Golang

(本文大部分内容根据官方文档翻译而来) 环境准备 golang 1.10+ mongodb mgm 模型定义 定义 定义模型 type Book struct { // DefaultModel adds _id, created_at and updated_at fields to the Model mgm.DefaultModel `bson:",inline"` Name string `json:"name" bson:"name"` Pages int `json:"pages" bson:"pages"` } func NewBook(name string, pages int) *Book { return &Book{ Name: name, Pages: pages, } } mgm 在创建表时会自动检测Model生成的Collection名称 book:=Book{} // Print your model collection name. collName := mgm.CollName(&book) fmt.Println(collName) // 打印: books 如果要自定义生成Collection的名称。需要实现CollectionNameGetter接口。 func (model *Book) CollectionName() string { return "my_books" } // mgm return "my_books" collection coll:=mgm....

TL;DR 环境准备 mongoDB 预备知识 MongoDB常见的数据类型 数据类型 示例 说明 Null {"x" : null} Boolean {"x" : true} Number {"x" : 3.14} {"x" : 3} {"x" : NumberInt("3")} {"x" : NumberLong("3")} 默认64位浮点数，整数需要使用NumberInt和NumberLong String {"x" : "foobar"} 编码格式为UTF-8 Date {"x" : new Date()} 64位时间戳(从January 1, 1970)，不存时区。通过new Date()进行调用。 Regular expression {"x" : /foobar/i} javascript 正则 Array {"x" : ["a", "b", "c"]} Embedded document {"x" : {"foo" : "bar"}} Object ID {"x" : ObjectId()} 文档12字节的ID Binary data 一个任意字节的字符串。是保存非UTF-8字符串到数据库的唯一方法。 Code {"x" : function() { /* ....

代码 package main import ( "fmt" "syscall" ) func main() { l, _ := ListenNetlink() for { msgs, err := l.ReadMsgs() if err != nil { fmt.Println("Could not read netlink: %s", err) } for _, m := range msgs { if IsNewAddr(&m) { fmt.Println("New Addr") } if IsDelAddr(&m) { fmt.Println("Del Addr") } } } } type NetlinkListener struct { fd int sa *syscall.SockaddrNetlink } func ListenNetlink() (*NetlinkListener, error) { groups := (1 << (syscall....

缘起 来自于一段prometheus代码 type stripeLock struct { sync.RWMutex // Padding to avoid multiple locks being on the same cache line. _ [40]byte } 简单地讲就是因为CPU读取数据的缓存机制问题，可能导致性能上的不同差异。参考资料见后文。 常见类型的内存占用大小（Go101）： Kinds of Types Value Size Required by Go Specification bool 1 byte not specified int8, uint8 (byte) 1 byte 1 byte int16, uint16 2 bytes 2 bytes int32 (rune), uint32, float32 4 bytes 4 bytes int64, uint64, float64, complex64 8 bytes 8 bytes complex128 16 bytes 16 bytes int, uint 1 word architecture dependent, 4 bytes on 32-bit architectures and 8 bytes on 64-bit architectures uintptr 1 word large enough to store the uninterpreted bits of a pointer value string 2 words not specified pointer (safe or unsafe) 1 word not specified slice 3 words not specified map 1 word not specified channel 1 word not specified function 1 word not specified interface 2 words not specified struct (the sum of sizes of all fields) + (the number of padding bytes) the size of a struct type is zero if it contains no fields that have a size greater than zero array (element value size) * (array length) the size of an array type is zero if its element type has zero size 参考 https://medium....

Csharp 安装Grpc.tools https://www.nuget.org/packages/Grpc.Tools/ 下载解压 nupkg文件（改扩展名为zip），也可以使用附件的7z包 解压 找到tools中对应系统架构的软件，设置下环境变量，让系统可以找到就行。 Linux 需要创建一个符号链接 ln -s `which grpc_csharp_plugin` /usr/bin/protoc-gen-grpc-csharp 修改Kratos项目的Make文件 在api这个make任务中添加下面内容 --csharp_out=./api/pipe/v1 \ --grpc-csharp_out=./api/pipe/v1 \ 完整内容为 .PHONY: api # generate api proto api: protoc --proto_path=./api \ --proto_path=./third_party \ --go_out=paths=source_relative:./api \ --go-http_out=paths=source_relative:./api \ --go-grpc_out=paths=source_relative:./api \ --csharp_out=./api/pipe/v1 \ --grpc-csharp_out=./api/pipe/v1 \ --openapi_out==paths=source_relative:. \ 参考 https://github.com/grpc/grpc/blob/master/src/csharp/BUILD-INTEGRATION.md 📎tools.7z Python 安装必要包 pip install grpclib protobuf 查询路径 which protoc-gen-grpclib_python 或者 which protoc-gen-python_grpc我这里返回信息如下： ➜ czyt which protoc-gen-grpclib_python /usr/sbin/protoc-gen-grpclib_python 如法炮制，创建软链接 ln -s /usr/sbin/protoc-gen-grpclib_python /usr/sbin/protoc-gen-grpc_python 修改Makefile 添加下面的内容,再执行make api生成api即可。 --python_out=....

