blob: 5c56e228872d47e195cd477643ca0ace2753703e [file] [log] [blame]
// Copyright 2015 The etcd 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 wal
import (
"errors"
"fmt"
"strings"
"github.com/coreos/etcd/pkg/fileutil"
)
var (
badWalName = errors.New("bad wal name")
)
func Exist(dirpath string) bool {
names, err := fileutil.ReadDir(dirpath)
if err != nil {
return false
}
return len(names) != 0
}
// searchIndex returns the last array index of names whose raft index section is
// equal to or smaller than the given index.
// The given names MUST be sorted.
func searchIndex(names []string, index uint64) (int, bool) {
for i := len(names) - 1; i >= 0; i-- {
name := names[i]
_, curIndex, err := parseWalName(name)
if err != nil {
plog.Panicf("parse correct name should never fail: %v", err)
}
if index >= curIndex {
return i, true
}
}
return -1, false
}
// names should have been sorted based on sequence number.
// isValidSeq checks whether seq increases continuously.
func isValidSeq(names []string) bool {
var lastSeq uint64
for _, name := range names {
curSeq, _, err := parseWalName(name)
if err != nil {
plog.Panicf("parse correct name should never fail: %v", err)
}
if lastSeq != 0 && lastSeq != curSeq-1 {
return false
}
lastSeq = curSeq
}
return true
}
func readWalNames(dirpath string) ([]string, error) {
names, err := fileutil.ReadDir(dirpath)
if err != nil {
return nil, err
}
wnames := checkWalNames(names)
if len(wnames) == 0 {
return nil, ErrFileNotFound
}
return wnames, nil
}
func checkWalNames(names []string) []string {
wnames := make([]string, 0)
for _, name := range names {
if _, _, err := parseWalName(name); err != nil {
// don't complain about left over tmp files
if !strings.HasSuffix(name, ".tmp") {
plog.Warningf("ignored file %v in wal", name)
}
continue
}
wnames = append(wnames, name)
}
return wnames
}
func parseWalName(str string) (seq, index uint64, err error) {
if !strings.HasSuffix(str, ".wal") {
return 0, 0, badWalName
}
_, err = fmt.Sscanf(str, "%016x-%016x.wal", &seq, &index)
return seq, index, err
}
func walName(seq, index uint64) string {
return fmt.Sprintf("%016x-%016x.wal", seq, index)
}