Latest from ChinaonRails: bd7lx

jruby-prof 往深里刨 ... no reply

bd7lx — Mon, 15 Mar 2010 10:04:13 +0800

http://danlucraft.com/blog/2010/03/jruby-prof/

参考ruby-prof
http://chinaonrails.com/q/ruby-prof

里面提到了著名的Java 性能探查工具yourkit

草坪躺椅Lawnchair - Client-side JSON document store ... no reply

bd7lx — Fri, 12 Mar 2010 13:50:35 +0800

http://brianleroux.github.com/lawnchair/

沙发couchdb引发各类文档式数据库横空出世

比couch要小更加简便

Perfect for webkit mobile apps that need a lightweight, simple and elegant persistence solution.

DHH合作的新书Rework，有人说读此书比MBA的创业课程更实用 ... 1 reply

bd7lx — Wed, 10 Mar 2010 16:50:12 +0800

http://37signals.com/rework/

节选下载
http://s3.amazonaws.com/37assets/svn/Rework-by-Jason-Fried-and-David-Heinemeier-Hansson-Excerpts.pdf

里面充斥着颠覆传统商业运作的诳语：
会议是毒药，创业起步找个对头单挑，计划就是瞎猜

不太理解的还有
不用尽全力去竞争Underdo your competition（体现在产品功能上不必求大而全多而杂）

程序员上火怎么办Programmers: What To Do If You Get Fired ... 3 replies

bd7lx — Wed, 10 Mar 2010 10:33:05 +0800

http://gilesbowkett.blogspot.com/2010/03/programmers-what-to-do-if-you-get-fired.html

不是靠喝汽水能解决的

主要探讨的还是声誉创造机会和财富

gemsday 每周gem秀 ... no reply

bd7lx — Mon, 08 Mar 2010 08:38:44 +0800

http://gemsday.org/

Share your favorite new RubyGems weekly. Tweet #gemsday and a list of gems on Wed!

JRuby Startup Time Tips 启动提速贴士 ... no reply

bd7lx — Tue, 02 Mar 2010 09:08:12 +0800

http://blog.headius.com/2010/03/jruby-startup-time-tips.html

说道选什么JVM

据说Oracle收了SUN后要把旗下两个JVM合成一个

下面的client backend需要留意

most JVM installs preferred the "client" backend, which meant JVM startup was about as fast as it could get. Unfortunately, many newer JVM releases on many operating systems are either defaulting to "server" or defaulting to a 64-bit JVM (which only has "server")

http://chinaonrails.com/topic/view/2934.html

New Relic 副总裁讲解 “应用性能指数”如何反映用户满意程度 ... no reply

bd7lx — Thu, 25 Feb 2010 17:16:25 +0800

http://blog.newrelic.com/2010/02/17/new-relic-ceo-lew-cirne-discusses-how-apdex-reveals-user-frustration-with-your-web-experience/

作为Apdex联盟之一，New Relic在丰富监控新兴各种服务器和架构的服务线同时，不遗余力地推广其客户满意程度的测量理念
http://www.rubyinside.com/new-relic-rpm-officially-supports-rack-and-sinatra-finally-3014.html

Apdex联盟，一个由众多网络分析技术公司和测量工业组成的联盟组织，它们联合起来开发了“应用性能指数”即“Apdex”(Application Performance Index)，用一句话来概括，Apdex是用户对应用性能满意度的量化值。它提供了一个统一的测量和报告用户体验的方法，第一次把最终用户的体验和应用性能联系在了一起。

http://hi.baidu.com/gimn/blog/item/cfcead3e37b4563571cf6cfb.html

不能说New Relic太张狂，只能怨FiveRuns死的太快
http://chinaonrails.com/topic/view/282.html

iPad 托管主机服务？你舍得吗 ... no reply

bd7lx — Thu, 25 Feb 2010 09:06:51 +0800

http://www.ipadcolo.net/
ipadcolo.net 这家公司提供的服务是：
host iPads to be used as web servers, mail servers, or whatever else you'd like.

