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// Copyright 2013 The Gorilla Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package handlers
import (
"io"
"net"
"net/http"
"net/url"
"strconv"
"time"
"unicode/utf8"
"github.com/felixge/httpsnoop"
)
// Logging
// LogFormatterParams is the structure any formatter will be handed when time to log comes.
type LogFormatterParams struct {
Request *http.Request
URL url.URL
TimeStamp time.Time
StatusCode int
Size int
}
// LogFormatter gives the signature of the formatter function passed to CustomLoggingHandler.
type LogFormatter func(writer io.Writer, params LogFormatterParams)
// loggingHandler is the http.Handler implementation for LoggingHandlerTo and its
// friends
type loggingHandler struct {
writer io.Writer
handler http.Handler
formatter LogFormatter
}
func (h loggingHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
t := time.Now()
logger, w := makeLogger(w)
url := *req.URL
h.handler.ServeHTTP(w, req)
if req.MultipartForm != nil {
err := req.MultipartForm.RemoveAll()
if err != nil {
return
}
}
params := LogFormatterParams{
Request: req,
URL: url,
TimeStamp: t,
StatusCode: logger.Status(),
Size: logger.Size(),
}
h.formatter(h.writer, params)
}
func makeLogger(w http.ResponseWriter) (*responseLogger, http.ResponseWriter) {
logger := &responseLogger{w: w, status: http.StatusOK}
return logger, httpsnoop.Wrap(w, httpsnoop.Hooks{
Write: func(httpsnoop.WriteFunc) httpsnoop.WriteFunc {
return logger.Write
},
WriteHeader: func(httpsnoop.WriteHeaderFunc) httpsnoop.WriteHeaderFunc {
return logger.WriteHeader
},
})
}
const lowerhex = "0123456789abcdef"
func appendQuoted(buf []byte, s string) []byte {
var runeTmp [utf8.UTFMax]byte
for width := 0; len(s) > 0; s = s[width:] { //nolint: wastedassign //TODO: why width starts from 0and reassigned as 1
r := rune(s[0])
width = 1
if r >= utf8.RuneSelf {
r, width = utf8.DecodeRuneInString(s)
}
if width == 1 && r == utf8.RuneError {
buf = append(buf, `\x`...)
buf = append(buf, lowerhex[s[0]>>4])
buf = append(buf, lowerhex[s[0]&0xF])
continue
}
if r == rune('"') || r == '\\' { // always backslashed
buf = append(buf, '\\')
buf = append(buf, byte(r))
continue
}
if strconv.IsPrint(r) {
n := utf8.EncodeRune(runeTmp[:], r)
buf = append(buf, runeTmp[:n]...)
continue
}
switch r {
case '\a':
buf = append(buf, `\a`...)
case '\b':
buf = append(buf, `\b`...)
case '\f':
buf = append(buf, `\f`...)
case '\n':
buf = append(buf, `\n`...)
case '\r':
buf = append(buf, `\r`...)
case '\t':
buf = append(buf, `\t`...)
case '\v':
buf = append(buf, `\v`...)
default:
switch {
case r < ' ':
buf = append(buf, `\x`...)
buf = append(buf, lowerhex[s[0]>>4])
buf = append(buf, lowerhex[s[0]&0xF])
case r > utf8.MaxRune:
r = 0xFFFD
fallthrough
case r < 0x10000:
buf = append(buf, `\u`...)
for s := 12; s >= 0; s -= 4 {
buf = append(buf, lowerhex[r>>uint(s)&0xF])
}
default:
buf = append(buf, `\U`...)
for s := 28; s >= 0; s -= 4 {
buf = append(buf, lowerhex[r>>uint(s)&0xF])
}
}
}
}
return buf
}
// buildCommonLogLine builds a log entry for req in Apache Common Log Format.
// ts is the timestamp with which the entry should be logged.
