directory structure change to work with glide

glide has its own requirements. My previous workaround caused me some
code checkin errors. Need to fix this.

weed/storage/needle_map.go

@@ -0,0 +1,123 @@
+package storage
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"sync"
+
+	"github.com/chrislusf/seaweedfs/weed/util"
+)
+
+type NeedleMapType int
+
+const (
+	NeedleMapInMemory NeedleMapType = iota
+	NeedleMapLevelDb
+	NeedleMapBoltDb
+)
+
+type NeedleMapper interface {
+	Put(key uint64, offset uint32, size uint32) error
+	Get(key uint64) (element *NeedleValue, ok bool)
+	Delete(key uint64) error
+	Close()
+	Destroy() error
+	ContentSize() uint64
+	DeletedSize() uint64
+	FileCount() int
+	DeletedCount() int
+	MaxFileKey() uint64
+	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 uint64, offset uint32, size uint32) {
+	key = util.BytesToUint64(bytes[:8])
+	offset = util.BytesToUint32(bytes[8:12])
+	size = util.BytesToUint32(bytes[12:16])
+	return
+}
+func (nm *baseNeedleMapper) appendToIndexFile(key uint64, offset uint32, size uint32) error {
+	bytes := make([]byte, 16)
+	util.Uint64toBytes(bytes[0:8], key)
+	util.Uint32toBytes(bytes[8:12], offset)
+	util.Uint32toBytes(bytes[12:16], 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())
+}
+
+type mapMetric struct {
+	indexFile *os.File
+
+	DeletionCounter     int    `json:"DeletionCounter"`
+	FileCounter         int    `json:"FileCounter"`
+	DeletionByteCounter uint64 `json:"DeletionByteCounter"`
+	FileByteCounter     uint64 `json:"FileByteCounter"`
+	MaximumFileKey      uint64 `json:"MaxFileKey"`
+}
+
+func (mm *mapMetric) logDelete(deletedByteCount uint32) {
+	mm.DeletionByteCounter = mm.DeletionByteCounter + uint64(deletedByteCount)
+	mm.DeletionCounter++
+}
+
+func (mm *mapMetric) logPut(key uint64, oldSize uint32, newSize uint32) {
+	if key > mm.MaximumFileKey {
+		mm.MaximumFileKey = key
+	}
+	mm.FileCounter++
+	mm.FileByteCounter = mm.FileByteCounter + uint64(newSize)
+	if oldSize > 0 {
+		mm.DeletionCounter++
+		mm.DeletionByteCounter = mm.DeletionByteCounter + uint64(oldSize)
+	}
+}
+
+func (mm mapMetric) ContentSize() uint64 {
+	return mm.FileByteCounter
+}
+func (mm mapMetric) DeletedSize() uint64 {
+	return mm.DeletionByteCounter
+}
+func (mm mapMetric) FileCount() int {
+	return mm.FileCounter
+}
+func (mm mapMetric) DeletedCount() int {
+	return mm.DeletionCounter
+}
+func (mm mapMetric) MaxFileKey() uint64 {
+	return mm.MaximumFileKey
+}