diff --git a/down/bt/metainfo/metainfo_test.go b/down/bt/metainfo/metainfo_test.go
deleted file mode 100644
index 042b09e3..00000000
--- a/down/bt/metainfo/metainfo_test.go
+++ /dev/null
@@ -1,15 +0,0 @@
-package metainfo
-
-import (
-	"fmt"
-	"testing"
-)
-
-func TestParseFromFile(t *testing.T) {
-	metaInfo, err := ParseFromFile("../testdata/Game.of.Thrones.S08E05.720p.WEB.H264-MEMENTO.torrent")
-	if err != nil {
-		panic(err)
-	}
-	fmt.Printf("%+v\n", metaInfo.AnnounceList)
-	fmt.Printf("%+v\n", metaInfo.Info.Files)
-}
diff --git a/down/bt/torrent/torrent_test.go b/down/bt/torrent/torrent_test.go
deleted file mode 100644
index 409249f1..00000000
--- a/down/bt/torrent/torrent_test.go
+++ /dev/null
@@ -1,32 +0,0 @@
-package torrent
-
-import (
-	"github.com/monkeyWie/gopeed/down/bt/metainfo"
-	"github.com/monkeyWie/gopeed/down/bt/peer"
-	"testing"
-)
-
-func TestTorrent_Download(t *testing.T) {
-	torrent := buildTorrent()
-	torrent.Download("e:/testbt/download")
-}
-
-func buildTorrent() *Torrent {
-	metaInfo, err := metainfo.ParseFromFile("../testdata/Game.of.Thrones.S08E05.720p.WEB.H264-MEMENTO.torrent")
-	if err != nil {
-		panic(err)
-	}
-	// metaInfo.Announce = "udp://exodus.desync.com:6969/announce"
-	// metaInfo.Announce = "udp://tracker.openbittorrent.com:80/announce"
-	// metaInfo.Announce = "udp://tracker.cyberia.is:6969/announce"
-	// metaInfo.Announce = "udp://9.rarbg.me:2780/announce"
-	// metaInfo.Announce = "udp://9.rarbg.to:2760/announce"
-	// metaInfo.Announce = "udp://tracker.leechers-paradise.org:6969"
-	metaInfo.AnnounceList = [][]string{}
-	metaInfo.AnnounceList = append(metaInfo.AnnounceList, []string{
-		"udp://exodus.desync.com:6969/announce",
-		"udp://tracker.openbittorrent.com:80/announce",
-		"udp://tracker.leechers-paradise.org:6969",
-	})
-	return NewTorrent(peer.GenPeerID(), metaInfo)
-}
diff --git a/go.mod b/go.mod
index f1f60be4..294d22c2 100644
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,7 @@ module github.com/monkeyWie/gopeed
 go 1.13
 
