Http context

Author: naeemaei

17-Http/06-Context/api/result.go

@@ -0,0 +1,44 @@
+package api
+
+import (
+"encoding/json"
+"net/http"
+)
+
+type ApiResult struct {
+Success bool `json:"success"`
+Result interface{} `json:"result"`
+Error string `json:"error"`
+}
+
+func SetResult(statusCode int, result interface{}, errorInfo error, w http.ResponseWriter) {
+w.Header().Add("Web-Server", "NGINX")
+w.Header().Set("Content-Type", "application/json")
+
+apiResult := &ApiResult{}
+if statusCode == http.StatusOK {
+apiResult.Success = true
+} else {
+apiResult.Success = false
+}
+
+apiResult.Result = result
+
+if errorInfo != nil {
+apiResult.Error = errorInfo.Error()
+}
+
+jsonResponse, err := json.Marshal(apiResult)
+if err != nil {
+apiResult.Success = false
+apiResult.Error = err.Error()
+w.WriteHeader(http.StatusInternalServerError)
+}
+
+w.WriteHeader(statusCode)
+_, err = w.Write(jsonResponse)
+if err != nil {
+panic(err)
+}
+
+}

17-Http/06-Context/examples/internal_cancel.go

@@ -0,0 +1,43 @@
+package examples
+
+import (
+"context"
+"time"
+)
+
+func InternalCancellationExample() {
+ctx := context.Background()
+ctx, cancel := context.WithCancel(ctx)
+
+//Timeout
+//ctx, cancel = context.WithTimeout(ctx, time.Second * 3)
+
+//Deadline
+//ctx, cancel = context.WithDeadline(ctx, time.Date(2022, time.February, 13, 23, 30, 0, 0, time.UTC))
+
+defer cancel()
+
+go func() {
+for {
+if time.Now().Second()%12 == 0 {
+cancel()
+}
+}
+}()
+
+Processor(ctx, 0)
+}
+
+func Processor(ctx context.Context, num int) {
+for {
+num++
+select {
+case <-ctx.Done():
+println("Canceled...")
+return
+default:
+println("processing", num)
+}
+time.Sleep(time.Millisecond * 500)
+}
+}

17-Http/06-Context/examples/send_value.go

@@ -0,0 +1,21 @@
+package examples
+
+import "context"
+
+func SendValueExample() {
+ctx := context.Background()
+
+ctx = context.WithValue(ctx, "api-key", "1234567890")
+ctx = context.WithValue(ctx, "api-key", "1234567891")
+ctx = context.WithValue(ctx, "validation-code", "1020304050")
+
+Print(ctx)
+
+}
+
+func Print(ctx context.Context) {
+var apiKey = ctx.Value("api-key")
+var validationCode = ctx.Value("validation-code")
+
+println(apiKey.(string), validationCode.(string))
+}

17-Http/06-Context/go.mod

@@ -0,0 +1,3 @@
+module context-examples
+
+go 1.18

17-Http/06-Context/main.go

@@ -0,0 +1,28 @@
+package main
+
+import (
+"context-examples/examples"
+"context-examples/management"
+)
+
+/*
+Context
+Creation
+Send value
+Cancellation from request
+Internal cancellation
+timeout
+Deadline
+
+*/
+func main() {
+// Creation
+examples.SendValueExample()
+
+//External Cancellation
+management.Run()
+
+// Internal Cancellation
+examples.InternalCancellationExample()
+
+}

17-Http/06-Context/management/server.go

@@ -0,0 +1,38 @@
+package management
+
+import (
+"fmt"
+"net/http"
+"time"
+)
+
+func Run() {
+mux := http.NewServeMux()
+mux.HandleFunc("/test/", TestHandler)
+
+server := &http.Server{
+Addr: ":8080",
+ReadTimeout: time.Second * 10,
+WriteTimeout: time.Second * 10,
+Handler: mux,
+}
+
+err := server.ListenAndServe()
+
+if err != nil {
+panic(err)
+}
+}
+
+func TestHandler(w http.ResponseWriter, r *http.Request) {
+ctx := r.Context()
+
+select {
+case <-time.After(time.Second * 5):
+fmt.Println("processing request")
+fmt.Fprintf(w, "Response")
+case <-ctx.Done():
+fmt.Println("cancel request")
+return
+}
+}