testing compilation with remove package

go/topology/configuration.go

@@ -0,0 +1,56 @@
+package topology
+
+import (
+	"encoding/xml"
+)
+
+type loc struct {
+	dcName   string
+	rackName string
+}
+type rack struct {
+	Name string   `xml:"name,attr"`
+	Ips  []string `xml:"Ip"`
+}
+type dataCenter struct {
+	Name  string `xml:"name,attr"`
+	Racks []rack `xml:"Rack"`
+}
+type topology struct {
+	DataCenters []dataCenter `xml:"DataCenter"`
+}
+type Configuration struct {
+	XMLName     xml.Name `xml:"Configuration"`
+	Topo        topology `xml:"Topology"`
+	ip2location map[string]loc
+}
+
+func NewConfiguration(b []byte) (*Configuration, error) {
+	c := &Configuration{}
+	err := xml.Unmarshal(b, c)
+	c.ip2location = make(map[string]loc)
+	for _, dc := range c.Topo.DataCenters {
+		for _, rack := range dc.Racks {
+			for _, ip := range rack.Ips {
+				c.ip2location[ip] = loc{dcName: dc.Name, rackName: rack.Name}
+			}
+		}
+	}
+	return c, err
+}
+
+func (c *Configuration) String() string {
+	if b, e := xml.MarshalIndent(c, "  ", "  "); e == nil {
+		return string(b)
+	}
+	return ""
+}
+
+func (c *Configuration) Locate(ip string) (dc string, rack string) {
+	if c != nil && c.ip2location != nil {
+		if loc, ok := c.ip2location[ip]; ok {
+			return loc.dcName, loc.rackName
+		}
+	}
+	return "DefaultDataCenter", "DefaultRack"
+}

go/topology/configuration_test.go

@@ -0,0 +1,42 @@
+package topology
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestLoadConfiguration(t *testing.T) {
+
+	confContent := `
+
+<?xml version="1.0" encoding="UTF-8" ?>
+<Configuration>
+  <Topology>
+    <DataCenter name="dc1">
+      <Rack name="rack1">
+        <Ip>192.168.1.1</Ip>
+      </Rack>
+    </DataCenter>
+    <DataCenter name="dc2">
+      <Rack name="rack1">
+        <Ip>192.168.1.2</Ip>
+      </Rack>
+      <Rack name="rack2">
+        <Ip>192.168.1.3</Ip>
+        <Ip>192.168.1.4</Ip>
+      </Rack>
+    </DataCenter>
+  </Topology>
+</Configuration>
+`
+	c, err := NewConfiguration([]byte(confContent))
+
+	fmt.Printf("%s\n", c)
+	if err != nil {
+		t.Fatalf("unmarshal error:%s", err.Error())
+	}
+
+	if len(c.Topo.DataCenters) <= 0 || c.Topo.DataCenters[0].Name != "dc1" {
+		t.Fatalf("unmarshal error:%s", c)
+	}
+}

go/topology/data_center.go

@@ -0,0 +1,41 @@
+package topology
+
+import ()
+
+type DataCenter struct {
+	NodeImpl
+}
+
+func NewDataCenter(id string) *DataCenter {
+	dc := &DataCenter{}
+	dc.id = NodeId(id)
+	dc.nodeType = "DataCenter"
+	dc.children = make(map[NodeId]Node)
+	dc.NodeImpl.value = dc
+	return dc
+}
+
+func (dc *DataCenter) GetOrCreateRack(rackName string) *Rack {
+	for _, c := range dc.Children() {
+		rack := c.(*Rack)
+		if string(rack.Id()) == rackName {
+			return rack
+		}
+	}
+	rack := NewRack(rackName)
+	dc.LinkChildNode(rack)
+	return rack
+}
+
+func (dc *DataCenter) ToMap() interface{} {
+	m := make(map[string]interface{})
+	m["Max"] = dc.GetMaxVolumeCount()
+	m["Free"] = dc.FreeSpace()
+	var racks []interface{}
+	for _, c := range dc.Children() {
+		rack := c.(*Rack)
+		racks = append(racks, rack.ToMap())
+	}
+	m["Racks"] = racks
+	return m
+}

go/topology/data_node.go

@@ -0,0 +1,60 @@
+package topology
+
+import (
+	_ "fmt"
+	"code.google.com/p/weed-fs/go/storage"
+	"strconv"
+)
+
+type DataNode struct {
+	NodeImpl
+	volumes   map[storage.VolumeId]storage.VolumeInfo
+	Ip        string
+	Port      int
+	PublicUrl string
+	LastSeen  int64 // unix time in seconds
+	Dead      bool
+}
+
+func NewDataNode(id string) *DataNode {
+	s := &DataNode{}
+	s.id = NodeId(id)
+	s.nodeType = "DataNode"
+	s.volumes = make(map[storage.VolumeId]storage.VolumeInfo)
+	s.NodeImpl.value = s
+	return s
+}
+func (dn *DataNode) AddOrUpdateVolume(v storage.VolumeInfo) {
+	if _, ok := dn.volumes[v.Id]; !ok {
+		dn.volumes[v.Id] = v
+		dn.UpAdjustVolumeCountDelta(1)
+		dn.UpAdjustActiveVolumeCountDelta(1)
+		dn.UpAdjustMaxVolumeId(v.Id)
+	} else {
+		dn.volumes[v.Id] = v
+	}
+}
+func (dn *DataNode) GetTopology() *Topology {
+	p := dn.parent
+	for p.Parent() != nil {
+		p = p.Parent()
+	}
+	t := p.(*Topology)
+	return t
+}
+func (dn *DataNode) MatchLocation(ip string, port int) bool {
+	return dn.Ip == ip && dn.Port == port
+}
+func (dn *DataNode) Url() string {
+	return dn.Ip + ":" + strconv.Itoa(dn.Port)
+}
+
+func (dn *DataNode) ToMap() interface{} {
+	ret := make(map[string]interface{})
+	ret["Url"] = dn.Url()
+	ret["Volumes"] = dn.GetVolumeCount()
+	ret["Max"] = dn.GetMaxVolumeCount()
+	ret["Free"] = dn.FreeSpace()
+	ret["PublicUrl"] = dn.PublicUrl
+	return ret
+}