 require (
+	github.com/RoaringBitmap/roaring v0.4.21
 	github.com/cenkalti/mse v0.0.0-20140930130441-6ef65f170972
 	github.com/marksamman/bencode v0.0.0-20150821143521-dc84f26e086e
 )
diff --git a/go.sum b/go.sum
index 4fb0ab47..d334cd5d 100644
--- a/go.sum
+++ b/go.sum
@@ -1,4 +1,35 @@
+github.com/RoaringBitmap/roaring v0.4.21 h1:WJ/zIlNX4wQZ9x8Ey33O1UaD9TCTakYsdLFSBcTwH+8=
+github.com/RoaringBitmap/roaring v0.4.21/go.mod h1:D0gp8kJQgE1A4LQ5wFLggQEyvDi06Mq5mKs52e1TwOo=
 github.com/cenkalti/mse v0.0.0-20140930130441-6ef65f170972 h1:FvAasVrPm/VUO8M0odLDqA9Y7VbALYq3PRAwmWGPw78=
 github.com/cenkalti/mse v0.0.0-20140930130441-6ef65f170972/go.mod h1:wGf99xKTJ8f/a8cC1inMqFz9cGEzISLLid5F6i5fI/g=
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/glycerine/go-unsnap-stream v0.0.0-20181221182339-f9677308dec2 h1:Ujru1hufTHVb++eG6OuNDKMxZnGIvF6o/u8q/8h2+I4=
+github.com/glycerine/go-unsnap-stream v0.0.0-20181221182339-f9677308dec2/go.mod h1:/20jfyN9Y5QPEAprSgKAUr+glWDY39ZiUEAYOEv5dsE=
+github.com/glycerine/goconvey v0.0.0-20190410193231-58a59202ab31 h1:gclg6gY70GLy3PbkQ1AERPfmLMMagS60DKF78eWwLn8=
+github.com/glycerine/goconvey v0.0.0-20190410193231-58a59202ab31/go.mod h1:Ogl1Tioa0aV7gstGFO7KhffUsb9M4ydbEbbxpcEDc24=
+github.com/golang/snappy v0.0.1 h1:Qgr9rKW7uDUkrbSmQeiDsGa8SjGyCOGtuasMWwvp2P4=
+github.com/golang/snappy v0.0.1/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
+github.com/gopherjs/gopherjs v0.0.0-20190910122728-9d188e94fb99 h1:twflg0XRTjwKpxb/jFExr4HGq6on2dEOmnL6FV+fgPw=
+github.com/gopherjs/gopherjs v0.0.0-20190910122728-9d188e94fb99/go.mod h1:wJfORRmW1u3UXTncJ5qlYoELFm8eSnnEO6hX4iZ3EWY=
+github.com/jtolds/gls v4.20.0+incompatible h1:xdiiI2gbIgH/gLH7ADydsJ1uDOEzR8yvV7C0MuV77Wo=
+github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
 github.com/marksamman/bencode v0.0.0-20150821143521-dc84f26e086e h1:KMs6SK8iDSR1+ZzOK10L5wGPpWDByyvOe5nrqk51g2U=
 github.com/marksamman/bencode v0.0.0-20150821143521-dc84f26e086e/go.mod h1:+AHfJo5+69p+fjvMJTmYajNP9rFBHQcaTDFmuXRRATI=
+github.com/mschoch/smat v0.0.0-20160514031455-90eadee771ae h1:VeRdUYdCw49yizlSbMEn2SZ+gT+3IUKx8BqxyQdz+BY=
+github.com/mschoch/smat v0.0.0-20160514031455-90eadee771ae/go.mod h1:qAyveg+e4CE+eKJXWVjKXM4ck2QobLqTDytGJbLLhJg=
+github.com/philhofer/fwd v1.0.0 h1:UbZqGr5Y38ApvM/V/jEljVxwocdweyH+vmYvRPBnbqQ=
+github.com/philhofer/fwd v1.0.0/go.mod h1:gk3iGcWd9+svBvR0sR+KPcfE+RNWozjowpeBVG3ZVNU=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
+github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
+github.com/tinylib/msgp v1.1.0 h1:9fQd+ICuRIu/ue4vxJZu6/LzxN0HwMds2nq/0cFvxHU=
+github.com/tinylib/msgp v1.1.0/go.mod h1:+d+yLhGm8mzTaHzB+wgMYrodPfmZrzkirds8fDWklFE=
+github.com/willf/bitset v1.1.10 h1:NotGKqX0KwQ72NUzqrjZq5ipPNDQex9lo3WpaS8L2sc=
+github.com/willf/bitset v1.1.10/go.mod h1:RjeCKbqT1RxIR/KWY6phxZiaY1IyutSBfGjNPySAYV4=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
diff --git a/main.go b/main.go
index 69342c01..31489a77 100644
--- a/main.go
+++ b/main.go
@@ -2,11 +2,11 @@ package main
 
 import (
 	"fmt"
-	"github.com/monkeyWie/gopeed/down/bt/metainfo"
-	"github.com/monkeyWie/gopeed/down/bt/peer"
-	"github.com/monkeyWie/gopeed/down/bt/torrent"
-	"github.com/monkeyWie/gopeed/down/bt/tracker"
-	"github.com/monkeyWie/gopeed/down/http"
+	"github.com/monkeyWie/gopeed/protocol/bt/metainfo"
+	"github.com/monkeyWie/gopeed/protocol/bt/peer"
+	"github.com/monkeyWie/gopeed/protocol/bt/torrent"
+	"github.com/monkeyWie/gopeed/protocol/bt/tracker"
+	"github.com/monkeyWie/gopeed/protocol/http"
 )
 
 func main() {
diff --git a/down/bt/client.go b/protocol/bt/client.go
similarity index 90%
rename from down/bt/client.go
rename to protocol/bt/client.go
index 0d2d368a..d4336ebd 100644
--- a/down/bt/client.go
+++ b/protocol/bt/client.go
@@ -2,8 +2,8 @@ package bt
 
 import (
 	"crypto/rand"
-	"github.com/monkeyWie/gopeed/down/bt/metainfo"
-	"github.com/monkeyWie/gopeed/down/bt/torrent"
+	"github.com/monkeyWie/gopeed/protocol/bt/metainfo"
+	"github.com/monkeyWie/gopeed/protocol/bt/torrent"
 	"net/url"
 )
 
diff --git a/down/bt/client_test.go b/protocol/bt/client_test.go
similarity index 100%
rename from down/bt/client_test.go
rename to protocol/bt/client_test.go
diff --git a/down/bt/metainfo/metainfo.go b/protocol/bt/metainfo/metainfo.go
similarity index 88%
rename from down/bt/metainfo/metainfo.go
rename to protocol/bt/metainfo/metainfo.go
index a8df3308..0c10bae5 100644
--- a/down/bt/metainfo/metainfo.go
+++ b/protocol/bt/metainfo/metainfo.go
@@ -29,10 +29,12 @@ type MetaInfo struct {
 
