From 588e0fffc8b9d8dec08bb74cc0b792afbc43c228 Mon Sep 17 00:00:00 2001
From: Wolfgang Welz <welzwo@gmail.com>
Date: Tue, 6 Aug 2019 10:26:21 +0200
Subject: [PATCH] Fix: race condition in Database.Get
---
packages/database/database.go | 37 +++++++++++++----------------------
1 file changed, 14 insertions(+), 23 deletions(-)
diff --git a/packages/database/database.go b/packages/database/database.go
index 573d0dd4..b69920b9 100644
--- a/packages/database/database.go
+++ b/packages/database/database.go
@@ -10,22 +10,19 @@ var dbMap = make(map[string]*prefixDb)
var mu sync.Mutex
type prefixDb struct {
- db *badger.DB
- name string
- prefix []byte
- openLock sync.Mutex
+ db *badger.DB
+ name string
+ prefix []byte
}
-func Get(name string) (Database, error) {
- // avoid locking if it's a clean hit
- if db, exists := dbMap[name]; exists {
- return db, nil
- }
+func getPrefix(name string) []byte {
+ return []byte(name + "_")
+}
+func Get(name string) (Database, error) {
mu.Lock()
defer mu.Unlock()
- // needs to be re-checked after locking
if db, exists := dbMap[name]; exists {
return db, nil
}
@@ -34,7 +31,7 @@ func Get(name string) (Database, error) {
db := &prefixDb{
db: badger,
name: name,
- prefix: []byte(name + "_"),
+ prefix: getPrefix(name),
}
dbMap[name] = db
@@ -43,21 +40,16 @@ func Get(name string) (Database, error) {
}
func (this *prefixDb) Set(key []byte, value []byte) error {
- if err := this.db.Update(func(txn *badger.Txn) error { return txn.Set(append(this.prefix, key...), value) }); err != nil {
- return err
- }
-
- return nil
+ err := this.db.Update(func(txn *badger.Txn) error {
+ return txn.Set(append(this.prefix, key...), value)
+ })
+ return err
}
func (this *prefixDb) Contains(key []byte) (bool, error) {
err := this.db.View(func(txn *badger.Txn) error {
_, err := txn.Get(append(this.prefix, key...))
- if err != nil {
- return err
- }
-
- return nil
+ return err
})
if err == badger.ErrKeyNotFound {
@@ -88,8 +80,7 @@ func (this *prefixDb) Get(key []byte) ([]byte, error) {
func (this *prefixDb) Delete(key []byte) error {
err := this.db.Update(func(txn *badger.Txn) error {
- err := txn.Delete(append(this.prefix, key...))
- return err
+ return txn.Delete(append(this.prefix, key...))
})
return err
}
--
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