basic implementation of bitswap, needs testing/verification that it works

bitswap/bitswap.go

@@ -10,7 +10,6 @@ import (
 
 	ds "github.com/jbenet/datastore.go"
 
-	"errors"
 	"time"
 )
 
@@ -74,24 +73,52 @@ func NewBitSwap(p *peer.Peer, net swarm.Network, d ds.Datastore, r routing.IpfsR
 }
 
 // GetBlock attempts to retrieve a particular block from peers, within timeout.
-func (bs *BitSwap) GetBlock(k u.Key, timeout time.Time) (
+func (bs *BitSwap) GetBlock(k u.Key, timeout time.Duration) (
 	*blocks.Block, error) {
 	begin := time.Now()
-	_, err := bs.routing.FindProviders(k, timeout)
+	provs, err := bs.routing.FindProviders(k, timeout)
 	if err != nil {
 		u.PErr("GetBlock error: %s\n", err)
-		return
+		return nil, err
+	}
+	tleft := timeout - time.Now().Sub(begin)
+
+	valchan := make(chan []byte)
+	after := time.After(tleft)
+	for _, p := range provs {
+		go func(pr *peer.Peer) {
+			ledger := bs.GetLedger(pr.Key())
+			blk, err := bs.getBlock(k, pr, tleft)
+			if err != nil {
+				u.PErr("%v\n", err)
+				return
+			}
+			// NOTE: this credits everyone who sends us a block,
+			//       even if we dont use it
+			ledger.ReceivedBytes(uint64(len(blk)))
+			select {
+			case valchan <- blk:
+			default:
+			}
+		}(p)
+	}
+
+	select {
+	case blkdata := <-valchan:
+		return blocks.NewBlock(blkdata)
+	case <-after:
+		return nil, u.ErrTimeout
 	}
-	tleft := timeout.Sub(time.Now().Sub(begin))
-	return nil, errors.New("not implemented")
 }
 
 func (bs *BitSwap) getBlock(k u.Key, p *peer.Peer, timeout time.Duration) ([]byte, error) {
+	//
 	mes := new(PBMessage)
-	mes.Id = proto.Uint64(swarm.GenerateID())
-	mes.Key = proto.String(k)
+	mes.Id = proto.Uint64(swarm.GenerateMessageID())
+	mes.Key = proto.String(string(k))
 	typ := PBMessage_GET_BLOCK
 	mes.Type = &typ
+	//
 
 	after := time.After(timeout)
 	resp := bs.listener.Listen(mes.GetId(), 1, timeout)
@@ -100,23 +127,89 @@ func (bs *BitSwap) getBlock(k u.Key, p *peer.Peer, timeout time.Duration) ([]byt
 
 	select {
 	case resp_mes := <-resp:
+		pmes := new(PBMessage)
+		err := proto.Unmarshal(resp_mes.Data, pmes)
+		if err != nil {
+			return nil, err
+		}
+		if pmes.GetSuccess() {
+			return pmes.GetValue(), nil
+		}
+		return nil, u.ErrNotFound
 	case <-after:
-		u.PErr("getBlock for '%s' timed out.", k)
+		u.PErr("getBlock for '%s' timed out.\n", k)
 		return nil, u.ErrTimeout
 	}
 }
 
 // HaveBlock announces the existance of a block to BitSwap, potentially sending
 // it to peers (Partners) whose WantLists include it.
-func (bs *BitSwap) HaveBlock(k u.Key) (*blocks.Block, error) {
-	return nil, errors.New("not implemented")
+func (bs *BitSwap) HaveBlock(k u.Key) error {
+	return bs.routing.Provide(k)
 }
 
 func (bs *BitSwap) handleMessages() {
 	for {
 		select {
-		case mes := bs.meschan.Incoming:
+		case mes := <-bs.meschan.Incoming:
+			pmes := new(PBMessage)
+			err := proto.Unmarshal(mes.Data, pmes)
+			if err != nil {
+				u.PErr("%v\n", err)
+				continue
+			}
+			if pmes.GetResponse() {
+				bs.listener.Respond(pmes.GetId(), mes)
+			}
+
+			switch pmes.GetType() {
+			case PBMessage_GET_BLOCK:
+				go bs.handleGetBlock(mes.Peer, pmes)
+			default:
+				u.PErr("Invalid message type.\n")
+			}
 		case <-bs.haltChan:
+			return
 		}
 	}
 }
+
+func (bs *BitSwap) handleGetBlock(p *peer.Peer, pmes *PBMessage) {
+	ledger := bs.GetLedger(p.Key())
+
+	idata, err := bs.datastore.Get(ds.NewKey(pmes.GetKey()))
+	if err != nil {
+		if err == ds.ErrNotFound {
+			return
+		}
+		u.PErr("%v\n", err)
+		return
+	}
+	data, ok := idata.([]byte)
+	if !ok {
+		u.PErr("Failed casting data from datastore.")
+		return
+	}
+
+	if ledger.ShouldSend() {
+		resp := &Message{
+			Value:    data,
+			Response: true,
+			ID:       pmes.GetId(),
+		}
+		bs.meschan.Outgoing <- swarm.NewMessage(p, resp.ToProtobuf())
+		ledger.SentBytes(uint64(len(data)))
+	}
+}
+
+func (bs *BitSwap) GetLedger(k u.Key) *Ledger {
+	l, ok := bs.partners[k]
+	if ok {
+		return l
+	}
+
+	l = new(Ledger)
+	l.Partner = peer.ID(k)
+	bs.partners[k] = l
+	return l
+}

