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# 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 ArrowFormat
  class Bitmap
    include Enumerable

    def initialize(buffer, n_values)
      @buffer = buffer
      @n_values = n_values
    end

    def each
      return to_enum(__method__) unless block_given?

      n_bytes = @n_values / 8
      @buffer.each(:U8, 0, n_bytes) do |offset, value|
        7.times do |i|
          yield(value & (1 << (i % 8)))
        end
      end
      remained_bits = @n_values % 8
      unless remained_bits.zero?
        value = @buffer.get_value(:U8, n_bytes)
        remained_bits.times do |i|
          yield(value & (1 << (i % 8)))
        end
      end
    end
  end
end