vendor/bundle/ruby/2.4.0/gems/ffi-1.9.18/lib/ffi/variadic.rb

#
# Copyright (C) 2008, 2009 Wayne Meissner
# Copyright (C) 2009 Luc Heinrich
#
# This file is part of ruby-ffi.
#
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice, this
#   list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright notice
#   this list of conditions and the following disclaimer in the documentation
#   and/or other materials provided with the distribution.
# * Neither the name of the Ruby FFI project nor the names of its contributors
#   may be used to endorse or promote products derived from this software
#   without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#

module FFI
  class VariadicInvoker    
    def init(arg_types, type_map)
      @fixed = Array.new
      @type_map = type_map
      arg_types.each_with_index do |type, i|
        @fixed << type unless type == Type::VARARGS
      end
    end


    def call(*args, &block)
      param_types = Array.new(@fixed)
      param_values = Array.new
      @fixed.each_with_index do |t, i|
        param_values << args[i]
      end
      i = @fixed.length
      while i < args.length
        param_types << FFI.find_type(args[i], @type_map)
        param_values << args[i + 1]
        i += 2
      end
      invoke(param_types, param_values, &block)
    end

    #
    # Attach the invoker to module +mod+ as +mname+
    #
    def attach(mod, mname)
      invoker = self
      params = "*args"
      call = "call"
      mod.module_eval <<-code
      @@#{mname} = invoker
      def self.#{mname}(#{params})
        @@#{mname}.#{call}(#{params})
      end
      def #{mname}(#{params})
        @@#{mname}.#{call}(#{params})
      end
      code
      invoker
    end
  end
end