其实就是负责帮你每天充电

他们早在mac mini刚刚出来的时候就提供过hosting的服务
其承诺网络速度不会有问题，又有当地3G后备
但ipad不支持多任务，如何遥控其服务停下来并重新启动呢？

有招：他们有一指功

读Sybase Advantage Database Server 文件的Ruby-ADT Gem ... no reply

bd7lx — Wed, 24 Feb 2010 17:11:26 +0800

http://chase.ratchetsoftware.com/2010/02/reading-advantage-database-server-files-adt-in-ruby/

Advantage Database Server 是一款功能全面的高性能客户端/服务器数据管理系统，专为满足商业应用程序开发人员的需求而设计。Advantage 在 Sybase 数据库产品中是独一无二的，原因在于它同时提供了对基于 ISAM（Indexed Sequential Access Method，索引顺序访问方法）表的数据和基于 SQL 的数据的访问，从而为旧数据库应用程序提供了一条迈向现代技术的发展之路。
优点

可通过本机关系 SQL 或直接的数据库导航命令进行灵活的数据访问。
数据访问经过优化，适用于所有开发环境，包括 Delphi、Visual Studio、Visual Objects、Visual Basic 等。
零管理，易于安装和控制 — 无需数据库管理员，从而消除了高昂的管理成本。
完整的参照完整性支持，包括主键/外键定义和级联的更新及删除。
基于服务器的完整的事务处理可避免数据库损坏，因此将大幅减少支持成本。
数据库安全性和加密支持。
一组源代码适用于本地、对等以及客户端/服务器环境 — 全面的可伸缩性。

http://github.com/chasemgray/Ruby-ADT
目前该ruby库只能读adt格式

require 'adt'

table = ADT::Table.new("test.adt")

table.each do |record|
puts record.name
puts record.email
end

有读foxpro的插件吗？
http://github.com/infused/dbf

DBF is a small fast Ruby library for reading dBase, xBase, Clipper and FoxPro database files

jruby能运行rails3吗？最新版本肯定行 ... no reply

bd7lx — Wed, 24 Feb 2010 16:42:19 +0800

http://blog.nicksieger.com/articles/2010/02/24/jruby-and-rails-3-sitting-in-a-tree

activerecord-jdbc-adapter 0.9.3 Released 支持rails3而来

jQuery Simple Multi-Select 点点即多选 ... no reply

bd7lx — Wed, 24 Feb 2010 10:55:19 +0800

http://ethanmiller.name/notes/jquery_simplemultiselect/

1.3以上

http://grover.open2space.com/node/247

jQuery Multiselect list plugin

http://www.erichynds.com/jquery/jquery-multiselect-plugin-with-themeroller-support/

http://www.erichynds.com/jquery/jquery-multiselect-plugin-with-themeroller-support/

rake和ant共建 ... no reply

bd7lx — Tue, 23 Feb 2010 13:46:30 +0800

沾上了想甩了就没那么容易，现实地折中是个不错的策略

http://www.engineyard.com/blog/2010/rake-and-ant-together-a-pick-it-n-stick-it-approach/

集成rake和ant 场景
JRuby’s Rake and Ant integration handles the following use cases:

Call any ant task or type from within Rake
Allow Rake to be invoked from within Ant
Allow Rake tasks to be imported as callable Ant targets
Allow Ant to be invoked from Rake
Allow Ant targets to be called as Rake tasks from within Rake

Rails 3 Upgrade Handbook 美刀12 ... no reply

bd7lx — Tue, 23 Feb 2010 12:37:18 +0800

http://www.railsupgradehandbook.com/

趁rails3刚出锅，赚快钱

还有新书
the Live Edition will include the Rails 3.x versions

http://broadcast.oreilly.com/2010/02/a-live-edition-for-learning-ra.html

作者在其博客omgbloglol 上传播rails3新知，声名鹊起

阶乘有不止一种写法，利用ruby的特性，奥妙各不相同 ... no reply

bd7lx — Wed, 17 Feb 2010 16:07:52 +0800

http://gist.github.com/295352

有多少种写法，还能怎么写

def factorial(x)
if x == 0
return 1
else
return x * factorial(x - 1)
end
end
puts factorial(6)
puts factorial(0)

