WIP (Further optimization by macthing on index limit at the tail)

lib/msgpax/unpacker.ex

@@ -28,10 +28,6 @@ defmodule Msgpax.Unpacker do
    unpack(buffer, [], options, [:root], 0, 1)
  end

  defp unpack(<<buffer::bits>>, result, options, [kind, index, length | outer], count, count) do
    unpack(buffer, build_collection(result, count, kind), options, outer, index + 1, length)
  end

  primitives = %{
    [quote(do: [0xC0])] => quote(do: nil),
    [quote(do: [0xC2])] => quote(do: false),
@@ -61,7 +57,13 @@ defmodule Msgpax.Unpacker do
  }
  for {formats, value} <- primitives, format <- formats do
    defp unpack(<<unquote_splicing(format), rest::bits>>, result, options, outer, index, count) when index < count do
      unpack(rest, [unquote(value) | result], options, outer, index + 1, count)
      result = [unquote(value) | result]
      case index + 1 do
        ^count ->
          unpack_continue(rest, options, outer, result, count)
        index ->
          unpack(rest, result, options, outer, index, count)
      end
    end
  end

@@ -72,7 +74,19 @@ defmodule Msgpax.Unpacker do
  ]
  for format <- lists do
    defp unpack(<<unquote_splicing(format), rest::bits>>, result, options, outer, index, count) when index < count do
      unpack(rest, result, options, [:list, index, count | outer], 0, unquote(quote(do: length)))
      case unquote(quote(do: length)) do
        0 ->
          result = [[] | result]
          case index + 1 do
            ^count ->
              unpack_continue(rest, options, outer, result, count)
            index ->
              unpack(rest, result, options, outer, index, count)
          end

        length ->
          unpack(rest, result, options, [:list, index, count | outer], 0, length)
      end
    end
  end

@@ -83,7 +97,19 @@ defmodule Msgpax.Unpacker do
  ]
  for format <- maps do
    defp unpack(<<unquote_splicing(format), rest::bits>>, result, options, outer, index, count) when index < count do
      unpack(rest, result, options, [:map, index, count | outer], 0, unquote(quote(do: length)) * 2)
      case unquote(quote(do: length)) do
        0 ->
          result = [%{} | result]
          case index + 1 do
            ^count ->
              unpack_continue(rest, options, outer, result, count)
            index ->
              unpack(rest, result, options, outer, index, count)
          end

        length ->
          unpack(rest, result, options, [:map, index, count | outer], 0, length * 2)
      end
    end
  end

@@ -95,7 +121,13 @@ defmodule Msgpax.Unpacker do
  for format <- binaries do
    defp unpack(<<unquote_splicing(format), rest::bits>>, result, options, outer, index, count) when index < count do
      value = unpack_binary(unquote(quote(do: content)), options)
      unpack(rest, [value | result], options, outer, index + 1, count)
      result = [value | result]
      case index + 1 do
        ^count ->
          unpack_continue(rest, options, outer, result, count)
        index ->
          unpack(rest, result, options, outer, index, count)
      end
    end
  end

@@ -112,14 +144,16 @@ defmodule Msgpax.Unpacker do
  for format <- extensions do
    defp unpack(<<unquote_splicing(format), rest::bits>>, result, options, outer, index, count) when index < count do
      value = unpack_ext(unquote(quote(do: type)), unquote(quote(do: content)), options)
      unpack(rest, [value | result], options, outer, index + 1, count)
      result = [value | result]
      case index + 1 do
        ^count ->
          unpack_continue(rest, options, outer, result, count)
        index ->
          unpack(rest, result, options, outer, index, count)
      end
    end
  end

  defp unpack(<<buffer::bits>>, [value], _options, [:root], count, count) do
    {value, buffer}
  end

  defp unpack(<<byte, _::bits>>, _result, _options, _outer, _index, _count) do
    throw {:bad_format, byte}
  end
@@ -128,6 +162,20 @@ defmodule Msgpax.Unpacker do
    throw :incomplete
  end

  defp unpack_continue(<<buffer::bits>>, options, [kind, index, length | outer], result, count) do
    result = build_collection(result, count, kind)
    case index + 1 do
      ^length ->
        unpack_continue(buffer, options, outer, result, length)
      index ->
        unpack(buffer, result, options, outer, index, length)
    end
  end

  defp unpack_continue(<<buffer::bits>>, _options, [:root], [value], 1) do
    {value, buffer}
  end

  defp unpack_binary(content, %{binary: true}) do
    Msgpax.Bin.new(content)
  end