github.com/klaytn/klaytn@v1.12.1/event/example_subscription_test.go (about) 1 // Modifications Copyright 2018 The klaytn Authors 2 // Copyright 2016 The go-ethereum Authors 3 // This file is part of the go-ethereum library. 4 // 5 // The go-ethereum library is free software: you can redistribute it and/or modify 6 // it under the terms of the GNU Lesser General Public License as published by 7 // the Free Software Foundation, either version 3 of the License, or 8 // (at your option) any later version. 9 // 10 // The go-ethereum library is distributed in the hope that it will be useful, 11 // but WITHOUT ANY WARRANTY; without even the implied warranty of 12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 // GNU Lesser General Public License for more details. 14 // 15 // You should have received a copy of the GNU Lesser General Public License 16 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>. 17 // 18 // This file is derived from event/example_subscription_test.go (2018/06/04). 19 // Modified and improved for the klaytn development. 20 21 package event_test 22 23 import ( 24 "fmt" 25 26 "github.com/klaytn/klaytn/event" 27 ) 28 29 func ExampleNewSubscription() { 30 // Create a subscription that sends 10 integers on ch. 31 ch := make(chan int) 32 sub := event.NewSubscription(func(quit <-chan struct{}) error { 33 for i := 0; i < 10; i++ { 34 select { 35 case ch <- i: 36 case <-quit: 37 fmt.Println("unsubscribed") 38 return nil 39 } 40 } 41 return nil 42 }) 43 44 // This is the consumer. It reads 5 integers, then aborts the subscription. 45 // Note that Unsubscribe waits until the producer has shut down. 46 for i := range ch { 47 fmt.Println(i) 48 if i == 4 { 49 sub.Unsubscribe() 50 break 51 } 52 } 53 // Output: 54 // 0 55 // 1 56 // 2 57 // 3 58 // 4 59 // unsubscribed 60 }