From 9455c047ce027050ae42fd9f358f207f4a7562ed Mon Sep 17 00:00:00 2001
From: Evan Han <iloversevan@gmail.com>
Date: Mon, 5 Sep 2022 19:15:38 +0800
Subject: [PATCH] Merge PR: check watchdb version when start node (#2502)

---
 x/evm/watcher/db.go      | 22 ++++++++++++++++++++++
 x/evm/watcher/watcher.go |  2 ++
 2 files changed, 24 insertions(+)

diff --git a/x/evm/watcher/db.go b/x/evm/watcher/db.go
index 1e19880a82..8ba0c1becd 100644
--- a/x/evm/watcher/db.go
+++ b/x/evm/watcher/db.go
@@ -1,7 +1,9 @@
 package watcher
 
 import (
+	"io/ioutil"
 	"log"
+	"os"
 	"path/filepath"
 	"sync"
 
@@ -47,9 +49,29 @@ func initDb() dbm.DB {
 		backend = string(dbm.GoLevelDBBackend)
 	}
 
+	versionPath := filepath.Join(dbPath, WatchDBName+".db", "VERSION")
+	if !checkVersion(versionPath) {
+		os.RemoveAll(filepath.Join(dbPath, WatchDBName+".db"))
+	}
+	db := dbm.NewDB(WatchDBName, dbm.BackendType(backend), dbPath)
+	writeVersion(versionPath)
+	return db
+
 	return dbm.NewDB(WatchDBName, dbm.BackendType(backend), dbPath)
 }
 
+func checkVersion(versionPath string) bool {
+	content, err := ioutil.ReadFile(versionPath)
+	if err != nil || string(content) != version {
+		return false
+	}
+	return true
+}
+
+func writeVersion(versionPath string) {
+	ioutil.WriteFile(versionPath, []byte(version), 0666)
+}
+
 func (w WatchStore) Set(key []byte, value []byte) {
 	err := w.db.Set(key, value)
 	if err != nil {
diff --git a/x/evm/watcher/watcher.go b/x/evm/watcher/watcher.go
index 6de2329b3a..56b268c8fd 100644
--- a/x/evm/watcher/watcher.go
+++ b/x/evm/watcher/watcher.go
@@ -22,6 +22,8 @@ import (
 	"github.com/spf13/viper"
 )
 
+const version = "v1"
+
 var itjs = jsoniter.ConfigCompatibleWithStandardLibrary
 
 type Watcher struct {