kubo/peer/queue/distance.go
Juan Batiz-Benet c84a714b16 peer change: peer.Peer -> peer.ID
this is a major refactor of the entire codebase
it changes the monolithic peer.Peer into using
a peer.ID and a peer.Peerstore.

Other changes:
- removed handshake3.
-	testutil vastly simplified peer
-	secio bugfix + debugging logs
-	testutil: RandKeyPair
-	backpressure bugfix: w.o.w.
-	peer: added hex enc/dec
-	peer: added a PeerInfo struct
  PeerInfo is a small struct used to pass around a peer with
 	a set of addresses and keys. This is not meant to be a
 	complete view of the system, but rather to model updates to
 	the peerstore. It is used by things like the routing system.
-	updated peer/queue + peerset
-	latency metrics
-	testutil: use crand for PeerID gen
 	RandPeerID generates random "valid" peer IDs. it does not
 	NEED to generate keys because it is as if we lost the key
 	right away. fine to read some randomness and hash it. to
 	generate proper keys and an ID, use:
 	  sk, pk, _ := testutil.RandKeyPair()
 	  id, _ := peer.IDFromPublicKey(pk)
 	Also added RandPeerIDFatal helper
- removed old spipe
- updated seccat
- core: cleanup initIdentity
- removed old getFromPeerList
2014-12-23 08:33:32 -08:00

102 lines
2.0 KiB
Go

package queue
import (
"container/heap"
"math/big"
"sync"
peer "github.com/jbenet/go-ipfs/peer"
ks "github.com/jbenet/go-ipfs/routing/keyspace"
u "github.com/jbenet/go-ipfs/util"
)
// peerMetric tracks a peer and its distance to something else.
type peerMetric struct {
// the peer
peer peer.ID
// big.Int for XOR metric
metric *big.Int
}
// peerMetricHeap implements a heap of peerDistances
type peerMetricHeap []*peerMetric
func (ph peerMetricHeap) Len() int {
return len(ph)
}
func (ph peerMetricHeap) Less(i, j int) bool {
return -1 == ph[i].metric.Cmp(ph[j].metric)
}
func (ph peerMetricHeap) Swap(i, j int) {
ph[i], ph[j] = ph[j], ph[i]
}
func (ph *peerMetricHeap) Push(x interface{}) {
item := x.(*peerMetric)
*ph = append(*ph, item)
}
func (ph *peerMetricHeap) Pop() interface{} {
old := *ph
n := len(old)
item := old[n-1]
*ph = old[0 : n-1]
return item
}
// distancePQ implements heap.Interface and PeerQueue
type distancePQ struct {
// from is the Key this PQ measures against
from ks.Key
// heap is a heap of peerDistance items
heap peerMetricHeap
sync.RWMutex
}
func (pq *distancePQ) Len() int {
pq.Lock()
defer pq.Unlock()
return len(pq.heap)
}
func (pq *distancePQ) Enqueue(p peer.ID) {
pq.Lock()
defer pq.Unlock()
distance := ks.XORKeySpace.Key([]byte(p)).Distance(pq.from)
heap.Push(&pq.heap, &peerMetric{
peer: p,
metric: distance,
})
}
func (pq *distancePQ) Dequeue() peer.ID {
pq.Lock()
defer pq.Unlock()
if len(pq.heap) < 1 {
panic("called Dequeue on an empty PeerQueue")
// will panic internally anyway, but we can help debug here
}
o := heap.Pop(&pq.heap)
p := o.(*peerMetric)
return p.peer
}
// NewXORDistancePQ returns a PeerQueue which maintains its peers sorted
// in terms of their distances to each other in an XORKeySpace (i.e. using
// XOR as a metric of distance).
func NewXORDistancePQ(fromKey u.Key) PeerQueue {
return &distancePQ{
from: ks.XORKeySpace.Key([]byte(fromKey)),
heap: peerMetricHeap{},
}
}