mirror of
https://github.com/ergochat/ergo.git
synced 2024-12-23 11:12:44 +01:00
134 lines
3.1 KiB
Go
134 lines
3.1 KiB
Go
// Copyright (c) 2017 Shivaram Lingamneni <slingamn@cs.stanford.edu>
|
|
// released under the MIT license
|
|
|
|
package irc
|
|
|
|
import (
|
|
"time"
|
|
)
|
|
|
|
// BrbTimer is a timer on the client as a whole (not an individual session) for implementing
|
|
// the BRB command and related functionality (where a client can remain online without
|
|
// having any connected sessions).
|
|
|
|
type BrbState uint
|
|
|
|
const (
|
|
// BrbDisabled is the default state; the client will be disconnected if it has no sessions
|
|
BrbDisabled BrbState = iota
|
|
// BrbEnabled allows the client to remain online without sessions; if a timeout is
|
|
// reached, it will be removed
|
|
BrbEnabled
|
|
// BrbDead is the state of a client after its timeout has expired; it will be removed
|
|
// and therefore new sessions cannot be attached to it
|
|
BrbDead
|
|
)
|
|
|
|
type BrbTimer struct {
|
|
// XXX we use client.stateMutex for synchronization, so we can atomically test
|
|
// conditions that use both brbTimer.state and client.sessions. This code
|
|
// is tightly coupled with the rest of Client.
|
|
client *Client
|
|
|
|
state BrbState
|
|
brbAt time.Time
|
|
duration time.Duration
|
|
timer *time.Timer
|
|
}
|
|
|
|
func (bt *BrbTimer) Initialize(client *Client) {
|
|
bt.client = client
|
|
}
|
|
|
|
// attempts to enable BRB for a client, returns whether it succeeded
|
|
func (bt *BrbTimer) Enable() (success bool, duration time.Duration) {
|
|
// TODO make this configurable
|
|
duration = ResumeableTotalTimeout
|
|
|
|
bt.client.stateMutex.Lock()
|
|
defer bt.client.stateMutex.Unlock()
|
|
|
|
if !bt.client.registered || bt.client.alwaysOn || bt.client.resumeID == "" {
|
|
return
|
|
}
|
|
|
|
switch bt.state {
|
|
case BrbDisabled, BrbEnabled:
|
|
bt.state = BrbEnabled
|
|
bt.duration = duration
|
|
bt.resetTimeout()
|
|
// only track the earliest BRB, if multiple sessions are BRB'ing at once
|
|
// TODO(#524) this is inaccurate in case of an auto-BRB
|
|
if bt.brbAt.IsZero() {
|
|
bt.brbAt = time.Now().UTC()
|
|
}
|
|
success = true
|
|
default:
|
|
// BrbDead
|
|
success = false
|
|
}
|
|
return
|
|
}
|
|
|
|
// turns off BRB for a client and stops the timer; used on resume and during
|
|
// client teardown
|
|
func (bt *BrbTimer) Disable() (brbAt time.Time) {
|
|
bt.client.stateMutex.Lock()
|
|
defer bt.client.stateMutex.Unlock()
|
|
|
|
if bt.state == BrbEnabled {
|
|
bt.state = BrbDisabled
|
|
brbAt = bt.brbAt
|
|
bt.brbAt = time.Time{}
|
|
}
|
|
bt.resetTimeout()
|
|
return
|
|
}
|
|
|
|
func (bt *BrbTimer) resetTimeout() {
|
|
if bt.timer != nil {
|
|
bt.timer.Stop()
|
|
}
|
|
if bt.state != BrbEnabled {
|
|
return
|
|
}
|
|
if bt.timer == nil {
|
|
bt.timer = time.AfterFunc(bt.duration, bt.processTimeout)
|
|
} else {
|
|
bt.timer.Reset(bt.duration)
|
|
}
|
|
}
|
|
|
|
func (bt *BrbTimer) processTimeout() {
|
|
dead := false
|
|
defer func() {
|
|
if dead {
|
|
bt.client.Quit(bt.client.AwayMessage(), nil)
|
|
bt.client.destroy(nil)
|
|
}
|
|
}()
|
|
|
|
bt.client.stateMutex.Lock()
|
|
defer bt.client.stateMutex.Unlock()
|
|
|
|
if bt.client.alwaysOn {
|
|
return
|
|
}
|
|
|
|
switch bt.state {
|
|
case BrbDisabled, BrbEnabled:
|
|
if len(bt.client.sessions) == 0 {
|
|
// client never returned, quit them
|
|
bt.state = BrbDead
|
|
dead = true
|
|
} else {
|
|
// client resumed, reattached, or has another active session
|
|
bt.state = BrbDisabled
|
|
bt.brbAt = time.Time{}
|
|
}
|
|
case BrbDead:
|
|
dead = true // shouldn't be possible but whatever
|
|
}
|
|
bt.resetTimeout()
|
|
}
|