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

97 lines
3.6 KiB
Go

package trakr
import (
"fmt"
"time"
"github.com/jzelinskie/trakr/bittorrent"
"github.com/jzelinskie/trakr/stopper"
)
// ErrResourceDoesNotExist is the error returned by all delete methods in the
// store if the requested resource does not exist.
var ErrResourceDoesNotExist = bittorrent.ClientError("resource does not exist")
// PeerStore is an interface that abstracts the interactions of storing and
// manipulating Peers such that it can be implemented for various data stores.
type PeerStore interface {
// PutSeeder adds a Seeder to the Swarm identified by the provided infoHash.
PutSeeder(infoHash bittorrent.InfoHash, p bittorrent.Peer) error
// DeleteSeeder removes a Seeder from the Swarm identified by the provided
// infoHash.
//
// If the Swarm or Peer does not exist, this function should return
// ErrResourceDoesNotExist.
DeleteSeeder(infoHash bittorrent.InfoHash, p bittorrent.Peer) error
// PutLeecher adds a Leecher to the Swarm identified by the provided
// infoHash.
PutLeecher(infoHash bittorrent.InfoHash, p bittorrent.Peer) error
// DeleteLeecher removes a Leecher from the Swarm identified by the provided
// infoHash.
//
// If the Swarm or Peer does not exist, this function should return
// ErrResourceDoesNotExist.
DeleteLeecher(infoHash bittorrent.InfoHash, p bittorrent.Peer) error
// GraduateLeecher promotes a Leecher to a Seeder in the Swarm identified by
// the provided infoHash.
//
// If the given Peer is not present as a Leecher, add the Peer as a Seeder
// and return no error.
GraduateLeecher(infoHash bittorrent.InfoHash, p bittorrent.Peer) error
// AnnouncePeers is a best effort attempt to return Peers from the Swarm
// identified by the provided infoHash. The returned Peers are required to be
// either all IPv4 or all IPv6.
//
// The returned Peers should strive be:
// - as close to length equal to numWant as possible without going over
// - all IPv4 or all IPv6 depending on the provided ipv6 boolean
// - if seeder is true, should ideally return more leechers than seeders
// - if seeder is false, should ideally return more seeders than leechers
AnnouncePeers(infoHash bittorrent.InfoHash, seeder bool, numWant int, ipv6 bool) (peers []bittorrent.Peer, err error)
// CollectGarbage deletes all Peers from the PeerStore which are older than
// the cutoff time. This function must be able to execute while other methods
// on this interface are being executed in parallel.
CollectGarbage(cutoff time.Time) error
// Stopper is an interface that expects a Stop method to stops the PeerStore.
// For more details see the documentation in the stopper package.
stopper.Stopper
}
// PeerStoreConstructor is a function used to create a new instance of a
// PeerStore.
type PeerStoreConstructor func(interface{}) (PeerStore, error)
var peerStores = make(map[string]PeerStoreConstructor)
// RegisterPeerStore makes a PeerStoreConstructor available by the provided
// name.
//
// If this function is called twice with the same name or if the
// PeerStoreConstructor is nil, it panics.
func RegisterPeerStore(name string, con PeerStoreConstructor) {
if con == nil {
panic("trakr: could not register nil PeerStoreConstructor")
}
if _, dup := peerStores[name]; dup {
panic("trakr: could not register duplicate PeerStoreConstructor: " + name)
}
peerStores[name] = con
}
// NewPeerStore creates an instance of the given PeerStore by name.
func NewPeerStore(name string, config interface{}) (PeerStore, error) {
con, ok := peerStores[name]
if !ok {
return nil, fmt.Errorf("trakr: unknown PeerStore %q (forgotten import?)", name)
}
return con(config)
}