package main
import (
"fmt"
"io"
"log"
"math/rand"
"net/http"
"time"
"github.com/globalsign/mgo"
"github.com/globalsign/mgo/bson"
)
var globalDB *mgo.Database
var account = "golang"
type currency struct {
ID bson.ObjectId `json:"id" bson:"_id,omitempty"`
Amount float64 `bson:"amount"`
Account string `bson:"account"`
Code string `bson:"code"`
}
// Random get random value
func Random(min, max int) int {
rand.Seed(time.Now().UTC().UnixNano())
return rand.Intn(max-min+1) + min
}
func pay(w http.ResponseWriter, r *http.Request) {
entry := currency{}
// step 1: get current amount
err := globalDB.C("test").Find(bson.M{"account": account}).One(&entry)
if err != nil {
panic(err)
}
wait := Random(1, 100)
time.Sleep(time.Duration(wait) * time.Millisecond)
//step 3: subtract current balance and update back to database
entry.Amount = entry.Amount + 50.000
err = globalDB.C("test").UpdateId(entry.ID, &entry)
if err != nil {
panic("update error")
}
fmt.Printf("%+v\n", entry)
io.WriteString(w, "ok")
}
func main() {
session, _ := mgo.Dial("172.20.10.10:27017")
globalDB = session.DB("queue")
globalDB.C("test").DropCollection()
user := currency{Account: account, Amount: 1000.00, Code: "USD"}
err := globalDB.C("test").Insert(&user)
if err != nil {
panic("insert error")
}
log.Println("Listen server on 3001 port")
http.HandleFunc("/", pay)
http.ListenAndServe(":3001", nil)
}
something error...