httpserver/main.go

111 lines
2.9 KiB
Go

package httpserver
import (
"crypto/tls"
"errors"
"fmt"
"net/http"
"strings"
"time"
)
// Fun fact: the reference time is the specific time Jan 2 15:04:05 2006 MST, which reads:
// 01 02 03 04 05 06 -0700
// 1234567. Very clever, Google.
var timeLayout = "02/Jan/2006 15:04:05"
func StartServer(port string, path string, address string, protocolVer string, throttleRate int64) (error, int) {
var httpServer *http.Server
addressPort := address + ":" + port
fileServer := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
filePath := path + r.URL.Path
http.ServeFile(w, r, filePath)
var ip string
if strings.Contains(r.RemoteAddr, ":") {
ip = strings.Split(r.RemoteAddr, ":")[0]
} else {
ip = r.RemoteAddr
}
fmt.Println(ip + " - - [" + time.Now().Format(timeLayout) + "] \"" + r.Method + " " + r.URL.Path + " " + r.Proto + "\" " + "200" + " -")
})
var throttledFileServer http.Handler
if throttleRate != -1 {
throttledFileServer = ThrottleMiddleware(throttleRate)(fileServer)
} else {
throttledFileServer = fileServer
}
fmt.Println("Serving HTTP on", address, "port", port, "(http://"+address+":"+port+"/) ...")
if protocolVer == "2.0" || protocolVer == "2" {
httpServer = &http.Server{Addr: addressPort, Handler: throttledFileServer, TLSNextProto: make(map[string]func(*http.Server, *tls.Conn, http.Handler))}
} else {
httpServer = &http.Server{Addr: addressPort, Handler: throttledFileServer}
}
err := httpServer.ListenAndServe()
if err != nil {
if err.Error() == "permission denied" || err.Error() == "listen tcp "+addressPort+": bind: permission denied" {
return errors.New("permission denied"), 1
} else {
return err, 1
}
}
return nil, 0
}
func ThrottleMiddleware(rate int64, burstSize ...int64) func(http.Handler) http.Handler {
defaultBurstSize := int64(128)
if len(burstSize) > 0 && burstSize[0] > 0 {
defaultBurstSize = burstSize[0]
}
return func(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
tw := &ThrottledResponseWriter{
writer: w,
rate: rate,
burstSize: defaultBurstSize,
}
next.ServeHTTP(tw, r)
})
}
}
type ThrottledResponseWriter struct {
writer http.ResponseWriter
rate int64
burstSize int64
}
func (tw *ThrottledResponseWriter) Write(p []byte) (int, error) {
if len(p) == 0 {
return 0, nil
}
var written int
for written < len(p) {
chunkSize := tw.burstSize
if int64(len(p)-written) < chunkSize {
chunkSize = int64(len(p) - written)
}
n, err := tw.writer.Write(p[written : written+int(chunkSize)])
if err != nil {
return written + n, err
}
written += n
time.Sleep(time.Duration(chunkSize*8*int64(time.Second)/tw.rate) * time.Nanosecond)
}
return written, nil
}
func (tw *ThrottledResponseWriter) Header() http.Header {
return tw.writer.Header()
}
func (tw *ThrottledResponseWriter) WriteHeader(statusCode int) {
tw.writer.WriteHeader(statusCode)
}