昨日はCでMySQLのUDFを作ってみたんだけど、今日はRubyで作ってみる。Rubyと言ってもmrubyだけど。
mrubyは5年ぶりくらいに使ってみたんだけど、相変わらずドキュメントが少なくてなかなかつらい…。
まず mruby のビルド。MySQLのUDFは共有ライブラリにしないといけないので、パッチをあてて make。
% git clone git@github.com:mruby/mruby.git % cd mruby % patch -p1 < /path/to/mruby-shared.patch % make
mruby-shared.patch はこれ
diff --git a/build_config.rb b/build_config.rb index 254a28ce..310191e3 100644 --- a/build_config.rb +++ b/build_config.rb @@ -35,6 +35,10 @@ MRuby::Build.new do |conf| # cc.compile_options = %Q[%{flags} -MMD -o "%{outfile}" -c "%{infile}"] # end + conf.cc do |cc| + cc.flags = '-fPIC' + end + # mrbc settings # conf.mrbc do |mrbc| # mrbc.compile_options = "-g -B%{funcname} -o-" # The -g option is required for line numbers @@ -59,6 +63,11 @@ MRuby::Build.new do |conf| # archiver.archive_options = 'rs "%{outfile}" %{objs}' # end + conf.archiver do |archiver| + archiver.command = 'gcc' + archiver.archive_options = '-shared -o %{outfile} %{objs}' + end + # Parser generator settings # conf.yacc do |yacc| # yacc.command = ENV['YACC'] || 'bison' diff --git a/lib/mruby/build.rb b/lib/mruby/build.rb index 8154b2b1..80f0b782 100644 --- a/lib/mruby/build.rb +++ b/lib/mruby/build.rb @@ -61,7 +61,7 @@ module MRuby if ENV['OS'] == 'Windows_NT' @exts = Exts.new('.o', '.exe', '.a') else - @exts = Exts.new('.o', '', '.a') + @exts = Exts.new('.o', '', '.so') end build_dir = build_dir || ENV['MRUBY_BUILD_DIR'] || "#{MRUBY_ROOT}/build"
関数のメインのRubyスクリプト fib.rb
LONG_LONG_MAX = 9223372036854775807 def fib(n) b = 1 c = 0 n.times do a, b = b, c c = a + b raise 'Overflow' if c > LONG_LONG_MAX end c end
一応ちゃんと動くか確認
% /path/to/mruby/bin/mruby -r./fib.rb -e 'p fib(10)'
55
% /path/to/mruby/bin/mruby -r./fib.rb -e 'p fib(100)'
trace (most recent call last):
[2] -e:1
[1] -e:6:in fib
-e:9:in fib: Overflow (RuntimeError)
mrubyバイトコードにコンパイル。
% /path/to/mruby/bin/mrbc -Bfib_mrb fib.rb
バイトコードが埋め込まれた fib.c が出来る。内容はこんなの。
/* dumped in little endian order. use `mrbc -E` option for big endian CPU. */ #include <stdint.h> #ifdef __cplusplus extern const uint8_t fib_mrb[]; #endif const uint8_t #if defined __GNUC__ __attribute__((aligned(4))) #elif defined _MSC_VER __declspec(align(4)) #endif fib_mrb[] = { 0x45,0x54,0x49,0x52,0x30,0x30,0x30,0x36,0x64,0x45,0x00,0x00,0x01,0x5f,0x4d,0x41, 0x54,0x5a,0x30,0x30,0x30,0x30,0x49,0x52,0x45,0x50,0x00,0x00,0x01,0x0e,0x30,0x30, 0x30,0x32,0x00,0x00,0x00,0x96,0x00,0x01,0x00,0x03,0x00,0x01,0x00,0x00,0x00,0x14, 0x02,0x01,0x00,0x1c,0x01,0x00,0x61,0x01,0x56,0x02,0x00,0x5d,0x01,0x01,0x0e,0x01, 0x01,0x37,0x01,0x67,0x00,0x00,0x00,0x01,0x01,0x00,0x13,0x39,0x32,0x32,0x33,0x33, 0x37,0x32,0x30,0x33,0x36,0x38,0x35,0x34,0x37,0x37,0x35,0x38,0x30,0x37,0x00,0x00, 0x00,0x02,0x00,0x0d,0x4c,0x4f,0x4e,0x47,0x5f,0x4c,0x4f,0x4e,0x47,0x5f,0x4d,0x41, 0x58,0x00,0x00,0x03,0x66,0x69,0x62,0x00,0x00,0x00,0x00,0x72,0x00,0x05,0x00,0x07, 0x00,0x01,0x00,0x00,0x00,0x14,0x00,0x00,0x33,0x04,0x00,0x00,0x07,0x03,0x06,0x04, 0x01,0x05,0x01,0x55,0x06,0x00,0x2f,0x05,0x00,0x00,0x37,0x04,0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x01,0x00,0x05,0x74,0x69,0x6d,0x65,0x73,0x00,0x00,0x00,0x01,0x31, 0x00,0x03,0x00,0x06,0x00,0x00,0x00,0x00,0x00,0x3d,0x00,0x00,0x33,0x00,0x00,0x00, 