go/topology/node.go

@@ -0,0 +1,200 @@
+package topology
+
+import (
+	"fmt"
+	"code.google.com/p/weed-fs/go/storage"
+)
+
+type NodeId string
+type Node interface {
+	Id() NodeId
+	String() string
+	FreeSpace() int
+	ReserveOneVolume(r int, vid storage.VolumeId) (bool, *DataNode)
+	UpAdjustMaxVolumeCountDelta(maxVolumeCountDelta int)
+	UpAdjustVolumeCountDelta(volumeCountDelta int)
+	UpAdjustActiveVolumeCountDelta(activeVolumeCountDelta int)
+	UpAdjustMaxVolumeId(vid storage.VolumeId)
+
+	GetVolumeCount() int
+	GetActiveVolumeCount() int
+	GetMaxVolumeCount() int
+	GetMaxVolumeId() storage.VolumeId
+	SetParent(Node)
+	LinkChildNode(node Node)
+	UnlinkChildNode(nodeId NodeId)
+	CollectDeadNodeAndFullVolumes(freshThreshHold int64, volumeSizeLimit uint64)
+
+	IsDataNode() bool
+	Children() map[NodeId]Node
+	Parent() Node
+
+	GetValue() interface{} //get reference to the topology,dc,rack,datanode
+}
+type NodeImpl struct {
+	id                NodeId
+	volumeCount       int
+	activeVolumeCount int
+	maxVolumeCount    int
+	parent            Node
+	children          map[NodeId]Node
+	maxVolumeId       storage.VolumeId
+
+	//for rack, data center, topology
+	nodeType string
+	value    interface{}
+}
+
+func (n *NodeImpl) IsDataNode() bool {
+	return n.nodeType == "DataNode"
+}
+func (n *NodeImpl) IsRack() bool {
+	return n.nodeType == "Rack"
+}
+func (n *NodeImpl) IsDataCenter() bool {
+	return n.nodeType == "DataCenter"
+}
+func (n *NodeImpl) String() string {
+	if n.parent != nil {
+		return n.parent.String() + ":" + string(n.id)
+	}
+	return string(n.id)
+}
+func (n *NodeImpl) Id() NodeId {
+	return n.id
+}
+func (n *NodeImpl) FreeSpace() int {
+	return n.maxVolumeCount - n.volumeCount
+}
+func (n *NodeImpl) SetParent(node Node) {
+	n.parent = node
+}
+func (n *NodeImpl) Children() map[NodeId]Node {
+	return n.children
+}
+func (n *NodeImpl) Parent() Node {
+	return n.parent
+}
+func (n *NodeImpl) GetValue() interface{} {
+	return n.value
+}
+func (n *NodeImpl) ReserveOneVolume(r int, vid storage.VolumeId) (bool, *DataNode) {
+	ret := false
+	var assignedNode *DataNode
+	for _, node := range n.children {
+		freeSpace := node.FreeSpace()
+		//fmt.Println("r =", r, ", node =", node, ", freeSpace =", freeSpace)
+		if freeSpace <= 0 {
+			continue
+		}
+		if r >= freeSpace {
+			r -= freeSpace
+		} else {
+			if node.IsDataNode() && node.FreeSpace() > 0 {
+				//fmt.Println("vid =", vid, " assigned to node =", node, ", freeSpace =", node.FreeSpace())
+				return true, node.(*DataNode)
+			}
+			ret, assignedNode = node.ReserveOneVolume(r, vid)
+			if ret {
+				break
+			}
+		}
+	}
+	return ret, assignedNode
+}
+
+func (n *NodeImpl) UpAdjustMaxVolumeCountDelta(maxVolumeCountDelta int) { //can be negative
+	n.maxVolumeCount += maxVolumeCountDelta
+	if n.parent != nil {
+		n.parent.UpAdjustMaxVolumeCountDelta(maxVolumeCountDelta)
+	}
+}
+func (n *NodeImpl) UpAdjustVolumeCountDelta(volumeCountDelta int) { //can be negative
+	n.volumeCount += volumeCountDelta
+	if n.parent != nil {
+		n.parent.UpAdjustVolumeCountDelta(volumeCountDelta)
+	}
+}
+func (n *NodeImpl) UpAdjustActiveVolumeCountDelta(activeVolumeCountDelta int) { //can be negative
+	n.activeVolumeCount += activeVolumeCountDelta
+	if n.parent != nil {
+		n.parent.UpAdjustActiveVolumeCountDelta(activeVolumeCountDelta)
+	}
+}
+func (n *NodeImpl) UpAdjustMaxVolumeId(vid storage.VolumeId) { //can be negative
+	if n.maxVolumeId < vid {
+		n.maxVolumeId = vid
+		if n.parent != nil {
+			n.parent.UpAdjustMaxVolumeId(vid)
+		}
+	}
+}
+func (n *NodeImpl) GetMaxVolumeId() storage.VolumeId {
+	return n.maxVolumeId
+}
+func (n *NodeImpl) GetVolumeCount() int {
+	return n.volumeCount
+}
+func (n *NodeImpl) GetActiveVolumeCount() int {
+	return n.activeVolumeCount
+}
+func (n *NodeImpl) GetMaxVolumeCount() int {
+	return n.maxVolumeCount
+}
+
+func (n *NodeImpl) LinkChildNode(node Node) {
+	if n.children[node.Id()] == nil {
+		n.children[node.Id()] = node
+		n.UpAdjustMaxVolumeCountDelta(node.GetMaxVolumeCount())
+		n.UpAdjustMaxVolumeId(node.GetMaxVolumeId())
+		n.UpAdjustVolumeCountDelta(node.GetVolumeCount())
+		n.UpAdjustActiveVolumeCountDelta(node.GetActiveVolumeCount())
+		node.SetParent(n)
+		fmt.Println(n, "adds child", node.Id())
+	}
+}
+
+func (n *NodeImpl) UnlinkChildNode(nodeId NodeId) {
+	node := n.children[nodeId]
+	node.SetParent(nil)
+	if node != nil {
+		delete(n.children, node.Id())
+		n.UpAdjustVolumeCountDelta(-node.GetVolumeCount())
+		n.UpAdjustActiveVolumeCountDelta(-node.GetActiveVolumeCount())
+		n.UpAdjustMaxVolumeCountDelta(-node.GetMaxVolumeCount())
+		fmt.Println(n, "removes", node, "volumeCount =", n.activeVolumeCount)
+	}
+}
+
+func (n *NodeImpl) CollectDeadNodeAndFullVolumes(freshThreshHold int64, volumeSizeLimit uint64) {
+	if n.IsRack() {
+		for _, c := range n.Children() {
+			dn := c.(*DataNode) //can not cast n to DataNode
+			if dn.LastSeen < freshThreshHold {
+				if !dn.Dead {
+					dn.Dead = true
+					n.GetTopology().chanDeadDataNodes <- dn
+				}
+			}
+			for _, v := range dn.volumes {
+				if uint64(v.Size) >= volumeSizeLimit {
+					//fmt.Println("volume",v.Id,"size",v.Size,">",volumeSizeLimit)
+					n.GetTopology().chanFullVolumes <- v
+				}
+			}
+		}
+	} else {
+		for _, c := range n.Children() {
+			c.CollectDeadNodeAndFullVolumes(freshThreshHold, volumeSizeLimit)
+		}
+	}
+}
+
+func (n *NodeImpl) GetTopology() *Topology {
+	var p Node
+	p = n
+	for p.Parent() != nil {
+		p = p.Parent()
+	}
+	return p.GetValue().(*Topology)
+}

