实现删除 trade 手动生成的localdb 记录

plugin/dapp/trade/executor/localdb_v1.go

 package executor
 
-import "fmt"
+import (
+	"bytes"
+
+	dbm "github.com/33cn/chain33/common/db"
+	"github.com/pkg/errors"
+)
 
 // 生成 key -> id 格式的本地数据库数据， 在下个版本这个文件可以全部删除
 // 由于数据库精简需要保存具体数据
@@ -24,9 +29,8 @@ const (
 )
 
 // UpdateLocalDBPart1 手动生成KV，需要在原有数据库中删除
-// TODO
-func UpdateLocalDBPart1() {
-	prefix := []string{
+func UpdateLocalDBPart1(localDB dbm.DB) error {
+	prefixes := []string{
 		sellOrderSHTAS,
 		sellOrderASTS,
 		sellOrderATSS,
@@ -37,5 +41,66 @@ func UpdateLocalDBPart1() {
 		buyOrderTSPAS,
 		orderASTHK,
 	}
-	fmt.Printf("%+v", prefix)
+
+	for _, prefix := range prefixes {
+		err := delOnePrefix(localDB, prefix)
+		if err != nil {
+			tradelog.Error("UpdateLocalDBPart1 failed", "err", err)
+			return errors.Cause(err)
+		}
+	}
+	return nil
+}
+
+func delOnePrefix(localDB dbm.DB, prefix string) (err error) {
+	allDeleted := false
+	total := 10000
+	for !allDeleted {
+		allDeleted, err = delOnePrefixLimit(localDB, prefix, total)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// 删除指定前缀的N个记录
+//  DB interface -> included IteratorDB interface
+//  IteratorDB interface -> Iterator func return Iterator interface
+//  Iterator interface -> Key func
+//  先写入固定的 start, end， 所有key 在这中间， 然后慢慢处理
+func delOnePrefixLimit(localDB dbm.DB, prefix string, total int) (allDeleted bool, err error) {
+	start := []byte(prefix)
+	err = localDB.SetSync(start, []byte(""))
+	if err != nil {
+		return allDeleted, errors.Wrap(err, "SetSync for prefix start:"+prefix)
+	}
+
+	keys := make([][]byte, total)
+
+	count := 0
+	it := localDB.Iterator(start, nil, false)
+	for it.Rewind(); it.Valid(); it.Next() {
+		keys[count] = it.Key()
+		count++
+		if count == total {
+			break
+		}
+	}
+
+	batch := localDB.NewBatch(false)
+	for i := 0; i < count; i++ {
+		// 保护下， 避免测试其他bug，误删其他key， 破坏数据库
+		if !bytes.HasPrefix(keys[i], start) {
+			tradelog.Error("delOnePrefixLimit delete key not match prefix", "prefix", prefix, "key", string(keys[i]))
+			panic("bug: " + "delOnePrefixLimit delete key not match prefix: " + prefix + " " + string(keys[i]))
+		}
+		batch.Delete(keys[i])
+	}
+	err = batch.Write()
+	if err != nil {
+		return allDeleted, errors.Wrap(err, "batch.Write when delete prefix keys: "+prefix)
+	}
+
+	return count < total, nil
 }