// Copyright 2015 The Prometheus 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 storage

import (
	clientmodel "github.com/prometheus/client_golang/model"
)

// SampleAppender is the interface to append samples to both, local and remote
// storage.
type SampleAppender interface {
	Append(*clientmodel.Sample)
}

// Tee is a SampleAppender that appends every sample to two other
// SampleAppenders.
type Tee struct {
	Appender1, Appender2 SampleAppender
}

// Append implements SampleAppender. It appends the provided sample first
// to Appender1, then to Appender2, waiting for each to return before
// proceeding.
func (t Tee) Append(s *clientmodel.Sample) {
	t.Appender1.Append(s)
	t.Appender2.Append(s)
}