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

122 lines
3.7 KiB
Go

// Copyright 2016 Jimmy Zelinskie
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package trakr implements a BitTorrent Tracker that supports multiple
// protocols and configurable Hooks that execute before and after a Response
// has been delivered to a BitTorrent client.
package backend
import (
"log"
"time"
"golang.org/x/net/context"
"github.com/jzelinskie/trakr/bittorrent"
"github.com/jzelinskie/trakr/frontend"
)
type BackendConfig struct {
AnnounceInterval time.Duration `yaml:"announce_interval"`
}
var _ frontend.TrackerFuncs = &Backend{}
func New(config BackendConfig, peerStore PeerStore, announcePreHooks, announcePostHooks, scrapePreHooks, scrapePostHooks []Hook) (*Backend, error) {
toReturn := &Backend{
announceInterval: config.AnnounceInterval,
peerStore: peerStore,
announcePreHooks: announcePreHooks,
announcePostHooks: announcePostHooks,
scrapePreHooks: scrapePreHooks,
scrapePostHooks: scrapePostHooks,
}
if len(toReturn.announcePreHooks) == 0 {
toReturn.announcePreHooks = []Hook{nopHook{}}
}
if len(toReturn.announcePostHooks) == 0 {
toReturn.announcePostHooks = []Hook{nopHook{}}
}
if len(toReturn.scrapePreHooks) == 0 {
toReturn.scrapePreHooks = []Hook{nopHook{}}
}
if len(toReturn.scrapePostHooks) == 0 {
toReturn.scrapePostHooks = []Hook{nopHook{}}
}
return toReturn, nil
}
// Backend is a protocol-agnostic backend of a BitTorrent tracker.
type Backend struct {
announceInterval time.Duration
peerStore PeerStore
announcePreHooks []Hook
announcePostHooks []Hook
scrapePreHooks []Hook
scrapePostHooks []Hook
}
// HandleAnnounce generates a response for an Announce.
func (b *Backend) HandleAnnounce(ctx context.Context, req *bittorrent.AnnounceRequest) (*bittorrent.AnnounceResponse, error) {
resp := &bittorrent.AnnounceResponse{
Interval: b.announceInterval,
}
for _, h := range b.announcePreHooks {
if err := h.HandleAnnounce(ctx, req, resp); err != nil {
return nil, err
}
}
return resp, nil
}
// AfterAnnounce does something with the results of an Announce after it
// has been completed.
func (b *Backend) AfterAnnounce(ctx context.Context, req *bittorrent.AnnounceRequest, resp *bittorrent.AnnounceResponse) {
for _, h := range b.announcePostHooks {
if err := h.HandleAnnounce(ctx, req, resp); err != nil {
log.Println("trakr: post-announce hooks failed:", err.Error())
return
}
}
}
// HandleScrape generates a response for a Scrape.
func (b *Backend) HandleScrape(ctx context.Context, req *bittorrent.ScrapeRequest) (*bittorrent.ScrapeResponse, error) {
resp := &bittorrent.ScrapeResponse{
Files: make(map[bittorrent.InfoHash]bittorrent.Scrape),
}
for _, h := range b.scrapePreHooks {
if err := h.HandleScrape(ctx, req, resp); err != nil {
return nil, err
}
}
return resp, nil
}
// AfterScrape does something with the results of a Scrape after it has been completed.
func (b *Backend) AfterScrape(ctx context.Context, req *bittorrent.ScrapeRequest, resp *bittorrent.ScrapeResponse) {
for _, h := range b.scrapePostHooks {
if err := h.HandleScrape(ctx, req, resp); err != nil {
log.Println("trakr: post-scrape hooks failed:", err.Error())
return
}
}
}