【黑马精品】Java架构师实战训练营wumi java

download:【黑马精品】Java架构师实战训练营 package main
import (

"fmt" "math/rand" "time"

)
var (

Web= fakeSearch("web") Image = fakeSearch("image") Video = fakeSearch("video")

)
type Result string
type Search func(query string) Result
func fakeSearch(kind string) Search {

return func(query string) Result { time.Sleep(time.Duration(rand.Intn(100)) * time.Millisecond) return Result(fmt.Sprintf("%s result for %q\n", kind, query)) }

}
func Google(query string) (results []Result) {

results = append(results, Web(query)) results = append(results, Image(query)) results = append(results, Video(query)) return

}
func main() {

rand.Seed(time.Now().UnixNano()) start := time.Now() results := Google("golang") elapsed := time.Since(start) fmt.Println(results) fmt.Println(elapsed)

}
运转结果如下:
[web result for "golang"
image result for "golang"
video result for "golang"
]
153.365484ms
谷歌搜索2.0 同时运转网页、图像和视频搜索，并等候一切结果。没有锁，没有条件变量，没有回调。
代码如下，关注Google函数。
package main
import (

"fmt" "math/rand" "time"

)
var (

Web= fakeSearch("web") Image = fakeSearch("image") Video = fakeSearch("video")

)
type Result string
type Search func(query string) Result
func fakeSearch(kind string) Search {

return func(query string) Result { time.Sleep(time.Duration(rand.Intn(100)) * time.Millisecond) return Result(fmt.Sprintf("%s result for %q\n", kind, query)) }

}
func Google(query string) (results []Result) {

c := make(chan Result) go func() { c <- Web(query) } () go func() { c <- Image(query) } () go func() { c <- Video(query) } () for i := 0; i < 3; i++ { result := <-c results = append(results, result) } return

}
func main() {

rand.Seed(time.Now().UnixNano()) start := time.Now() results := Google("golang") elapsed := time.Since(start) fmt.Println(results) fmt.Println(elapsed)

}
谷歌搜索2.1 不要等候迟缓的效劳器。没有锁，无条件变量，没有回调。经过select的超时完成，需求把time.After定义的超时通道放在for循环外层。 package main
import (

"fmt" "math/rand" "time"

)
var (

Web= fakeSearch("web") Image = fakeSearch("image") Video = fakeSearch("video")

)
type Result string
type Search func(query string) Result
func fakeSearch(kind string) Search {

return func(query string) Result { time.Sleep(time.Duration(rand.Intn(100)) * time.Millisecond) return Result(fmt.Sprintf("%s result for %q\n", kind, query)) }

}
func Google(query string) (results []Result) {

c := make(chan Result) go func() { c <- Web(query) } () go func() { c <- Image(query) } () go func() { c <- Video(query) } () timeout := time.After(80 * time.Millisecond) for i := 0; i < 3; i++ { select { case result := <-c: results = append(results, result) case <-timeout: fmt.Println("timed out") return } } return

}
func main() {

rand.Seed(time.Now().UnixNano()) start := time.Now() results := Google("golang") elapsed := time.Since(start) fmt.Println(results) fmt.Println(elapsed)

【【黑马精品】Java架构师实战训练营wumi】}