Add clang format (#4)

* Add clang format

Copied from apache arrow

Signed-off-by: Junwang Zhao <[email protected]>

* make clang-format language-specific

Signed-off-by: Junwang Zhao <[email protected]>

* use Regroup for IncludeBlocks and add IncludeCategories

Signed-off-by: Junwang Zhao <[email protected]>

---------

Signed-off-by: Junwang Zhao <[email protected]>

Author: zhjwpku

.clang-format

@@ -0,0 +1,32 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+---
+Language: Cpp
+BasedOnStyle: Google
+ColumnLimit: 90
+DerivePointerAlignment: false
+IncludeBlocks: Regroup
+IncludeCategories:
+- Regex: '^<.*/' # Like <boost/lexical_cast.hpp>
+  Priority: 3
+- Regex: '^<.*\.' # Like <fcntl.h>
+  Priority: 1
+- Regex: '^<' # Like <vector>
+  Priority: 2
+- Regex: '^"' # Like "util/auth-util.h"
+  Priority: 4
+IndentPPDirectives: AfterHash