/
server.go
78 lines (73 loc) · 1.79 KB
/
server.go
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package main
import (
"github.com/gorilla/pat"
"net/http"
"log"
"encoding/json"
"strconv"
"io/ioutil"
"time"
)
type HttpResponse struct {
url string
body string
err error
}
func WriteJSONResponse(responses map[string]string, code int, res http.ResponseWriter) {
js, err := json.MarshalIndent(responses, "", " ")
if err != nil {
log.Printf("JSON serialization error: %v", err)
return
}
res.Header().Set("Content-Length", strconv.Itoa(len(js)+1))
res.WriteHeader(code)
res.Write(js)
res.Write([]byte("\n"))
return
}
func MultigetHandler(res http.ResponseWriter, req *http.Request) {
res.Header().Set("Content-Type", "text/javascript")
urls := req.URL.Query()["url"]
ch := make(chan *HttpResponse)
for _, url := range urls {
go func(url string) {
resp, err := http.Get(url)
if err != nil {
log.Printf("Encountered an error with %s: %v", url, err)
ch <- &HttpResponse{url, "", nil}
} else {
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
ch <- &HttpResponse{url, string(body), err}
}
}(url)
}
responses := make(map[string]string)
for {
select {
case r := <-ch:
log.Printf("Got %s", r.url)
responses[r.url] = string(r.body)
if len(responses) == len(urls) {
WriteJSONResponse(responses, 200, res)
return
}
case <-time.After(5 * time.Second):
if len(responses) > 0 {
WriteJSONResponse(responses, 206, res)
} else {
WriteJSONResponse(responses, 204, res)
}
return
}
}
}
func main() {
r := pat.New()
r.Get("/multiget", MultigetHandler)
http.Handle("/", r)
err := http.ListenAndServe(":12345", nil)
if err != nil {
log.Fatal("ListenAndServe: ", err)
}
}