luikore

Mysql doesn't auto lock or version lock records when select in repeatable read transactions. While PG can forbid concurrent updates.

The test table DDL in PG:

create table articles (
  "id" serial,
  "n" integer
);

luikore

/*

benchmark with gtime -f "%M"

pool alloc:

time: 0.028571
22331392

malloc:

luikore

// Use Gists to store code you would like to remember later on
console.log(window); // log the "window" object to the console

luikore

# need to install ghostscript first
pdf-shrink() {
  if [[ -e $1 ]]; then
    gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dQUIET -dBATCH -sOutputFile=$2 $1
  else
    echo 'usage: pdf-shrink in.pdf out.pdf'
  fi
}

luikore

def cn_id_verify id, gender=nil
  return false if id !~ /\A\d{17}[\dX]\z/i
  r = 0
  x = 1
  id.chars.take(17).reverse_each {|a|
    x = (x * 2) % 11
    r += a.to_i * x
  }
  last = (12 - r % 11)
  last = 'X' if last == 10

luikore

gist is...

the way to markdown

• and so you can edit/delete post

luikore

# generate a regexp for match full-width characters
# data from 
#
# A         ; Ambiguous    不确定
# F         ; Fullwidth    全宽
# H         ; Halfwidth    半宽
# N         ; Neutral      中性
# Na        ; Narrow       窄
# W         ; Wide         宽
#

luikore

require 'state_machine'
class StateMachine::Machine
  def par_event events, test_field, trans
    i = 1
    # binary 11....1
    full = (1 << events.size) - 1
    events.each do |e|
      j = i
      event e do
        transition(hash.merge(:if => (lambda{ |obj|

luikore

# 99 bottles of beer
class Fixnum
  def bottle
    "#{self} bottles of beer".
      sub(/^-1/,'99').
      sub(/^0/,'no more').
      sub(/^(1\ .+)s/, '\1')
  end
  def wall
    "#{self.bottle} on the wall"

luikore

# state lexer

require 'strscan'

class StateLexer
  attr_reader :state

  class ScanError < StandardError; end

  def initialize opts = {:states => []}