seaweedfs/weed/storage/needle_map.go

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package storage
import (
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"fmt"
"io/ioutil"
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"os"
"sync"
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"github.com/chrislusf/seaweedfs/weed/storage/needle"
. "github.com/chrislusf/seaweedfs/weed/storage/types"
"github.com/chrislusf/seaweedfs/weed/util"
)
type NeedleMapType int
const (
NeedleMapInMemory NeedleMapType = iota
NeedleMapLevelDb // small memory footprint, 4MB total, 1 write buffer, 3 block buffer
NeedleMapLevelDbMedium // medium memory footprint, 8MB total, 3 write buffer, 5 block buffer
NeedleMapLevelDbLarge // large memory footprint, 12MB total, 4write buffer, 8 block buffer
)
type NeedleMapper interface {
Put(key NeedleId, offset Offset, size uint32) error
Get(key NeedleId) (element *needle.NeedleValue, ok bool)
Delete(key NeedleId, offset Offset) error
Close()
Destroy() error
ContentSize() uint64
DeletedSize() uint64
FileCount() int
DeletedCount() int
MaxFileKey() NeedleId
IndexFileSize() uint64
IndexFileContent() ([]byte, error)
IndexFileName() string
}
type baseNeedleMapper struct {
indexFile *os.File
indexFileAccessLock sync.Mutex
mapMetric
}
func (nm *baseNeedleMapper) IndexFileSize() uint64 {
stat, err := nm.indexFile.Stat()
if err == nil {
return uint64(stat.Size())
}
return 0
}
func (nm *baseNeedleMapper) IndexFileName() string {
return nm.indexFile.Name()
}
func IdxFileEntry(bytes []byte) (key NeedleId, offset Offset, size uint32) {
key = BytesToNeedleId(bytes[:NeedleIdSize])
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offset = BytesToOffset(bytes[NeedleIdSize : NeedleIdSize+OffsetSize])
size = util.BytesToUint32(bytes[NeedleIdSize+OffsetSize : NeedleIdSize+OffsetSize+SizeSize])
return
}
func (nm *baseNeedleMapper) appendToIndexFile(key NeedleId, offset Offset, size uint32) error {
bytes := make([]byte, NeedleIdSize+OffsetSize+SizeSize)
NeedleIdToBytes(bytes[0:NeedleIdSize], key)
OffsetToBytes(bytes[NeedleIdSize:NeedleIdSize+OffsetSize], offset)
util.Uint32toBytes(bytes[NeedleIdSize+OffsetSize:NeedleIdSize+OffsetSize+SizeSize], size)
nm.indexFileAccessLock.Lock()
defer nm.indexFileAccessLock.Unlock()
if _, err := nm.indexFile.Seek(0, 2); err != nil {
return fmt.Errorf("cannot seek end of indexfile %s: %v",
nm.indexFile.Name(), err)
}
_, err := nm.indexFile.Write(bytes)
return err
}
func (nm *baseNeedleMapper) IndexFileContent() ([]byte, error) {
nm.indexFileAccessLock.Lock()
defer nm.indexFileAccessLock.Unlock()
return ioutil.ReadFile(nm.indexFile.Name())
}