Improve extension API: C++ as better language for extension - Kouhei Sutou

Ad1:
Ad1: I'm
I'm distributing
distributing
shocker
shocker combatmen
combatmen to
to Rabbit
Rabbit
users
users
宣伝1：Rabbitユーザーに
宣伝1：Rabbitユーザーに
ショッカー戦闘員を配布中
ショッカー戦闘員を配布中

Ad2: Silver sponsor
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Ad3: Red Data Tools
✓ Project that provides data
processing tools for Ruby
Ruby用のデータ処理ツール群を提供するプロジェクト
✓ https://red-data-tools.github.io/
✓ Workshop during the afternoon
break on the 2nd day (today!)
2日目（今日！）の午後休憩中にワークショップがあるよ！
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Ad4: OSS Gate
✓ Project that increases people
who join OSS development
OSSの開発に継続的に参加する人を継続的に増やす取り組み
✓ https://oss-gate.github.io/
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Ad4: OSS Gate
✓ Ruby is OSS
RubyもOSS
✓ OSS Gate wants to increase people
to join Ruby itself and RubyGems
development!
OSS GateではRuby本体の開発や各種RubyGemの開発に参加
する人も増やしたい！
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Ad4: OSS Gate
✓ Now, in Tokyo, Sapporo, Osaka
and Kyoto
現在は東京・札幌・大阪・京都で活動中
✓ If you live near by, join "OSS
Gate workshop"!
これらの地域に住んでいる人は「OSS Gateワークショッ
プ」に参加しよう！
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Ad4: OSS Gate
✓ Want to expand to Hiroshima
and other areas all over the
world!
広島や世界中のいろんな地域で活動したい！
✓ If you're interested in increasing
people who join OSS development,
talk to me!
OSSの開発に参加する人が増えることに興味のある人は私
に声をかけて！
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

What I want to do
やりたいこと
Improve performance
with C/C++ libraries
C/C++のライブラリーを使った高速化
✓ Not create binding
バインディングを作りたいわけじゃない
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Point of improving perf
高速化するために大事なこと
Done in C/C++
as much as possible
できるだけC/C++内で完結させる
✓ Don't move between
C/C++ and Ruby
C/C++とRuby間でいったりきたりしない
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Example: #sum
例：#sum
numbers = (1..100000).to_a
# Move between C and Ruby: 25.1ms
numbers.inject(&:+)
# Done in C:
0.5ms
# 50x faster（50倍速い）
numbers.sum
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

FYI: #inject(symbol)
参考情報：#inject(symbol)
numbers = (1..100000).to_a
# Move between C and Ruby: 25.1ms
numbers.inject(&:+)
# Done in C:
0.5ms
# 50x faster（50倍速い）
numbers.inject(:+)
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Extension and binding
拡張ライブラリーとバインディング
✓ Extension（拡張ライブラリー）
✓ Ruby library implemented in C
Cで実装されたRubyのライブラリー
✓ Binding（バインディング）
✓ Ruby library to use library
implemented in other languages
他言語実装のライブラリを使うためのRubyのライブラリ
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Binding usage
バインディングの使い方
✓ Export each API to Ruby
それぞれのAPIをRubyで使えるようにする
✓ Combine exported APIs in Ruby
バインディングが提供するAPIをRubyレベルで組み合わせる
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Binding usage example
バインディングの使い方例
require "cairo"
include Cairo
# Combine APIs
s = PDFSurface.new("red.pdf", 10, 10) # API
context = Context.new(s)
# API
context.set_source_color(:red)
# API
context.paint
# API
context.show_page
# API
s.finish
# API
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Perf improvement example
高速化例
# Don't combine APIs in Ruby
# RubyレベルでAPIを組み合わせない
## context.set_source_color(:red) # API
## context.paint
# API
## context.show_page
# API
# Just call higher level API in Ruby
# Rubyからはもっと高レベルなAPIを呼び出す
context.show_red_page # Implemented in C
# ここはCで実装
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Use case
高速化したい場面
✓ Machine learning
機械学習
✓ Combine array/matrix operations
配列・行列に対する演算をまとめる
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Raw C API for extension
拡張ライブラリー用の生のC API
Not bad but can be verbose
because of C
悪くないんだけどCなので冗長
✓ Need better approach
もっといい感じの方法を使いたい
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Requirements
要件
✓ Easy to use C/C++ libraries
C/C++のライブラリーを簡単に使えること
✓ Easy to write as much as possible
できるだけ書きやすいこと
✓ Easy to debug as much as possible
できるだけデバッグしやすいこと
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Approaches（実現方法）
✓ Extend language to support
writing extension
拡張ライブラリーを書けるように言語を拡張
✓ Not based on C
C以外の言語を使う
✓ Provide convenient API
便利APIを提供
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Recommended approach
オススメの実現方法
✓ Extend language to support
writing extension
拡張ライブラリーを書けるように言語を拡張
✓ Not based on C
C以外の言語を使う
✓ Provide convenient API
便利APIを提供
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Provide convenient API
便利なAPIを提供
✓ Rice: C++ + Ruby
✓ Ext++: C++11 + Ruby
✓ Boost.Python: C++ + Python
✓ pybind11: C++11 + Python
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Useful C++ properties
C++の便利の性質
✓ C++ can use C API directory
C++ではCのAPIを直接使える
✓ No wrapper API or libffi
ラッパーAPIもlibffiもいらない
✓ C++11 or later has many
convenient features
C++11以降には便利機能がたくさんある
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

