metrics: add hit counter for ARC and bloom caches

License: MIT
Signed-off-by: Jakub Sztandera <kubuxu@protonmail.ch>

blocks/blockstore/arc_cache.go

 package blockstore
 
 import (
-	"github.com/ipfs/go-ipfs/blocks"
 	key "gx/ipfs/Qmce4Y4zg3sYr7xKM5UueS67vhNni6EeWgCRnb7MbLJMew/go-key"
 
+	"github.com/ipfs/go-ipfs/blocks"
+
+	"gx/ipfs/QmRg1gKTHzc3CZXSKzem8aR4E3TubFhbgXwfVuWnSK5CC5/go-metrics-interface"
 	lru "gx/ipfs/QmVYxfoJQiZijTgPNHCHgHELvQpbsJNTg6Crmc3dQkj3yy/golang-lru"
 	context "gx/ipfs/QmZy2y8t9zQH2a1b8q2ZSLKp17ATuJoCNxxyMFG5qFExpt/go-net/context"
 	ds "gx/ipfs/QmbzuUusHqaLLoNTDEVLcSF6vZDHZDLPC7p4bztRvvkXxU/go-datastore"
@@ -12,15 +14,21 @@ import (
 type arccache struct {
 	arc        *lru.ARCCache
 	blockstore Blockstore
+
+	hits  metrics.Counter
+	total metrics.Counter
 }
 
-func arcCached(bs Blockstore, lruSize int) (*arccache, error) {
+func newARCCachedBS(bs Blockstore, ctx context.Context, lruSize int) (*arccache, error) {
 	arc, err := lru.NewARC(lruSize)
 	if err != nil {
 		return nil, err
 	}
+	c := &arccache{arc: arc, blockstore: bs}
+	c.hits = metrics.NewCtx(ctx, "arc.hits_total", "Number of ARC cache hits").Counter()
+	c.total = metrics.NewCtx(ctx, "arc_total", "Total number of ARC cache requests").Counter()
 
-	return &arccache{arc: arc, blockstore: bs}, nil
+	return c, nil
 }
 
 func (b *arccache) DeleteBlock(k key.Key) error {
@@ -42,6 +50,7 @@ func (b *arccache) DeleteBlock(k key.Key) error {
 // if ok == false has is inconclusive
 // if ok == true then has respons to question: is it contained
 func (b *arccache) hasCached(k key.Key) (has bool, ok bool) {
+	b.total.Inc()
 	if k == "" {
 		// Return cache invalid so the call to blockstore happens
 		// in case of invalid key and correct error is created.
@@ -50,6 +59,7 @@ func (b *arccache) hasCached(k key.Key) (has bool, ok bool) {
 
 	h, ok := b.arc.Get(k)
 	if ok {
+		b.hits.Inc()
 		return h.(bool), true
 	}
 	return false, false

blocks/blockstore/arc_cache_test.go

@@ -140,7 +140,7 @@ func TestGetAndDeleteFalseShortCircuit(t *testing.T) {
 }
 
 func TestArcCreationFailure(t *testing.T) {
-	if arc, err := arcCached(nil, -1); arc != nil || err == nil {
+	if arc, err := newARCCachedBS(nil, context.TODO(), -1); arc != nil || err == nil {
 		t.Fatal("expected error and no cache")
 	}
 }

blocks/blockstore/bloom_cache.go

@@ -6,6 +6,7 @@ import (
 	"github.com/ipfs/go-ipfs/blocks"
 	key "gx/ipfs/Qmce4Y4zg3sYr7xKM5UueS67vhNni6EeWgCRnb7MbLJMew/go-key"
 
+	"gx/ipfs/QmVWBQQAz4Cd2XgW9KgQoqXXrU8KJoCb9WCrhWRFVBKvFe/go-metrics-interface"
 	bloom "gx/ipfs/QmWQ2SJisXwcCLsUXLwYCKSfyExXjFRW2WbBH5sqCUnwX5/bbloom"
 	context "gx/ipfs/QmZy2y8t9zQH2a1b8q2ZSLKp17ATuJoCNxxyMFG5qFExpt/go-net/context"
 )
@@ -18,6 +19,10 @@ func bloomCached(bs Blockstore, ctx context.Context, bloomSize, hashCount int) (
 		return nil, err
 	}
 	bc := &bloomcache{blockstore: bs, bloom: bl}
+	bc.hits = metrics.NewCtx(ctx, "bloom.hits_total",
+		"Number of cache hits in bloom cache").Counter()
+	bc.total = metrics.NewCtx(ctx, "bloom_total",
+		"Total number of requests to bloom cache").Counter()
 	bc.Invalidate()
 	go bc.Rebuild(ctx)
 
@@ -33,8 +38,8 @@ type bloomcache struct {
 	blockstore  Blockstore
 
 	// Statistics
-	hits   uint64
-	misses uint64
+	hits  metrics.Counter
+	total metrics.Counter
 }
 
 func (b *bloomcache) Invalidate() {
@@ -84,6 +89,7 @@ func (b *bloomcache) DeleteBlock(k key.Key) error {
 // if ok == false has is inconclusive
 // if ok == true then has respons to question: is it contained
 func (b *bloomcache) hasCached(k key.Key) (has bool, ok bool) {
+	b.total.Inc()
 	if k == "" {
 		// Return cache invalid so call to blockstore
 		// in case of invalid key is forwarded deeper
@@ -92,6 +98,7 @@ func (b *bloomcache) hasCached(k key.Key) (has bool, ok bool) {
 	if b.BloomActive() {
 		blr := b.bloom.HasTS([]byte(k))
 		if blr == false { // not contained in bloom is only conclusive answer bloom gives
+			b.hits.Inc()
 			return false, true
 		}
 	}

blocks/blockstore/caching.go

@@ -3,6 +3,7 @@ package blockstore
 import (
 	"errors"
 
+	"gx/ipfs/QmVWBQQAz4Cd2XgW9KgQoqXXrU8KJoCb9WCrhWRFVBKvFe/go-metrics-interface"
 	context "gx/ipfs/QmZy2y8t9zQH2a1b8q2ZSLKp17ATuJoCNxxyMFG5qFExpt/go-net/context"
 )
 
@@ -33,11 +34,14 @@ func CachedBlockstore(bs GCBlockstore,
 	if opts.HasBloomFilterSize != 0 && opts.HasBloomFilterHashes == 0 {
 		return nil, errors.New("bloom filter hash count can't be 0 when there is size set")
 	}
+
+	ctx = metrics.CtxSubScope(ctx, "bs.cache")
+
 	if opts.HasBloomFilterSize != 0 {
 		cbs, err = bloomCached(cbs, ctx, opts.HasBloomFilterSize, opts.HasBloomFilterHashes)
 	}
 	if opts.HasARCCacheSize > 0 {
-		cbs, err = arcCached(cbs, opts.HasARCCacheSize)
+		cbs, err = newARCCachedBS(cbs, ctx, opts.HasARCCacheSize)
 	}
 
 	return cbs, err