bitswap/ledger.go

@@ -1,6 +1,8 @@
 package bitswap
 
 import (
+	"math/rand"
+
 	peer "github.com/jbenet/go-ipfs/peer"
 	u "github.com/jbenet/go-ipfs/util"
 
@@ -13,11 +15,8 @@ type Ledger struct {
 	// Partner is the ID of the remote Peer.
 	Partner peer.ID
 
-	// BytesSent counts the number of bytes the local peer sent to Partner
-	BytesSent uint64
-
-	// BytesReceived counts the number of bytes local peer received from Partner
-	BytesReceived uint64
+	// Accounting tracks bytes sent and recieved.
+	Accounting debtRatio
 
 	// FirstExchnage is the time of the first data exchange.
 	FirstExchange *time.Time
@@ -31,3 +30,15 @@ type Ledger struct {
 
 // LedgerMap lists Ledgers by their Partner key.
 type LedgerMap map[u.Key]*Ledger
+
+func (l *Ledger) ShouldSend() bool {
+	return rand.Float64() <= probabilitySend(l.Accounting.Value())
+}
+
+func (l *Ledger) SentBytes(n uint64) {
+	l.Accounting.BytesSent += n
+}
+
+func (l *Ledger) ReceivedBytes(n uint64) {
+	l.Accounting.BytesRecv += n
+}

bitswap/message.go

@@ -0,0 +1,30 @@
+package bitswap
+
+import (
+	"code.google.com/p/goprotobuf/proto"
+	u "github.com/jbenet/go-ipfs/util"
+)
+
+type Message struct {
+	ID       uint64
+	Response bool
+	Key      u.Key
+	Value    []byte
+	Success  bool
+}
+
+func (m *Message) ToProtobuf() *PBMessage {
+	pmes := new(PBMessage)
+	pmes.Id = &m.ID
+	if m.Response {
+		pmes.Response = proto.Bool(true)
+	}
+
+	if m.Success {
+		pmes.Success = proto.Bool(true)
+	}
+
+	pmes.Key = proto.String(string(m.Key))
+	pmes.Value = m.Value
+	return pmes
+}

bitswap/message.pb.go

@@ -56,6 +56,7 @@ type PBMessage struct {
 	Key              *string                `protobuf:"bytes,3,req,name=key" json:"key,omitempty"`
 	Value            []byte                 `protobuf:"bytes,4,opt,name=value" json:"value,omitempty"`
 	Response         *bool                  `protobuf:"varint,5,opt,name=response" json:"response,omitempty"`
+	Success          *bool                  `protobuf:"varint,6,opt,name=success" json:"success,omitempty"`
 	XXX_unrecognized []byte                 `json:"-"`
 }
 
@@ -98,6 +99,13 @@ func (m *PBMessage) GetResponse() bool {
 	return false
 }
 
+func (m *PBMessage) GetSuccess() bool {
+	if m != nil && m.Success != nil {
+		return *m.Success
+	}
+	return false
+}
+
 func init() {
 	proto.RegisterEnum("bitswap.PBMessage_MessageType", PBMessage_MessageType_name, PBMessage_MessageType_value)
 }

bitswap/message.proto

@@ -10,4 +10,5 @@ message PBMessage {
 	required string key = 3;
 	optional bytes value = 4;
 	optional bool response = 5;
+	optional bool success = 6;
 }

blocks/blocks.go

@@ -1,8 +1,6 @@
 package blocks
 
 import (
-	"fmt"
-	ds "github.com/jbenet/datastore.go"
 	u "github.com/jbenet/go-ipfs/util"
 	mh "github.com/jbenet/go-multihash"
 )
@@ -27,45 +25,3 @@ func NewBlock(data []byte) (*Block, error) {
 func (b *Block) Key() u.Key {
 	return u.Key(b.Multihash)
 }
-
-// BlockService is a block datastore.
-// It uses an internal `datastore.Datastore` instance to store values.
-type BlockService struct {
-	Datastore ds.Datastore
-	// Remote *bitswap.BitSwap // eventually.
-}
-
-// NewBlockService creates a BlockService with given datastore instance.
-func NewBlockService(d ds.Datastore) (*BlockService, error) {
-	if d == nil {
-		return nil, fmt.Errorf("BlockService requires valid datastore")
-	}
-	return &BlockService{Datastore: d}, nil
-}
-
-// AddBlock adds a particular block to the service, Putting it into the datastore.
-func (s *BlockService) AddBlock(b *Block) (u.Key, error) {
-	k := b.Key()
-	dsk := ds.NewKey(string(k))
-	return k, s.Datastore.Put(dsk, b.Data)
-}
-
-// GetBlock retrieves a particular block from the service,
-// Getting it from the datastore using the key (hash).
-func (s *BlockService) GetBlock(k u.Key) (*Block, error) {
-	dsk := ds.NewKey(string(k))
-	datai, err := s.Datastore.Get(dsk)
-	if err != nil {
-		return nil, err
-	}
-
-	data, ok := datai.([]byte)
-	if !ok {
-		return nil, fmt.Errorf("data associated with %s is not a []byte", k)
-	}
-
-	return &Block{
-		Multihash: mh.Multihash(k),
-		Data:      data,
-	}, nil
-}

