move timedValue -> cachevalue package (#19114)

cmd/bucket-quota.go

@@ -25,6 +25,7 @@ import (
 	"time"
 
 	"github.com/minio/madmin-go/v3"
+	"github.com/minio/minio/internal/cachevalue"
 	"github.com/minio/minio/internal/logger"
 )
 
@@ -42,7 +43,7 @@ func NewBucketQuotaSys() *BucketQuotaSys {
 	return &BucketQuotaSys{}
 }
 
-var bucketStorageCache = newTimedValue[DataUsageInfo]()
+var bucketStorageCache = cachevalue.New[DataUsageInfo]()
 
 // Init initialize bucket quota.
 func (sys *BucketQuotaSys) Init(objAPI ObjectLayer) {

cmd/data-usage.go

@@ -24,6 +24,7 @@ import (
 	"time"
 
 	jsoniter "github.com/json-iterator/go"
+	"github.com/minio/minio/internal/cachevalue"
 	"github.com/minio/minio/internal/logger"
 )
 
@@ -62,7 +63,7 @@ func storeDataUsageInBackend(ctx context.Context, objAPI ObjectLayer, dui <-chan
 	}
 }
 
-var prefixUsageCache = newTimedValue[map[string]uint64]()
+var prefixUsageCache = cachevalue.New[map[string]uint64]()
 
 // loadPrefixUsageFromBackend returns prefix usages found in passed buckets
 //

cmd/erasure-server-pool.go

@@ -39,6 +39,7 @@ import (
 	"github.com/minio/minio-go/v7/pkg/set"
 	"github.com/minio/minio-go/v7/pkg/tags"
 	"github.com/minio/minio/internal/bpool"
+	"github.com/minio/minio/internal/cachevalue"
 	"github.com/minio/minio/internal/config/storageclass"
 	xioutil "github.com/minio/minio/internal/ioutil"
 	"github.com/minio/minio/internal/logger"
@@ -1840,7 +1841,7 @@ func (z *erasureServerPools) deleteAll(ctx context.Context, bucket, prefix strin
 	}
 }
 
-var listBucketsCache = newTimedValue[[]BucketInfo]()
+var listBucketsCache = cachevalue.New[[]BucketInfo]()
 
 // List all buckets from one of the serverPools, we are not doing merge
 // sort here just for simplification. As per design it is assumed

cmd/metrics-v2.go

@@ -32,6 +32,7 @@ import (
 	"github.com/minio/kes-go"
 	"github.com/minio/madmin-go/v3"
 	"github.com/minio/minio/internal/bucket/lifecycle"
+	"github.com/minio/minio/internal/cachevalue"
 	xioutil "github.com/minio/minio/internal/ioutil"
 	"github.com/minio/minio/internal/logger"
 	"github.com/minio/minio/internal/mcontext"
@@ -330,7 +331,7 @@ type Metric struct {
 
 // MetricsGroup are a group of metrics that are initialized together.
 type MetricsGroup struct {
-	metricsCache     *timedValue[[]Metric] `msg:"-"`
+	metricsCache     *cachevalue.Cache[[]Metric] `msg:"-"`
 	cacheInterval    time.Duration
 	metricsGroupOpts MetricsGroupOpts
 }
@@ -354,7 +355,7 @@ type MetricsGroupOpts struct {
 // RegisterRead register the metrics populator function to be used
 // to populate new values upon cache invalidation.
 func (g *MetricsGroup) RegisterRead(read func(ctx context.Context) []Metric) {
-	g.metricsCache = newTimedValue[[]Metric]()
+	g.metricsCache = cachevalue.New[[]Metric]()
 	g.metricsCache.Once.Do(func() {
 		g.metricsCache.Relax = true
 		g.metricsCache.TTL = g.cacheInterval

cmd/storage-rest-client.go

@@ -35,6 +35,7 @@ import (
 	"time"
 
