github.com/graybobo/golang.org-package-offline-cache@v0.0.0-20200626051047-6608995c132f/x/talks/2012/concurrency/support/google2.3.go (about)

     1  // +build OMIT
     2  
     3  package main
     4  
     5  import (
     6  	"fmt"
     7  	"math/rand"
     8  	"time"
     9  )
    10  
    11  type Result string
    12  type Search func(query string) Result
    13  
    14  // START1 OMIT
    15  func First(query string, replicas ...Search) Result {
    16  	c := make(chan Result)
    17  	searchReplica := func(i int) { c <- replicas[i](query) }
    18  	for i := range replicas {
    19  		go searchReplica(i)
    20  	}
    21  	return <-c
    22  }
    23  // STOP1 OMIT
    24  
    25  // START2 OMIT
    26  func main() {
    27  	rand.Seed(time.Now().UnixNano())
    28  	start := time.Now()
    29  	result := First("golang",
    30  		fakeSearch("replica 1"),
    31  		fakeSearch("replica 2"))
    32  	elapsed := time.Since(start)
    33  	fmt.Println(result)
    34  	fmt.Println(elapsed)
    35  }
    36  // STOP2 OMIT
    37  
    38  func fakeSearch(kind string) Search {
    39          return func(query string) Result {
    40  	          time.Sleep(time.Duration(rand.Intn(100)) * time.Millisecond)
    41  	          return Result(fmt.Sprintf("%s result for %q\n", kind, query))
    42          }
    43  }
    44