[WIP] Create a file-based lockstore component

lock/in-memory/in-memory.go

@@ -0,0 +1,131 @@
+/*
+Copyright 2024 The Dapr Authors
+Licensed 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 inmemory
+
+// duplicate redis/standalone.go using in-memory file instead of redis
+// Refer state/in-memory/in-memory.go
+import (
+	"context"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/dapr/components-contrib/lock"
+	"github.com/dapr/components-contrib/metadata"
+	"github.com/dapr/kit/logger"
+	"k8s.io/utils/clock"
+)
+
+type inMemoryLockStore struct {
+	items   map[string]*inMemoryLockItem
+	lock    sync.Mutex
+	log     logger.Logger
+	clock   clock.Clock
+	closeCh chan struct{}
+	closed  atomic.Bool
+	wg      sync.WaitGroup
+}
+
+func NewInMemoryLockStore(log logger.Logger) lock.Store {
+	return newLockStore(log)
+}
+
+func newLockStore(log logger.Logger) *inMemoryLockStore {
+	return &inMemoryLockStore{
+		items:   map[string]*inMemoryLockItem{},
+		log:     log,
+		clock:   clock.RealClock{},
+		closeCh: make(chan struct{}),
+	}
+}
+
+func (store *inMemoryLockStore) InitLockStore(ctx context.Context, metadata lock.Metadata) error {
+	// start a background go routine to clean expired items
+	store.wg.Add(1)
+	go func() {
+		defer store.wg.Done()
+		store.startCleanThread()
+	}()
+	return nil
+}
+
+func (store *inMemoryLockStore) TryLock(ctx context.Context, req *lock.TryLockRequest) (*lock.TryLockResponse, error) {
+	store.lock.Lock()
+	defer store.lock.Unlock()
+
+	return &lock.TryLockResponse{Success: true}, nil
+}
+
+func (store *inMemoryLockStore) Unlock(ctx context.Context, req *lock.UnlockRequest) (*lock.UnlockResponse, error) {
+	store.lock.Lock()
+	defer store.lock.Unlock()
+
+	return &lock.UnlockResponse{}, nil
+}
+
+func (store *inMemoryLockStore) Close() error {
+	if store.closed.CompareAndSwap(false, true) {
+		close(store.closeCh)
+	}
+
+	// release memory reference
+	store.lock.Lock()
+	defer store.lock.Unlock()
+	for k := range store.items {
+		delete(store.items, k)
+	}
+
+	store.wg.Wait()
+
+	return nil
+}
+
+func (store *inMemoryLockStore) GetComponentMetadata() (metadataInfo metadata.MetadataMap) {
+	// no metadata, hence no metadata struct to convert here
+	return
+}
+
+func (store *inMemoryLockStore) startCleanThread() {
+	for {
+		select {
+		case <-time.After(time.Second):
+			store.doCleanExpiredItems()
+		case <-store.closeCh:
+			return
+		}
+	}
+}
+
+func (store *inMemoryLockStore) doCleanExpiredItems() {
+	store.lock.Lock()
+	defer store.lock.Unlock()
+
+	for key, item := range store.items {
+		if item.expire != nil && item.isExpired(store.clock.Now()) {
+			delete(store.items, key)
+		}
+	}
+}
+
+type inMemoryLockItem struct {
+	value  string
+	expire *time.Time
+}
+
+func (item *inMemoryLockItem) isExpired(now time.Time) bool {
+	if item == nil || item.expire == nil {
+		return false
+	}
+	return now.After(*item.expire)
+}

lock/in-memory/in-memory_test.go

@@ -0,0 +1,14 @@
+/*
+Copyright 2024 The Dapr Authors
+Licensed 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 inmemory_test