From b816156e7778c7eaa507bb514bed5de46ec3e33e Mon Sep 17 00:00:00 2001
From: "Gerasimos (Makis) Maropoulos" <kataras2006@hotmail.com>
Date: Fri, 16 Oct 2020 09:53:22 +0300
Subject: [PATCH] accesslog: new HumanTime option as requested at #1661

---
 middleware/accesslog/json.go      | 42 +++++++++++++++++++++++++++++++
 middleware/accesslog/json_easy.go | 14 ++++++++---
 2 files changed, 52 insertions(+), 4 deletions(-)

diff --git a/middleware/accesslog/json.go b/middleware/accesslog/json.go
index d978fdbd..1120b50c 100644
--- a/middleware/accesslog/json.go
+++ b/middleware/accesslog/json.go
@@ -1,7 +1,9 @@
 package accesslog
 
 import (
+	"bytes"
 	"io"
+	"strconv"
 	"strings"
 
 	jsoniter "github.com/json-iterator/go"
@@ -13,6 +15,7 @@ type JSON struct {
 	// Note that, if set to > 0 then jsoniter is used instead of easyjson.
 	Indent     string
 	EscapeHTML bool
+	HumanTime  bool
 
 	jsoniter jsoniter.API
 	ac       *AccessLog
@@ -23,6 +26,8 @@ type JSON struct {
 func (f *JSON) SetOutput(dest io.Writer) {
 	f.ac, _ = dest.(*AccessLog)
 	if indentStep := strings.Count(f.Indent, " "); indentStep > 0 {
+		// Note that: indent setting should always be spaces
+		// as the jsoniter does not support other chars.
 		f.jsoniter = jsoniter.Config{
 			TagKey:        "json",
 			IndentionStep: indentStep,
@@ -32,15 +37,52 @@ func (f *JSON) SetOutput(dest io.Writer) {
 	}
 }
 
+var (
+	timestampKeyB        = []byte(`"timestamp":`)
+	timestampKeyIndentB  = append(timestampKeyB, ' ')
+	timestampKeyVB       = append(timestampKeyB, '0')
+	timestampIndentKeyVB = append(timestampKeyIndentB, '0')
+)
+
 // Format prints the logs in JSON format.
 // Writes to the destination directly,
 // locks on each Format call.
 func (f *JSON) Format(log *Log) (bool, error) {
 	if f.jsoniter != nil {
+		if f.HumanTime {
+			// 1. Don't write the unix timestamp,
+			// key will be visible though as we don't omit the field.
+			log.Timestamp = 0
+		}
+
 		b, err := f.jsoniter.Marshal(log)
 		if err != nil {
 			return true, err
 		}
+
+		if f.HumanTime {
+			// 2. Get the time text based on the configuration.
+			t := log.Now.Format(log.TimeFormat)
+
+			// 3. Find the "timestamp:$indent"
+			// and set it to the text one.
+			var (
+				oldT  []byte
+				tsKey []byte
+			)
+
+			if f.Indent != "" {
+				oldT = timestampIndentKeyVB
+				tsKey = timestampKeyIndentB
+			} else {
+				oldT = timestampKeyVB
+				tsKey = timestampKeyB
+			}
+
+			newT := append(tsKey, strconv.Quote(t)...)
+			b = bytes.Replace(b, oldT, newT, 1)
+		}
+
 		f.ac.Write(append(b, newLine))
 		return true, nil
 	}
diff --git a/middleware/accesslog/json_easy.go b/middleware/accesslog/json_easy.go
index 468db4ad..2613233b 100644
--- a/middleware/accesslog/json_easy.go
+++ b/middleware/accesslog/json_easy.go
@@ -25,7 +25,13 @@ func (f *JSON) writeEasyJSON(in *Log) error {
 		} else {
 			out.RawString(prefix)
 		}
-		out.Int64(int64(in.Timestamp))
+
+		if f.HumanTime {
+			t := in.Now.Format(in.TimeFormat)
+			out.String(t)
+		} else {
+			out.Int64(in.Timestamp)
+		}
 	}
 	{
 		const prefix string = ",\"latency\":"
@@ -40,17 +46,17 @@ func (f *JSON) writeEasyJSON(in *Log) error {
 	{
 		const prefix string = ",\"method\":"
 		out.RawString(prefix)
-		out.String(string(in.Method))
+		out.String(in.Method)
 	}
 	{
 		const prefix string = ",\"path\":"
 		out.RawString(prefix)
-		out.String(string(in.Path))
+		out.String(in.Path)
 	}
 	if in.IP != "" {
 		const prefix string = ",\"ip\":"
 		out.RawString(prefix)
-		out.String(string(in.IP))
+		out.String(in.IP)
 	}
 	if len(in.Query) != 0 {
 		const prefix string = ",\"query\":"