From f601e441f3be2695063fd335901ab4e20d2e0828 Mon Sep 17 00:00:00 2001
From: wangle <285273592@qq.com>
Date: Sat, 25 Jul 2020 02:56:02 +0800
Subject: [PATCH] Backup only when content changes

---
 internal/app/module/beegopro/render.go | 26 +++++++++++++----
 internal/app/module/beegopro/util.go   | 40 ++++++++++++++++++++++++++
 2 files changed, 61 insertions(+), 5 deletions(-)

diff --git a/internal/app/module/beegopro/render.go b/internal/app/module/beegopro/render.go
index f2e49c3..64c52fc 100644
--- a/internal/app/module/beegopro/render.go
+++ b/internal/app/module/beegopro/render.go
@@ -6,6 +6,8 @@ import (
 	"github.com/davecgh/go-spew/spew"
 	"github.com/flosch/pongo2"
 	"github.com/smartwalle/pongo2render"
+	"io/ioutil"
+	"os"
 	"path"
 	"path/filepath"
 )
@@ -114,10 +116,24 @@ func (r *RenderFile) Exec(name string) {
 		beeLogger.Log.Fatalf("Could not create the %s render tmpl: %s", name, err)
 		return
 	}
-	err = r.write(r.FlushFile, buf)
-	if err != nil {
-		beeLogger.Log.Fatalf("Could not create file: %s", err)
-		return
+	_, err = os.Stat(r.Descriptor.DstPath)
+	var orgContent []byte
+	if err == nil {
+		if org, err := os.OpenFile(r.Descriptor.DstPath, os.O_RDONLY, 0666); err == nil {
+			defer org.Close()
+			orgContent,_ = ioutil.ReadAll(org)
+		} else {
+			beeLogger.Log.Infof("file err %s", err)
+		}
+	}
+	// Replace or create when content changes
+	if len(orgContent) == 0 || FileContentChange(string(orgContent),buf) {
+		err = r.write(r.FlushFile, buf)
+		if err != nil {
+			beeLogger.Log.Fatalf("Could not create file: %s", err)
+			return
+		}
+		beeLogger.Log.Infof("create file '%s' from %s", r.FlushFile, r.PackageName)
 	}
-	beeLogger.Log.Infof("create file '%s' from %s", r.FlushFile, r.PackageName)
 }
+
diff --git a/internal/app/module/beegopro/util.go b/internal/app/module/beegopro/util.go
index e1491bd..2cbfe23 100644
--- a/internal/app/module/beegopro/util.go
+++ b/internal/app/module/beegopro/util.go
@@ -1,6 +1,7 @@
 package beegopro
 
 import (
+	"crypto/md5"
 	"errors"
 	"fmt"
 	"github.com/beego/bee/internal/pkg/utils"
@@ -10,6 +11,7 @@ import (
 	"os"
 	"path"
 	"path/filepath"
+	"regexp"
 	"strings"
 	"time"
 )
@@ -188,3 +190,41 @@ func getModelType(orm string) (inputType, goType, mysqlType, tag string) {
 	}
 	return
 }
+
+func FileContentChange(org,new string) bool {
+	if org == "" {
+		return false
+	}
+	var orgContent,newContent string
+	jump := false
+	// expect tab character and blank space and "import（***）"
+	reg := regexp.MustCompile("\\s+")
+	for i, s := range strings.Split(org, "\n") {
+		if s == "import (" {
+			jump = true
+		}
+		if jump && s == ")" {
+			jump = false
+		}
+		if i > 2 && !jump {
+			orgContent += reg.ReplaceAllString(s, "")
+		}
+	}
+	for i, s := range strings.Split(new, "\n") {
+		if s == "import (" {
+			jump = true
+		}
+		if jump && s == ")" {
+			jump = false
+		}
+		if i > 2 && !jump {
+			newContent += reg.ReplaceAllString(s, "")
+		}
+	}
+	orgMd5 := md5.Sum([]byte(orgContent))
+	newMd5:= md5.Sum([]byte(newContent))
+	if orgMd5 != newMd5 {
+		return true
+	}
+	return false
+}
\ No newline at end of file