go/topology/node_list.go

@@ -0,0 +1,69 @@
+package topology
+
+import (
+	"fmt"
+	"math/rand"
+	"code.google.com/p/weed-fs/go/storage"
+)
+
+type NodeList struct {
+	nodes  map[NodeId]Node
+	except map[string]Node
+}
+
+func NewNodeList(nodes map[NodeId]Node, except map[string]Node) *NodeList {
+	m := make(map[NodeId]Node, len(nodes)-len(except))
+	for _, n := range nodes {
+		if except[n.String()] == nil {
+			m[n.Id()] = n
+		}
+	}
+	nl := &NodeList{nodes: m}
+	return nl
+}
+
+func (nl *NodeList) FreeSpace() int {
+	freeSpace := 0
+	for _, n := range nl.nodes {
+		freeSpace += n.FreeSpace()
+	}
+	return freeSpace
+}
+
+func (nl *NodeList) RandomlyPickN(n int, min int) ([]Node, bool) {
+	var list []Node
+	for _, n := range nl.nodes {
+		if n.FreeSpace() >= min {
+			list = append(list, n)
+		}
+	}
+	if n > len(list) {
+		return nil, false
+	}
+	for i := n; i > 0; i-- {
+		r := rand.Intn(i)
+		t := list[r]
+		list[r] = list[i-1]
+		list[i-1] = t
+	}
+	return list[len(list)-n:], true
+}
+
+func (nl *NodeList) ReserveOneVolume(randomVolumeIndex int, vid storage.VolumeId) (bool, *DataNode) {
+	for _, node := range nl.nodes {
+		freeSpace := node.FreeSpace()
+		if randomVolumeIndex >= freeSpace {
+			randomVolumeIndex -= freeSpace
+		} else {
+			if node.IsDataNode() && node.FreeSpace() > 0 {
+				fmt.Println("vid =", vid, " assigned to node =", node, ", freeSpace =", node.FreeSpace())
+				return true, node.(*DataNode)
+			}
+			children := node.Children()
+			newNodeList := NewNodeList(children, nl.except)
+			return newNodeList.ReserveOneVolume(randomVolumeIndex, vid)
+		}
+	}
+	return false, nil
+
+}

go/topology/node_list_test.go

@@ -0,0 +1,39 @@
+package topology
+
+import (
+	_ "fmt"
+	"strconv"
+	"testing"
+)
+
+func TestXYZ(t *testing.T) {
+	topo := NewTopology("topo", "/etc/weed.conf", "/tmp", "test", 234, 5)
+	for i := 0; i < 5; i++ {
+		dc := NewDataCenter("dc" + strconv.Itoa(i))
+		dc.activeVolumeCount = i
+		dc.maxVolumeCount = 5
+		topo.LinkChildNode(dc)
+	}
+	nl := NewNodeList(topo.Children(), nil)
+
+	picked, ret := nl.RandomlyPickN(1)
+	if !ret || len(picked) != 1 {
+		t.Errorf("need to randomly pick 1 node")
+	}
+
+	picked, ret = nl.RandomlyPickN(4)
+	if !ret || len(picked) != 4 {
+		t.Errorf("need to randomly pick 4 nodes")
+	}
+
+	picked, ret = nl.RandomlyPickN(5)
+	if !ret || len(picked) != 5 {
+		t.Errorf("need to randomly pick 5 nodes")
+	}
+
+	picked, ret = nl.RandomlyPickN(6)
+	if ret || len(picked) != 0 {
+		t.Errorf("can not randomly pick 6 nodes:", ret, picked)
+	}
+
+}

