Implement meta cache

common/constant/key.go

@@ -416,3 +416,10 @@ const (
 	MetricsMetadata = "dubbo.metrics.metadata"
 	MetricApp       = "dubbo.metrics.app"
 )
+
+// default meta cache config
+const (
+	DefaultMetaCacheName = "dubbo.meta"
+	DefaultMetaFileName  = "dubbo.metadata"
+	DefaultEntrySize     = 100
+)

go.mod

@@ -30,6 +30,7 @@ require (
 	github.com/google/uuid v1.3.0
 	github.com/gopherjs/gopherjs v0.0.0-20190910122728-9d188e94fb99 // indirect
 	github.com/grpc-ecosystem/grpc-opentracing v0.0.0-20180507213350-8e809c8a8645
+	github.com/hashicorp/golang-lru v0.5.4
 	github.com/hashicorp/vault/sdk v0.7.0
 	github.com/influxdata/tdigest v0.0.1
 	github.com/jinzhu/copier v0.3.5

go.sum

@@ -801,6 +801,7 @@ github.com/hashicorp/go-version v1.2.0/go.mod h1:fltr4n8CU8Ke44wwGCBoEymUuxUHl09
 github.com/hashicorp/go.net v0.0.1/go.mod h1:hjKkEWcCURg++eb33jQU7oqQcI9XDCnUzHA0oac0k90=
 github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/hashicorp/golang-lru v0.5.1/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
+github.com/hashicorp/golang-lru v0.5.4 h1:YDjusn29QI/Das2iO9M0BHnIbxPeyuCHsjMW+lJfyTc=
 github.com/hashicorp/golang-lru v0.5.4/go.mod h1:iADmTwqILo4mZ8BN3D2Q6+9jd8WM5uGBxy+E8yxSoD4=
 github.com/hashicorp/hcl v1.0.0 h1:0Anlzjpi4vEasTeNFn2mLJgTSwt0+6sfsiTG8qcWGx4=
 github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=

registry/servicediscovery/service_instances_changed_listener_impl.go

@@ -32,9 +32,22 @@ import (
 	"dubbo.apache.org/dubbo-go/v3/common/constant"
 	"dubbo.apache.org/dubbo-go/v3/common/extension"
 	"dubbo.apache.org/dubbo-go/v3/registry"
+	"dubbo.apache.org/dubbo-go/v3/registry/servicediscovery/store"
 	"dubbo.apache.org/dubbo-go/v3/remoting"
 )
 
+var (
+	metaCache *store.CacheManager
+)
+
+func init() {
+	cache, err := store.NewCacheManager(constant.DefaultMetaCacheName, constant.DefaultMetaFileName, constant.DefaultEntrySize)
+	if err != nil {
+		logger.Fatal("Failed to create cache [%s],the err is %v", constant.DefaultMetaCacheName, err)
+	}
+	metaCache = cache
+}
+
 // ServiceInstancesChangedListenerImpl The Service Discovery Changed  Event Listener
 type ServiceInstancesChangedListenerImpl struct {
 	serviceNames       *gxset.HashSet
@@ -88,9 +101,14 @@ func (lstn *ServiceInstancesChangedListenerImpl) OnEvent(e observer.Event) error
 			revisionToInstances[revision] = append(subInstances, instance)
 			metadataInfo := lstn.revisionToMetadata[revision]
 			if metadataInfo == nil {
-				metadataInfo, err = GetMetadataInfo(instance, revision)
-				if err != nil {
-					return err
+				if val, ok := metaCache.Get(revision); ok {
+					metadataInfo = val.(*common.MetadataInfo)
+				} else {
+					metadataInfo, err = GetMetadataInfo(instance, revision)
+					if err != nil {
+						return err
+					}
+					metaCache.Set(revision, metadataInfo)
 				}
 			}
 			instance.SetServiceMetadata(metadataInfo)
@@ -104,6 +122,10 @@ func (lstn *ServiceInstancesChangedListenerImpl) OnEvent(e observer.Event) error
 			newRevisionToMetadata[revision] = metadataInfo
 		}
 		lstn.revisionToMetadata = newRevisionToMetadata
+		for revision, metadataInfo := range newRevisionToMetadata {
+			metaCache.Set(revision, metadataInfo)
+		}
+		metaCache.DumpCache()
 
 		for serviceInfo, revisions := range localServiceToRevisions {
 			revisionsToUrls := protocolRevisionsToUrls[serviceInfo.Protocol]
@@ -187,6 +209,11 @@ func (lstn *ServiceInstancesChangedListenerImpl) GetEventType() reflect.Type {
 
