Module: Kiwi::Compiler

Defined in:
lib/kiwi/compiler.rb

Class Method Summary collapse

Class Method Details

.compile(schema) ⇒ Object 



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# File 'lib/kiwi/compiler.rb', line 5

def self.compile(schema)
  definitions = {}
  rb = []

  schema.definitions.each_with_index do |definition, index|
    definitions[index] = definition
  end

  schema.definitions.each do |definition|
    case definition.kind
    when Definition::KIND_ENUM
      rb << "#{definition.name} = {"
      definition.fields.each do |field|
        rb << "  '#{field.name}' => #{field.value},"
        rb << "  #{field.value} => '#{field.name}',"
      end
      rb << "}.freeze"
      rb << ""
    when Definition::KIND_STRUCT, Definition::KIND_MESSAGE
      rb << "def decode_#{definition.name.downcase}(bb)"
      rb << compile_decode(definition, definitions)
      rb << "end"
      rb << ""
      rb << "def encode_#{definition.name.downcase}(message, bb = Kiwi::ByteBuffer.new)"
      rb << compile_encode(definition, definitions)
      rb << "end"
      rb << ""
    else
      raise "Invalid definition kind: #{definition.kind}"
    end
  end

  rb.join("\n")
end

.compile_decode(definition, definitions) ⇒ Object 



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# File 'lib/kiwi/compiler.rb', line 40

def self.compile_decode(definition, definitions)
  lines = []
  indent = "  "

  lines << "  result = {}"

  if definition.kind == Definition::KIND_MESSAGE
    lines << "  loop do"
    lines << "    case bb.read_var_uint"
    lines << "    when 0"
    lines << "      return result"
    indent = "    "
  end

  definition.fields.each do |field|
    code = ""

    case field.type_id
    when Field::TYPE_BOOL
      code = "bb.read_bool"
    when Field::TYPE_BYTE
      code = "bb.read_byte"
    when Field::TYPE_INT
      code = "bb.read_var_int"
    when Field::TYPE_UINT
      code = "bb.read_var_uint"
    when Field::TYPE_FLOAT
      code = "bb.read_var_float"
    when Field::TYPE_STRING
      code = "bb.read_string"
    else
      type = definitions[field.type]
 
      if (!type)
        raise "Invalid field type: #{field.type} for field #{field.name}"
      elsif type.kind == Definition::KIND_ENUM
        code = "#{type.name}[bb.read_var_uint]"
      else
        code = "decode_#{type.name.downcase}(bb)"
      end
    end

    if definition.kind == Definition::KIND_MESSAGE
      lines << "    when #{field.value}"
    end

    if field.is_array
      if field.type_id == Field::TYPE_BYTE
        lines << indent + "  result['#{field.name}'] = bb.read_byte_array"
      else
        lines << indent + "  length = bb.read_var_uint"
        lines << indent + "  values = result['#{field.name}'] = Array.new(length)"
        lines << indent + "  length.times { |i| values[i] = #{code} }"
      end
    else
      lines << indent + "  result['#{field.name}'] = #{code}"
    end
  end

  if definition.kind == Definition::KIND_MESSAGE
    lines << "    else"
    lines << "      raise RuntimeError, 'Attempted to parse invalid message'"
    lines << "    end"
    lines << "  end"
  else
    lines << "  return result"
  end

  lines.join("\n")
end

.compile_encode(definition, definitions) ⇒ Object 



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# File 'lib/kiwi/compiler.rb', line 111

def self.compile_encode(definition, definitions)
  lines = []

  definition.fields.each do |field|
    code = ""

    case field.type_id
    when Field::TYPE_BOOL
      code = "bb.write_bool(value)"
    when Field::TYPE_BYTE
      code = "bb.write_byte(value)"
    when Field::TYPE_INT
      code = "bb.write_var_int(value)"
    when Field::TYPE_UINT
      code = "bb.write_var_uint(value)"
    when Field::TYPE_FLOAT
      code = "bb.write_var_float(value)"
    when Field::TYPE_STRING
      code = "bb.write_string(value)"
    else
      type = definitions[field.type]
 
      if (!type)
        raise "Invalid field type: #{field.type} for field #{field.name}"
      elsif type.kind == Definition::KIND_ENUM
        code = <<~CODE
          encoded = #{type.name}[value]
          raise "Invalid value for enum #{type.name}" if !encoded
          bb.write_var_uint(encoded)
        CODE
      else
        code = "encode_#{type.name.downcase}(value, bb)"
      end
    end

    lines << "  value = message['#{field.name}']"
    lines << "  if !value.nil?"

    if definition.kind == Definition::KIND_MESSAGE
      lines << "    bb.write_var_uint(#{field.value})"
    end

    if field.is_array
      if field.type_id == Field::TYPE_BYTE
        lines << "    bb.write_byte_array(value)"
      else
        lines << "    bb.write_var_uint(value.length)"
        lines << "    value.each do |value|"
        lines << "      #{code}"
        lines << "    end"
      end
    else
      lines << "    #{code}"
    end

    if definition.kind == Definition::KIND_STRUCT
      lines << "  else"
      lines << "    raise \"Missing required field: #{field.name}\""
    end

    lines << "  end"
    lines << ""
  end

  if definition.kind == Definition::KIND_MESSAGE
    lines << "  bb.write_var_uint(0)"
  end

  lines << ""
  lines << "  return bb"

  lines.join("\n")
end