 	"github.com/minio/madmin-go/v3"
+	"github.com/minio/minio/internal/cachevalue"
 	"github.com/minio/minio/internal/grid"
 	xhttp "github.com/minio/minio/internal/http"
 	xioutil "github.com/minio/minio/internal/ioutil"
@@ -166,7 +167,7 @@ type storageRESTClient struct {
 	formatData  []byte
 	formatMutex sync.RWMutex
 
-	diskInfoCache *timedValue[DiskInfo]
+	diskInfoCache *cachevalue.Cache[DiskInfo]
 
 	// Indexes, will be -1 until assigned a set.
 	poolIndex, setIndex, diskIndex int
@@ -893,6 +894,6 @@ func newStorageRESTClient(endpoint Endpoint, healthCheck bool, gm *grid.Manager)
 	return &storageRESTClient{
 		endpoint: endpoint, restClient: restClient, poolIndex: -1, setIndex: -1, diskIndex: -1,
 		gridConn:      conn,
-		diskInfoCache: newTimedValue[DiskInfo](),
+		diskInfoCache: cachevalue.New[DiskInfo](),
 	}, nil
 }

cmd/utils.go

@@ -926,102 +926,6 @@ func iamPolicyClaimNameSA() string {
 	return "sa-policy"
 }
 
-// timedValue contains a synchronized value that is considered valid
-// for a specific amount of time.
-// An Update function must be set to provide an updated value when needed.
-type timedValue[I any] struct {
-	// Update must return an updated value.
-	// If an error is returned the cached value is not set.
-	// Only one caller will call this function at any time, others will be blocking.
-	// The returned value can no longer be modified once returned.
-	// Should be set before calling Get().
-	Update func() (item I, err error)
-
-	// TTL for a cached value.
-	// If not set 1 second TTL is assumed.
-	// Should be set before calling Get().
-	TTL time.Duration
-
-	// When set to true, return the last cached value
-	// even if updating the value errors out
-	Relax bool
-
-	// Once can be used to initialize values for lazy initialization.
-	// Should be set before calling Get().
-	Once sync.Once
-
-	// Managed values.
-	value      I
-	valueSet   bool
-	lastUpdate time.Time
-	mu         sync.RWMutex
-}
-
-// newTimedValue
-func newTimedValue[I any]() *timedValue[I] {
-	return &timedValue[I]{}
-}
-
-// Get will return a cached value or fetch a new one.
-// If the Update function returns an error the value is forwarded as is and not cached.
-func (t *timedValue[I]) Get() (item I, err error) {
-	item, ok := t.get(t.ttl())
-	if ok {
-		return item, nil
-	}
-
-	item, err = t.Update()
-	if err != nil {
-		if t.Relax {
-			// if update fails, return current
-			// cached value along with error.
-			//
-			// Let the caller decide if they want
-			// to use the returned value based
-			// on error.
-			item, ok = t.get(0)
-			if ok {
-				return item, err
-			}
-		}
-		return item, err
-	}
-
-	t.update(item)
-	return item, nil
-}
-
-func (t *timedValue[_]) ttl() time.Duration {
-	ttl := t.TTL
-	if ttl <= 0 {
-		ttl = time.Second
-	}
-	return ttl
-}
-
-func (t *timedValue[I]) get(ttl time.Duration) (item I, ok bool) {
-	t.mu.RLock()
-	defer t.mu.RUnlock()
-	if t.valueSet {
-		item = t.value
-		if ttl <= 0 {
-			return item, true
-		}
-		if time.Since(t.lastUpdate) < ttl {
-			return item, true
-		}
-	}
-	return item, false
-}
-
-func (t *timedValue[I]) update(item I) {
-	t.mu.Lock()
-	defer t.mu.Unlock()
-	t.value = item
-	t.valueSet = true
-	t.lastUpdate = time.Now()
-}
-
 // On MinIO a directory object is stored as a regular object with "__XLDIR__" suffix.
 // For ex. "prefix/" is stored as "prefix__XLDIR__"
 func encodeDirObject(object string) string {

cmd/utils_test.go

@@ -26,7 +26,6 @@ import (
 	"reflect"
 	"strings"
 	"testing"
-	"time"
 )
 
