collector.go

package main

import (
  "fmt"
  "net/http"
  "time"
)

// A buffered channel that we can send work requests on.
var WorkQueue = make(chan WorkRequest, 100)

func Collector(w http.ResponseWriter, r *http.Request) {
  // Make sure we can only be called with an HTTP POST request.
  if r.Method != "POST" {
    w.Header().Set("Allow", "POST")
    w.WriteHeader(http.StatusMethodNotAllowed)
    return
  }

  // Parse the delay.
  delay, err := time.ParseDuration(r.FormValue("delay"))
  if err != nil {
    http.Error(w, "Bad delay value: "+err.Error(), http.StatusBadRequest)
    return
  }
  
  // Check to make sure the delay is anywhere from 1 to 10 seconds.
  if delay.Seconds() < 1 || delay.Seconds() > 10 {
    http.Error(w, "The delay must be between 1 and 10 seconds, inclusively.", http.StatusBadRequest)
    return
  }
  
  // Now, we retrieve the person's name from the request.
  name := r.FormValue("name")
  
  // Just do a quick bit of sanity checking to make sure the client actually provided us with a name.
  if name == "" {
    http.Error(w, "You must specify a name.", http.StatusBadRequest)
    return
  }
  
  // Now, we take the delay, and the person's name, and make a WorkRequest out of them.
  work := WorkRequest{Name: name, Delay: delay}
  
  // Push the work onto the queue.
  WorkQueue <- work
  fmt.Println("Work request queued")
  
  // And let the user know their work request was created.
  w.WriteHeader(http.StatusCreated)
  return
}