# Discovered #upto
def factorial(x)
factorial = 1
1.upto(x) do |i|
factorial *= i
end
factorial
end
puts factorial(6)
puts factorial(0)

# Discovered Enumerators
def factorial(x)
x.downto(1).inject(1) { |m, i| m * i }
end
puts factorial(6)
puts factorial(0)

# Discovered Range+Inject
def factorial(x)
(1..x).inject(1) { |m, i| m * i }
end
puts factorial(6)
puts factorial(0)

# Embraced 1.8.7/1.9
def factorial(x)
(1..x).inject(:*) || 1
end
puts factorial(6)
puts factorial(0)

# Discovered Ternary Operators
def fac(x); x == 0 ? 1 : x * fac(x - 1);end
puts fac(6)
puts fac(0)

# Discovered Operator Precedence
def factorial(x)
i = 1 and (i *= x and x -= 1 while x > 0) or i
end
puts factorial(6)
puts factorial(0)

# Discovered Rails
class Numeric
def fact
(1..self).inject(:*) || 1
end
end
puts 6.fact
puts 0.fact

# Discovered Camping
def F(x)((1..x).inject(:*)||1)end;p(F(6));p(F(0))

# Discovered Magic
module Math
extend self

def method_missing(method, *args)
if method.to_s =~ /^fact(orial)?/
class_eval <<-EOS
def #{method}(x)
(1..x).inject(:*) || 1
end
EOS
send(method, *args)
else
super
end

end
end
puts Math.fact(6)
puts Math.fact(0)

# Discovered Hash Magic
FACTORIALS = Hash.new { |h, k| h[k] = (1..k).inject(:*) || 1 }
puts FACTORIALS[6]
puts FACTORIALS[0]

# Attends Seattle.rb
require 'rubygems'
require 'inline'
class Factorial
class << self
inline do |builder|
builder.c %q{
long factorial(int value) {
long result = 1, i = 1;
for (i = 1; i <= value; i++) {
result *= i;
}
return result;
}
}
end
end
end
puts Factorial.factorial(6)
puts Factorial.factorial(0)

# Premature Optimizer + eval
class << self; class_eval "def factorial(x); case x; #{(0..100).map{|i|"when #{i} then #{(1..i).inject(:*) || 1};"}}; else (1..x).inject(:*) || 1 end end" end
puts factorial(6)
puts factorial(0)

1.8.7的枚举技巧待一小会儿take_while 和 drop_while过了一小会儿 ... no reply

bd7lx — Wed, 17 Feb 2010 11:55:11 +0800

http://www.aimred.com/news/developers/2010/02/14/neat_ruby_tricks_take_while_and_drop_while/

[ 1, 2, 5, 4, 3 ].take_while{ |num| num < 5 }
=> [1, 2]

[ 1, 2, 5, 4, 3 ].drop_while{ |num| num < 5 }
=> [5, 4, 3]

http://chinaonrails.com/topic/view/2032.html

http://www.globalnerdy.com/2008/08/01/enumerating-enumerable-enumerableeach_with_index/

超级模特supermodel：与AR相配的内存数据库 ... no reply

bd7lx — Wed, 17 Feb 2010 10:27:39 +0800

http://github.com/maccman/supermodel

如果你还记得曾经提到过的桌面开发-绳结Bowline

http://chinaonrails.com/topic/view/3209.html

Simple in-memory database using ActiveModel.

Primarily developed for Bowline applications.
http://github.com/maccman/bowline

当内存数据库来用的ruby库，sequel可能会有点心不甘

http://chinaonrails.com/topic/view/1691.html

海港harbor：新框架招商 ... no reply

bd7lx — Tue, 16 Feb 2010 10:17:16 +0800

http://wiecklabs.com/

git clone git://github.com/wiecklabs/harbor
git checkout -b 0.18.4 0.18.4
rake install

Harbor 是Ruby 做的新框架来拯救开发人员的负担

海港里面有港口

利用港口 ports 现成的应用，重组配置集成多个应用，就获得成为自己的码头

现在已经有开发出来的港口有

http://wiecklabs.com/marketplace

Buzzr: 让谷歌嗡嗡叫 ... no reply

bd7lx — Fri, 12 Feb 2010 08:28:02 +0800

Buzzr: Google Buzz Library For Ruby

http://github.com/conorh/buzzr

A simple wrapper to help retrieve and parse the Google Buzz Atom Feed.

