From 7c0c490f1c62301719388fd44df9c29a64213cfb Mon Sep 17 00:00:00 2001
From: hantmac <hantmac@outlook.com>
Date: Sun, 1 Sep 2019 00:06:26 +0800
Subject: [PATCH 1/2] bug fix:fix read log file oom

---
 backend/services/log.go | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/backend/services/log.go b/backend/services/log.go
index c6e4f090..2e6f25ed 100644
--- a/backend/services/log.go
+++ b/backend/services/log.go
@@ -34,9 +34,16 @@ func GetLocalLog(logPath string) (fileBytes []byte, err error) {
 		return nil, err
 	}
 	defer f.Close()
-	logBuf := make([]byte, 2048)
-	n, err := f.ReadAt(logBuf, fi.Size()-int64(len(logBuf)))
-	if err != nil {
+	const bufLen = 2048
+	logBuf := make([]byte, bufLen)
+	off := int64(0)
+	if fi.Size() > int64(len(logBuf)) {
+		off = fi.Size() - int64(len(logBuf))
+	}
+	n, err := f.ReadAt(logBuf, off)
+
+	//到文件结尾会有EOF标识
+	if err != nil && err.Error() != "EOF" {
 		log.Error(err.Error())
 		debug.PrintStack()
 		return nil, err

From d5dfe648af5afefd87d312a5024662ded6cddd8b Mon Sep 17 00:00:00 2001
From: hantmac <hantmac@outlook.com>
Date: Sun, 1 Sep 2019 00:07:18 +0800
Subject: [PATCH 2/2] add unit test for GetLocalLog

---
 backend/services/log_test.go | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/backend/services/log_test.go b/backend/services/log_test.go
index 0a52747c..a0b049c5 100644
--- a/backend/services/log_test.go
+++ b/backend/services/log_test.go
@@ -2,9 +2,11 @@ package services
 
 import (
 	"crawlab/config"
+	"fmt"
 	"github.com/apex/log"
 	. "github.com/smartystreets/goconvey/convey"
 	"github.com/spf13/viper"
+	"os"
 	"testing"
 )
 
@@ -20,3 +22,29 @@ func TestDeleteLogPeriodically(t *testing.T) {
 		DeleteLogPeriodically()
 	})
 }
+
+func TestGetLocalLog(t *testing.T) {
+	//create a log file for test
+	logPath := "../logs/crawlab/test.log"
+	f, err := os.Create(logPath)
+	defer f.Close()
+	if err != nil {
+		fmt.Println(err.Error())
+
+	} else {
+		_, err = f.Write([]byte("This is for test"))
+	}
+
+	Convey("Test GetLocalLog", t, func() {
+		Convey("Test response", func() {
+			logStr, err := GetLocalLog(logPath)
+			log.Info(string(logStr))
+			fmt.Println(err)
+			So(err, ShouldEqual, nil)
+
+		})
+	})
+	//delete the test log file
+	os.Remove(logPath)
+
+}