/*
 * Copyright 2023 CloudWeGo 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 contextmap

import (
	"context"
	"sync"
)

type contextMapKey struct{}

// WithContextMap returns a new context that carries a sync.Map
// It's useful if you want to share a sync.Map between middlewares, especially for
// StreamMiddleware and RecvMiddleware/SendMiddleware, since in recv/send middlewares,
// we can only get the stream.Context() which is a fixed node in the context tree.
//
// Note: it's not added to context by default, and you should add it yourself if needed.
func WithContextMap(ctx context.Context) context.Context {
	return context.WithValue(ctx, contextMapKey{}, &sync.Map{})
}

// GetContextMap returns the sync.Map in the given context
func GetContextMap(ctx context.Context) (m *sync.Map, ok bool) {
	if ctx != nil {
		m, ok = ctx.Value(contextMapKey{}).(*sync.Map)
	}
	return
}