go/topology/rack.go

@@ -0,0 +1,64 @@
+package topology
+
+import (
+	"strconv"
+	"time"
+)
+
+type Rack struct {
+	NodeImpl
+}
+
+func NewRack(id string) *Rack {
+	r := &Rack{}
+	r.id = NodeId(id)
+	r.nodeType = "Rack"
+	r.children = make(map[NodeId]Node)
+	r.NodeImpl.value = r
+	return r
+}
+
+func (r *Rack) FindDataNode(ip string, port int) *DataNode {
+	for _, c := range r.Children() {
+		dn := c.(*DataNode)
+		if dn.MatchLocation(ip, port) {
+			return dn
+		}
+	}
+	return nil
+}
+func (r *Rack) GetOrCreateDataNode(ip string, port int, publicUrl string, maxVolumeCount int) *DataNode {
+	for _, c := range r.Children() {
+		dn := c.(*DataNode)
+		if dn.MatchLocation(ip, port) {
+			dn.LastSeen = time.Now().Unix()
+			if dn.Dead {
+				dn.Dead = false
+				r.GetTopology().chanRecoveredDataNodes <- dn
+				dn.UpAdjustMaxVolumeCountDelta(maxVolumeCount - dn.maxVolumeCount)
+			}
+			return dn
+		}
+	}
+	dn := NewDataNode(ip + ":" + strconv.Itoa(port))
+	dn.Ip = ip
+	dn.Port = port
+	dn.PublicUrl = publicUrl
+	dn.maxVolumeCount = maxVolumeCount
+	dn.LastSeen = time.Now().Unix()
+	r.LinkChildNode(dn)
+	return dn
+}
+
+func (rack *Rack) ToMap() interface{} {
+	m := make(map[string]interface{})
+	m["Max"] = rack.GetMaxVolumeCount()
+	m["Free"] = rack.FreeSpace()
+	var dns []interface{}
+	for _, c := range rack.Children() {
+		dn := c.(*DataNode)
+		dns = append(dns, dn.ToMap())
+	}
+	m["DataNodes"] = dns
+	return m
+}

go/topology/topo_test.go

@@ -0,0 +1,127 @@
+package topology
+
+import (
+	"encoding/json"
+	"fmt"
+	"math/rand"
+	"code.google.com/p/weed-fs/go/storage"
+	"testing"
+	"time"
+)
+
+var topologyLayout = `
+{
+  "dc1":{
+    "rack1":{
+      "server1":{
+        "volumes":[
+          {"id":1, "size":12312},
+          {"id":2, "size":12312},
+          {"id":3, "size":12312}
+        ],
+        "limit":3
+      },
+      "server2":{
+        "volumes":[
+          {"id":4, "size":12312},
+          {"id":5, "size":12312},
+          {"id":6, "size":12312}
+        ],
+        "limit":10
+      }
+    },
+    "rack2":{
+      "server1":{
+        "volumes":[
+          {"id":4, "size":12312},
+          {"id":5, "size":12312},
+          {"id":6, "size":12312}
+        ],
+        "limit":4
+      },
+      "server2":{
+        "volumes":[],
+        "limit":4
+      },
+      "server3":{
+        "volumes":[
+          {"id":2, "size":12312},
+          {"id":3, "size":12312},
+          {"id":4, "size":12312}
+        ],
+        "limit":2
+      }
+    }
+  },
+  "dc2":{
+  },
+  "dc3":{
+    "rack2":{
+      "server1":{
+        "volumes":[
+          {"id":1, "size":12312},
+          {"id":3, "size":12312},
+          {"id":5, "size":12312}
+        ],
+        "limit":4
+      }
+    }
+  }
+}
+`
+
+func setup(topologyLayout string) *Topology {
+	var data interface{}
+	err := json.Unmarshal([]byte(topologyLayout), &data)
+	if err != nil {
+		fmt.Println("error:", err)
+	}
+
+	//need to connect all nodes first before server adding volumes
+	topo := NewTopology("mynetwork", "/etc/weed.conf", "/tmp", "test", 234, 5)
+	mTopology := data.(map[string]interface{})
+	for dcKey, dcValue := range mTopology {
+		dc := NewDataCenter(dcKey)
+		dcMap := dcValue.(map[string]interface{})
+		topo.LinkChildNode(dc)
+		for rackKey, rackValue := range dcMap {
+			rack := NewRack(rackKey)
+			rackMap := rackValue.(map[string]interface{})
+			dc.LinkChildNode(rack)
+			for serverKey, serverValue := range rackMap {
+				server := NewDataNode(serverKey)
+				serverMap := serverValue.(map[string]interface{})
+				rack.LinkChildNode(server)
+				for _, v := range serverMap["volumes"].([]interface{}) {
+					m := v.(map[string]interface{})
+					vi := storage.VolumeInfo{Id: storage.VolumeId(int64(m["id"].(float64))), Size: int64(m["size"].(float64)), Version: storage.CurrentVersion}
+					server.AddOrUpdateVolume(vi)
+				}
+				server.UpAdjustMaxVolumeCountDelta(int(serverMap["limit"].(float64)))
+			}
+		}
+	}
+
+	return topo
+}
+
+func TestRemoveDataCenter(t *testing.T) {
+	topo := setup(topologyLayout)
+	topo.UnlinkChildNode(NodeId("dc2"))
+	if topo.GetActiveVolumeCount() != 15 {
+		t.Fail()
+	}
+	topo.UnlinkChildNode(NodeId("dc3"))
+	if topo.GetActiveVolumeCount() != 12 {
+		t.Fail()
+	}
+}
+
+func TestReserveOneVolume(t *testing.T) {
+	topo := setup(topologyLayout)
+	rand.Seed(time.Now().UnixNano())
+	rand.Seed(1)
+	ret, node, vid := topo.RandomlyReserveOneVolume()
+	fmt.Println("assigned :", ret, ", node :", node, ", volume id:", vid)
+
+}

