go

What is the point in setting a slice's capacity?

由 ╄→гoц情女王★ 提交于 2021-02-04 12:08:40
问题 In Golang, we can use the builtin make() function to create a slice with a given initial length and capacity. Consider the following lines, the slice's length is set to 1, and its capacity 3: func main() { var slice = make([]int, 1, 3) slice[0] = 1 slice = append(slice, 6, 0, 2, 4, 3, 1) fmt.Println(slice) } I was surprised to see that this program prints: [1 6 0 2 4 3 1] This got me wondering- what is the point of initially defining a slice's capacity if append() can simply blow past it? Are

What is the point in setting a slice's capacity?

由 岁酱吖の 提交于 2021-02-04 12:08:19
问题 In Golang, we can use the builtin make() function to create a slice with a given initial length and capacity. Consider the following lines, the slice's length is set to 1, and its capacity 3: func main() { var slice = make([]int, 1, 3) slice[0] = 1 slice = append(slice, 6, 0, 2, 4, 3, 1) fmt.Println(slice) } I was surprised to see that this program prints: [1 6 0 2 4 3 1] This got me wondering- what is the point of initially defining a slice's capacity if append() can simply blow past it? Are

What is the point in setting a slice's capacity?

由 天大地大妈咪最大 提交于 2021-02-04 12:07:48
问题 In Golang, we can use the builtin make() function to create a slice with a given initial length and capacity. Consider the following lines, the slice's length is set to 1, and its capacity 3: func main() { var slice = make([]int, 1, 3) slice[0] = 1 slice = append(slice, 6, 0, 2, 4, 3, 1) fmt.Println(slice) } I was surprised to see that this program prints: [1 6 0 2 4 3 1] This got me wondering- what is the point of initially defining a slice's capacity if append() can simply blow past it? Are

What is the point in setting a slice's capacity?

由 自古美人都是妖i 提交于 2021-02-04 12:07:46
问题 In Golang, we can use the builtin make() function to create a slice with a given initial length and capacity. Consider the following lines, the slice's length is set to 1, and its capacity 3: func main() { var slice = make([]int, 1, 3) slice[0] = 1 slice = append(slice, 6, 0, 2, 4, 3, 1) fmt.Println(slice) } I was surprised to see that this program prints: [1 6 0 2 4 3 1] This got me wondering- what is the point of initially defining a slice's capacity if append() can simply blow past it? Are

Golang实战群：日志的处理机制

由 懵懂的女人 提交于 2021-02-04 09:32:01
日志的处理机制 1 golang日志库可以考虑 tmlog https://github.com/heiyeluren/go-tmlog --黑夜路人@北京 2 老谢，你这个是异步库，一旦log gr 出问题不就坑爹了 可以考虑加上阻塞方式的，效率低点，但是安全 log库不必也没必要追求效率 --于雨@北京 3 行啊，回头再考虑实时写入临时日志 --黑夜路人 @北京 4 一般的逻辑处理，瓶颈不可能在log上，务求不丢不乱就行了 --于雨@北京 5 前阵子看过一篇文章，一个老外做的分析，系统性能消耗有不少的部分浪费在同步log上 --郭军@360 6 主要是磁盘io慢啊慢 --黑夜路人 @北京 9 确实，我们client的log都出于效率原因从同步实时改成异步分批写入了 --类库@上海-意励 8 log太多了吧，会对io造成压力 --kyle@成都-风际游戏 9 异步的本质都是为了不阻塞当前执行协程 --黑夜路人 @北京 10 瓶颈还真有可能在log上 --Xargin@北京-didi 11 可以开启raid卡wb，对比下，如果差异巨大，可能是log导致的 --谭俊青@途牛 12 去年写proxy 日志info级别性能下降蛮多的 还是要少打日志的。业务对性能要求不苛刻就无所谓了 --董泽润@北京-nice 13 不要用文本日志，改成二进制代号 --kingsword@广州-kg 14

