tracker/bittorrent/bittorrent.go
2016-09-08 16:02:01 -04:00

132 lines
3 KiB
Go

// Package bittorrent implements all of the abstractions used to decouple the
// protocol of a BitTorrent tracker from the logic of handling Announces and
// Scrapes.
package bittorrent
import (
"net"
"time"
)
// PeerID represents a peer ID.
type PeerID [20]byte
// PeerIDFromBytes creates a PeerID from a byte slice.
//
// It panics if b is not 20 bytes long.
func PeerIDFromBytes(b []byte) PeerID {
if len(b) != 20 {
panic("peer ID must be 20 bytes")
}
var buf [20]byte
copy(buf[:], b)
return PeerID(buf)
}
// PeerIDFromString creates a PeerID from a string.
//
// It panics if s is not 20 bytes long.
func PeerIDFromString(s string) PeerID {
if len(s) != 20 {
panic("peer ID must be 20 bytes")
}
var buf [20]byte
copy(buf[:], s)
return PeerID(buf)
}
// InfoHash represents an infohash.
type InfoHash [20]byte
// InfoHashFromBytes creates an InfoHash from a byte slice.
//
// It panics if b is not 20 bytes long.
func InfoHashFromBytes(b []byte) InfoHash {
if len(b) != 20 {
panic("infohash must be 20 bytes")
}
var buf [20]byte
copy(buf[:], b)
return InfoHash(buf)
}
// InfoHashFromString creates an InfoHash from a string.
//
// It panics if s is not 20 bytes long.
func InfoHashFromString(s string) InfoHash {
if len(s) != 20 {
panic("infohash must be 20 bytes")
}
var buf [20]byte
copy(buf[:], s)
return InfoHash(buf)
}
// AnnounceRequest represents the parsed parameters from an announce request.
type AnnounceRequest struct {
Event Event
InfoHash InfoHash
Compact bool
NumWant uint32
Left uint64
Downloaded uint64
Uploaded uint64
Peer
Params
}
// AnnounceResponse represents the parameters used to create an announce
// response.
type AnnounceResponse struct {
Compact bool
Complete uint32
Incomplete uint32
Interval time.Duration
MinInterval time.Duration
IPv4Peers []Peer
IPv6Peers []Peer
}
// ScrapeRequest represents the parsed parameters from a scrape request.
type ScrapeRequest struct {
InfoHashes []InfoHash
Params Params
}
// ScrapeResponse represents the parameters used to create a scrape response.
type ScrapeResponse struct {
Files map[InfoHash]Scrape
}
// Scrape represents the state of a swarm that is returned in a scrape response.
type Scrape struct {
Snatches uint32
Complete uint32
Incomplete uint32
}
// Peer represents the connection details of a peer that is returned in an
// announce response.
type Peer struct {
ID PeerID
IP net.IP
Port uint16
}
// Equal reports whether p and x are the same.
func (p Peer) Equal(x Peer) bool { return p.EqualEndpoint(x) && p.ID == x.ID }
// EqualEndpoint reports whether p and x have the same endpoint.
func (p Peer) EqualEndpoint(x Peer) bool { return p.Port == x.Port && p.IP.Equal(x.IP) }
// ClientError represents an error that should be exposed to the client over
// the BitTorrent protocol implementation.
type ClientError string
// Error implements the error interface for ClientError.
func (c ClientError) Error() string { return string(c) }