fs: Re-implement object layer to remember the fd (#3509)

This patch re-writes FS backend to support shared backend sharing locks for safe concurrent access across multiple servers.

cmd/commands_test.go

@@ -0,0 +1,41 @@
+/*
+ * Minio Cloud Storage, (C) 2017 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package cmd
+
+import (
+	"testing"
+
+	"github.com/minio/cli"
+)
+
+// Tests register command function.
+func TestRegisterCommand(t *testing.T) {
+	registerCommand(cli.Command{
+		Name: "test1",
+	})
+	ccount := len(commands)
+	if ccount != 1 {
+		t.Fatalf("Unexpected number of commands found %d", ccount)
+	}
+	registerCommand(cli.Command{
+		Name: "test2",
+	})
+	ccount = len(commands)
+	if ccount != 2 {
+		t.Fatalf("Unexpected number of commands found %d", ccount)
+	}
+}