0x1f,0x03,0x03,0x00,0x1f,0x04,0x04,0x00,0x01,0x02,0x03,0x20,0x04,0x03,0x00,0x01, 0x03,0x02,0x1f,0x04,0x03,0x00,0x3b,0x03,0x20,0x03,0x04,0x00,0x1f,0x03,0x04,0x00, 0x1b,0x04,0x00,0x44,0x03,0x23,0x03,0x00,0x39,0x10,0x03,0x4f,0x04,0x00,0x2e,0x03, 0x01,0x01,0x21,0x00,0x3b,0x0f,0x03,0x37,0x03,0x00,0x00,0x00,0x01,0x00,0x00,0x08, 0x4f,0x76,0x65,0x72,0x66,0x6c,0x6f,0x77,0x00,0x00,0x00,0x02,0x00,0x0d,0x4c,0x4f, 0x4e,0x47,0x5f,0x4c,0x4f,0x4e,0x47,0x5f,0x4d,0x41,0x58,0x00,0x00,0x05,0x72,0x61, 0x69,0x73,0x65,0x00,0x4c,0x56,0x41,0x52,0x00,0x00,0x00,0x33,0x00,0x00,0x00,0x05, 0x00,0x01,0x6e,0x00,0x01,0x26,0x00,0x01,0x62,0x00,0x01,0x63,0x00,0x01,0x61,0x00, 0x00,0x00,0x01,0x00,0x01,0x00,0x02,0x00,0x02,0x00,0x03,0x00,0x03,0x00,0x04,0x00, 0x01,0x00,0x01,0x00,0x04,0x00,0x02,0x45,0x4e,0x44,0x00,0x00,0x00,0x00,0x08, };
MySQLのUDFからfibメソッドを実行するためのファイル fib_udf.c を作成。
#include <stdio.h> #include <string.h> #include "mruby.h" #include "mruby/string.h" #include "mruby/irep.h" #include "mysql.h" extern const uint8_t fib_mrb[]; bool fib_init(UDF_INIT *initid, UDF_ARGS *args, char *message) { if (args->arg_count != 1) { // 引数が1個じゃなければエラー strcpy(message, "fib() requires one argument"); return true; } args->arg_type[0] = INT_RESULT; // 引数は整数に自動変換する mrb_state *mrb = mrb_open(); if (!mrb) { // mruby 初期化でエラーになった strcpy(message, "mrb_open() error"); return true; } initid->ptr = (void *)mrb; mrb_load_irep(mrb, fib_mrb); if (mrb->exc) { // mrb 実行でエラーになった // 例外オブジェクトを inspect mrb_value s = mrb_funcall(mrb, mrb_obj_value(mrb->exc), "inspect", 0); // C文字列化 const char *cs = mrb_string_value_cstr(mrb, &s); // MySQLのエラーメッセージに設定 strncpy(message, cs, MYSQL_ERRMSG_SIZE); // 標準エラー出力にも書き出し fprintf(stderr, "%s\n", cs); return true; } return false; } void fib_deinit(UDF_INIT *initid) { mrb_state *mrb = (mrb_state *)initid->ptr; if (mrb) { mrb_close(mrb); } } long long fib(UDF_INIT *initid, UDF_ARGS *args, char *is_null, char *error) { mrb_state *mrb = (mrb_state *)initid->ptr; long long n = *((long long *)args->args[0]); // トップレベルの fib メソッド呼び出し mrb_value ret = mrb_funcall(mrb, mrb_top_self(mrb), "fib", 1, mrb_fixnum_value(n)); if (mrb->exc) { // 例外が発生した // 例外オブジェクトを inspect mrb_value s = mrb_funcall(mrb, mrb_obj_value(mrb->exc), "inspect", 0); // 標準エラー出力に書き出し fprintf(stderr, "fib(%lld): %s\n", n, mrb_string_value_cstr(mrb, &s)); // 戻り値は NULL *is_null = true; return 0; } // Integerオブジェクトを long long に変換して返す return mrb_fixnum(ret); }
コンパイル。
LD_RUN_PATH=/path/to/mruby/build/host/lib gcc -shared -fPIC -I /usr/local/mysql/include -I /path/to/mruby/include fib_udf.c fib.c -L /path/to/mruby/build/host/lib -lmruby -lm -o fib.so
配置。既に同じ名前のファイルを使ってた場合は、mysql で drop function fib してからじゃないと、mysqld が落ちるので注意。
% sudo cp fib.so /usr/local/mysql/lib/plugin/
使う。
% mysql -uroot mysql> create function fib returns integer soname 'fib.so'; Query OK, 0 rows affected (0.03 sec) mysql> select fib(10); +---------+ | fib(10) | +---------+ | 55 | +---------+ 1 row in set (0.04 sec) mysql> select fib(100); +----------+ | fib(100) | +----------+ | NULL | +----------+ 1 row in set (0.03 sec)
オーバーフローが起きた場合はエラーログに出力される。
fib(100): Overflow (RuntimeError)