安装
gem install buzzr

Buzzr is hosted on the Gemcutter repository. 依赖 RAtom library - http://github.com/seangeo/ratom

Google Buzz发布会上着重介绍的功能之一就是所谓的“自动跟随”系统，Buzz会自动将你经常写信或聊天的人加入好友列表里，这对一些人来说可能会是不合的导火索。

http://chinaonrails.com/topic/view/3012.html

也可以一键关停，不让它吱啦哇嘞叫

rake db：size 获得数据库及表的大小 ... no reply

bd7lx — Tue, 09 Feb 2010 14:06:04 +0800

使用在mysql和postgresql

http://gist.github.com/296719

# Run rake db:size to get a print of your database size in bytes.
# Run rake db:tables:size to get the sizes for individual tables
# Works for MySQL and PostgreSQL. Not tested elsewhere.

namespace :db do
desc 'Print data size for entire database'
task :size => :environment do

database_name = ActiveRecord::Base.connection.instance_variable_get("@config")[:database]
adapter = ActiveRecord::Base.connection.adapter_name.downcase
case adapter
when "mysql"
sql = "select FORMAT(SUM(data_length + index_length), 0) as bytes from information_schema.TABLES where table_schema = '#{database_name}'"
puts ActiveRecord::Base.connection.execute(sql).fetch_hash.values.first
when "postgres", "postgresql"
sql = "SELECT pg_size_pretty(pg_database_size('#{database_name}'));"
puts ActiveRecord::Base.connection.execute(sql)[0]["pg_size_pretty"]
when "oracle", "oci"
sql = "select a.data_size+b.temp_size+c.redo_size+d.controlfile_size from ( select sum(bytes) data_size from dba_data_files) a, ( select nvl(sum(bytes),0) temp_size from dba_temp_files ) b, ( select sum(bytes) redo_size from sys.v_$log ) c, ( select sum(BLOCK_SIZE*FILE_SIZE_BLKS) controlfile_size from v$controlfile) d;"
puts ActiveRecord::Base.connection.execute(sql).fetch_hash.values.first
else
raise "#{adapter} is not supported"
end
end

namespace :tables do
desc 'Print data size for all tables'
task :size => :environment do

database_name = ActiveRecord::Base.connection.instance_variable_get("@config")[:database]
adapter = ActiveRecord::Base.connection.adapter_name.downcase
case adapter
when "mysql"
sql = "select TABLE_NAME, FORMAT((data_length + index_length), 0) as bytes from information_schema.TABLES where table_schema = '#{database_name}' ORDER BY (data_length + index_length) DESC"
result = ActiveRecord::Base.connection.execute(sql)
while (row = result.fetch_hash) do
puts "#{row['TABLE_NAME']} #{row['bytes']}"
end
when "postgres", "postgresql"
sql = "SELECT tablename FROM pg_tables WHERE schemaname = 'public' ORDER BY tablename;"
tables = ActiveRecord::Base.connection.execute(sql)
tables.each do |table|
name = table['tablename']
sql = "SELECT pg_size_pretty(pg_total_relation_size('#{name}'));"
res = ActiveRecord::Base.connection.execute(sql)
puts "#{name} #{res[0]['pg_size_pretty']}"
end
else
raise "#{adapter} is not supported"
end
end
end
end

rails server之后发生了什么？ rails3代码启动过程代码分析 ... no reply

bd7lx — Tue, 09 Feb 2010 13:40:24 +0800

http://ryanbigg.com/guides/initialization.html

目前很多网站的头header上都打着导游guides的旗号

The Rails Initialization Process
This guide explains how the initialization process in Rails works as of Rails 3.

rails改变了命令行的习惯，对windows的用户不友好，没有顾忌他们的感受

Using rails server
Using Passenger