 type Info struct {
 	Name        string `json:"name"`
-	PieceLength uint64 `json:"piece length"`
+	PieceLength int    `json:"piece length"`
 	Pieces      [][20]byte
-	Length      uint64 `json:"length"`
-	Files       []File `json:"files"`
+	// 单个文件时，length为该文件的长度
+	Length uint64 `json:"length"`
+	// 多个文件
+	Files []File `json:"files"`
 }
 
 type File struct {
@@ -47,6 +49,12 @@ type FileDetail struct {
 	End    int64
 }
 
+type PieceMapping struct {
+	file  int
+	begin int64
+	end   int64
+}
+
 func ParseFromFile(path string) (*MetaInfo, error) {
 	file, err := os.Open(path)
 	if err != nil {
@@ -85,12 +93,12 @@ func ParseFromFile(path string) (*MetaInfo, error) {
 }
 
 // 获取某个分片的大小
-func (metaInfo *MetaInfo) GetPieceSize(index int) uint64 {
+func (metaInfo *MetaInfo) GetPieceLength(index int) int {
 	// 是否为最后一个分片
 	if index == len(metaInfo.Info.Pieces)-1 {
-		size := metaInfo.totalSize % metaInfo.Info.PieceLength
+		size := metaInfo.totalSize % uint64(metaInfo.Info.PieceLength)
 		if size > 0 {
-			return size
+			return int(size)
 		}
 	}
 	return metaInfo.Info.PieceLength
diff --git a/protocol/bt/metainfo/metainfo_test.go b/protocol/bt/metainfo/metainfo_test.go
new file mode 100644
index 00000000..10a03465
--- /dev/null
+++ b/protocol/bt/metainfo/metainfo_test.go
@@ -0,0 +1,29 @@
+package metainfo
+
+import (
+	"encoding/hex"
+	"fmt"
+	"github.com/RoaringBitmap/roaring"
+	"testing"
+)
+
+func TestParseFromFile(t *testing.T) {
+	// metaInfo, err := ParseFromFile("../testdata/Game.of.Thrones.S08E05.720p.WEB.H264-MEMENTO.torrent")
+	metaInfo, err := ParseFromFile("../testdata/office.torrent")
+	if err != nil {
+		panic(err)
+	}
+	fmt.Printf("%+v\n", metaInfo.AnnounceList)
+	fmt.Printf("%+v\n", metaInfo.Info.Files)
+	fmt.Printf("%+v\n", metaInfo.Info.PieceLength)
+	fmt.Printf("%+v\n", hex.EncodeToString(metaInfo.infoHash[:]))
+}
+
+func TestParseFromFile2(t *testing.T) {
+	bitmap := roaring.NewBitmap()
+	bitmap.AddMany([]uint32{1, 2, 3, 4, 5, 6, 7, 10, 20, 9, 9, 1})
+	fmt.Println(bitmap.Contains(1))
+	fmt.Println(bitmap.Contains(2))
+	fmt.Println(bitmap.Contains(8))
+	fmt.Println(bitmap.GetCardinality())
+}
diff --git a/down/bt/peer/handshake.go b/protocol/bt/peer/handshake.go
similarity index 100%
rename from down/bt/peer/handshake.go
rename to protocol/bt/peer/handshake.go
diff --git a/down/bt/peer/message/message.go b/protocol/bt/peer/message/message.go
similarity index 100%
rename from down/bt/peer/message/message.go
rename to protocol/bt/peer/message/message.go
diff --git a/down/bt/peer/message/msg_bitfield.go b/protocol/bt/peer/message/msg_bitfield.go
similarity index 100%
rename from down/bt/peer/message/msg_bitfield.go
rename to protocol/bt/peer/message/msg_bitfield.go
diff --git a/down/bt/peer/message/msg_bitfield_test.go b/protocol/bt/peer/message/msg_bitfield_test.go
similarity index 100%
rename from down/bt/peer/message/msg_bitfield_test.go
rename to protocol/bt/peer/message/msg_bitfield_test.go
