*: add hash set check for not changed value.

pazhang · Nov 9, 2015 · 7bab524 · 7bab524
1 parent 34100b6
commit 7bab524
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Showing 3 changed files with 38 additions and 7 deletions.
diff --git a/store/localstore/txn.go b/store/localstore/txn.go
@@ -231,7 +231,7 @@ func (txn *dbTxn) Commit() error {
 		txn.close()
 	}()
 
-	return txn.doCommit()
+	return errors.Trace(txn.doCommit())
 }
 
 func (txn *dbTxn) CommittedVersion() (kv.Version, error) {

diff --git a/structure/hash.go b/structure/hash.go
@@ -105,8 +105,9 @@ func (t *TxStructure) updateHash(key []byte, field []byte, fn func(oldValue []by
 		return errors.Trace(err)
 	}
 
+	newMeta := meta
 	if oldValue == nil {
-		meta.Length++
+		newMeta.Length++
 	}
 
 	var newValue []byte
@@ -115,11 +116,21 @@ func (t *TxStructure) updateHash(key []byte, field []byte, fn func(oldValue []by
 		return errors.Trace(err)
 	}
 
-	if err = t.txn.Set(dataKey, newValue); err != nil {
-		return errors.Trace(err)
+	// Check if hash field has been changed.
+	if bytes.Compare(oldValue, newValue) != 0 {
+		if err = t.txn.Set(dataKey, newValue); err != nil {
+			return errors.Trace(err)
+		}
+	}
+
+	// Check if hash meta has been changed.
+	if bytes.Compare(meta.Value(), newMeta.Value()) != 0 {
+		if err = t.txn.Set(metaKey, newMeta.Value()); err != nil {
+			return errors.Trace(err)
+		}
 	}
 
-	return errors.Trace(t.txn.Set(metaKey, meta.Value()))
+	return nil
 }
 
 // HLen gets the number of fields in a hash.

diff --git a/structure/structure_test.go b/structure/structure_test.go
@@ -193,7 +193,7 @@ func (s *tesTxStructureSuite) TestHash(c *C) {
 
 	value, err = tx.HGet(key, []byte("fake"))
 	c.Assert(err, IsNil)
-	c.Assert(err, IsNil)
+	c.Assert(value, IsNil)
 
 	keys, err := tx.HKeys(key)
 	c.Assert(err, IsNil)
@@ -224,13 +224,33 @@ func (s *tesTxStructureSuite) TestHash(c *C) {
 	c.Assert(err, IsNil)
 	c.Assert(l, Equals, int64(2))
 
+	// Test set new value which equals to old value.
+	err = tx.HSet(key, []byte("1"), []byte("1"))
+	c.Assert(err, IsNil)
+
+	value, err = tx.HGet(key, []byte("1"))
+	c.Assert(err, IsNil)
+	c.Assert(value, DeepEquals, []byte("1"))
+
+	l, err = tx.HLen(key)
+	c.Assert(err, IsNil)
+	c.Assert(l, Equals, int64(2))
+
 	n, err = tx.HInc(key, []byte("1"), 1)
 	c.Assert(err, IsNil)
 	c.Assert(n, Equals, int64(2))
 
+	l, err = tx.HLen(key)
+	c.Assert(err, IsNil)
+	c.Assert(l, Equals, int64(2))
+
+	n, err = tx.HInc(key, []byte("1"), 1)
+	c.Assert(err, IsNil)
+	c.Assert(n, Equals, int64(3))
+
 	n, err = tx.HGetInt64(key, []byte("1"))
 	c.Assert(err, IsNil)
-	c.Assert(n, Equals, int64(2))
+	c.Assert(n, Equals, int64(3))
 
 	l, err = tx.HLen(key)
 	c.Assert(err, IsNil)