seaweedfs/weed/storage/erasure_coding/ec_volume.go
2019-06-05 23:20:26 -07:00

192 lines
4.9 KiB
Go

package erasure_coding
import (
"fmt"
"math"
"os"
"sort"
"sync"
"time"
"github.com/chrislusf/seaweedfs/weed/pb/master_pb"
"github.com/chrislusf/seaweedfs/weed/storage/idx"
"github.com/chrislusf/seaweedfs/weed/storage/needle"
"github.com/chrislusf/seaweedfs/weed/storage/types"
)
type EcVolume struct {
VolumeId needle.VolumeId
Collection string
dir string
ecxFile *os.File
ecxFileSize int64
ecxCreatedAt time.Time
Shards []*EcVolumeShard
ShardLocations map[ShardId][]string
ShardLocationsRefreshTime time.Time
ShardLocationsLock sync.RWMutex
Version needle.Version
}
func NewEcVolume(dir string, collection string, vid needle.VolumeId) (ev *EcVolume, err error) {
ev = &EcVolume{dir: dir, Collection: collection, VolumeId: vid}
baseFileName := EcShardFileName(collection, dir, int(vid))
// open ecx file
if ev.ecxFile, err = os.OpenFile(baseFileName+".ecx", os.O_RDONLY, 0644); err != nil {
return nil, fmt.Errorf("cannot read ec volume index %s.ecx: %v", baseFileName, err)
}
ecxFi, statErr := ev.ecxFile.Stat()
if statErr != nil {
return nil, fmt.Errorf("can not stat ec volume index %s.ecx: %v", baseFileName, statErr)
}
ev.ecxFileSize = ecxFi.Size()
ev.ecxCreatedAt = ecxFi.ModTime()
ev.ShardLocations = make(map[ShardId][]string)
return
}
func (ev *EcVolume) AddEcVolumeShard(ecVolumeShard *EcVolumeShard) bool {
for _, s := range ev.Shards {
if s.ShardId == ecVolumeShard.ShardId {
return false
}
}
ev.Shards = append(ev.Shards, ecVolumeShard)
sort.Slice(ev.Shards, func(i, j int) bool {
return ev.Shards[i].VolumeId < ev.Shards[j].VolumeId ||
ev.Shards[i].VolumeId == ev.Shards[j].VolumeId && ev.Shards[i].ShardId < ev.Shards[j].ShardId
})
return true
}
func (ev *EcVolume) DeleteEcVolumeShard(shardId ShardId) (ecVolumeShard *EcVolumeShard, deleted bool) {
foundPosition := -1
for i, s := range ev.Shards {
if s.ShardId == shardId {
foundPosition = i
}
}
if foundPosition < 0 {
return nil, false
}
ecVolumeShard = ev.Shards[foundPosition]
ev.Shards = append(ev.Shards[:foundPosition], ev.Shards[foundPosition+1:]...)
return ecVolumeShard, true
}
func (ev *EcVolume) FindEcVolumeShard(shardId ShardId) (ecVolumeShard *EcVolumeShard, found bool) {
for _, s := range ev.Shards {
if s.ShardId == shardId {
return s, true
}
}
return nil, false
}
func (ev *EcVolume) Close() {
for _, s := range ev.Shards {
s.Close()
}
if ev.ecxFile != nil {
_ = ev.ecxFile.Close()
ev.ecxFile = nil
}
}
func (ev *EcVolume) Destroy() {
ev.Close()
for _, s := range ev.Shards {
s.Destroy()
}
os.Remove(ev.FileName() + ".ecx")
}
func (ev *EcVolume) FileName() string {
return EcShardFileName(ev.Collection, ev.dir, int(ev.VolumeId))
}
func (ev *EcVolume) ShardSize() int64 {
if len(ev.Shards) > 0 {
return ev.Shards[0].Size()
}
return 0
}
func (ev *EcVolume) CreatedAt() time.Time {
return ev.ecxCreatedAt
}
func (ev *EcVolume) ShardIdList() (shardIds []ShardId) {
for _, s := range ev.Shards {
shardIds = append(shardIds, s.ShardId)
}
return
}
func (ev *EcVolume) ToVolumeEcShardInformationMessage() (messages []*master_pb.VolumeEcShardInformationMessage) {
prevVolumeId := needle.VolumeId(math.MaxUint32)
var m *master_pb.VolumeEcShardInformationMessage
for _, s := range ev.Shards {
if s.VolumeId != prevVolumeId {
m = &master_pb.VolumeEcShardInformationMessage{
Id: uint32(s.VolumeId),
Collection: s.Collection,
}
messages = append(messages, m)
}
prevVolumeId = s.VolumeId
m.EcIndexBits = uint32(ShardBits(m.EcIndexBits).AddShardId(s.ShardId))
}
return
}
func (ev *EcVolume) LocateEcShardNeedle(n *needle.Needle, version needle.Version) (offset types.Offset, size uint32, intervals []Interval, err error) {
// find the needle from ecx file
offset, size, err = ev.findNeedleFromEcx(n.Id)
if err != nil {
return types.Offset{}, 0, nil, fmt.Errorf("findNeedleFromEcx: %v", err)
}
shard := ev.Shards[0]
// calculate the locations in the ec shards
intervals = LocateData(ErasureCodingLargeBlockSize, ErasureCodingSmallBlockSize, DataShardsCount*shard.ecdFileSize, offset.ToAcutalOffset(), uint32(needle.GetActualSize(size, version)))
return
}
func (ev *EcVolume) findNeedleFromEcx(needleId types.NeedleId) (offset types.Offset, size uint32, err error) {
var key types.NeedleId
buf := make([]byte, types.NeedleMapEntrySize)
l, h := int64(0), ev.ecxFileSize/types.NeedleMapEntrySize
for l < h {
m := (l + h) / 2
if _, err := ev.ecxFile.ReadAt(buf, m*types.NeedleMapEntrySize); err != nil {
return types.Offset{}, 0, fmt.Errorf("ecx file %d read at %d: %v", ev.ecxFileSize, m*types.NeedleMapEntrySize, err)
}
key, offset, size = idx.IdxFileEntry(buf)
if key == needleId {
return
}
if key < needleId {
l = m + 1
} else {
h = m
}
}
err = fmt.Errorf("needle id %d not found", needleId)
return
}