go/topology/topology.go

@@ -0,0 +1,148 @@
+package topology
+
+import (
+	"errors"
+	"io/ioutil"
+	"math/rand"
+	"code.google.com/p/weed-fs/go/directory"
+	"code.google.com/p/weed-fs/go/sequence"
+	"code.google.com/p/weed-fs/go/storage"
+)
+
+type Topology struct {
+	NodeImpl
+
+	//transient vid~servers mapping for each replication type
+	replicaType2VolumeLayout []*VolumeLayout
+
+	pulse int64
+
+	volumeSizeLimit uint64
+
+	sequence sequence.Sequencer
+
+	chanDeadDataNodes      chan *DataNode
+	chanRecoveredDataNodes chan *DataNode
+	chanFullVolumes        chan storage.VolumeInfo
+
+	configuration *Configuration
+}
+
+func NewTopology(id string, confFile string, dirname string, sequenceFilename string, volumeSizeLimit uint64, pulse int) *Topology {
+	t := &Topology{}
+	t.id = NodeId(id)
+	t.nodeType = "Topology"
+	t.NodeImpl.value = t
+	t.children = make(map[NodeId]Node)
+	t.replicaType2VolumeLayout = make([]*VolumeLayout, storage.LengthRelicationType)
+	t.pulse = int64(pulse)
+	t.volumeSizeLimit = volumeSizeLimit
+
+	t.sequence = sequence.NewSequencer(dirname, sequenceFilename)
+
+	t.chanDeadDataNodes = make(chan *DataNode)
+	t.chanRecoveredDataNodes = make(chan *DataNode)
+	t.chanFullVolumes = make(chan storage.VolumeInfo)
+
+	t.loadConfiguration(confFile)
+
+	return t
+}
+
+func (t *Topology) loadConfiguration(configurationFile string) error {
+	b, e := ioutil.ReadFile(configurationFile)
+	if e == nil {
+		t.configuration, e = NewConfiguration(b)
+	}
+	return e
+}
+
+func (t *Topology) Lookup(vid storage.VolumeId) []*DataNode {
+	for _, vl := range t.replicaType2VolumeLayout {
+		if vl != nil {
+			if list := vl.Lookup(vid); list != nil {
+				return list
+			}
+		}
+	}
+	return nil
+}
+
+func (t *Topology) RandomlyReserveOneVolume() (bool, *DataNode, *storage.VolumeId) {
+	if t.FreeSpace() <= 0 {
+		return false, nil, nil
+	}
+	vid := t.NextVolumeId()
+	ret, node := t.ReserveOneVolume(rand.Intn(t.FreeSpace()), vid)
+	return ret, node, &vid
+}
+
+func (t *Topology) RandomlyReserveOneVolumeExcept(except []Node) (bool, *DataNode, *storage.VolumeId) {
+	freeSpace := t.FreeSpace()
+	for _, node := range except {
+		freeSpace -= node.FreeSpace()
+	}
+	if freeSpace <= 0 {
+		return false, nil, nil
+	}
+	vid := t.NextVolumeId()
+	ret, node := t.ReserveOneVolume(rand.Intn(freeSpace), vid)
+	return ret, node, &vid
+}
+
+func (t *Topology) NextVolumeId() storage.VolumeId {
+	vid := t.GetMaxVolumeId()
+	return vid.Next()
+}
+
+func (t *Topology) PickForWrite(repType storage.ReplicationType, count int) (string, int, *DataNode, error) {
+	replicationTypeIndex := repType.GetReplicationLevelIndex()
+	if t.replicaType2VolumeLayout[replicationTypeIndex] == nil {
+		t.replicaType2VolumeLayout[replicationTypeIndex] = NewVolumeLayout(repType, t.volumeSizeLimit, t.pulse)
+	}
+	vid, count, datanodes, err := t.replicaType2VolumeLayout[replicationTypeIndex].PickForWrite(count)
+	if err != nil {
+		return "", 0, nil, errors.New("No writable volumes avalable!")
+	}
+	fileId, count := t.sequence.NextFileId(count)
+	return directory.NewFileId(*vid, fileId, rand.Uint32()).String(), count, datanodes.Head(), nil
+}
+
+func (t *Topology) GetVolumeLayout(repType storage.ReplicationType) *VolumeLayout {
+	replicationTypeIndex := repType.GetReplicationLevelIndex()
+	if t.replicaType2VolumeLayout[replicationTypeIndex] == nil {
+		t.replicaType2VolumeLayout[replicationTypeIndex] = NewVolumeLayout(repType, t.volumeSizeLimit, t.pulse)
+	}
+	return t.replicaType2VolumeLayout[replicationTypeIndex]
+}
+
+func (t *Topology) RegisterVolumeLayout(v *storage.VolumeInfo, dn *DataNode) {
+	t.GetVolumeLayout(v.RepType).RegisterVolume(v, dn)
+}
+
+func (t *Topology) RegisterVolumes(init bool, volumeInfos []storage.VolumeInfo, ip string, port int, publicUrl string, maxVolumeCount int) {
+	dcName, rackName := t.configuration.Locate(ip)
+	dc := t.GetOrCreateDataCenter(dcName)
+	rack := dc.GetOrCreateRack(rackName)
+	dn := rack.FindDataNode(ip, port)
+	if init && dn != nil {
+		t.UnRegisterDataNode(dn)
+	}
+	dn = rack.GetOrCreateDataNode(ip, port, publicUrl, maxVolumeCount)
+	for _, v := range volumeInfos {
+		dn.AddOrUpdateVolume(v)
+		t.RegisterVolumeLayout(&v, dn)
+	}
+}
+
+func (t *Topology) GetOrCreateDataCenter(dcName string) *DataCenter {
+	for _, c := range t.Children() {
+		dc := c.(*DataCenter)
+		if string(dc.Id()) == dcName {
+			return dc
+		}
+	}
+	dc := NewDataCenter(dcName)
+	t.LinkChildNode(dc)
+	return dc
+}