C++ convenient feature1
C++の便利機能1
Type detection with "auto"
autoで型推論（C++11）
int n = 10;
auto square = n * n;
// square's type is "int"
// squareの型は「int」
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

C++ convenient feature2
C++の便利機能2
Lambda expression (C++11)
ラムダ式（C++11）
// In Ruby: ->(n) {n * n}
auto square = [](int n) {
return n * n; // Return type is detected
};
square(10); // => 100
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

C++ convenient feature3
C++の便利機能3
Default argument
デフォルト引数
// In Ruby: def square(n=10)
int square(int n=10) {
return n * n;
}
// square() == square(10)
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Convenient API example1
便利なAPI例1
# Ruby: Normal
class Sample
def hello
"Hello"
end
end
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Convenient API example1
便利なAPI例1
# Ruby: No syntax sugar
Sample = Class.new do
define_method(:hello) do
"Hello"
end
end
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

$Convenient API example1 便利なAPI例1 // C++: Ext++ #include <ruby.hpp> extern "C" void Init_sample(void) { // Parent class (rb_cObject) is omittable rb::Class("Sample"). // class Sample in Ruby define_method("hello", // def hello in Ruby [](VALUE self) { // ->() {"Hello"} in Ruby return rb_str_new_static("Hello"); }); } Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$ $Convenient API example1 便利なAPI例1 /* C */ #include <ruby.h> static VALUE rb_sample_hello(VALUE self) { return rb_str_new_static("Hello"); } /* ↑Definition. */ void Init_sample(void) { /* ↓Must specify parent class. */ VALUE sample = rb_define_class("Sample", rb_cObject); /* ↓Registration. They are separated. */ rb_define_method(sample, "hello", rb_sample_hello, 0); } Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$ C++ convenient feature4
C++の便利機能4
Custom type conversion
型変換のカスタマイズ
✓ "Cast" is customizable
「キャスト」をカスタマイズできるということ
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

C++ convenient feature4
C++の便利機能4
Custom type conversion
型変換のカスタマイズ
✓ "Cast" is customizable
「キャスト」をカスタマイズできるということ
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

$Custom type conversion 型変換のカスタマイズ // Wrapper class of VALUE class Object { public: // def initialize(rb_object) // @rb_object_ = rb_object // end Object(VALUE rb_object) : rb_object_(rb_object) {} private: VALUE rb_object_; }; Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$ $Custom type conversion 型変換のカスタマイズ class Object { operator bool() const { return RTEST(rb_object_); } }; // Object nil(Qnil); // Qnil wrapper // if (nil) { → if (RTEST(Qnil)) { Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$ Custom type conversion
型変換のカスタマイズ
// Trap1（罠1）
// bool→int cast is available
// Implicit Object→bool→ int cast
// bool→intのキャストができるので
// 暗黙的にObject→bool→intとキャスト
Object(Qture) + 1; // → RTEST(Qtrue) + 1
// → 1 + 1
// → 2
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Custom type conversion
型変換のカスタマイズ
// Trap1（罠1）
// bool→int cast is available
// Implicit Object→bool→ int cast
// bool→intのキャストができるので
// 暗黙的にObject→bool→intとキャスト
Object(Qture) + 1; // → RTEST(Qtrue) + 1
// → 1 + 1
// → 2
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

