feat: cache generation and sequence to reduce TSM filename parsing

tsdb/engine/tsm1/compact.go

@@ -161,11 +161,6 @@ type DefaultPlanner struct {
 	lastPlanCheck time.Time
 
 	mu sync.RWMutex
-	// lastFindGenerations is the last time findGenerations was run
-	lastFindGenerations time.Time
-
-	// lastGenerations is the last set of generations found by findGenerations
-	lastGenerations tsmGenerations
 
 	// forceFull causes the next full plan requests to plan any files
 	// that may need to be compacted.  Normally, these files are skipped and scheduled
@@ -184,7 +179,7 @@ type DefaultPlanner struct {
 type fileStore interface {
 	Stats() []ExtFileStat
 	LastModified() time.Time
-	ParseFileName(path string) (int, int, error)
+	ParseFileName(path string) (generation int, sequence int, err error)
 	NextGeneration() int
 	TSMReader(path string) (*TSMReader, error)
 }
@@ -202,15 +197,13 @@ func NewDefaultPlanner(fs fileStore, writeColdDuration time.Duration) *DefaultPl
 // 000001-01.tsm, 000001-02.tsm would be in the same generation
 // 000001 each with different sequence numbers.
 type tsmGeneration struct {
-	id            int
-	files         []ExtFileStat
-	parseFileName ParseFileNameFunc
+	id    int
+	files []ExtFileStat
 }
 
-func newTsmGeneration(id int, parseFileNameFunc ParseFileNameFunc) *tsmGeneration {
+func newTsmGeneration(id int) *tsmGeneration {
 	return &tsmGeneration{
-		id:            id,
-		parseFileName: parseFileNameFunc,
+		id: id,
 	}
 }
 
@@ -227,13 +220,12 @@ func (t *tsmGeneration) size() uint64 {
 func (t *tsmGeneration) level() int {
 	// Level 0 is always created from the result of a cache compaction.  It generates
 	// 1 file with a sequence num of 1.  Level 2 is generated by compacting multiple
-	// level 1 files.  Level 3 is generate by compacting multiple level 2 files.  Level
+	// level 1 files.  Level 3 is generated by compacting multiple level 2 files.  Level
 	// 4 is for anything else.
-	_, seq, _ := t.parseFileName(t.files[0].Path)
-	if seq < 4 {
-		return seq
-	}
 
+	if t.files[0].Sequence < 4 {
+		return t.files[0].Sequence
+	}
 	return 4
 }
 
@@ -264,10 +256,6 @@ func (c *DefaultPlanner) SetFileStore(fs *FileStore) {
 	c.FileStore = fs
 }
 
-func (c *DefaultPlanner) ParseFileName(path string) (int, int, error) {
-	return c.FileStore.ParseFileName(path)
-}
-
 func (c *DefaultPlanner) generationsFullyCompacted(gens tsmGenerations) (bool, string) {
 	if len(gens) > 1 {
 		return false, "not fully compacted and not idle because of more than one generation"
@@ -707,28 +695,18 @@ func (c *DefaultPlanner) findGenerations(skipInUse bool) tsmGenerations {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
-	last := c.lastFindGenerations
-	lastGen := c.lastGenerations
-
-	if !last.IsZero() && c.FileStore.LastModified().Equal(last) {
-		return lastGen
-	}
-
-	genTime := c.FileStore.LastModified()
 	tsmStats := c.FileStore.Stats()
 	generations := make(map[int]*tsmGeneration, len(tsmStats))
 	for _, f := range tsmStats {
-		gen, _, _ := c.ParseFileName(f.Path)
-
 		// Skip any files that are assigned to a current compaction plan
 		if _, ok := c.filesInUse[f.Path]; skipInUse && ok {
 			continue
 		}
 
-		group := generations[gen]
+		group := generations[f.Generation]
 		if group == nil {
-			group = newTsmGeneration(gen, c.ParseFileName)
-			generations[gen] = group
+			group = newTsmGeneration(f.Generation)
+			generations[f.Generation] = group
 		}
 		group.files = append(group.files, f)
 	}
@@ -741,9 +719,6 @@ func (c *DefaultPlanner) findGenerations(skipInUse bool) tsmGenerations {
 		sort.Sort(orderedGenerations)
 	}
 
-	c.lastFindGenerations = genTime
-	c.lastGenerations = orderedGenerations
-
 	return orderedGenerations
 }
 
@@ -800,7 +775,6 @@ type Compactor struct {
 	RateLimit limiter.Rate
 
 	formatFileName FormatFileNameFunc
-	parseFileName  ParseFileNameFunc
 
 	mu                 sync.RWMutex
 	snapshotsEnabled   bool
@@ -823,18 +797,13 @@ type Compactor struct {
 func NewCompactor() *Compactor {
 	return &Compactor{
 		formatFileName: DefaultFormatFileName,
-		parseFileName:  DefaultParseFileName,
 	}
 }
 
 func (c *Compactor) WithFormatFileNameFunc(formatFileNameFunc FormatFileNameFunc) {
 	c.formatFileName = formatFileNameFunc
 }
 
-func (c *Compactor) WithParseFileNameFunc(parseFileNameFunc ParseFileNameFunc) {
-	c.parseFileName = parseFileNameFunc
-}
-
 // Open initializes the Compactor.
 func (c *Compactor) Open() {
 	c.mu.Lock()
@@ -1000,8 +969,12 @@ func (c *Compactor) compact(fast bool, tsmFiles []string, logger *zap.Logger, po
 	// set.  We need to find that max generation as well as the max sequence
 	// number to ensure we write to the next unique location.
 	var maxGeneration, maxSequence int
+
+	if c.FileStore == nil {
+		return nil, fmt.Errorf("compactor for %s has no file store: %w", c.Dir, errCompactionsDisabled)
+	}
 	for _, f := range tsmFiles {
-		gen, seq, err := c.parseFileName(f)
+		gen, seq, err := c.FileStore.ParseFileName(f)
 		if err != nil {
 			return nil, err
 		}