1/* 2Copyright 2016 The Kubernetes Authors. 3 4Licensed under the Apache License, Version 2.0 (the "License"); 5you may not use this file except in compliance with the License. 6You may obtain a copy of the License at 7 8 http://www.apache.org/licenses/LICENSE-2.0 9 10Unless required by applicable law or agreed to in writing, software 11distributed under the License is distributed on an "AS IS" BASIS, 12WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13See the License for the specific language governing permissions and 14limitations under the License. 15*/ 16 17package term 18 19import ( 20 "time" 21 22 "k8s.io/apimachinery/pkg/util/runtime" 23 "k8s.io/client-go/tools/remotecommand" 24) 25 26// monitorResizeEvents spawns a goroutine that periodically gets the terminal size and tries to send 27// it to the resizeEvents channel if the size has changed. The goroutine stops when the stop channel 28// is closed. 29func monitorResizeEvents(fd uintptr, resizeEvents chan<- remotecommand.TerminalSize, stop chan struct{}) { 30 go func() { 31 defer runtime.HandleCrash() 32 33 size := GetSize(fd) 34 if size == nil { 35 return 36 } 37 lastSize := *size 38 39 for { 40 // see if we need to stop running 41 select { 42 case <-stop: 43 return 44 default: 45 } 46 47 size := GetSize(fd) 48 if size == nil { 49 return 50 } 51 52 if size.Height != lastSize.Height || size.Width != lastSize.Width { 53 lastSize.Height = size.Height 54 lastSize.Width = size.Width 55 resizeEvents <- *size 56 } 57 58 // sleep to avoid hot looping 59 time.Sleep(250 * time.Millisecond) 60 } 61 }() 62} 63