$Custom type conversion 型変換のカスタマイズ class Object { // Deny explicit cast (C++11) // 暗黙のキャストを禁止（C++11） explicit operator bool() const { return RTEST(rb_object_); } }; // Object(Qtrue) + 1; // → Compile error Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$ $Custom type conversion 型変換のカスタマイズ // Trap2（罠2） class Object { public: // Used as implicit VALUE→Object cast // 暗黙のVALUE→Objectキャストに使われる Object(VALUE rb_object); }; Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$ Custom type conversion
型変換のカスタマイズ
// Trap2（罠2）
// VALUE is just a number（VALUEはただの数値）
typedef unsigned long VALUE;
Object identify(Object x) {return x;}
// Implicit VALUE→Object cast
// 暗黙的にVALUE→Objectとキャスト
identify(100); // == identify(Object(100));
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Custom type conversion
型変換のカスタマイズ
// Trap2（罠2）
// VALUE is just a number（VALUEはただの数値）
typedef unsigned long VALUE;
Object identify(Object x) {return x;}
// Implicit VALUE→Object cast
// 暗黙的にVALUE→Objectとキャスト
identify(100); // == identify(Object(100));
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

$Custom type conversion 型変換のカスタマイズ class Object { // Deny explicit cast // 暗黙のキャストを禁止 explicit Object(VALUE rb_object); }; // identify(100); // → Compile error Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$ $Custom type conversion 型変換のカスタマイズ class Object { operator VALUE() const {return rb_object_;} }; // Convenient（便利） rb_p(Object(Qnil)); // → rb_p(Qnil); // Not compile error. Hmm... Object(Qnil) + 1; // → Qnil + 1; // → 8 + 1; // → 9; Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$ C++ convenient feature5
C++の便利機能5
Template and specialization
テンプレートと特殊化
✓
Consistent cast API
一貫性のあるキャストAPIに使える
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

C++ convenient feature5
C++の便利機能5
Template and specialization
テンプレートと特殊化
✓
Consistent cast API
一貫性のあるキャストAPIに使える
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

$Consistent cast API 一貫性のあるキャストAPI namespace rb { // Consistent cast API // Example: rb::cast<int32_t>(Object(NUM2INT(10)); // Example: rb::cast<Object>(10); // FYI: C++ cast syntax: static_cast<TYPE>(expression) template <typename RETURN_TYPE, typename ARGUMENT_TYPE> inline RETURN_TYPE cast(ARGUMENT_TYPE object); } Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$ $Consistent cast API 一貫性のあるキャストAPI template <> // rb::cast<int32_t>(Object(NUM2INT(10)); inline int32_t cast<int32_t, Object>(Object rb_object) { return NUM2INT(rb_object); } template <> // rb::cast<Object>(10); inline Object cast<Object, int32_t>(int32_t n) { return Object(INT2NUM(n)); } Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$ $Consistent cast API 一貫性のあるキャストAPI // rb::cast<const char *>(Object(rb_str_new_cstr("X")); template <> inline const char *cast<const char *, Object>(Object rb_object) { VALUE rb_object_raw = rb_object; return StringValueCStr(rb_object_raw); } template <> inline // rb::cast<Object>("hello"); Object cast<Object, const char *>(const char *c_string) { return Object(rb_str_new_cstr(c_string)); } Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$ C++ convenient feature6
C++の便利機能6
Initializer list (C++11)
初期化リスト（C++11）
✓ "{A,B,...}" is customizable
「{A, B, ...}」をカスタマイズできる
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

C++ convenient feature6
C++の便利機能6
Initializer list (C++11)
初期化リスト（C++11）
✓ "{A,B,...}" is customizable
「{A, B, ...}」をカスタマイズできる
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

