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  }