 // Tests maximum object size.
@@ -400,29 +399,3 @@ func TestGetMinioMode(t *testing.T) {
 	globalIsDistErasure, globalIsErasure = false, false
 	testMinioMode(globalMinioModeFS)
 }
-
-func TestTimedValue(t *testing.T) {
-	cache := newTimedValue[time.Time]()
-	t.Parallel()
-	cache.Once.Do(func() {
-		cache.TTL = 2 * time.Second
-		cache.Update = func() (time.Time, error) {
-			return time.Now(), nil
-		}
-	})
-
-	t1, _ := cache.Get()
-
-	t2, _ := cache.Get()
-
-	if !t1.Equal(t2) {
-		t.Fatalf("expected time to be equal: %s != %s", t1, t2)
-	}
-
-	time.Sleep(3 * time.Second)
-	t3, _ := cache.Get()
-
-	if t1.Equal(t3) {
-		t.Fatalf("expected time to be un-equal: %s == %s", t1, t3)
-	}
-}

cmd/xl-storage-disk-id-check.go

@@ -31,6 +31,7 @@ import (
 	"time"
 
 	"github.com/minio/madmin-go/v3"
+	"github.com/minio/minio/internal/cachevalue"
 	xioutil "github.com/minio/minio/internal/ioutil"
 	"github.com/minio/minio/internal/logger"
 )
@@ -89,7 +90,7 @@ type xlStorageDiskIDCheck struct {
 	health       *diskHealthTracker
 	healthCheck  bool
 
-	metricsCache *timedValue[DiskMetrics]
+	metricsCache *cachevalue.Cache[DiskMetrics]
 	diskCtx      context.Context
 	diskCancel   context.CancelFunc
 }
@@ -179,7 +180,7 @@ func newXLStorageDiskIDCheck(storage *xlStorage, healthCheck bool) *xlStorageDis
 		storage:      storage,
 		health:       newDiskHealthTracker(),
 		healthCheck:  healthCheck && globalDriveMonitoring,
-		metricsCache: newTimedValue[DiskMetrics](),
+		metricsCache: cachevalue.New[DiskMetrics](),
 	}
 
 	xl.totalWrites.Store(xl.storage.getWriteAttribute())

cmd/xl-storage.go

@@ -43,6 +43,7 @@ import (
 	"github.com/klauspost/filepathx"
 	"github.com/minio/madmin-go/v3"
 	"github.com/minio/minio/internal/bucket/lifecycle"
+	"github.com/minio/minio/internal/cachevalue"
 	"github.com/minio/minio/internal/config/storageclass"
 	"github.com/minio/minio/internal/disk"
 	xioutil "github.com/minio/minio/internal/ioutil"
@@ -112,7 +113,7 @@ type xlStorage struct {
 	formatLegacy    bool
 	formatLastCheck time.Time
 
-	diskInfoCache *timedValue[DiskInfo]
+	diskInfoCache *cachevalue.Cache[DiskInfo]
 	sync.RWMutex
 
 	formatData []byte
@@ -233,7 +234,7 @@ func newXLStorage(ep Endpoint, cleanUp bool) (s *xlStorage, err error) {
 		drivePath:     ep.Path,
 		endpoint:      ep,
 		globalSync:    globalFSOSync,
-		diskInfoCache: newTimedValue[DiskInfo](),
+		diskInfoCache: cachevalue.New[DiskInfo](),
 		poolIndex:     -1,
 		setIndex:      -1,
 		diskIndex:     -1,