go/topology/topology_compact.go

@@ -0,0 +1,150 @@
+package topology
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/url"
+	"code.google.com/p/weed-fs/go/storage"
+	"code.google.com/p/weed-fs/go/util"
+	"time"
+)
+
+func batchVacuumVolumeCheck(vl *VolumeLayout, vid storage.VolumeId, locationlist *VolumeLocationList, garbageThreshold string) bool {
+	ch := make(chan bool, locationlist.Length())
+	for index, dn := range locationlist.list {
+		go func(index int, url string, vid storage.VolumeId) {
+			//fmt.Println(index, "Check vacuuming", vid, "on", dn.Url())
+			if e, ret := vacuumVolume_Check(url, vid, garbageThreshold); e != nil {
+				//fmt.Println(index, "Error when checking vacuuming", vid, "on", url, e)
+				ch <- false
+			} else {
+				//fmt.Println(index, "Checked vacuuming", vid, "on", url, "needVacuum", ret)
+				ch <- ret
+			}
+		}(index, dn.Url(), vid)
+	}
+	isCheckSuccess := true
+	for _ = range locationlist.list {
+		select {
+		case canVacuum := <-ch:
+			isCheckSuccess = isCheckSuccess && canVacuum
+		case <-time.After(30 * time.Minute):
+			isCheckSuccess = false
+			break
+		}
+	}
+	return isCheckSuccess
+}
+func batchVacuumVolumeCompact(vl *VolumeLayout, vid storage.VolumeId, locationlist *VolumeLocationList) bool {
+	vl.removeFromWritable(vid)
+	ch := make(chan bool, locationlist.Length())
+	for index, dn := range locationlist.list {
+		go func(index int, url string, vid storage.VolumeId) {
+			fmt.Println(index, "Start vacuuming", vid, "on", dn.Url())
+			if e := vacuumVolume_Compact(url, vid); e != nil {
+				fmt.Println(index, "Error when vacuuming", vid, "on", url, e)
+				ch <- false
+			} else {
+				fmt.Println(index, "Complete vacuuming", vid, "on", url)
+				ch <- true
+			}
+		}(index, dn.Url(), vid)
+	}
+	isVacuumSuccess := true
+	for _ = range locationlist.list {
+		select {
+		case _ = <-ch:
+		case <-time.After(30 * time.Minute):
+			isVacuumSuccess = false
+			break
+		}
+	}
+	return isVacuumSuccess
+}
+func batchVacuumVolumeCommit(vl *VolumeLayout, vid storage.VolumeId, locationlist *VolumeLocationList) bool {
+	isCommitSuccess := true
+	for _, dn := range locationlist.list {
+		fmt.Println("Start Commiting vacuum", vid, "on", dn.Url())
+		if e := vacuumVolume_Commit(dn.Url(), vid); e != nil {
+			fmt.Println("Error when committing vacuum", vid, "on", dn.Url(), e)
+			isCommitSuccess = false
+		} else {
+			fmt.Println("Complete Commiting vacuum", vid, "on", dn.Url())
+		}
+	}
+	if isCommitSuccess {
+		vl.setVolumeWritable(vid)
+	}
+	return isCommitSuccess
+}
+func (t *Topology) Vacuum(garbageThreshold string) int {
+	for _, vl := range t.replicaType2VolumeLayout {
+		if vl != nil {
+			for vid, locationlist := range vl.vid2location {
+				if batchVacuumVolumeCheck(vl, vid, locationlist, garbageThreshold) {
+					if batchVacuumVolumeCompact(vl, vid, locationlist) {
+						batchVacuumVolumeCommit(vl, vid, locationlist)
+					}
+				}
+			}
+		}
+	}
+	return 0
+}
+
+type VacuumVolumeResult struct {
+	Result bool
+	Error  string
+}
+
+func vacuumVolume_Check(urlLocation string, vid storage.VolumeId, garbageThreshold string) (error, bool) {
+	values := make(url.Values)
+	values.Add("volume", vid.String())
+	values.Add("garbageThreshold", garbageThreshold)
+	jsonBlob, err := util.Post("http://"+urlLocation+"/admin/vacuum_volume_check", values)
+	if err != nil {
+		fmt.Println("parameters:", values)
+		return err, false
+	}
+	var ret VacuumVolumeResult
+	if err := json.Unmarshal(jsonBlob, &ret); err != nil {
+		return err, false
+	}
+	if ret.Error != "" {
+		return errors.New(ret.Error), false
+	}
+	return nil, ret.Result
+}
+func vacuumVolume_Compact(urlLocation string, vid storage.VolumeId) error {
+	values := make(url.Values)
+	values.Add("volume", vid.String())
+	jsonBlob, err := util.Post("http://"+urlLocation+"/admin/vacuum_volume_compact", values)
+	if err != nil {
+		return err
+	}
+	var ret VacuumVolumeResult
+	if err := json.Unmarshal(jsonBlob, &ret); err != nil {
+		return err
+	}
+	if ret.Error != "" {
+		return errors.New(ret.Error)
+	}
+	return nil
+}
+func vacuumVolume_Commit(urlLocation string, vid storage.VolumeId) error {
+	values := make(url.Values)
+	values.Add("volume", vid.String())
+	jsonBlob, err := util.Post("http://"+urlLocation+"/admin/vacuum_volume_commit", values)
+	if err != nil {
+		return err
+	}
+	var ret VacuumVolumeResult
+	if err := json.Unmarshal(jsonBlob, &ret); err != nil {
+		return err
+	}
+	if ret.Error != "" {
+		return errors.New(ret.Error)
+	}
+	return nil
+}