blockservice/blockservice.go

@@ -0,0 +1,54 @@
+package blockservice
+
+import (
+	"fmt"
+
+	ds "github.com/jbenet/datastore.go"
+	bitswap "github.com/jbenet/go-ipfs/bitswap"
+	blocks "github.com/jbenet/go-ipfs/blocks"
+	u "github.com/jbenet/go-ipfs/util"
+
+	mh "github.com/jbenet/go-multihash"
+)
+
+// BlockService is a block datastore.
+// It uses an internal `datastore.Datastore` instance to store values.
+type BlockService struct {
+	Datastore ds.Datastore
+	Remote    *bitswap.BitSwap
+}
+
+// NewBlockService creates a BlockService with given datastore instance.
+func NewBlockService(d ds.Datastore) (*BlockService, error) {
+	if d == nil {
+		return nil, fmt.Errorf("BlockService requires valid datastore")
+	}
+	return &BlockService{Datastore: d}, nil
+}
+
+// AddBlock adds a particular block to the service, Putting it into the datastore.
+func (s *BlockService) AddBlock(b *blocks.Block) (u.Key, error) {
+	k := b.Key()
+	dsk := ds.NewKey(string(k))
+	return k, s.Datastore.Put(dsk, b.Data)
+}
+
+// GetBlock retrieves a particular block from the service,
+// Getting it from the datastore using the key (hash).
+func (s *BlockService) GetBlock(k u.Key) (*blocks.Block, error) {
+	dsk := ds.NewKey(string(k))
+	datai, err := s.Datastore.Get(dsk)
+	if err != nil {
+		return nil, err
+	}
+
+	data, ok := datai.([]byte)
+	if !ok {
+		return nil, fmt.Errorf("data associated with %s is not a []byte", k)
+	}
+
+	return &blocks.Block{
+		Multihash: mh.Multihash(k),
+		Data:      data,
+	}, nil
+}

core/core.go

@@ -2,8 +2,9 @@ package core
 
 import (
 	"fmt"
+
 	ds "github.com/jbenet/datastore.go"
-	blocks "github.com/jbenet/go-ipfs/blocks"
+	bserv "github.com/jbenet/go-ipfs/blockservice"
 	config "github.com/jbenet/go-ipfs/config"
 	merkledag "github.com/jbenet/go-ipfs/merkledag"
 	path "github.com/jbenet/go-ipfs/path"
@@ -35,7 +36,7 @@ type IpfsNode struct {
 	// BitSwap *bitswap.BitSwap
 
 	// the block service, get/add blocks.
-	Blocks *blocks.BlockService
+	Blocks *bserv.BlockService
 
 	// the merkle dag service, get/add objects.
 	DAG *merkledag.DAGService
@@ -58,7 +59,7 @@ func NewIpfsNode(cfg *config.Config) (*IpfsNode, error) {
 		return nil, err
 	}
 
-	bs, err := blocks.NewBlockService(d)
+	bs, err := bserv.NewBlockService(d)
 	if err != nil {
 		return nil, err
 	}

merkledag/merkledag.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 
 	blocks "github.com/jbenet/go-ipfs/blocks"
+	bserv "github.com/jbenet/go-ipfs/blockservice"
 	u "github.com/jbenet/go-ipfs/util"
 	mh "github.com/jbenet/go-multihash"
 )
@@ -93,7 +94,7 @@ func (n *Node) Key() (u.Key, error) {
 // - the root is virtual (like a forest)
 // - stores nodes' data in a BlockService
 type DAGService struct {
-	Blocks *blocks.BlockService
+	Blocks *bserv.BlockService
 }
 
 // Put adds a node to the DAGService, storing the block in the BlockService

routing/dht/dht.go

@@ -603,6 +603,7 @@ func (dht *IpfsDHT) findProvidersSingle(p *peer.Peer, key u.Key, level int, time
 	}
 }
 
+// TODO: Could be done async
 func (dht *IpfsDHT) addPeerList(key u.Key, peers []*PBDHTMessage_PBPeer) []*peer.Peer {
 	var provArr []*peer.Peer
 	for _, prov := range peers {