// status and size are used to provide the response HTTP status and size.
func buildCommonLogLine(req *http.Request, url url.URL, ts time.Time, status int, size int) []byte {
username := "-"
if url.User != nil {
if name := url.User.Username(); name != "" {
username = name
}
}
host, _, err := net.SplitHostPort(req.RemoteAddr)
if err != nil {
host = req.RemoteAddr
}
uri := req.RequestURI
// Requests using the CONNECT method over HTTP/2.0 must use
// the authority field (aka r.Host) to identify the target.
// Refer: https://httpwg.github.io/specs/rfc7540.html#CONNECT
if req.ProtoMajor == 2 && req.Method == "CONNECT" {
uri = req.Host
}
if uri == "" {
uri = url.RequestURI()
}
buf := make([]byte, 0, 3*(len(host)+len(username)+len(req.Method)+len(uri)+len(req.Proto)+50)/2)
buf = append(buf, host...)
buf = append(buf, " - "...)
buf = append(buf, username...)
buf = append(buf, " ["...)
buf = append(buf, ts.Format("02/Jan/2006:15:04:05 -0700")...)
buf = append(buf, `] "`...)
buf = append(buf, req.Method...)
buf = append(buf, " "...)
buf = appendQuoted(buf, uri)
buf = append(buf, " "...)
buf = append(buf, req.Proto...)
buf = append(buf, `" `...)
buf = append(buf, strconv.Itoa(status)...)
buf = append(buf, " "...)
buf = append(buf, strconv.Itoa(size)...)
return buf
}
// writeLog writes a log entry for req to w in Apache Common Log Format.
// ts is the timestamp with which the entry should be logged.
// status and size are used to provide the response HTTP status and size.
func writeLog(writer io.Writer, params LogFormatterParams) {
buf := buildCommonLogLine(params.Request, params.URL, params.TimeStamp, params.StatusCode, params.Size)
buf = append(buf, '\n')
_, _ = writer.Write(buf)
}
// writeCombinedLog writes a log entry for req to w in Apache Combined Log Format.
// ts is the timestamp with which the entry should be logged.
// status and size are used to provide the response HTTP status and size.
func writeCombinedLog(writer io.Writer, params LogFormatterParams) {
buf := buildCommonLogLine(params.Request, params.URL, params.TimeStamp, params.StatusCode, params.Size)
buf = append(buf, ` "`...)
buf = appendQuoted(buf, params.Request.Referer())
buf = append(buf, `" "`...)
buf = appendQuoted(buf, params.Request.UserAgent())
buf = append(buf, '"', '\n')
_, _ = writer.Write(buf)
}
// CombinedLoggingHandler return a http.Handler that wraps h and logs requests to out in
// Apache Combined Log Format.
//
// See http://httpd.apache.org/docs/2.2/logs.html#combined for a description of this format.
//
// LoggingHandler always sets the ident field of the log to -.
func CombinedLoggingHandler(out io.Writer, h http.Handler) http.Handler {
return loggingHandler{out, h, writeCombinedLog}
}
// LoggingHandler return a http.Handler that wraps h and logs requests to out in
// Apache Common Log Format (CLF).
//
// See http://httpd.apache.org/docs/2.2/logs.html#common for a description of this format.
//
// LoggingHandler always sets the ident field of the log to -
//
// Example:
//
// r := mux.NewRouter()
// r.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
// w.Write([]byte("This is a catch-all route"))
// })
// loggedRouter := handlers.LoggingHandler(os.Stdout, r)
// http.ListenAndServe(":1123", loggedRouter)
func LoggingHandler(out io.Writer, h http.Handler) http.Handler {
return loggingHandler{out, h, writeLog}
}
// CustomLoggingHandler provides a way to supply a custom log formatter
// while taking advantage of the mechanisms in this package.
func CustomLoggingHandler(out io.Writer, h http.Handler, f LogFormatter) http.Handler {
return loggingHandler{out, h, f}
}
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