safe_hash.rb

# frozen_string_literal: true

class SafeHash < Hash
  def initialize(namespace)
    @namespace = namespace
    @lock = Concurrent::ReadWriteLock.new
    super
    merge!({ @namespace => Concurrent::Map.new })
  end

  def []=(key, value)
    fetch(@namespace, {})[key] = value
  end

  def [](key)
    fetch(@namespace, {})[key]
  end

  def size
    fetch(@namespace, {}).size
  end

  def keys
    fetch(@namespace, {}).keys
  end

  def values
    fetch(@namespace, {}).values
  end

  def clear
    fetch(@namespace, {}).clear
  end

  def copy_and_clear
    copy = {}
    @lock.with_write_lock do
      copy = delete(@namespace)
      merge!({ @namespace => Concurrent::Map.new })
    end
    return copy
  end
end