blob: a3f314bb126892b0e0b66267537bf8d664614c90 [file] [log] [blame]
khenaidoo59ce9dd2019-11-11 13:05:32 -05001// Copyright 2015 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 wal
16
17import (
18 "errors"
19 "fmt"
20 "strings"
21
22 "go.etcd.io/etcd/pkg/fileutil"
23
24 "go.uber.org/zap"
25)
26
27var errBadWALName = errors.New("bad wal name")
28
29// Exist returns true if there are any files in a given directory.
30func Exist(dir string) bool {
31 names, err := fileutil.ReadDir(dir, fileutil.WithExt(".wal"))
32 if err != nil {
33 return false
34 }
35 return len(names) != 0
36}
37
38// searchIndex returns the last array index of names whose raft index section is
39// equal to or smaller than the given index.
40// The given names MUST be sorted.
41func searchIndex(lg *zap.Logger, names []string, index uint64) (int, bool) {
42 for i := len(names) - 1; i >= 0; i-- {
43 name := names[i]
44 _, curIndex, err := parseWALName(name)
45 if err != nil {
46 if lg != nil {
47 lg.Panic("failed to parse WAL file name", zap.String("path", name), zap.Error(err))
48 } else {
49 plog.Panicf("parse correct name should never fail: %v", err)
50 }
51 }
52 if index >= curIndex {
53 return i, true
54 }
55 }
56 return -1, false
57}
58
59// names should have been sorted based on sequence number.
60// isValidSeq checks whether seq increases continuously.
61func isValidSeq(lg *zap.Logger, names []string) bool {
62 var lastSeq uint64
63 for _, name := range names {
64 curSeq, _, err := parseWALName(name)
65 if err != nil {
66 if lg != nil {
67 lg.Panic("failed to parse WAL file name", zap.String("path", name), zap.Error(err))
68 } else {
69 plog.Panicf("parse correct name should never fail: %v", err)
70 }
71 }
72 if lastSeq != 0 && lastSeq != curSeq-1 {
73 return false
74 }
75 lastSeq = curSeq
76 }
77 return true
78}
79
80func readWALNames(lg *zap.Logger, dirpath string) ([]string, error) {
81 names, err := fileutil.ReadDir(dirpath)
82 if err != nil {
83 return nil, err
84 }
85 wnames := checkWalNames(lg, names)
86 if len(wnames) == 0 {
87 return nil, ErrFileNotFound
88 }
89 return wnames, nil
90}
91
92func checkWalNames(lg *zap.Logger, names []string) []string {
93 wnames := make([]string, 0)
94 for _, name := range names {
95 if _, _, err := parseWALName(name); err != nil {
96 // don't complain about left over tmp files
97 if !strings.HasSuffix(name, ".tmp") {
98 if lg != nil {
99 lg.Warn(
100 "ignored file in WAL directory",
101 zap.String("path", name),
102 )
103 } else {
104 plog.Warningf("ignored file %v in wal", name)
105 }
106 }
107 continue
108 }
109 wnames = append(wnames, name)
110 }
111 return wnames
112}
113
114func parseWALName(str string) (seq, index uint64, err error) {
115 if !strings.HasSuffix(str, ".wal") {
116 return 0, 0, errBadWALName
117 }
118 _, err = fmt.Sscanf(str, "%016x-%016x.wal", &seq, &index)
119 return seq, index, err
120}
121
122func walName(seq, index uint64) string {
123 return fmt.Sprintf("%016x-%016x.wal", seq, index)
124}