class TensorStream::Freezer

Public Instance Methods

convert(session, checkpoint_folder, output_file) click to toggle source

Utility class to convert variables to constants for production deployment

# File lib/tensor_stream/utils/freezer.rb, line 8
def convert(session, checkpoint_folder, output_file)
  model_file = File.join(checkpoint_folder, "model.yaml")
  TensorStream.graph.as_default do |current_graph|
    YamlLoader.new.load_from_string(File.read(model_file))
    saver = TensorStream::Train::Saver.new
    saver.restore(session, checkpoint_folder)

    # collect all assign ops and remove them from the graph
    remove_nodes = Set.new(current_graph.nodes.values.select { |op| op.is_a?(TensorStream::Operation) && op.operation == :assign }.map { |op| op.consumers.to_a }.flatten.uniq)

    output_buffer = TensorStream::Yaml.new.get_string(current_graph) { |graph, node_key|
      node = graph.get_tensor_by_name(node_key)
      case node.operation
      when :variable_v2
        value = Evaluator.read_variable(node.graph, node.options[:var_name])
       if value.nil?
         raise "#{node.options[:var_name]} has no value"
       end

        options = {
          value: value,
          data_type: node.data_type,
          shape: shape_eval(value),
        }
        const_op = TensorStream::Operation.new(current_graph, inputs: [], options: options)
        const_op.name = node.name
        const_op.operation = :const
        const_op.data_type = node.data_type
        const_op.shape = TensorShape.new(shape_eval(value))

        const_op
      when :assign
        nil
      else
        remove_nodes.include?(node.name) ? nil : node
      end
    }
    File.write(output_file, output_buffer)
  end
end