ARROW-4034: [Ruby] Add support :append option to FileOutputStream

Author: Kouhei Sutou <[email protected]>

Closes apache#3193 from kou/ruby-file-output-stream-append and squashes the following commits:

6240f4b <Kouhei Sutou>  Add support :append option to FileOutputStream

ruby/red-arrow/lib/arrow/field.rb

@@ -18,6 +18,7 @@
 module Arrow
   class Field
     alias_method :initialize_raw, :initialize
+    private :initialize_raw
     def initialize(name, data_type)
       case data_type
       when String, Symbol

ruby/red-arrow/lib/arrow/file-output-stream.rb

@@ -0,0 +1,34 @@
+# 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.
+
+module Arrow
+  class FileOutputStream
+    alias_method :initialize_raw, :initialize
+    private :initialize_raw
+    def initialize(path, options={})
+      append = nil
+      case options
+      when true, false
+        append = options
+      when Hash
+        append = options[:append]
+      end
+      append = false if append.nil?
+      initialize_raw(path, append)
+    end
+  end
+end

ruby/red-arrow/lib/arrow/loader.rb

@@ -44,6 +44,7 @@ def require_libraries
       require "arrow/date64-array"
       require "arrow/date64-array-builder"
       require "arrow/field"
+      require "arrow/file-output-stream"
       require "arrow/path-extension"
       require "arrow/record"
       require "arrow/record-batch"

ruby/red-arrow/lib/arrow/table.rb

@@ -29,6 +29,7 @@ def load(path, options={})
     end
 
     alias_method :initialize_raw, :initialize
+    private :initialize_raw
     def initialize(schema_or_raw_table_or_columns, columns=nil)
       if columns.nil?
         if schema_or_raw_table_or_columns[0].is_a?(Column)

ruby/red-arrow/test/test-file-output-stream.rb

@@ -0,0 +1,54 @@
+# 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.
+
+class TestFileOutputStream < Test::Unit::TestCase
+  sub_test_case(".open") do
+    def setup
+      @file = Tempfile.open("arrow-file-output-stream")
+      @file.write("Hello")
+      @file.close
+    end
+
+    def test_default
+      Arrow::FileOutputStream.open(@file.path) do |file|
+        file.write(" World")
+      end
+      assert_equal(" World", File.read(@file.path))
+    end
+
+    def test_options_append
+      Arrow::FileOutputStream.open(@file.path, append: true) do |file|
+        file.write(" World")
+      end
+      assert_equal("Hello World", File.read(@file.path))
+    end
+
+    def test_append_true
+      Arrow::FileOutputStream.open(@file.path, true) do |file|
+        file.write(" World")
+      end
+      assert_equal("Hello World", File.read(@file.path))
+    end
+
+    def test_append_false
+      Arrow::FileOutputStream.open(@file.path, false) do |file|
+        file.write(" World")
+      end
+      assert_equal(" World", File.read(@file.path))
+    end
+  end
+end