diff --git a/down/bt/peer/message/msg_choke.go b/protocol/bt/peer/message/msg_choke.go
similarity index 100%
rename from down/bt/peer/message/msg_choke.go
rename to protocol/bt/peer/message/msg_choke.go
diff --git a/down/bt/peer/message/msg_interested.go b/protocol/bt/peer/message/msg_interested.go
similarity index 100%
rename from down/bt/peer/message/msg_interested.go
rename to protocol/bt/peer/message/msg_interested.go
diff --git a/down/bt/peer/message/msg_keepalive.go b/protocol/bt/peer/message/msg_keepalive.go
similarity index 100%
rename from down/bt/peer/message/msg_keepalive.go
rename to protocol/bt/peer/message/msg_keepalive.go
diff --git a/down/bt/peer/message/msg_not_interested.go b/protocol/bt/peer/message/msg_not_interested.go
similarity index 100%
rename from down/bt/peer/message/msg_not_interested.go
rename to protocol/bt/peer/message/msg_not_interested.go
diff --git a/down/bt/peer/message/msg_piece.go b/protocol/bt/peer/message/msg_piece.go
similarity index 100%
rename from down/bt/peer/message/msg_piece.go
rename to protocol/bt/peer/message/msg_piece.go
diff --git a/down/bt/peer/message/msg_request.go b/protocol/bt/peer/message/msg_request.go
similarity index 100%
rename from down/bt/peer/message/msg_request.go
rename to protocol/bt/peer/message/msg_request.go
diff --git a/down/bt/peer/message/msg_unchoke.go b/protocol/bt/peer/message/msg_unchoke.go
similarity index 100%
rename from down/bt/peer/message/msg_unchoke.go
rename to protocol/bt/peer/message/msg_unchoke.go
diff --git a/down/bt/peer/peer.go b/protocol/bt/peer/peer.go
similarity index 100%
rename from down/bt/peer/peer.go
rename to protocol/bt/peer/peer.go
diff --git a/down/bt/testdata/Game.of.Thrones.S08E05.720p.WEB.H264-MEMENTO.torrent b/protocol/bt/testdata/Game.of.Thrones.S08E05.720p.WEB.H264-MEMENTO.torrent
similarity index 100%
rename from down/bt/testdata/Game.of.Thrones.S08E05.720p.WEB.H264-MEMENTO.torrent
rename to protocol/bt/testdata/Game.of.Thrones.S08E05.720p.WEB.H264-MEMENTO.torrent
diff --git a/protocol/bt/testdata/office.torrent b/protocol/bt/testdata/office.torrent
new file mode 100644
index 00000000..15768d09
Binary files /dev/null and b/protocol/bt/testdata/office.torrent differ
diff --git a/down/bt/torrent/peer_conn.go b/protocol/bt/torrent/peer_conn.go
similarity index 83%
rename from down/bt/torrent/peer_conn.go
rename to protocol/bt/torrent/peer_conn.go
index 1af8f463..62b1f1b2 100644
--- a/down/bt/torrent/peer_conn.go
+++ b/protocol/bt/torrent/peer_conn.go
@@ -7,18 +7,23 @@ import (
 	"errors"
 	"fmt"
 	"github.com/cenkalti/mse"
-	"github.com/monkeyWie/gopeed/down/bt/metainfo"
-	"github.com/monkeyWie/gopeed/down/bt/peer"
-	"github.com/monkeyWie/gopeed/down/bt/peer/message"
+	"github.com/monkeyWie/gopeed/protocol/bt/metainfo"
+	"github.com/monkeyWie/gopeed/protocol/bt/peer"
+	"github.com/monkeyWie/gopeed/protocol/bt/peer/message"
+	"path/filepath"
+	"sync/atomic"
+
 	"io"
 	"math"
 	"net"
 	"os"
 	"path"
-	"sync"
 	"time"
 )
 