$Initializer list 初期化リスト Object Object::send( ID name_id, std::initializer_list<VALUE> args); // Ruby: "hello".send(:tr, "e", "E") Object(rb_str_new_cstr("hello")). send(rb_intern("tr"), {rb_str_new_cstr("e"), rb_str_new_cstr("E")}); Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$ $Initializer list 初期化リスト Object Object::send( ID name_id, std::initializer_list<VALUE> args, VALUE (*block)(VALUE data)); // Ruby: array.send(:collect) {true} Object(array). send(rb_intern("collect"), {}, // Clear API than variable arguments [](VALUE data) {return Qtrue;}); Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$ $Convenient API example2 便利なAPI例2 // C++: Ext++ rb::Object(rb_n). send("step", // Implicit Object→VALUE cast {rb::cast<rb::Object>(10)}, [](VALUE i) {return rb_p(i)}); // n.step(10) {|i| p i} Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$ $Convenient API example3 便利なAPI例3 // C++: Rice #include <rice/Class.hpp> static const char * // Not VALUE! (Auto convert) rb_sample_hello(Rice::Object self) { return "Hello"; } extern "C" void Init_sample() { Rice::define_class("Sample"). define_method("hello", &rb_sample_hello); } Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$ C++ based API: Pros1
C++ベースのAPI：長所1
Easier to write than C
Cより書きやすい
✓ Require C++11 or later
C++11以降なら
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

C++ based API: Pros1
C++ベースのAPI：長所1
Easier to write than C
Cより書きやすい
✓ Require C++11 or later
C++11以降なら
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

C++ based API: Pros2
C++ベースのAPI：長所2
Easy to use for C API users
既存のC APIを使っている人なら使いやすい
✓ Use C directly incl macro
マクロも含めてCの機能を直接使える
✓ Don't need to migrate to all
convenient API at once
一気に書き換えるのではなく徐々に移行できる
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

C++ based API: Pros3
C++ベースのAPI：長所3
Easy to debug for C API users
既存のC APIを使っている人ならデバッグしやすい
✓ Can use GDB/LLDB directly
GDB/LLDBを直接使える
✓ GDB/LLDB have built-in C++ support
GDB/LLDBは組み込みでC++をサポート
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

C++ based API: Pros4
C++ベースのAPI：長所4
Easy to optimize
最適化しやすい
✓ [Feature #13434] better
method definition in C API
Cのメソッド定義APIの改良
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Better method definition
メソッド定義の改良
✓ Metadata for optimization
最適化のためにメタデータを付与
✓ e.g.: Reduce memory allocations
例：メモリーアロケーションを減らす
✓ Lazy method definition
必要になるまでメソッド定義を遅らせる
✓ e.g.: Reduce start-up time
例：起動時間の高速化
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Argument metadata
引数のメタデータ
class Hello
# Default argument is just for
# example. Other metadata will
# be more useful for optimization.
def hello(name, message="world")
end
end
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Argument metadata
引数のメタデータ
// C++: Rice
cHello.
define_method(
"hello",
&hello,
(Rice::Arg("name"), // ↓Default
Rice::Arg("message")="world"));
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Lazy method definition
遅延メソッド定義
class X
def a; end # Not define yet
def b; end # Not define yet
end
x = X.new
x.a # Define #a and #b
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

$Lazy method definition 遅延メソッド定義 /* One of new C API ideas */ struct rb_method_entries entries[] = { "a", ..., "b", ..., }; /* The definitions aren't defined at once. */ /* They are defined when the next method call. */ rb_define_method_with_table(rb_cX, entries); Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$ $Lazy method definition 遅延メソッド定義 // C++ implementation sample { rb::Class("X"). // Don't call rb_define_method() yet. define_method("a", ...). // Don't call rb_define_method() yet. define_method("b", ...); // Destructor is called. // Call rb_define_method_with_table() // in destructor. } Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$

Lazy method definition
遅延メソッド定義
// Ext++ implementation is just for test
rb::Class("X").
// Call rb_define_method() immediately.
define_method("a", ...).
// Don't call rb_define_method() in
// the following define_method()s.
enable_lazy_define_method().
// Don't call rb_define_method() yet.
define_method("b", ...);
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

