| /* |
| * 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 discovery |
| |
| import ( |
| "github.com/apache/servicecomb-service-center/pkg/util" |
| "strings" |
| "sync" |
| "time" |
| ) |
| |
| // KvCache implements Cache. |
| // KvCache is dedicated to stores service discovery data, |
| // e.g. service, instance, lease. |
| type KvCache struct { |
| Cfg *Config |
| name string |
| store map[string]map[string]*KeyValue |
| rwMux sync.RWMutex |
| lastRefresh time.Time |
| lastMaxSize int |
| } |
| |
| func (c *KvCache) Name() string { |
| return c.name |
| } |
| |
| func (c *KvCache) Size() (l int) { |
| c.rwMux.RLock() |
| l = int(util.Sizeof(c.store)) |
| c.rwMux.RUnlock() |
| return |
| } |
| |
| func (c *KvCache) Get(key string) (v *KeyValue) { |
| c.rwMux.RLock() |
| prefix := c.prefix(key) |
| if p, ok := c.store[prefix]; ok { |
| v, _ = p[key] |
| } |
| c.rwMux.RUnlock() |
| return |
| } |
| |
| func (c *KvCache) GetAll(arr *[]*KeyValue) (count int) { |
| c.rwMux.RLock() |
| count = c.getPrefixKey(arr, c.Cfg.Key) |
| c.rwMux.RUnlock() |
| return |
| } |
| |
| func (c *KvCache) GetPrefix(prefix string, arr *[]*KeyValue) (count int) { |
| c.rwMux.RLock() |
| count = c.getPrefixKey(arr, prefix) |
| c.rwMux.RUnlock() |
| return |
| } |
| |
| func (c *KvCache) Put(key string, v *KeyValue) { |
| c.rwMux.Lock() |
| c.addPrefixKey(key, v) |
| c.rwMux.Unlock() |
| } |
| |
| func (c *KvCache) Remove(key string) { |
| c.rwMux.Lock() |
| c.deletePrefixKey(key) |
| c.rwMux.Unlock() |
| } |
| |
| func (c *KvCache) ForEach(iter func(k string, v *KeyValue) (next bool)) { |
| c.rwMux.RLock() |
| loopParent: |
| for _, p := range c.store { |
| for k, v := range p { |
| if v == nil { |
| continue loopParent |
| } |
| if !iter(k, v) { |
| break loopParent |
| } |
| } |
| } |
| c.rwMux.RUnlock() |
| } |
| |
| func (c *KvCache) prefix(key string) string { |
| if len(key) == 0 { |
| return "" |
| } |
| return key[:strings.LastIndex(key[:len(key)-1], "/")+1] |
| } |
| |
| func (c *KvCache) getPrefixKey(arr *[]*KeyValue, prefix string) (count int) { |
| keysRef, ok := c.store[prefix] |
| if !ok { |
| return 0 |
| } |
| |
| // TODO support sort option |
| if arr == nil { |
| for key := range keysRef { |
| if n := c.getPrefixKey(nil, key); n > 0 { |
| count += n |
| continue |
| } |
| count++ |
| } |
| return |
| } |
| |
| for key, val := range keysRef { |
| if n := c.getPrefixKey(arr, key); n > 0 { |
| count += n |
| continue |
| } |
| *arr = append(*arr, val) |
| count++ |
| } |
| return |
| } |
| |
| func (c *KvCache) addPrefixKey(key string, val *KeyValue) { |
| if len(c.Cfg.Key) >= len(key) { |
| return |
| } |
| prefix := c.prefix(key) |
| if len(prefix) == 0 { |
| return |
| } |
| keys, ok := c.store[prefix] |
| if !ok { |
| // build parent index key and new child nodes |
| keys = make(map[string]*KeyValue) |
| c.store[prefix] = keys |
| } else if _, ok := keys[key]; ok { |
| if val != nil { |
| // override the value |
| keys[key] = val |
| } |
| return |
| } |
| |
| keys[key], key = val, prefix |
| c.addPrefixKey(key, nil) |
| } |
| |
| func (c *KvCache) deletePrefixKey(key string) { |
| prefix := c.prefix(key) |
| m, ok := c.store[prefix] |
| if !ok { |
| return |
| } |
| delete(m, key) |
| |
| // remove parent which has no child |
| if len(m) == 0 { |
| delete(c.store, prefix) |
| c.deletePrefixKey(prefix) |
| } |
| } |
| |
| func NewKvCache(name string, cfg *Config) *KvCache { |
| return &KvCache{ |
| Cfg: cfg, |
| name: name, |
| store: make(map[string]map[string]*KeyValue), |
| lastRefresh: time.Now(), |
| } |
| } |