+// 现在主流客户端的block大小都是16KB
+const BlockSize = 2 << 13
+
 type peerConn struct {
 	torrent *Torrent
 	peer    *peer.Peer
@@ -32,13 +37,16 @@ type peerConn struct {
 	// peer is interested in this client
 	peerInterested bool
 
-	bitfield          *message.Bitfield
-	readyComplete     bool
-	pieceDownloadedCh chan bool
+	bitfield      *message.Bitfield
+	readyComplete bool
+
+	downloadedCh chan bool
+	// block个数
+	blockCount int
+	// 已经下载的block个数
+	blockDownloadedCount int32
 	// block下载队列，官方推荐为5
-	pieceBlockQueue chan interface{}
-	// piece上所有的block下载状态
-	pieceBlockState sync.Map
+	blockQueue chan interface{}
 }
 
 func NewPeerConn(torrent *Torrent, peer *peer.Peer) *peerConn {
@@ -168,42 +176,49 @@ func (pc *peerConn) ready() error {
 		pc.conn.Close()
 		return err
 	}
-	pc.pieceBlockQueue = make(chan interface{}, 5)
+	pc.blockQueue = make(chan interface{}, 5)
 	return nil
 }
 
 // 下载指定piece
 func (pc *peerConn) downloadPiece(index int) error {
-	pc.pieceDownloadedCh = make(chan bool)
-	defer close(pc.pieceDownloadedCh)
-	pc.pieceBlockState = sync.Map{}
-	pieceLength := pc.torrent.MetaInfo.GetPieceSize(index)
-	lastOffset := uint64(0)
+	pieceLength := pc.torrent.MetaInfo.GetPieceLength(index)
+	lastOffset := 0
+
+	pc.blockCount = int(math.Ceil(float64(pieceLength) / BlockSize))
+	pc.downloadedCh = make(chan bool)
+	defer close(pc.downloadedCh)
 
 	waitDuration := time.Second * 30
 	timer := time.NewTimer(waitDuration)
 	defer timer.Stop()
 	// 按块下载分片
-	for lastOffset < pieceLength {
-		blockLength := math.Min(2<<13, float64(pieceLength-lastOffset))
+	for i := 0; i < pc.blockCount; i++ {
+		offset := pieceLength * i
+		var blockLength uint32
+		if i == pc.blockCount-1 {
+			// 最后一个block大小需要计算出来
+			blockLength = uint32(pieceLength - offset)
+		} else {
+			blockLength = BlockSize
+		}
 		// 标记block开始下载
-		lastOffset32 := uint32(lastOffset)
-		pc.pieceBlockState.Store(lastOffset32, false)
+		offset32 := uint32(lastOffset)
 		// block下载排队，并做超时处理
 		timer.Reset(waitDuration)
 		select {
-		case pc.pieceBlockQueue <- nil:
+		case pc.blockQueue <- nil:
 		case <-timer.C:
 			return errors.New("download timeout")
 		}
-		_, err := pc.conn.Write(message.NewRequest(uint32(index), lastOffset32, uint32(blockLength)).Encode())
+		// 发起request，对方会响应piece
+		_, err := pc.conn.Write(message.NewRequest(uint32(index), offset32, blockLength).Encode())
 		if err != nil {
 			fmt.Println(err)
 		}
-		lastOffset += uint64(blockLength)
 	}
 	// 监听是否下载完成
-	<-pc.pieceDownloadedCh
+	<-pc.downloadedCh
 	return nil
 }
 
@@ -237,7 +252,7 @@ func (pc *peerConn) handleBitfield(buf []byte) {
 	}
 }
 
-// 处理分片下载响应
+// 处理下载响应，每次接收到响应直接将block写入到对应文件中
 func (pc *peerConn) handlePiece(buf []byte) {
 	piece := &message.Piece{}
 	piece.Decode(buf)
@@ -246,7 +261,7 @@ func (pc *peerConn) handlePiece(buf []byte) {
 	blockLength := int64(len(piece.Block))
 	pieceBegin := int64(piece.Index) * int64(info.PieceLength)
 	blockBegin := pieceBegin + int64(piece.Begin)
-	// 获取对应要的文件
+	// 计算block对应要写到的文件偏移
 	var fileBlocks []fileBlock
 	if len(info.Files) == 0 {
 		// 单文件
@@ -269,7 +284,7 @@ func (pc *peerConn) handlePiece(buf []byte) {
 			// 计算block剩余写入字节数
 			blockWritable := blockLength - blockSeek
 			fb := fileBlock{
-				filepath:   f.Path[0],
+				filepath:   filepath.Join(f.Path...),
 				fileSeek:   blockFileBegin - f.Begin,
 				blockBegin: blockSeek,
 			}
@@ -287,10 +302,10 @@ func (pc *peerConn) handlePiece(buf []byte) {
 			}
 		}
 	}
-	// fmt.Println(fileBlocks)
+	// 开始写入文件
 	for _, f := range fileBlocks {
 		func() {
-			name := path.Join(pc.torrent.Path, f.filepath)
+			name := filepath.Join(pc.torrent.Path, f.filepath)
 			file, err := os.OpenFile(name, os.O_RDWR|os.O_CREATE, 0644)
 			if err != nil {
 				panic(err)
@@ -298,28 +313,18 @@ func (pc *peerConn) handlePiece(buf []byte) {
 			defer file.Close()
 			_, err = file.WriteAt(piece.Block[f.blockBegin:f.blockEnd], f.fileSeek)
 			if err != nil {
-				fmt.Println(err)
+				panic(err)
 			}
 		}()
 	}
-	pc.pieceBlockState.Store(piece.Begin, true)
 	// 出队
-	<-pc.pieceBlockQueue
-	flag := true
-	// fmt.Printf("index %d: %v\n", piece.Index, pc.pieceBlockState)
-	pc.pieceBlockState.Range(func(key, value interface{}) bool {
-		// 如果有还没下载完的block
-		if !value.(bool) {
-			flag = false
-			return false
-		}
-		return true
-	})
+	<-pc.blockQueue
+
 	// piece全部下载完
-	if flag {
+	if atomic.AddInt32(&pc.blockDownloadedCount, 1) == int32(pc.blockCount) {
 		// 计算piece对应的文件偏移
 		sha1 := sha1.New()
-		pieceLength := pc.torrent.MetaInfo.GetPieceSize(int(piece.Index))
+		pieceLength := pc.torrent.MetaInfo.GetPieceLength(int(piece.Index))
 		writeIndex := getWriteFile(pieceBegin, fds)
 		fileBegin := pieceBegin - fds[writeIndex].Begin
 		for _, fd := range fds[writeIndex:] {
@@ -339,7 +344,7 @@ func (pc *peerConn) handlePiece(buf []byte) {
 						panic(err)
 					}
 				}
-				pieceLength -= uint64(written)
+				pieceLength -= int(written)
 			}()
 			if pieceLength > 0 {
 				// 	继续读下个文件
@@ -357,7 +362,7 @@ func (pc *peerConn) handlePiece(buf []byte) {
 			fmt.Printf("piece %d 校验失败\n", piece.Index)
 		}
 		// piece下载完成
-		pc.pieceDownloadedCh <- true
+		pc.downloadedCh <- true
 	}
 }
 