$Lazy method definition 遅延メソッド定義 # Define only benchmark code in Ruby. # Benchmark target code is in C++. n = 10000 Bench = Class.new do n.times do |i| define_method("method#{i}") do end end end Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$ $Lazy method definition 遅延メソッド定義 # Call benchmark code in Ruby. # Benchmark target code is in C++. n = 10000 bench = Bench.new n.times do |i| bench.__send__("method#{i}") end Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$ Lazy method definition
遅延メソッド定義
Type
Normal
Lazy
Define only
5ms
1ms
Called
5ms
5ms
5x faster when any methods
aren't called
メソッドが呼ばれなければ5倍速い
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Lazy method definition
遅延メソッド定義
Type
Normal
Lazy
Define only
5ms
1ms
Called
5ms
5ms
5x faster when any methods
aren't called
メソッドが呼ばれなければ5倍速い
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

C++ based API: Cons1
C++ベースのAPI：短所1
C++ is difficult
C++は難しい
✓ e.g.: Template
たとえばテンプレート
✓ Easy to write unreadable code
簡単にリーダブルじゃないコードを書ける
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

C++ based API: Cons2
C++ベースのAPI：短所2
Slower build
ビルドが遅い
✓ It may reduce try&error cycle
試行錯誤しにくくなるかも
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

C++ based API: Problem
C++ベースのAPI：課題
Exception
例外
✓ Ruby exception breaks C++
RAII (destructor)
(Resource Acquisition Is Initialization)
Rubyの例外発生→C++のRAII（デストラクター）が動かない
✓ Because it uses setjmp/longjmp
Rubyの例外はsetjmp/longjmpを使っているから
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Exception: Solution
例外：解決法
1. Rescue Ruby exception
Rubyの例外をrescue
2. Throw C++ exception
C++の例外にしてthrow
3. Re-raise the Ruby exception
安全な場所でRubyの例外を再raise
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Conclusion
まとめ
✓ C++ based API is useful
C++ベースのAPIは便利
✓ For writing ext uses C/C++ library
C/C++のライブラリを使う拡張ライブラリを書くとき
✓ For optimizing w/ easy to use API
例：使いやすいAPIを維持したまま最適化するとき
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Appendix
付録
Introduce easy to write
extension approaches
拡張ライブラリーを簡単に実装する方法を紹介
✓ The following contents are
used only when time is
remained
以降の内容は時間が残っている場合だけ使う
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Extend language
言語を拡張
✓ Rubex: Extended Ruby
Rubex：Rubyを拡張
✓ Cython: Extended Python
Cython：Pythonを拡張
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

How to run
動かし方
✓ Translate extension code to C
拡張言語で書かれたコードをCにコンパイル
✓ Compile C code
コンパイルされたCコードをビルド
✓ Load the built extension
ビルドした拡張ライブラリーを読み込む
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Extended syntax
拡張された構文
✓ Type information
型情報を書ける
✓ C code snippet
Cのコードを書ける
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

How to run: Rubex
Rubexの動かし方
# fibonacci.rubex
class Fibonacci
# "int" is type information
def compute(int n)
# ...
end
end
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

How to run: Rubex
Rubexの動かし方
% rubex fibonacci.rubex
% cd fibonacci
% ruby extconf.rb
% make
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

How to run: Rubex
Rubexの動かし方
require_relative "fibonacci.so"
p Fibonacci.new.compute(100)
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Extend language: Pros1
拡張言語：長所1
Friendly syntax for
base language users
ベースの言語のユーザーにはなじみやすい構文
✓ Most syntax is the same
構文の大部分は同じだから
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Extend language: Pros2
拡張言語：長所2
Easy to migrate from base lang
ベースの言語からの移行が容易
✓ Because upward compatibility
上位互換だから
✓ Code for base language works
without modification
ベースの言語で書かれたコードは変更なしで動く
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Extend language: Pros3
拡張言語：長所3
Doesn't require much C knowledge
そんなにCの知識は必要ない
✓ Most code can be written with
base language knowledge
コードの大部分はベースの言語の知識で書ける
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Extend language: Cons1
拡張言語：短所1
You realize that it's not
friendly syntax when you use it
使うとそんなになじみやすい文法ではないと気づく
✓ Small differences will
confuse you
小さな違いがいろいろあってわかりにくい
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Extend language: Cons2
拡張言語：短所2
Difficult to debug
デバッグが難しい
✓ Need base language, extend
language and C knowledge
ベースの言語の知識も拡張言語の知識もCの知識も必要
Cython has GDB integration to solve this problem
Cythonはこの問題を解決するためにGDB用の便利機能を提供
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Extend language: Cons3
拡張言語：短所2
Hard to maintain
(For maintainers, not for users)
（ユーザーではなくメンテナーが）メンテナンスが大変
✓ Base language introduces a
new syntax then extend
language should implement it
ベースの言語が新しい構文を導入→拡張言語でも実装
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Not based on C
C言語以外をベースにする
✓ JRuby: Java + Ruby
✓ Helix: Rust + Ruby
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