go/topology/topology_event_handling.go

@@ -0,0 +1,67 @@
+package topology
+
+import (
+	"fmt"
+	"math/rand"
+	"code.google.com/p/weed-fs/go/storage"
+	"time"
+)
+
+func (t *Topology) StartRefreshWritableVolumes(garbageThreshold string) {
+	go func() {
+		for {
+			freshThreshHold := time.Now().Unix() - 3*t.pulse //3 times of sleep interval
+			t.CollectDeadNodeAndFullVolumes(freshThreshHold, t.volumeSizeLimit)
+			time.Sleep(time.Duration(float32(t.pulse*1e3)*(1+rand.Float32())) * time.Millisecond)
+		}
+	}()
+	go func(garbageThreshold string) {
+		c := time.Tick(15 * time.Minute)
+		for _ = range c {
+			t.Vacuum(garbageThreshold)
+		}
+	}(garbageThreshold)
+	go func() {
+		for {
+			select {
+			case v := <-t.chanFullVolumes:
+				t.SetVolumeCapacityFull(v)
+			case dn := <-t.chanRecoveredDataNodes:
+				t.RegisterRecoveredDataNode(dn)
+				fmt.Println("DataNode", dn, "is back alive!")
+			case dn := <-t.chanDeadDataNodes:
+				t.UnRegisterDataNode(dn)
+				fmt.Println("DataNode", dn, "is dead!")
+			}
+		}
+	}()
+}
+func (t *Topology) SetVolumeCapacityFull(volumeInfo storage.VolumeInfo) bool {
+	vl := t.GetVolumeLayout(volumeInfo.RepType)
+	if !vl.SetVolumeCapacityFull(volumeInfo.Id) {
+		return false
+	}
+	for _, dn := range vl.vid2location[volumeInfo.Id].list {
+		dn.UpAdjustActiveVolumeCountDelta(-1)
+	}
+	return true
+}
+func (t *Topology) UnRegisterDataNode(dn *DataNode) {
+	for _, v := range dn.volumes {
+		fmt.Println("Removing Volume", v.Id, "from the dead volume server", dn)
+		vl := t.GetVolumeLayout(v.RepType)
+		vl.SetVolumeUnavailable(dn, v.Id)
+	}
+	dn.UpAdjustVolumeCountDelta(-dn.GetVolumeCount())
+	dn.UpAdjustActiveVolumeCountDelta(-dn.GetActiveVolumeCount())
+	dn.UpAdjustMaxVolumeCountDelta(-dn.GetMaxVolumeCount())
+	dn.Parent().UnlinkChildNode(dn.Id())
+}
+func (t *Topology) RegisterRecoveredDataNode(dn *DataNode) {
+	for _, v := range dn.volumes {
+		vl := t.GetVolumeLayout(v.RepType)
+		if vl.isWritable(&v) {
+			vl.SetVolumeAvailable(dn, v.Id)
+		}
+	}
+}

go/topology/topology_map.go

@@ -0,0 +1,50 @@
+package topology
+
+import ()
+
+func (t *Topology) ToMap() interface{} {
+	m := make(map[string]interface{})
+	m["Max"] = t.GetMaxVolumeCount()
+	m["Free"] = t.FreeSpace()
+	var dcs []interface{}
+	for _, c := range t.Children() {
+		dc := c.(*DataCenter)
+		dcs = append(dcs, dc.ToMap())
+	}
+	m["DataCenters"] = dcs
+	var layouts []interface{}
+	for _, layout := range t.replicaType2VolumeLayout {
+		if layout != nil {
+			layouts = append(layouts, layout.ToMap())
+		}
+	}
+	m["layouts"] = layouts
+	return m
+}
+
+func (t *Topology) ToVolumeMap() interface{} {
+	m := make(map[string]interface{})
+	m["Max"] = t.GetMaxVolumeCount()
+	m["Free"] = t.FreeSpace()
+	dcs := make(map[NodeId]interface{})
+	for _, c := range t.Children() {
+		dc := c.(*DataCenter)
+		racks := make(map[NodeId]interface{})
+		for _, r := range dc.Children() {
+			rack := r.(*Rack)
+			dataNodes := make(map[NodeId]interface{})
+			for _, d := range rack.Children() {
+				dn := d.(*DataNode)
+				var volumes []interface{}
+				for _, v := range dn.volumes {
+					volumes = append(volumes, v)
+				}
+				dataNodes[d.Id()] = volumes
+			}
+			racks[r.Id()] = dataNodes
+		}
+		dcs[dc.Id()] = racks
+	}
+	m["DataCenters"] = dcs
+	return m
+}