diff --git a/down/bt/torrent/peer_conn_test.go b/protocol/bt/torrent/peer_conn_test.go
similarity index 84%
rename from down/bt/torrent/peer_conn_test.go
rename to protocol/bt/torrent/peer_conn_test.go
index 09656843..31e41c0e 100644
--- a/down/bt/torrent/peer_conn_test.go
+++ b/protocol/bt/torrent/peer_conn_test.go
@@ -2,8 +2,9 @@ package torrent
 
 import (
 	"fmt"
-	"github.com/monkeyWie/gopeed/down/bt/peer"
-	"github.com/monkeyWie/gopeed/down/bt/tracker"
+	"github.com/monkeyWie/gopeed/protocol/bt/peer"
+	"github.com/monkeyWie/gopeed/protocol/bt/tracker"
+	"os"
 	"sync"
 	"testing"
 	"time"
@@ -104,7 +105,6 @@ func getUsablePeerMore() chan *peerConn {
 	if err != nil {
 		panic(err)
 	}
-	fmt.Printf("Tracker end,peer count:%d\n", len(peers))
 	ch := make(chan *peerConn)
 	for i := range peers {
 		go peerTest(torrent, &peers[i], ch)
@@ -145,3 +145,22 @@ func TestSome(t *testing.T) {
 	fmt.Println("111")
 
 }
+
+func TestSome2(t *testing.T) {
+	wg := sync.WaitGroup{}
+	wg.Add(10)
+	file, err := os.OpenFile("e:/testbt/test.data", os.O_RDWR|os.O_CREATE, 0644)
+	for i := 0; i < 10; i++ {
+		go func(i int) {
+			for j := 0; j < 100; j++ {
+				if err != nil {
+					panic(err)
+				}
+				_, err = file.WriteAt([]byte{byte(i)}, int64(i*8))
+			}
+			wg.Done()
+		}(i)
+	}
+	wg.Wait()
+
+}
diff --git a/down/bt/torrent/peer_pool.go b/protocol/bt/torrent/peer_pool.go
similarity index 96%
rename from down/bt/torrent/peer_pool.go
rename to protocol/bt/torrent/peer_pool.go
index 77dd6231..41e444a1 100644
--- a/down/bt/torrent/peer_pool.go
+++ b/protocol/bt/torrent/peer_pool.go
@@ -1,7 +1,7 @@
 package torrent
 
 import (
-	"github.com/monkeyWie/gopeed/down/bt/peer"
+	"github.com/monkeyWie/gopeed/protocol/bt/peer"
 	"sync"
 )
 
diff --git a/down/bt/torrent/peer_pool_test.go b/protocol/bt/torrent/peer_pool_test.go
similarity index 90%
rename from down/bt/torrent/peer_pool_test.go
rename to protocol/bt/torrent/peer_pool_test.go
index bd35c213..765b4080 100644
--- a/down/bt/torrent/peer_pool_test.go
+++ b/protocol/bt/torrent/peer_pool_test.go
@@ -2,7 +2,7 @@ package torrent
 
 import (
 	"fmt"
-	"github.com/monkeyWie/gopeed/down/bt/peer"
+	"github.com/monkeyWie/gopeed/protocol/bt/peer"
 	"testing"
 )
 
diff --git a/down/bt/torrent/piece_state.go b/protocol/bt/torrent/piece_state.go
similarity index 100%
rename from down/bt/torrent/piece_state.go
rename to protocol/bt/torrent/piece_state.go
diff --git a/down/bt/torrent/torrent.go b/protocol/bt/torrent/torrent.go
similarity index 81%
rename from down/bt/torrent/torrent.go
rename to protocol/bt/torrent/torrent.go
index ae31d32c..6e669348 100644
--- a/down/bt/torrent/torrent.go
+++ b/protocol/bt/torrent/torrent.go
@@ -2,8 +2,8 @@ package torrent
 
