1// Copyright 2021 Google LLC 2// 3// Licensed under the Apache License, Version 2.0 (the "License"); 4// you may not use this file except in compliance with the License. 5// You may obtain a copy of the License at 6// 7// https://www.apache.org/licenses/LICENSE-2.0 8// 9// Unless required by applicable law or agreed to in writing, software 10// distributed under the License is distributed on an "AS IS" BASIS, 11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12// See the License for the specific language governing permissions and 13 14package wire 15 16import ( 17 "sync" 18 "time" 19) 20 21type requestTimerStatus int 22 23const ( 24 requestTimerNew requestTimerStatus = iota 25 requestTimerStopped 26 requestTimerTriggered 27) 28 29// requestTimer bounds the duration of a request and executes `onTimeout` if 30// the timer is triggered. 31type requestTimer struct { 32 onTimeout func() 33 timeoutErr error 34 timer *time.Timer 35 mu sync.Mutex 36 status requestTimerStatus 37} 38 39func newRequestTimer(duration time.Duration, onTimeout func(), timeoutErr error) *requestTimer { 40 rt := &requestTimer{ 41 onTimeout: onTimeout, 42 timeoutErr: timeoutErr, 43 status: requestTimerNew, 44 } 45 rt.timer = time.AfterFunc(duration, rt.onTriggered) 46 return rt 47} 48 49func (rt *requestTimer) onTriggered() { 50 rt.mu.Lock() 51 defer rt.mu.Unlock() 52 if rt.status == requestTimerNew { 53 rt.status = requestTimerTriggered 54 rt.onTimeout() 55 } 56} 57 58// Stop should be called upon a successful request to prevent the timer from 59// expiring. 60func (rt *requestTimer) Stop() { 61 rt.mu.Lock() 62 defer rt.mu.Unlock() 63 if rt.status == requestTimerNew { 64 rt.status = requestTimerStopped 65 rt.timer.Stop() 66 } 67} 68 69// ResolveError returns `timeoutErr` if the timer triggered, or otherwise 70// `originalErr`. 71func (rt *requestTimer) ResolveError(originalErr error) error { 72 rt.mu.Lock() 73 defer rt.mu.Unlock() 74 if rt.status == requestTimerTriggered { 75 return rt.timeoutErr 76 } 77 return originalErr 78} 79