internal/cachevalue/cache.go

@@ -0,0 +1,119 @@
+// Copyright (c) 2015-2024 MinIO, Inc.
+//
+// This file is part of MinIO Object Storage stack
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package cachevalue
+
+import (
+	"sync"
+	"time"
+)
+
+// Cache contains a synchronized value that is considered valid
+// for a specific amount of time.
+// An Update function must be set to provide an updated value when needed.
+type Cache[I any] struct {
+	// Update must return an updated value.
+	// If an error is returned the cached value is not set.
+	// Only one caller will call this function at any time, others will be blocking.
+	// The returned value can no longer be modified once returned.
+	// Should be set before calling Get().
+	Update func() (item I, err error)
+
+	// TTL for a cached value.
+	// If not set 1 second TTL is assumed.
+	// Should be set before calling Get().
+	TTL time.Duration
+
+	// When set to true, return the last cached value
+	// even if updating the value errors out
+	Relax bool
+
+	// Once can be used to initialize values for lazy initialization.
+	// Should be set before calling Get().
+	Once sync.Once
+
+	// Managed values.
+	value      I         // our cached value
+	valueSet   bool      // 'true' if the value 'I' has a value
+	lastUpdate time.Time // indicates when value 'I' was updated last, used for invalidation.
+	mu         sync.RWMutex
+}
+
+// New initializes a new cached value instance.
+func New[I any]() *Cache[I] {
+	return &Cache[I]{}
+}
+
+// Get will return a cached value or fetch a new one.
+// If the Update function returns an error the value is forwarded as is and not cached.
+func (t *Cache[I]) Get() (item I, err error) {
+	item, ok := t.get(t.ttl())
+	if ok {
+		return item, nil
+	}
+
+	item, err = t.Update()
+	if err != nil {
+		if t.Relax {
+			// if update fails, return current
+			// cached value along with error.
+			//
+			// Let the caller decide if they want
+			// to use the returned value based
+			// on error.
+			item, ok = t.get(0)
+			if ok {
+				return item, err
+			}
+		}
+		return item, err
+	}
+
+	t.update(item)
+	return item, nil
+}
+
+func (t *Cache[_]) ttl() time.Duration {
+	ttl := t.TTL
+	if ttl <= 0 {
+		ttl = time.Second
+	}
+	return ttl
+}
+
+func (t *Cache[I]) get(ttl time.Duration) (item I, ok bool) {
+	t.mu.RLock()
+	defer t.mu.RUnlock()
+	if t.valueSet {
+		item = t.value
+		if ttl <= 0 {
+			return item, true
+		}
+		if time.Since(t.lastUpdate) < ttl {
+			return item, true
+		}
+	}
+	return item, false
+}
+
+func (t *Cache[I]) update(item I) {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	t.value = item
+	t.valueSet = true
+	t.lastUpdate = time.Now()
+}

internal/cachevalue/cache_test.go

@@ -0,0 +1,68 @@
+// Copyright (c) 2015-2024 MinIO, Inc.
+//
+// This file is part of MinIO Object Storage stack
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package cachevalue
+
+import (
+	"testing"
+	"time"
+)
+
+func TestCache(t *testing.T) {
+	cache := New[time.Time]()
+	t.Parallel()
+	cache.Once.Do(func() {
+		cache.TTL = 2 * time.Second
+		cache.Update = func() (time.Time, error) {
+			return time.Now(), nil
+		}
+	})
+
+	t1, _ := cache.Get()
+
+	t2, _ := cache.Get()
+
+	if !t1.Equal(t2) {
+		t.Fatalf("expected time to be equal: %s != %s", t1, t2)
+	}
+
+	time.Sleep(3 * time.Second)
+	t3, _ := cache.Get()
+
+	if t1.Equal(t3) {
+		t.Fatalf("expected time to be un-equal: %s == %s", t1, t3)
+	}
+}
+
+func BenchmarkCache(b *testing.B) {
+	cache := New[time.Time]()
+	cache.Once.Do(func() {
+		cache.TTL = 1 * time.Microsecond
+		cache.Update = func() (time.Time, error) {
+			return time.Now(), nil
+		}
+	})
+
+	b.ReportAllocs()
+	b.ResetTimer()
+
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			cache.Get()
+		}
+	})
+}