add xhexists cmd

ledis/t_hash.go

@@ -509,3 +509,15 @@ func (db *DB) HPersist(key []byte) (int64, error) {
 	err = t.Commit()
 	return n, err
 }
+
+func (db *DB) XHExists(key []byte) (int64, error) {
+	if err := checkKeySize(key); err != nil {
+		return 0, err
+	}
+	sk := db.hEncodeSizeKey(key)
+	v, err := db.bucket.Get(sk)
+	if v != nil && err == nil {
+		return 1, nil
+	}
+	return 0, err
+}

ledis/t_hash_test.go

@@ -79,6 +79,29 @@ func TestHashPersist(t *testing.T) {
 		t.Fatal(n)
 	}
 }
+func TestXHashExists(t *testing.T) {
+	db := getTestDB()
+	key := []byte("xhexists_test")
+	v, err := db.XHExists(key)
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+	if v != 0 {
+		t.Fatal("invalid value ", v)
+	}
+
+	if _, err := db.HSet(key, []byte("hello"), []byte("world")); err != nil {
+		t.Fatal(err.Error())
+	}
+
+	v, err = db.XHExists(key)
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+	if v != 1 {
+		t.Fatal("invalid value ", v)
+	}
+}
 
 func TestHFlush(t *testing.T) {
 	db := getTestDB()

server/cmd_hash.go

@@ -300,6 +300,19 @@ func hxrevscanCommand(c *client) error {
 	return xscanGeneric(c, c.db.HRevScan)
 }
 
+func hxexistsCommand(c *client) error {
+	args := c.args
+	if len(args) != 1 {
+		return ErrCmdParams
+	}
+	if n, err := c.db.XHExists(args[0]); err != nil {
+		return err
+	} else {
+		c.resp.writeInteger(n)
+	}
+	return nil
+}
+
 func init() {
 	register("hdel", hdelCommand)
 	register("hexists", hexistsCommand)
@@ -325,4 +338,5 @@ func init() {
 	register("hxrevscan", hxrevscanCommand)
 	register("xhscan", hxscanCommand)
 	register("xhrevscan", hxrevscanCommand)
+	register("xhexists", hxexistsCommand)
 }

server/cmd_hash_test.go

@@ -12,11 +12,22 @@ func TestHash(t *testing.T) {
 	defer c.Close()
 
 	key := []byte("a")
+	if n, err := ledis.Int(c.Do("xhexists", key)); err != nil {
+		t.Fatal(err)
+	} else if n != 0 {
+		t.Fatal(n)
+	}
+
 	if n, err := ledis.Int(c.Do("hset", key, 1, 0)); err != nil {
 		t.Fatal(err)
 	} else if n != 1 {
 		t.Fatal(n)
 	}
+	if n, err := ledis.Int(c.Do("xhexists", key)); err != nil {
+		t.Fatal(err)
+	} else if n != 1 {
+		t.Fatal(n)
+	}
 
 	if n, err := ledis.Int(c.Do("hexists", key, 1)); err != nil {
 		t.Fatal(err)
@@ -296,5 +307,4 @@ func TestHashErrorParams(t *testing.T) {
 	if _, err := c.Do("hpersist"); err == nil {
 		t.Fatal("invalid err of %v", err)
 	}
-
 }