go/topology/volume_layout.go

@@ -0,0 +1,116 @@
+package topology
+
+import (
+	"errors"
+	"fmt"
+	"math/rand"
+	"code.google.com/p/weed-fs/go/storage"
+)
+
+type VolumeLayout struct {
+	repType         storage.ReplicationType
+	vid2location    map[storage.VolumeId]*VolumeLocationList
+	writables       []storage.VolumeId // transient array of writable volume id
+	pulse           int64
+	volumeSizeLimit uint64
+}
+
+func NewVolumeLayout(repType storage.ReplicationType, volumeSizeLimit uint64, pulse int64) *VolumeLayout {
+	return &VolumeLayout{
+		repType:         repType,
+		vid2location:    make(map[storage.VolumeId]*VolumeLocationList),
+		writables:       *new([]storage.VolumeId),
+		pulse:           pulse,
+		volumeSizeLimit: volumeSizeLimit,
+	}
+}
+
+func (vl *VolumeLayout) RegisterVolume(v *storage.VolumeInfo, dn *DataNode) {
+	if _, ok := vl.vid2location[v.Id]; !ok {
+		vl.vid2location[v.Id] = NewVolumeLocationList()
+	}
+	if vl.vid2location[v.Id].Add(dn) {
+		if len(vl.vid2location[v.Id].list) == v.RepType.GetCopyCount() {
+			if vl.isWritable(v) {
+				vl.writables = append(vl.writables, v.Id)
+			}
+		}
+	}
+}
+
+func (vl *VolumeLayout) isWritable(v *storage.VolumeInfo) bool {
+	return uint64(v.Size) < vl.volumeSizeLimit && v.Version == storage.CurrentVersion
+}
+
+func (vl *VolumeLayout) Lookup(vid storage.VolumeId) []*DataNode {
+	return vl.vid2location[vid].list
+}
+
+func (vl *VolumeLayout) PickForWrite(count int) (*storage.VolumeId, int, *VolumeLocationList, error) {
+	len_writers := len(vl.writables)
+	if len_writers <= 0 {
+		fmt.Println("No more writable volumes!")
+		return nil, 0, nil, errors.New("No more writable volumes!")
+	}
+	vid := vl.writables[rand.Intn(len_writers)]
+	locationList := vl.vid2location[vid]
+	if locationList != nil {
+		return &vid, count, locationList, nil
+	}
+	return nil, 0, nil, errors.New("Strangely vid " + vid.String() + " is on no machine!")
+}
+
+func (vl *VolumeLayout) GetActiveVolumeCount() int {
+	return len(vl.writables)
+}
+
+func (vl *VolumeLayout) removeFromWritable(vid storage.VolumeId) bool {
+	for i, v := range vl.writables {
+		if v == vid {
+			fmt.Println("Volume", vid, "becomes unwritable")
+			vl.writables = append(vl.writables[:i], vl.writables[i+1:]...)
+			return true
+		}
+	}
+	return false
+}
+func (vl *VolumeLayout) setVolumeWritable(vid storage.VolumeId) bool {
+	for _, v := range vl.writables {
+		if v == vid {
+			return false
+		}
+	}
+	fmt.Println("Volume", vid, "becomes writable")
+	vl.writables = append(vl.writables, vid)
+	return true
+}
+
+func (vl *VolumeLayout) SetVolumeUnavailable(dn *DataNode, vid storage.VolumeId) bool {
+	if vl.vid2location[vid].Remove(dn) {
+		if vl.vid2location[vid].Length() < vl.repType.GetCopyCount() {
+			fmt.Println("Volume", vid, "has", vl.vid2location[vid].Length(), "replica, less than required", vl.repType.GetCopyCount())
+			return vl.removeFromWritable(vid)
+		}
+	}
+	return false
+}
+func (vl *VolumeLayout) SetVolumeAvailable(dn *DataNode, vid storage.VolumeId) bool {
+	if vl.vid2location[vid].Add(dn) {
+		if vl.vid2location[vid].Length() >= vl.repType.GetCopyCount() {
+			return vl.setVolumeWritable(vid)
+		}
+	}
+	return false
+}
+
+func (vl *VolumeLayout) SetVolumeCapacityFull(vid storage.VolumeId) bool {
+	return vl.removeFromWritable(vid)
+}
+
+func (vl *VolumeLayout) ToMap() interface{} {
+	m := make(map[string]interface{})
+	m["replication"] = vl.repType.String()
+	m["writables"] = vl.writables
+	//m["locations"] = vl.vid2location
+	return m
+}

go/topology/volume_location.go

@@ -0,0 +1,58 @@
+package topology
+
+import ()
+
+type VolumeLocationList struct {
+	list []*DataNode
+}
+
+func NewVolumeLocationList() *VolumeLocationList {
+	return &VolumeLocationList{}
+}
+
+func (dnll *VolumeLocationList) Head() *DataNode {
+	return dnll.list[0]
+}
+
+func (dnll *VolumeLocationList) Length() int {
+	return len(dnll.list)
+}
+
+func (dnll *VolumeLocationList) Add(loc *DataNode) bool {
+	for _, dnl := range dnll.list {
+		if loc.Ip == dnl.Ip && loc.Port == dnl.Port {
+			return false
+		}
+	}
+	dnll.list = append(dnll.list, loc)
+	return true
+}
+
+func (dnll *VolumeLocationList) Remove(loc *DataNode) bool {
+	for i, dnl := range dnll.list {
+		if loc.Ip == dnl.Ip && loc.Port == dnl.Port {
+			dnll.list = append(dnll.list[:i], dnll.list[i+1:]...)
+			return true
+		}
+	}
+	return false
+}
+
+func (dnll *VolumeLocationList) Refresh(freshThreshHold int64) {
+	var changed bool
+	for _, dnl := range dnll.list {
+		if dnl.LastSeen < freshThreshHold {
+			changed = true
+			break
+		}
+	}
+	if changed {
+		var l []*DataNode
+		for _, dnl := range dnll.list {
+			if dnl.LastSeen >= freshThreshHold {
+				l = append(l, dnl)
+			}
+		}
+		dnll.list = l
+	}
+}