GH-50569: [Ruby] Add ArrowFormat::RecordBatch.new(values)

ruby/red-arrow-format/lib/arrow-format/record-batch.rb

@@ -26,7 +26,14 @@ class RecordBatch
     alias_method :length, :n_rows
     attr_reader :columns
     attr_reader :message_metadata
-    def initialize(schema, n_rows, columns, message_metadata: nil)
+    def initialize(*args, message_metadata: nil)
+      n_args = args.size
+      args = build(args[0]) if n_args == 1
+      if args.size != 3
+        message = "wrong number of arguments (given #{n_args}, expected 1 or 3)"
+        raise ArgumentError, message
+      end
+      schema, n_rows, columns = args
       @schema = schema
       @n_rows = n_rows
       @columns = columns
@@ -101,5 +108,57 @@ def all_buffers_enumerator
         end
       end
     end
+
+    private
+    def build(data)
+      records = nil
+      fields = []
+      columns = []
+      mode = nil
+      i = 0
+      data.each do |name, column|
+        if i.zero?
+          if column.nil?
+            mode = :record
+            records = {}
+          else
+            mode = :column
+          end
+        end
+
+        if mode == :record
+          record = name
+          record.each do |n, value|
+            values = (records[n] ||= [])
+            while values.size < i
+              values << nil
+            end
+            values << value
+          end
+        else
+          fields << Field.new(name, column.type)
+          columns << column
+        end
+        i += 1
+      end
+
+      if mode == :record
+        records.each do |name, values|
+          column = Array.build(values)
+          fields << Field.new(name, column.type)
+          columns << column
+        end
+      end
+
+      raise ArgumentError, "no data" if columns.empty?
+      all_n_rows = columns.collect(&:size)
+      if all_n_rows.uniq.size != 1
+        message =
+          "inconsistent the number of rows: #{all_n_rows.join(", ")}"
+        raise ArgumentError, message
+      end
+
+      return Schema.new(fields), n_rows, columns
+    end
   end
 end

ruby/red-arrow-format/test/test-record-batch.rb

@@ -0,0 +1,75 @@
+# 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 TestRecordBatch < Test::Unit::TestCase
+  sub_test_case("#initialize") do
+    def setup
+      @boolean_array = ArrowFormat::BooleanArray.new([true, nil, false])
+      @int32_array = ArrowFormat::Int32Array.new([-(2 ** 31), 0, (2 ** 31) - 1])
+    end
+
+    test("{}") do
+      error = ArgumentError.new("no data")
+      assert_raise(error) do
+        ArrowFormat::RecordBatch.new({})
+      end
+    end
+
+    test("{Symbol => Array}") do
+      raw_records = {
+        boolean: @boolean_array,
+        int32: @int32_array,
+      }
+      record_batch = ArrowFormat::RecordBatch.new(raw_records)
+      assert_equal(raw_records, record_batch.to_h)
+    end
+
+    test("{String => Array}") do
+      raw_records = {
+        "boolean" => @boolean_array,
+        "int32" => @int32_array,
+      }
+      record_batch = ArrowFormat::RecordBatch.new(raw_records)
+      assert_equal(raw_records, record_batch.to_h)
+    end
+
+    test("[{}]") do
+      raw_records = [
+        {boolean: true,  int32: -(2 ** 31)},
+        {                int32: 0},
+        {boolean: false, int32: (2 ** 31) - 1},
+      ]
+      record_batch = ArrowFormat::RecordBatch.new(raw_records)
+      assert_equal({
+                     boolean: @boolean_array,
+                     int32: @int32_array,
+                   },
+                   record_batch.to_h)
+    end
+
+    test("inconsistent n_rows") do
+      raw_records = {
+        boolean: ArrowFormat::BooleanArray.new([true, nil]),
+        int32: ArrowFormat::Int32Array.new([-(2 ** 31), 0, (2 ** 31) - 1]),
+      }
+      error = ArgumentError.new("inconsistent the number of rows: 2, 3")
+      assert_raise(error) do
+        ArrowFormat::RecordBatch.new(raw_records)
+      end
+    end
+  end
+end