tracker/storage/memory/peer_store.go
2016-08-16 22:17:10 -04:00

371 lines
7.3 KiB
Go

package memory
import (
"encoding/binary"
"log"
"net"
"runtime"
"sync"
"time"
"github.com/jzelinskie/trakr/bittorrent"
"github.com/jzelinskie/trakr/storage"
)
// TODO(jzelinskie): separate ipv4 and ipv6 swarms
type Config struct {
ShardCount int `yaml:"shard_count"`
}
func New(cfg Config) (storage.PeerStore, error) {
shardCount := 1
if cfg.ShardCount > 0 {
shardCount = cfg.ShardCount
}
shards := make([]*peerShard, shardCount)
for i := 0; i < shardCount; i++ {
shards[i] = &peerShard{}
shards[i].swarms = make(map[swarmKey]swarm)
}
return &peerStore{
shards: shards,
closed: make(chan struct{}),
}, nil
}
type serializedPeer string
type swarmKey [21]byte
func newSwarmKey(ih bittorrent.InfoHash, p bittorrent.Peer) (key swarmKey) {
for i, ihbyte := range ih {
key[i] = ihbyte
}
if len(p.IP) == net.IPv4len {
key[20] = byte(4)
} else {
key[20] = byte(6)
}
return
}
type peerShard struct {
swarms map[swarmKey]swarm
sync.RWMutex
}
type swarm struct {
// map serialized peer to mtime
seeders map[serializedPeer]int64
leechers map[serializedPeer]int64
}
type peerStore struct {
shards []*peerShard
closed chan struct{}
}
var _ storage.PeerStore = &peerStore{}
func (s *peerStore) shardIndex(infoHash bittorrent.InfoHash) uint32 {
return binary.BigEndian.Uint32(infoHash[:4]) % uint32(len(s.shards))
}
func newPeerKey(p bittorrent.Peer) serializedPeer {
b := make([]byte, 20+2+len(p.IP))
copy(b[:20], p.ID[:])
binary.BigEndian.PutUint16(b[20:22], p.Port)
copy(b[22:], p.IP)
return serializedPeer(b)
}
func decodePeerKey(pk serializedPeer) bittorrent.Peer {
return bittorrent.Peer{
ID: bittorrent.PeerIDFromString(string(pk[:20])),
Port: binary.BigEndian.Uint16([]byte(pk[20:22])),
IP: net.IP(pk[22:]),
}
}
func (s *peerStore) PutSeeder(ih bittorrent.InfoHash, p bittorrent.Peer) error {
select {
case <-s.closed:
panic("attempted to interact with stopped memory store")
default:
}
sk := newSwarmKey(ih, p)
pk := newPeerKey(p)
shard := s.shards[s.shardIndex(ih)]
shard.Lock()
if _, ok := shard.swarms[sk]; !ok {
shard.swarms[sk] = swarm{
seeders: make(map[serializedPeer]int64),
leechers: make(map[serializedPeer]int64),
}
}
shard.swarms[sk].seeders[pk] = time.Now().UnixNano()
shard.Unlock()
return nil
}
func (s *peerStore) DeleteSeeder(ih bittorrent.InfoHash, p bittorrent.Peer) error {
select {
case <-s.closed:
panic("attempted to interact with stopped memory store")
default:
}
sk := newSwarmKey(ih, p)
pk := newPeerKey(p)
shard := s.shards[s.shardIndex(ih)]
shard.Lock()
if _, ok := shard.swarms[sk]; !ok {
shard.Unlock()
return storage.ErrResourceDoesNotExist
}
if _, ok := shard.swarms[sk].seeders[pk]; !ok {
shard.Unlock()
return storage.ErrResourceDoesNotExist
}
delete(shard.swarms[sk].seeders, pk)
if len(shard.swarms[sk].seeders)|len(shard.swarms[sk].leechers) == 0 {
delete(shard.swarms, sk)
}
shard.Unlock()
return nil
}
func (s *peerStore) PutLeecher(ih bittorrent.InfoHash, p bittorrent.Peer) error {
select {
case <-s.closed:
panic("attempted to interact with stopped memory store")
default:
}
sk := newSwarmKey(ih, p)
pk := newPeerKey(p)
shard := s.shards[s.shardIndex(ih)]
shard.Lock()
if _, ok := shard.swarms[sk]; !ok {
shard.swarms[sk] = swarm{
seeders: make(map[serializedPeer]int64),
leechers: make(map[serializedPeer]int64),
}
}
shard.swarms[sk].leechers[pk] = time.Now().UnixNano()
shard.Unlock()
return nil
}
func (s *peerStore) DeleteLeecher(ih bittorrent.InfoHash, p bittorrent.Peer) error {
select {
