go-common/vendor/github.com/dgraph-io/badger/util.go
2019-04-22 18:49:16 +08:00

140 lines
3.3 KiB
Go

/*
* Copyright 2017 Dgraph Labs, Inc. and Contributors
*
* 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 badger
import (
"io/ioutil"
"math/rand"
"sync/atomic"
"time"
"github.com/dgraph-io/badger/table"
"github.com/dgraph-io/badger/y"
"github.com/pkg/errors"
)
// summary is produced when DB is closed. Currently it is used only for testing.
type summary struct {
fileIDs map[uint64]bool
}
func (s *levelsController) getSummary() *summary {
out := &summary{
fileIDs: make(map[uint64]bool),
}
for _, l := range s.levels {
l.getSummary(out)
}
return out
}
func (s *levelHandler) getSummary(sum *summary) {
s.RLock()
defer s.RUnlock()
for _, t := range s.tables {
sum.fileIDs[t.ID()] = true
}
}
func (s *DB) validate() error { return s.lc.validate() }
func (s *levelsController) validate() error {
for _, l := range s.levels {
if err := l.validate(); err != nil {
return errors.Wrap(err, "Levels Controller")
}
}
return nil
}
// Check does some sanity check on one level of data or in-memory index.
func (s *levelHandler) validate() error {
if s.level == 0 {
return nil
}
s.RLock()
defer s.RUnlock()
numTables := len(s.tables)
for j := 1; j < numTables; j++ {
if j >= len(s.tables) {
return errors.Errorf("Level %d, j=%d numTables=%d", s.level, j, numTables)
}
if y.CompareKeys(s.tables[j-1].Biggest(), s.tables[j].Smallest()) >= 0 {
return errors.Errorf(
"Inter: %q vs %q: level=%d j=%d numTables=%d",
string(s.tables[j-1].Biggest()), string(s.tables[j].Smallest()), s.level, j, numTables)
}
if y.CompareKeys(s.tables[j].Smallest(), s.tables[j].Biggest()) > 0 {
return errors.Errorf(
"Intra: %q vs %q: level=%d j=%d numTables=%d",
s.tables[j].Smallest(), s.tables[j].Biggest(), s.level, j, numTables)
}
}
return nil
}
// func (s *KV) debugPrintMore() { s.lc.debugPrintMore() }
// // debugPrintMore shows key ranges of each level.
// func (s *levelsController) debugPrintMore() {
// s.Lock()
// defer s.Unlock()
// for i := 0; i < s.kv.opt.MaxLevels; i++ {
// s.levels[i].debugPrintMore()
// }
// }
// func (s *levelHandler) debugPrintMore() {
// s.RLock()
// defer s.RUnlock()
// s.elog.Printf("Level %d:", s.level)
// for _, t := range s.tables {
// y.Printf(" [%s, %s]", t.Smallest(), t.Biggest())
// }
// y.Printf("\n")
// }
// reserveFileID reserves a unique file id.
func (s *levelsController) reserveFileID() uint64 {
id := atomic.AddUint64(&s.nextFileID, 1)
return id - 1
}
func getIDMap(dir string) map[uint64]struct{} {
fileInfos, err := ioutil.ReadDir(dir)
y.Check(err)
idMap := make(map[uint64]struct{})
for _, info := range fileInfos {
if info.IsDir() {
continue
}
fileID, ok := table.ParseFileID(info.Name())
if !ok {
continue
}
idMap[fileID] = struct{}{}
}
return idMap
}
func init() {
rand.Seed(time.Now().UnixNano())
}