 import (
 	"fmt"
-	"github.com/monkeyWie/gopeed/down/bt/metainfo"
-	"github.com/monkeyWie/gopeed/down/bt/tracker"
+	"github.com/monkeyWie/gopeed/protocol/bt/metainfo"
+	"github.com/monkeyWie/gopeed/protocol/bt/tracker"
 	"sync"
 	"time"
 )
@@ -43,7 +43,6 @@ func (t *Torrent) Download(path string) {
 		go func(index int) {
 			peer := t.peerPool.get()
 			if peer == nil {
-				fmt.Println("no peer")
 				time.Sleep(time.Second * 10)
 				t.PiecesState.setState(index, stateReady)
 				<-taskCh
@@ -58,7 +57,12 @@ func (t *Torrent) Download(path string) {
 				fmt.Printf("peer ready:%s,download %d\n", peer.Address(), index)
 				err = pc.downloadPiece(index)
 				if err != nil {
-					t.PiecesState.setState(index, stateDownloading)
+					fmt.Println(err)
+					// 下载失败
+					t.PiecesState.setState(index, stateReady)
+				} else {
+					// 下载完成
+					t.PiecesState.setState(index, stateFinished)
 				}
 				t.peerPool.release(peer)
 			}
@@ -73,11 +77,7 @@ func (t *Torrent) fetchPeers() {
 		PeerID:   t.PeerID,
 		MetaInfo: t.MetaInfo,
 	}
-	urls := []string{
-		"udp://exodus.desync.com:6969/announce",
-		"udp://tracker.openbittorrent.com:80/announce",
-		"udp://tracker.leechers-paradise.org:6969",
-	}
+	urls := tracker.MetaInfo.AnnounceList[0]
 	var wg sync.WaitGroup
 	ch := make(chan interface{})
 	wg.Add(len(urls))
@@ -86,7 +86,7 @@ func (t *Torrent) fetchPeers() {
 			defer wg.Done()
 			peers, err := tracker.DoTracker(url)
 			if err == nil {
-				fmt.Println("tracker end:" + url)
+				fmt.Printf("Tracker end,url:%s,count:%d\n", url, len(peers))
 				ch <- nil
 				t.peerPool.put(peers)
 			}
diff --git a/protocol/bt/torrent/torrent_test.go b/protocol/bt/torrent/torrent_test.go
new file mode 100644
index 00000000..feb799c9
--- /dev/null
+++ b/protocol/bt/torrent/torrent_test.go
@@ -0,0 +1,44 @@
+package torrent
+
+import (
+	"github.com/monkeyWie/gopeed/protocol/bt/metainfo"
+	"github.com/monkeyWie/gopeed/protocol/bt/peer"
+	"testing"
+)
+
+func TestTorrent_Download(t *testing.T) {
+	torrent := buildTorrent()
+	torrent.Download("e:/testbt/download")
+}
+
+func buildTorrent() *Torrent {
+	// metaInfo, err := metainfo.ParseFromFile("../testdata/Game.of.Thrones.S08E05.720p.WEB.H264-MEMENTO.torrent")
+	metaInfo, err := metainfo.ParseFromFile("../testdata/office.torrent")
+	if err != nil {
+		panic(err)
+	}
+
+	metaInfo.AnnounceList[0] = append(metaInfo.AnnounceList[0], []string{
+		"udp://tracker.coppersurfer.tk:6969/announce",
+		"udp://tracker.leechers-paradise.org:6969/announce",
+		"udp://tracker.opentrackr.org:1337/announce",
+		"udp://p4p.arenabg.com:1337/announce",
+		"udp://9.rarbg.to:2710/announce",
+		"udp://9.rarbg.me:2710/announce",
+		"udp://tracker.internetwarriors.net:1337/announce",
+		"udp://exodus.desync.com:6969/announce",
+		"udp://tracker.tiny-vps.com:6969/announce",
+		"udp://tracker.sbsub.com:2710/announce",
+		"udp://retracker.lanta-net.ru:2710/announce",
+		"udp://open.stealth.si:80/announce",
+		"udp://open.demonii.si:1337/announce",
+		"udp://tracker.torrent.eu.org:451/announce",
+		"udp://tracker.moeking.me:6969/announce",
+		"udp://tracker.cyberia.is:6969/announce",
+		"udp://denis.stalker.upeer.me:6969/announce",
+		"udp://ipv4.tracker.harry.lu:80/announce",
+		"udp://zephir.monocul.us:6969/announce",
+		"udp://xxxtor.com:2710/announce",
+	}...)
+	return NewTorrent(peer.GenPeerID(), metaInfo)
+}
diff --git a/down/bt/tracker/errors.go b/protocol/bt/tracker/errors.go
similarity index 100%
rename from down/bt/tracker/errors.go
rename to protocol/bt/tracker/errors.go
diff --git a/down/bt/tracker/tracker.go b/protocol/bt/tracker/tracker.go
similarity index 99%
rename from down/bt/tracker/tracker.go
rename to protocol/bt/tracker/tracker.go
index f652ba35..5dd6f114 100644
--- a/down/bt/tracker/tracker.go
+++ b/protocol/bt/tracker/tracker.go
@@ -4,8 +4,8 @@ import (
 	"encoding/binary"
 	"errors"
 	"fmt"
-	"github.com/monkeyWie/gopeed/down/bt/metainfo"
-	"github.com/monkeyWie/gopeed/down/bt/peer"
+	"github.com/monkeyWie/gopeed/protocol/bt/metainfo"
+	"github.com/monkeyWie/gopeed/protocol/bt/peer"
 	"io"
 	"io/ioutil"
 	"math"
diff --git a/down/bt/tracker/tracker_test.go b/protocol/bt/tracker/tracker_test.go
similarity index 90%
rename from down/bt/tracker/tracker_test.go
rename to protocol/bt/tracker/tracker_test.go
index 906de0b7..123601b2 100644
--- a/down/bt/tracker/tracker_test.go
+++ b/protocol/bt/tracker/tracker_test.go
@@ -2,7 +2,7 @@ package tracker
 