下载 官方下载 https://go.dev/dl/ Google 香港镜像 Golang Downloads Mirrors 更多请参考 Thanks Mirror 环境设置 设置proxy go env -w GOPROXY=https://goproxy.io,https://goproxy.cn,direct 安装相关工具 进程工具 goreman go install github.com/mattn/goreman@latest 框架Cli kratos go install github.com/go-kratos/kratos/cmd/kratos/v2@latest wire go install github.com/google/wire/cmd/wire@latest ent go install entgo.io/ent/cmd/ent@latest entimport go install ariga.io/entimport/cmd/entimport@latest entproto go install entgo.io/contrib/entproto/cmd/entproto@latest 代码Lint golangci-lint go install github.com/golangci/golangci-lint/cmd/golangci-lint@latest golines go install github.com/segmentio/golines@latest Go into the Goland settings and click “Tools” -> “File Watchers” then click the plus to create a new file watcher Set the following properties and confirm by clicking OK: Name: golines File type: Go files Scope: Project Files Program: golines Arguments: $FilePath$ -w Output paths to refresh: $FilePath$ gofumpt go install mvdan....

下载protoc，打开链接 下载后将对应的文件解压到gopath的bin目录。 下载protoc的golang插件。下载地址 链接 下载后放在protoc的同级目录（需要改扩展名为exe） 测试，定义一个Proto syntax = "proto3"; option go_package = ".;hello"; package main; message String { string value = 1; } 然后执行命令 protoc hello.proto --go_out=. ,大功告成，生成的文件内容如下： // Code generated by protoc-gen-go. DO NOT EDIT. // versions: // protoc-gen-go v1.24.0-devel // protoc v3.12.3 // source: hello.proto package hello import ( proto "github.com/golang/protobuf/proto" protoreflect "google.golang.org/protobuf/reflect/protoreflect" protoimpl "google.golang.org/protobuf/runtime/protoimpl" reflect "reflect" sync "sync" ) const ( // Verify that this generated code is sufficiently up-to-date....

package main import ( "fmt" "net/http" ) func main() { http.HandleFunc("/favicon.ico", favicon) http.HandleFunc("/", hello) fmt.Printf("listening on http://localhost:8000/\n") http.ListenAndServe("localhost:8000", nil) } func favicon(w http.ResponseWriter, r *http.Request) { fmt.Printf("%s\n", r.RequestURI) w.Header().Set("Content-Type", "image/x-icon") w.Header().Set("Cache-Control", "public, max-age=7776000") fmt.Fprintln(w, "data:image/x-icon;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQEAYAAABPYyMiAAAABmJLR0T///////8JWPfcAAAACXBIWXMAAABIAAAASABGyWs+AAAAF0lEQVRIx2NgGAWjYBSMglEwCkbBSAcACBAAAeaR9cIAAAAASUVORK5CYII=\n") } func hello(w http.ResponseWriter, r *http.Request) { fmt.Printf("%s\n", r.RequestURI) fmt.Fprintln(w, "Hello, World!") }

reddit链接 On Linux it might be possible to use the memfd_create system call, but that’s not portable to other operating systems. need go 1.16 + package main import ( _ "embed" "log" "os" "os/exec" "strconv" "golang.org/x/sys/unix" ) //go:embed binary var embeddedBinary []byte func main() { fd, err := unix.MemfdCreate("embedded_binary", 0) if err != nil { log.Fatal(err) } path := "/proc/" + strconv.Itoa(os.Getpid()) + "/fd/" + strconv.Itoa(int(fd)) err = os.WriteFile(path, embeddedBinary, 0755) if err !...

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