tracker/middleware/logic.go

125 lines
3.8 KiB
Go

package middleware
import (
"context"
"time"
"github.com/chihaya/chihaya/bittorrent"
"github.com/chihaya/chihaya/frontend"
"github.com/chihaya/chihaya/pkg/log"
"github.com/chihaya/chihaya/pkg/stop"
"github.com/chihaya/chihaya/storage"
)
// ResponseConfig holds the configuration used for the actual response.
//
// TODO(jzelinskie): Evaluate whether we would like to make this optional.
// We can make Chihaya extensible enough that you can program a new response
// generator at the cost of making it possible for users to create config that
// won't compose a functional tracker.
type ResponseConfig struct {
AnnounceInterval time.Duration `yaml:"announce_interval"`
MinAnnounceInterval time.Duration `yaml:"min_announce_interval"`
}
var _ frontend.TrackerLogic = &Logic{}
// NewLogic creates a new instance of a TrackerLogic that executes the provided
// middleware hooks.
func NewLogic(cfg ResponseConfig, peerStore storage.PeerStore, preHooks, postHooks []Hook) *Logic {
return &Logic{
announceInterval: cfg.AnnounceInterval,
minAnnounceInterval: cfg.MinAnnounceInterval,
peerStore: peerStore,
preHooks: append(preHooks, &responseHook{store: peerStore}),
postHooks: append(postHooks, &swarmInteractionHook{store: peerStore}),
}
}
// Logic is an implementation of the TrackerLogic that functions by
// executing a series of middleware hooks.
type Logic struct {
announceInterval time.Duration
minAnnounceInterval time.Duration
peerStore storage.PeerStore
preHooks []Hook
postHooks []Hook
}
// HandleAnnounce generates a response for an Announce.
func (l *Logic) HandleAnnounce(ctx context.Context, req *bittorrent.AnnounceRequest) (_ context.Context, resp *bittorrent.AnnounceResponse, err error) {
resp = &bittorrent.AnnounceResponse{
Interval: l.announceInterval,
MinInterval: l.minAnnounceInterval,
Compact: req.Compact,
}
for _, h := range l.preHooks {
if ctx, err = h.HandleAnnounce(ctx, req, resp); err != nil {
return nil, nil, err
}
}
log.Debug("generated announce response", resp)
return ctx, resp, nil
}
// AfterAnnounce does something with the results of an Announce after it has
// been completed.
func (l *Logic) AfterAnnounce(ctx context.Context, req *bittorrent.AnnounceRequest, resp *bittorrent.AnnounceResponse) {
var err error
for _, h := range l.postHooks {
if ctx, err = h.HandleAnnounce(ctx, req, resp); err != nil {
log.Error("post-announce hooks failed", log.Err(err))
return
}
}
}
// HandleScrape generates a response for a Scrape.
func (l *Logic) HandleScrape(ctx context.Context, req *bittorrent.ScrapeRequest) (_ context.Context, resp *bittorrent.ScrapeResponse, err error) {
resp = &bittorrent.ScrapeResponse{
Files: make([]bittorrent.Scrape, 0, len(req.InfoHashes)),
}
for _, h := range l.preHooks {
if ctx, err = h.HandleScrape(ctx, req, resp); err != nil {
return nil, nil, err
}
}
log.Debug("generated scrape response", resp)
return ctx, resp, nil
}
// AfterScrape does something with the results of a Scrape after it has been
// completed.
func (l *Logic) AfterScrape(ctx context.Context, req *bittorrent.ScrapeRequest, resp *bittorrent.ScrapeResponse) {
var err error
for _, h := range l.postHooks {
if ctx, err = h.HandleScrape(ctx, req, resp); err != nil {
log.Error("post-scrape hooks failed", log.Err(err))
return
}
}
}
// Stop stops the Logic.
//
// This stops any hooks that implement stop.Stopper.
func (l *Logic) Stop() stop.Result {
stopGroup := stop.NewGroup()
for _, hook := range l.preHooks {
stoppable, ok := hook.(stop.Stopper)
if ok {
stopGroup.Add(stoppable)
}
}
for _, hook := range l.postHooks {
stoppable, ok := hook.(stop.Stopper)
if ok {
stopGroup.Add(stoppable)
}
}
return stopGroup.Stop()
}