卧槽！GitHub还有这么有趣的项目！！

由 血红的双手。 提交于 2021-02-04 09:29:52
点击上方“ 前端开发博客 ”，选择“星标” 回复“ 签到 ” ，每日领红包 最近在GitHub发现了2个很有趣的项目， 不得不说GitHub真的是无奇不有，相信经常去逛这个网站的小伙伴也知道，小编表示真的很佩服那些天马行空的作者， 哈哈，话不多说，一起来看看是什么有趣的项目吧！ 一、themostdangerouswritingapp 网址：https://github.com/maebert/themostdangerouswritingapp 对于程序员来说，不知道你是否经历过这种情况， 在你准备设计个博客时，突然仿佛失去了写作能力，脑子一片空白，码不出字的时候，会不会想，有什么办法能能够让让自己疯狂输出！ 还真有办法，最近小编在 GitHub发现了一个甚是有趣的项目，还可以说是有点丧心病狂， 哈哈！ 它的简介是： 最危险的写作应用旨在，让您进入流畅的状态。 如果 您停止输入超过五秒钟，所有进度将丢失，也就是说当你超过5秒钟没有码字的时候，那么非常抱歉，你的稿子将会被删除。。。。 不知道大家看到这段话内心的想法是什么， 我们先来看看关于这个项目网友的评价： “太恐怖了，谢谢”，“创建了作家的噩梦神器”，“我不想喜欢他，我喜欢”，“花时间在这个程序上实际上会让你更有效率”，真的是又爱又恨的感觉。 你能想象到这个项目是 作者在某一天下午，用两杯酒的时间写的吗 ，而且还是开源项目

How to parse JSON array in Go

由 偶尔善良 提交于 2021-02-04 09:01:27
问题 How to parse a string (which is an array) in Go using json package? type JsonType struct{ Array []string } func main(){ dataJson = `["1","2","3"]` arr := JsonType{} unmarshaled := json.Unmarshal([]byte(dataJson), &arr.Array) log.Printf("Unmarshaled: %v", unmarshaled) } 回答1: The return value of Unmarshal is an err, and this is what you are printing out: // Return value type of Unmarshal is error. err := json.Unmarshal([]byte(dataJson), &arr) You can get rid of the JsonType as well and just use

beego项目和go项目 打包部署到linux

由 跟風遠走 提交于 2021-02-04 08:31:16
【beego项目】 一. 打包 打开Terminal 定位到工程的 main.go 文件夹目录 执行命令,打包 　　linux打包: bee pack -be GOOS=linux 　　windows打包: bee pack -be GOOS=windows 二. 部署 　　1. 如何部署到阿里云上 会产生 xxx.tar.gz文件（当然 前提 不出现错误），通过工具或命令将该压缩文件发送到阿里云ECS指定的目录下；然后 登录阿里云ECS 并进入相应的目录对发送过来的文件解压缩； 解压缩成功后 可以看到2个文件：conf 、目标文件（可执行文件），运行目标文件 ，运行成功后结束； 以上是Golang beego项目部署到阿里云基本流程 【Go项目】 一. 打包 a. Mac 下编译 Linux 和 Windows 64位可执行程序 CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build main.go CGO_ENABLED=0 GOOS=windows GOARCH=amd64 go build main.go b. Linux 下编译 Mac 和 Windows 64位可执行程序 CGO_ENABLED=0 GOOS=darwin GOARCH=amd64 go build main.go CGO_ENABLED=0 GOOS

Should a Firestore client be created per a request with Google App Engine?

由 感情迁移 提交于 2021-02-04 08:00:34
问题 I'm confused on how to approach this. It seems to be that GAE wants every client library to use a context.Context scoped to a http.Request. I previously have experience doing something like this: main.go type server struct { db *firestore.Client } func main() { // Setup server s := &server{db: NewFirestoreClient()} // Setup Router http.HandleFunc("/people", s.peopleHandler()) // Starts the server to receive requests appengine.Main() } func (s *server) peopleHandler() http.HandlerFunc { //

How to cancel goroutines after certain amount of time

由 十年热恋 提交于 2021-02-04 07:30:42
问题 I am making a load testing tool that makes multiple HTTP calls in goroutines, and it works, but now I am trying to allow it to run for only a specified duration. How can I cancel the goroutines when the sleep has finished? What I am currently attempting to do is to make a goroutine that does time.Sleep() for the specified duration, and when that is finished it will broadcast a message to the channel. In my infinite loop, I listen for the message in the switch statement, and when it is there I
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