storj/pkg/kademlia/routing.go
2018-12-18 13:04:46 -05:00

213 lines
5.9 KiB
Go

// Copyright (C) 2018 Storj Labs, Inc.
// See LICENSE for copying information.
package kademlia
import (
"encoding/binary"
"sync"
"time"
"github.com/zeebo/errs"
"storj.io/storj/pkg/dht"
"storj.io/storj/pkg/pb"
"storj.io/storj/pkg/storj"
"storj.io/storj/pkg/utils"
"storj.io/storj/storage"
)
const (
// KademliaBucket is the string representing the bucket used for the kademlia routing table k-bucket ids
KademliaBucket = "kbuckets"
// NodeBucket is the string representing the bucket used for the kademlia routing table node ids
NodeBucket = "nodes"
)
// RoutingErr is the class for all errors pertaining to routing table operations
var RoutingErr = errs.Class("routing table error")
// Bucket IDs exist in the same address space as node IDs
type bucketID [len(storj.NodeID{})]byte
// RoutingTable implements the RoutingTable interface
type RoutingTable struct {
self pb.Node
kadBucketDB storage.KeyValueStore
nodeBucketDB storage.KeyValueStore
transport *pb.NodeTransport
mutex *sync.Mutex
seen map[storj.NodeID]*pb.Node
replacementCache map[bucketID][]*pb.Node
bucketSize int // max number of nodes stored in a kbucket = 20 (k)
rcBucketSize int // replacementCache bucket max length
}
// NewRoutingTable returns a newly configured instance of a RoutingTable
func NewRoutingTable(localNode pb.Node, kdb, ndb storage.KeyValueStore) (*RoutingTable, error) {
rt := &RoutingTable{
self: localNode,
kadBucketDB: kdb,
nodeBucketDB: ndb,
transport: &defaultTransport,
mutex: &sync.Mutex{},
seen: make(map[storj.NodeID]*pb.Node),
replacementCache: make(map[bucketID][]*pb.Node),
bucketSize: *flagBucketSize,
rcBucketSize: *flagReplacementCacheSize,
}
ok, err := rt.addNode(&localNode)
if !ok || err != nil {
return nil, RoutingErr.New("could not add localNode to routing table: %s", err)
}
return rt, nil
}
// Close closes underlying databases
func (rt *RoutingTable) Close() error {
return utils.CombineErrors(
rt.kadBucketDB.Close(),
rt.nodeBucketDB.Close(),
)
}
// Local returns the local nodes ID
func (rt *RoutingTable) Local() pb.Node {
return rt.self
}
// K returns the currently configured maximum of nodes to store in a bucket
func (rt *RoutingTable) K() int {
return rt.bucketSize
}
// CacheSize returns the total current size of the replacement cache
func (rt *RoutingTable) CacheSize() int {
return rt.rcBucketSize
}
// GetNodes retrieves nodes within the same kbucket as the given node id
// Note: id doesn't need to be stored at time of search
func (rt *RoutingTable) GetNodes(id storj.NodeID) ([]*pb.Node, bool) {
bID, err := rt.getKBucketID(id)
if err != nil {
return nil, false
}
if bID == (bucketID{}) {
return nil, false
}
unmarshaledNodes, err := rt.getUnmarshaledNodesFromBucket(bID)
if err != nil {
return nil, false
}
return unmarshaledNodes, true
}
// GetBucketIds returns a storage.Keys type of bucket ID's in the Kademlia instance
func (rt *RoutingTable) GetBucketIds() (storage.Keys, error) {
kbuckets, err := rt.kadBucketDB.List(nil, 0)
if err != nil {
return nil, err
}
return kbuckets, nil
}
// FindNear returns the node corresponding to the provided nodeID
// returns all Nodes closest via XOR to the provided nodeID up to the provided limit
// always returns limit + self
func (rt *RoutingTable) FindNear(id storj.NodeID, limit int) (nodes []*pb.Node, err error) {
// if id is not in the routing table
nodeIDsKeys, err := rt.nodeBucketDB.List(nil, 0)
if err != nil {
return nodes, RoutingErr.New("could not get node ids %s", err)
}
sortByXOR(nodeIDsKeys, id.Bytes())
if len(nodeIDsKeys) >= limit {
nodeIDsKeys = nodeIDsKeys[:limit]
}
nodeIDs, err := storj.NodeIDsFromBytes(nodeIDsKeys.ByteSlices())
if err != nil {
return nodes, RoutingErr.Wrap(err)
}
nodes, err = rt.getNodesFromIDsBytes(nodeIDs)
if err != nil {
return nodes, RoutingErr.New("could not get nodes %s", err)
}
return nodes, nil
}
// ConnectionSuccess updates or adds a node to the routing table when
// a successful connection is made to the node on the network
func (rt *RoutingTable) ConnectionSuccess(node *pb.Node) error {
// valid to connect to node without ID but don't store connection
if node.Id == (storj.NodeID{}) {
return nil
}
rt.mutex.Lock()
rt.seen[node.Id] = node
rt.mutex.Unlock()
v, err := rt.nodeBucketDB.Get(storage.Key(node.Id.Bytes()))
if err != nil && !storage.ErrKeyNotFound.Has(err) {
return RoutingErr.New("could not get node %s", err)
}
if v != nil {
err = rt.updateNode(node)
if err != nil {
return RoutingErr.New("could not update node %s", err)
}
return nil
}
_, err = rt.addNode(node)
if err != nil {
return RoutingErr.New("could not add node %s", err)
}
return nil
}
// ConnectionFailed removes a node from the routing table when
// a connection fails for the node on the network
func (rt *RoutingTable) ConnectionFailed(node *pb.Node) error {
err := rt.removeNode(node.Id)
if err != nil {
return RoutingErr.New("could not remove node %s", err)
}
return nil
}
// SetBucketTimestamp updates the last updated time for a bucket
func (rt *RoutingTable) SetBucketTimestamp(bIDBytes []byte, now time.Time) error {
rt.mutex.Lock()
defer rt.mutex.Unlock()
err := rt.createOrUpdateKBucket(keyToBucketID(bIDBytes), now)
if err != nil {
return NodeErr.New("could not update bucket timestamp %s", err)
}
return nil
}
// GetBucketTimestamp retrieves the last updated time for a bucket
func (rt *RoutingTable) GetBucketTimestamp(bIDBytes []byte, bucket dht.Bucket) (time.Time, error) {
t, err := rt.kadBucketDB.Get(bIDBytes)
if err != nil {
return time.Now(), RoutingErr.New("could not get bucket timestamp %s", err)
}
timestamp, _ := binary.Varint(t)
return time.Unix(0, timestamp).UTC(), nil
}
func (rt *RoutingTable) iterate(opts storage.IterateOptions, f func(it storage.Iterator) error) error {
return rt.nodeBucketDB.Iterate(opts, f)
}