 // GetMetadataInfo get metadata info when MetadataStorageTypePropertyName is null
 func GetMetadataInfo(instance registry.ServiceInstance, revision string) (*common.MetadataInfo, error) {
+
+	if metadataInfo, ok := metaCache.Get(revision); ok {
+		return metadataInfo.(*common.MetadataInfo), nil
+	}
+
 	var metadataStorageType string
 	var metadataInfo *common.MetadataInfo
 	if instance.GetMetadata() == nil {
@@ -212,5 +239,9 @@ func GetMetadataInfo(instance registry.ServiceInstance, revision string) (*commo
 			return nil, err
 		}
 	}
+
+	metaCache.Set(revision, metadataInfo)
+	metaCache.DumpCache()
+
 	return metadataInfo, nil
 }

registry/servicediscovery/store/cache_manager.go

@@ -0,0 +1,156 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package store
+
+import (
+	"encoding/gob"
+	"os"
+	"sync"
+)
+
+import (
+	"github.com/dubbogo/gost/log/logger"
+
+	"github.com/hashicorp/golang-lru"
+)
+
+type CacheManager struct {
+	name      string     // The name of the cache manager
+	cacheFile string     // The file path where the cache is stored
+	cache     *lru.Cache // The LRU cache implementation
+	lock      sync.Mutex
+}
+
+type Item struct {
+	Key   string
+	Value interface{}
+}
+
+// NewCacheManager creates a new CacheManager instance.
+// It initializes the cache manager with the provided parameters and starts a routine for cache expiration.
+func NewCacheManager(name, cacheFile string, maxCacheSize int) (*CacheManager, error) {
+	cm := &CacheManager{
+		name:      name,
+		cacheFile: cacheFile,
+	}
+	cache, err := lru.New(maxCacheSize)
+	if err != nil {
+		return nil, err
+	}
+	cm.cache = cache
+
+	// Check if the cache file exists and load the cache if it does
+	if _, err := os.Stat(cacheFile); err == nil {
+		if err = cm.loadCache(); err != nil {
+			logger.Warnf("Failed to load the cache file:[%s].The err is %v", cm.cacheFile, err)
+		}
+	}
+
+	return cm, nil
+}
+
+// Get retrieves the value associated with the given key from the cache.
+func (cm *CacheManager) Get(key string) (interface{}, bool) {
+	return cm.cache.Get(key)
+}
+
+// Set sets the value associated with the given key in the cache.
+func (cm *CacheManager) Set(key string, value interface{}) {
+	cm.cache.Add(key, value)
+}
+
+// Delete removes the value associated with the given key from the cache.
+func (cm *CacheManager) Delete(key string) {
+	cm.cache.Remove(key)
+}
+
+// GetAll returns all the key-value pairs in the cache.
+func (cm *CacheManager) GetAll() map[string]interface{} {
+	keys := cm.cache.Keys()
+
+	result := make(map[string]interface{})
+	for _, k := range keys {
+		result[k.(string)], _ = cm.cache.Get(k)
+	}
+
+	return result
+}
+
+// loadCache loads the cache from the cache file.
+func (cm *CacheManager) loadCache() error {
+	cf, err := os.Open(cm.cacheFile)
+	if err != nil {
+		return err
+	}
+
+	decoder := gob.NewDecoder(cf)
+	for {
+		var it Item
+		err = decoder.Decode(&it)
+		if err != nil {
+			if err.Error() == "EOF" {
+				break // Reached end of file
+			}
+			return err
+		}
+		// Add the loaded keys to the front of the LRU list
+		cm.cache.Add(it.Key, it.Value)
+	}
+
+	return cf.Close()
+}
+
+// dumpCache dumps the cache to the cache file.
+func (cm *CacheManager) DumpCache() error {
+
+	cm.lock.Lock()
+	defer cm.lock.Unlock()
+
+	items := cm.GetAll()
+
+	file, err := os.Create(cm.cacheFile)
+	if err != nil {
+		return err
+	}
+
+	encoder := gob.NewEncoder(file)
+	for k, v := range items {
+		gob.Register(v)
+		err = encoder.Encode(&Item{
+			Key:   k,
+			Value: v,
+		})
+		if err != nil {
+			return err
+		}
+	}
+	return file.Close()
+
+}
+
+// destroy stops the cache expiration routine, clears the cache and removes the cache file.
+func (cm *CacheManager) destroy() {
+	cm.cache.Purge() // Clear the cache
+
+	// Delete the cache file if it exists
+	if _, err := os.Stat(cm.cacheFile); err == nil {
+		if err := os.Remove(cm.cacheFile); err == nil {
+			logger.Infof("The cacheFile [%s] was cleared", cm.cacheFile)
+		}
+	}
+}