 import (
 	"fmt"
-	"github.com/monkeyWie/gopeed/down/bt/metainfo"
+	"github.com/monkeyWie/gopeed/protocol/bt/metainfo"
 	"testing"
 )
 
diff --git a/down/http/down.go b/protocol/http/down.go
similarity index 92%
rename from down/http/down.go
rename to protocol/http/down.go
index 2b405b2a..8dba50aa 100644
--- a/down/http/down.go
+++ b/protocol/http/down.go
@@ -101,10 +101,7 @@ func Down(request *Request) error {
 	if response.Range {
 		cons := 16
 		chunkSize := response.Size / int64(cons)
-		var (
-			waitGroup = &sync.WaitGroup{}
-			fileLock  = &sync.Mutex{}
-		)
+		waitGroup := &sync.WaitGroup{}
 		waitGroup.Add(cons)
 		for i := 0; i < cons; i++ {
 			start := int64(i) * chunkSize
@@ -112,11 +109,11 @@ func Down(request *Request) error {
 			if i == cons-1 {
 				end = response.Size
 			}
-			go downChunk(request, file, start, end-1, waitGroup, fileLock)
+			go downChunk(request, file, start, end-1, waitGroup)
 		}
 		waitGroup.Wait()
 	} else {
-		downChunk(request, file, 0, response.Size, nil, nil)
+		downChunk(request, file, 0, response.Size, nil)
 	}
 	return nil
 }
@@ -148,7 +145,7 @@ func BuildHTTPClient() *http.Client {
 	return &http.Client{Jar: jar}
 }
 
-func downChunk(request *Request, file *os.File, start int64, end int64, waitGroup *sync.WaitGroup, fileLock *sync.Mutex) {
+func downChunk(request *Request, file *os.File, start int64, end int64, waitGroup *sync.WaitGroup) {
 	if waitGroup != nil {
 		defer waitGroup.Done()
 	}
@@ -163,13 +160,11 @@ func downChunk(request *Request, file *os.File, start int64, end int64, waitGrou
 	}
 	defer httpResponse.Body.Close()
 	buf := make([]byte, 8192)
-	writeIndex := int64(start)
+	writeIndex := start
 	for {
 		n, err := httpResponse.Body.Read(buf)
 		if n > 0 {
-			fileLock.Lock()
 			writeSize, err := file.WriteAt(buf[0:n], writeIndex)
-			fileLock.Unlock()
 			if err != nil {
 				fmt.Println(err)
 				return
diff --git a/down/http/down_test.go b/protocol/http/down_test.go
similarity index 99%
rename from down/http/down_test.go
rename to protocol/http/down_test.go
index f644e1c6..30f9b6ed 100644
--- a/down/http/down_test.go
+++ b/protocol/http/down_test.go
@@ -49,6 +49,7 @@ func TestDown(t *testing.T) {
 				return
 			}
 			downMd5 := fileMd5("favicon.ico")
+			os.Remove("favicon.ico")
 			if "8de7a6a2e786861013d61b77b2394012" != downMd5 {
 				t.Errorf("error md5= %v", downMd5)
 				return
diff --git a/down/http/request.go b/protocol/http/request.go
similarity index 100%
rename from down/http/request.go
rename to protocol/http/request.go
diff --git a/down/http/response.go b/protocol/http/response.go
similarity index 100%
rename from down/http/response.go
rename to protocol/http/response.go