmentVersion SegmentVersion = 0
 
 	// SipHashSegmentVersion is the version when the siphash hash function was introduced for sharding.
-	SipHashSegmentVersion
+	SipHashSegmentVersion SegmentVersion = 1
 
 	// ValueSizeSegmentVersion adds the length of values to the key file. Previously, only the key and the address were
 	// stored in the key file. It also adds the key count to the segment metadata file.
-	ValueSizeSegmentVersion
+	ValueSizeSegmentVersion SegmentVersion = 2
 )
 
 // LatestSegmentVersion always refers to the latest version of the segment serialization format.