case <-s.closed:
panic("attempted to interact with stopped memory store")
default:
}
sk := newSwarmKey(ih, p)
pk := newPeerKey(p)
shard := s.shards[s.shardIndex(ih)]
shard.Lock()
if _, ok := shard.swarms[sk]; !ok {
shard.Unlock()
return storage.ErrResourceDoesNotExist
}
if _, ok := shard.swarms[sk].leechers[pk]; !ok {
shard.Unlock()
return storage.ErrResourceDoesNotExist
}
delete(shard.swarms[sk].leechers, pk)
if len(shard.swarms[sk].seeders)|len(shard.swarms[sk].leechers) == 0 {
delete(shard.swarms, sk)
}
shard.Unlock()
return nil
}
func (s *peerStore) GraduateLeecher(ih bittorrent.InfoHash, p bittorrent.Peer) error {
select {
case <-s.closed:
panic("attempted to interact with stopped memory store")
default:
}
sk := newSwarmKey(ih, p)
pk := newPeerKey(p)
shard := s.shards[s.shardIndex(ih)]
shard.Lock()
if _, ok := shard.swarms[sk]; !ok {
shard.swarms[sk] = swarm{
seeders: make(map[serializedPeer]int64),
leechers: make(map[serializedPeer]int64),
}
}
delete(shard.swarms[sk].leechers, pk)
shard.swarms[sk].seeders[pk] = time.Now().UnixNano()
shard.Unlock()
return nil
}
func (s *peerStore) CollectGarbage(cutoff time.Time) error {
select {
case <-s.closed:
panic("attempted to interact with stopped memory store")
default:
}
log.Printf("memory: collecting garbage. Cutoff time: %s", cutoff.String())
cutoffUnix := cutoff.UnixNano()
for _, shard := range s.shards {
shard.RLock()
var swarmKeys []swarmKey
for sk := range shard.swarms {
swarmKeys = append(swarmKeys, sk)
}
shard.RUnlock()
runtime.Gosched()
for _, sk := range swarmKeys {
shard.Lock()
if _, stillExists := shard.swarms[sk]; !stillExists {
shard.Unlock()
runtime.Gosched()
continue
}
for pk, mtime := range shard.swarms[sk].leechers {
if mtime <= cutoffUnix {
delete(shard.swarms[sk].leechers, pk)
}
}
for pk, mtime := range shard.swarms[sk].seeders {
if mtime <= cutoffUnix {
delete(shard.swarms[sk].seeders, pk)
}
}
if len(shard.swarms[sk].seeders)|len(shard.swarms[sk].leechers) == 0 {
delete(shard.swarms, sk)
}
shard.Unlock()
runtime.Gosched()
}
runtime.Gosched()
}
return nil
}
func (s *peerStore) AnnouncePeers(ih bittorrent.InfoHash, seeder bool, numWant int, announcer bittorrent.Peer) (peers []bittorrent.Peer, err error) {
select {
case <-s.closed:
panic("attempted to interact with stopped memory store")
default:
}
sk := newSwarmKey(ih, announcer)
shard := s.shards[s.shardIndex(ih)]
shard.RLock()
if _, ok := shard.swarms[sk]; !ok {
shard.RUnlock()
return nil, storage.ErrResourceDoesNotExist
}
if seeder {
// Append leechers as possible.
leechers := shard.swarms[sk].leechers
for p := range leechers {
decodedPeer := decodePeerKey(p)
if numWant == 0 {
break
}
peers = append(peers, decodedPeer)
numWant--
}
} else {
// Append as many seeders as possible.
seeders := shard.swarms[sk].seeders
for p := range seeders {
decodedPeer := decodePeerKey(p)
if numWant == 0 {
break
}
peers = append(peers, decodedPeer)
numWant--
}
// Append leechers until we reach numWant.
leechers := shard.swarms[sk].leechers
if numWant > 0 {
for p := range leechers {
decodedPeer := decodePeerKey(p)
if numWant == 0 {
break
}
if decodedPeer.Equal(announcer) {
continue
}
peers = append(peers, decodedPeer)
numWant--
}
}
}
shard.RUnlock()
return
}
func (s *peerStore) Stop() <-chan error {
toReturn := make(chan error)
go func() {
shards := make([]*peerShard, len(s.shards))
for i := 0; i < len(s.shards); i++ {
shards[i] = &peerShard{}
shards[i].swarms = make(map[swarmKey]swarm)
}
s.shards = shards
close(s.closed)
close(toReturn)
}()
return toReturn
}