1// Copyright 2016 The etcd Authors
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package v3compactor
16
17import (
18	"context"
19	"fmt"
20	"time"
21
22	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
23
24	"github.com/jonboulle/clockwork"
25	"go.uber.org/zap"
26)
27
28const (
29	ModePeriodic = "periodic"
30	ModeRevision = "revision"
31)
32
33// Compactor purges old log from the storage periodically.
34type Compactor interface {
35	// Run starts the main loop of the compactor in background.
36	// Use Stop() to halt the loop and release the resource.
37	Run()
38	// Stop halts the main loop of the compactor.
39	Stop()
40	// Pause temporally suspend the compactor not to run compaction. Resume() to unpose.
41	Pause()
42	// Resume restarts the compactor suspended by Pause().
43	Resume()
44}
45
46type Compactable interface {
47	Compact(ctx context.Context, r *pb.CompactionRequest) (*pb.CompactionResponse, error)
48}
49
50type RevGetter interface {
51	Rev() int64
52}
53
54// New returns a new Compactor based on given "mode".
55func New(
56	lg *zap.Logger,
57	mode string,
58	retention time.Duration,
59	rg RevGetter,
60	c Compactable,
61) (Compactor, error) {
62	if lg == nil {
63		lg = zap.NewNop()
64	}
65	switch mode {
66	case ModePeriodic:
67		return newPeriodic(lg, clockwork.NewRealClock(), retention, rg, c), nil
68	case ModeRevision:
69		return newRevision(lg, clockwork.NewRealClock(), int64(retention), rg, c), nil
70	default:
71		return nil, fmt.Errorf("unsupported compaction mode %s", mode)
72	}
73}
74