little-cui closed pull request #281: SCB-337 Add a concurrent map impl URL: https://github.com/apache/incubator-servicecomb-service-center/pull/281
This is a PR merged from a forked repository. As GitHub hides the original diff on merge, it is displayed below for the sake of provenance: As this is a foreign pull request (from a fork), the diff is supplied below (as it won't show otherwise due to GitHub magic): diff --git a/pkg/util/concurrent_map.go b/pkg/util/concurrent_map.go new file mode 100644 index 00000000..b7ec0399 --- /dev/null +++ b/pkg/util/concurrent_map.go @@ -0,0 +1,120 @@ +/* + * 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 util + +import "sync" + +type MapItem struct { + Key interface{} + Value interface{} +} + +type ConcurrentMap struct { + items map[interface{}]interface{} + size int + mux sync.RWMutex + once sync.Once +} + +func (cm *ConcurrentMap) resize() { + cm.items = make(map[interface{}]interface{}, cm.size) +} + +func (cm *ConcurrentMap) init() { + cm.once.Do(cm.resize) +} + +func (cm *ConcurrentMap) Put(key, val interface{}) (old interface{}) { + cm.init() + cm.mux.Lock() + old, cm.items[key] = cm.items[key], val + cm.mux.Unlock() + return +} + +func (cm *ConcurrentMap) PutIfAbsent(key, val interface{}) (old interface{}) { + var b bool + cm.init() + cm.mux.Lock() + old, b = cm.items[key] + if !b { + cm.items[key] = val + } + cm.mux.Unlock() + return +} + +func (cm *ConcurrentMap) Get(key interface{}) (val interface{}, b bool) { + cm.init() + cm.mux.RLock() + val, b = cm.items[key] + cm.mux.RUnlock() + return +} + +func (cm *ConcurrentMap) Remove(key interface{}) (old interface{}) { + var b bool + cm.init() + cm.mux.Lock() + old, b = cm.items[key] + if b { + delete(cm.items, key) + } + cm.mux.Unlock() + return +} + +func (cm *ConcurrentMap) Clear() { + cm.mux.Lock() + cm.resize() + cm.mux.Unlock() +} + +func (cm *ConcurrentMap) Size() (s int) { + return len(cm.items) +} + +func (cm *ConcurrentMap) ForEach(f func(item MapItem) (next bool)) { + cm.mux.RLock() + s := len(cm.items) + if s == 0 { + cm.mux.RUnlock() + return + } + // avoid dead lock in function 'f' + ch := make(chan MapItem, s) + for k, v := range cm.items { + ch <- MapItem{k, v} + } + cm.mux.RUnlock() + + for { + select { + case item := <-ch: + if b := f(item); b { + continue + } + default: + } + break + } + close(ch) +} + +func NewConcurrentMap(size int) ConcurrentMap { + return ConcurrentMap{size: size} +} diff --git a/pkg/util/concurrent_map_test.go b/pkg/util/concurrent_map_test.go new file mode 100644 index 00000000..b0cc1c6c --- /dev/null +++ b/pkg/util/concurrent_map_test.go @@ -0,0 +1,177 @@ +/* + * 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 util + +import ( + "fmt" + "testing" +) + +func TestConcurrentMap(t *testing.T) { + cm := ConcurrentMap{} + s := cm.Size() + if s != 0 { + fmt.Println("TestConcurrentMap Size failed.") + t.Fail() + } + v, b := cm.Get("a") + if b || v != nil { + fmt.Println("TestConcurrentMap Get a not exist item failed.") + t.Fail() + } + v = cm.Put("a", "1") + if v != nil { + fmt.Println("TestConcurrentMap Put a new item failed.") + t.Fail() + } + v, b = cm.Get("a") + if !b || v.(string) != "1" { + fmt.Println("TestConcurrentMap Get an exist item failed.") + t.Fail() + } + v = cm.Put("a", "2") + if v.(string) != "1" { + fmt.Println("TestConcurrentMap Put an item again failed.") + t.Fail() + } + v = cm.PutIfAbsent("b", "1") + if v != nil { + fmt.Println("TestConcurrentMap PutIfAbsent a not exist item failed.") + t.Fail() + } + v = cm.PutIfAbsent("a", "3") + if v.(string) != "2" { + fmt.Println("TestConcurrentMap PutIfAbsent an item failed.") + t.Fail() + } + v, b = cm.Get("a") + if !b || v.(string) != "2" { + fmt.Println("TestConcurrentMap Get an item after PutIfAbsent failed.") + t.Fail() + } + v = cm.Remove("a") + if v.(string) != "2" { + fmt.Println("TestConcurrentMap Remove an item failed.") + t.Fail() + } + v, b = cm.Get("a") + if b || v != nil { + fmt.Println("TestConcurrentMap Get an item after Remove failed.") + t.Fail() + } + s = cm.Size() + if s != 1 { // only 'b' is left + fmt.Println("TestConcurrentMap Size after Put failed.") + t.Fail() + } + cm.Clear() + s = cm.Size() + if s != 0 { + fmt.Println("TestConcurrentMap Size after Clear failed.") + t.Fail() + } +} + +func TestConcurrentMap_ForEach(t *testing.T) { + l := 0 + cm := ConcurrentMap{} + cm.ForEach(func(item MapItem) bool { + l++ + return true + }) + if l != 0 { + fmt.Println("TestConcurrentMap_ForEach failed.") + t.Fail() + } + for i := 0; i < 1000; i++ { + cm.Put(i, i) + } + cm.ForEach(func(item MapItem) bool { + l++ + cm.Remove(item.Key) + return true + }) + if l != 1000 || cm.Size() != 0 { + fmt.Println("TestConcurrentMap_ForEach does not empty failed.") + t.Fail() + } +} + +func TestNewConcurrentMap(t *testing.T) { + cm := NewConcurrentMap(100) + if cm.size != 100 { + fmt.Println("TestNewConcurrentMap failed.") + t.Fail() + } +} + +func BenchmarkConcurrentMap_Get(b *testing.B) { + var v interface{} + cm := ConcurrentMap{} + cm.Put("a", "1") + b.ResetTimer() + b.RunParallel(func(pb *testing.PB) { + for pb.Next() { + v, _ = cm.Get("a") + } + }) + b.ReportAllocs() + // 20000000 88.7 ns/op 0 B/op 0 allocs/op +} + +func BenchmarkConcurrentMap_Put(b *testing.B) { + cm := &ConcurrentMap{} + b.ResetTimer() + b.RunParallel(func(pb *testing.PB) { + for pb.Next() { + cm.Put("a", "1") + } + }) + b.ReportAllocs() + // 3000000 420 ns/op 32 B/op 2 allocs/op +} + +func BenchmarkConcurrentMap_PutAndGet(b *testing.B) { + var v interface{} + cm := &ConcurrentMap{} + b.ResetTimer() + b.RunParallel(func(pb *testing.PB) { + for pb.Next() { + cm.Put("a", "1") + v, _ = cm.Get("a") + } + }) + b.ReportAllocs() + // 3000000 560 ns/op 32 B/op 2 allocs/op +} + +func BenchmarkConcurrentMap_ForEach(b *testing.B) { + cm := ConcurrentMap{} + for i := 0; i < 100; i++ { + cm.Put(i, i) + } + b.ResetTimer() + b.RunParallel(func(pb *testing.PB) { + for pb.Next() { + cm.ForEach(func(item MapItem) bool { + return true + }) + } + }) + b.ReportAllocs() + // 500000 3148 ns/op 3296 B/op 2 allocs/op +} ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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