Add Memory String Lock provider

coa/pkg/apis/v1alpha2/providers/stringlock/memorystringlock/memorystringlock.go

@@ -0,0 +1,168 @@
+/*
+ * Copyright (c) Microsoft Corporation.
+ * Licensed under the MIT license.
+ * SPDX-License-Identifier: MIT
+ */
+
+package memorystringlock
+
+import (
+	"encoding/json"
+	"errors"
+	"sync"
+	"time"
+
+	"github.com/eclipse-symphony/symphony/coa/pkg/apis/v1alpha2/providers"
+	"github.com/eclipse-symphony/symphony/coa/pkg/apis/v1alpha2/providers/stringlock"
+	"github.com/eclipse-symphony/symphony/coa/pkg/logger"
+)
+
+var sLog = logger.NewLogger("coa.runtime")
+
+type MemoryStringLockProvider struct {
+	lm            *LockManager
+	cleanInterval int //seconds
+	purgeDuration int // 12 hours before
+}
+
+type MemoryStringLockProviderConfig struct {
+	CleanInterval int `json:"cleanInterval"`
+	PurgeDuration int `json:"purgeDuration"`
+}
+
+func toMemoryStringLockProviderConfig(config providers.IProviderConfig) (MemoryStringLockProviderConfig, error) {
+	ret := MemoryStringLockProviderConfig{}
+	data, err := json.Marshal(config)
+	if err != nil {
+		return ret, err
+	}
+	err = json.Unmarshal(data, &ret)
+	return ret, err
+}
+
+func (mslp *MemoryStringLockProvider) Init(config providers.IProviderConfig) error {
+	stringLockConfig, err := toMemoryStringLockProviderConfig(config)
+	if err != nil {
+		sLog.Errorf("  P (String Lock): failed to parse provider config %+v", err)
+		return errors.New("expected MemoryStringLockProviderConfig")
+	}
+	if stringLockConfig.CleanInterval > 0 {
+		mslp.cleanInterval = stringLockConfig.CleanInterval
+	} else {
+		mslp.cleanInterval = 30 // default: 30 seconds
+	}
+	if stringLockConfig.PurgeDuration > 0 {
+		mslp.purgeDuration = stringLockConfig.PurgeDuration
+	} else {
+		mslp.purgeDuration = 60 * 60 * 12 // default: 12 hours
+	}
+	mslp.lm = NewLockManager()
+	go func() {
+		for {
+			mslp.lm.clean(-mslp.purgeDuration)
+			time.Sleep(time.Duration(mslp.cleanInterval) * time.Second)
+		}
+	}()
+	return nil
+}
+
+func (mslp *MemoryStringLockProvider) Lock(key string) stringlock.UnLock {
+	mslp.lm.getLockNode(key).Lock()
+
+	return func() {
+		mslp.lm.getLockNode(key).Unlock()
+		go mslp.lm.updateLockLRU(key)
+	}
+}
+
+type LockNode struct {
+	lastUsedTime time.Time
+	key          string
+	lock         sync.Mutex
+	prev         *LockNode
+	next         *LockNode
+}
+
+type LockManager struct {
+	m    *sync.Map
+	head *LockNode
+	tail *LockNode
+	mu   sync.Mutex
+}
+
+func NewLockManager() *LockManager {
+	lm := LockManager{
+		m:    &sync.Map{},
+		head: nil,
+		tail: nil,
+	}
+	lm.head = &LockNode{prev: nil, next: nil} // dummyhead
+	lm.tail = &LockNode{prev: nil, next: nil} // dummytail
+	lm.head.next = lm.tail
+	lm.tail.prev = lm.head
+	return &lm
+}
+
+func (lm *LockManager) moveToHead(node *LockNode) {
+	if lm.head.next == node {
+		return
+	}
+	if node.prev != nil {
+		node.prev.next = node.next
+	}
+	if node.next != nil {
+		node.next.prev = node.prev
+	}
+
+	node.prev = lm.head
+	node.next = lm.head.next
+	node.next.prev = node
+	lm.head.next = node
+}
+
+func (lm *LockManager) getLockNode(key string) *sync.Mutex {
+	locknode, _ := lm.m.LoadOrStore(key, &LockNode{key: key, prev: nil, next: nil})
+	if ln, ok := locknode.(*LockNode); ok {
+		return &ln.lock
+	} else {
+		print("unexpected behavior")
+		panic("unexpected behavior")
+	}
+}
+
+func (lm *LockManager) updateLockLRU(key string) {
+	lm.mu.Lock()
+	defer lm.mu.Unlock()
+
+	locknode, ok := lm.m.Load(key)
+
+	if ok {
+		locknode.(*LockNode).lastUsedTime = time.Now()
+
+		lm.moveToHead(locknode.(*LockNode))
+	}
+}
+
+func (lm *LockManager) cleanLast(purgeDuration int) bool {
+	if lm.tail.prev == lm.head || lm.tail.prev.lastUsedTime.After(time.Now().Add(time.Duration(purgeDuration)*time.Second)) {
+		return false
+	}
+
+	node := lm.tail.prev
+	if node.prev != nil {
+		node.prev.next = node.next
+	}
+	if node.next != nil {
+		node.next.prev = node.prev
+	}
+
+	lm.m.Delete(node.key)
+	return true
+}
+
+func (lm *LockManager) clean(purgeDuration int) {
+	lm.mu.Lock()
+	defer lm.mu.Unlock()
+	for lm.cleanLast(purgeDuration) {
+	}
+}