How to run: JRuby
JRubyでの動かし方
// Fibonacci.java
public class Fibonacci {
public long[] compute(int n) {
// ...
}
}
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

How to run: JRuby
JRubyでの動かし方
% javac Fibonacci.java
% jar cf fibonacci.jar Fibonacci.class
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

How to run: JRuby
JRubyでの動かし方
require "fibonacci.jar"
java_import "Fibonacci"
p Fibonacci.new.compute(100)
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Not based on C: Pros1
C言語以外をベースにする：長所1
Easier to write than C
Cより書きやすい
✓ Simpler syntax
洗練された構文
✓ Rich features compared to C
Cより機能が多い
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Not based on C: Pros2
C言語以外をベースにする：長所2
Can use libraries
in base language
ベース言語のライブラリーを使える
✓ Major languages have many libs
広く使われている言語はライブラリーも多い
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Not based on C: Cons1
C言語以外をベースにする：短所1
Need base language knowledge
ベース言語の知識が必要
✓ Java for JRuby（JRubyならJava）
✓ Rust for Helix（HelixならRust）
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Not based on C: Cons2
C言語以外をベースにする：短所2
May need C knowledge
(When Ruby implementation is MRI)
Rubyの実装がMRIならCの知識が必要かもしれない
✓ Base language wraps Ruby C API
ベースの言語はRubyのC APIをラップしている
✓ e.g.: sys::RSTRING_PTR on Helix
例：Helixならsys::RSTRING_PTRがラップしたAPI
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Not based on C: Cons3
C言語以外をベースにする：短所3
Hard to maintain
(When Ruby implementation is MRI)
Rubyの実装がMRIならメンテナンスが大変かも
✓ Ruby introduces a new API
then base language may need
to implement it
Rubyが新しいAPIを追加→ベース言語でも実装？
✓ e.g.: rb_gc_adjust_memory_usage()
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

$How to run: Rice Riceの動かし方 #include <rice/Class.hpp> static const char * // Not VALUE! rb_sample_hello(Rice::Object self) { return "Hello"; } extern "C" void Init_sample() { Rice::define_class("Sample"). define_method("hello", &rb_sample_hello); } Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$ How to run: Rice
Riceの動かし方
# extconf.rb
require "mkmf-rice"
create_makefile("sample")
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

How to run: Rice
Riceの動かし方
# extconf.rb
require "mkmf-rice"
create_makefile("sample")
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

How to run: Rice
Riceの動かし方
% ruby extconf.rb
% make
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

How to run: Rice
Riceの動かし方
require_relative "sample.so"
p Sample.new.hello
# => "Hello"
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Provide C++ API: Pros
C++ APIを提供：長所
Omit
省略
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Provide C++ API: Cons
C++ APIを提供：短所
Omit
省略
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

Provide C++ API: ConsN
C++ APIを提供：短所N
Conv from Ruby may be a bother
Ruby実装の移植が面倒
✓ C++ with convenient Ruby C
API needs more code than Ruby
RubyのC APIにC++の便利APIがあっても
Rubyよりもたくさんコードが必要
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

From Ruby: Rice
RubyからRiceに移植
def fib(n)
prev = 1
current = 1
1.step(n - 1).collect do
prev, current = current, current + prev
prev
end
end
Improve extension API - C++ as better language for extension
Powered by Rabbit 2.2.2

$From Ruby: Rice RubyからRiceに移植 std::vector<uint64_t> fib(Rice::Object self, int n) { uint64_t prev = 1, current = 1; std::vector<uint64_t> numbers; for (int i = 1; i < n; ++i) { auto temp = current; current += prev; prev = temp; numbers.push_back(prev); } return numbers; } Improve extension API - C++ as better language for extension Powered by Rabbit 2.2.2$