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

83 lines
2.7 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
import (
"fmt"
"golang.org/x/net/context"
"github.com/jzelinskie/trakr/bittorrent"
)
// Hook abstracts the concept of anything that needs to interact with a
// BitTorrent client's request and response to a BitTorrent tracker.
type Hook interface {
HandleAnnounce(context.Context, *bittorrent.AnnounceRequest, *bittorrent.AnnounceResponse) error
HandleScrape(context.Context, *bittorrent.ScrapeRequest, *bittorrent.ScrapeResponse) error
}
// HookConstructor is a function used to create a new instance of a Hook.
type HookConstructor func(interface{}) (Hook, error)
var preHooks = make(map[string]HookConstructor)
// RegisterPreHook makes a HookConstructor available by the provided name.
//
// If this function is called twice with the same name or if the
// HookConstructor is nil, it panics.
func RegisterPreHook(name string, con HookConstructor) {
if con == nil {
panic("trakr: could not register nil HookConstructor")
}
if _, dup := preHooks[name]; dup {
panic("trakr: could not register duplicate HookConstructor: " + name)
}
preHooks[name] = con
}
// NewPreHook creates an instance of the given PreHook by name.
func NewPreHook(name string, config interface{}) (Hook, error) {
con, ok := preHooks[name]
if !ok {
return nil, fmt.Errorf("trakr: unknown PreHook %q (forgotten import?)", name)
}
return con(config)
}
var postHooks = make(map[string]HookConstructor)
// RegisterPostHook makes a HookConstructor available by the provided name.
//
// If this function is called twice with the same name or if the
// HookConstructor is nil, it panics.
func RegisterPostHook(name string, con HookConstructor) {
if con == nil {
panic("trakr: could not register nil HookConstructor")
}
if _, dup := postHooks[name]; dup {
panic("trakr: could not register duplicate HookConstructor: " + name)
}
preHooks[name] = con
}
// NewPostHook creates an instance of the given PostHook by name.
func NewPostHook(name string, config interface{}) (Hook, error) {
con, ok := preHooks[name]
if !ok {
return nil, fmt.Errorf("trakr: unknown PostHook %q (forgotten import?)", name)
}
return con(config)
}