Cassandra in Action with Twitter's Ruby Client
有一个全新的项目,因为考虑到将来的数据扩展性能,所以考虑用Cassandra做数据存储,前端用Lighttpd + FastCGI + Rails。在使用Cassandra的时候,觉得有一些东西可能大家都需要,就写了一个简单的指南。因为内容比较长(16页),就弄了个PDF文件给大家下载。
Cassandra in Action with Twitter's Ruby Client.pdf
如果下载链接有问题,请给我邮件:spanzhang@gmail.com。需要说明一下的是,这个指南是用英语写的,不过都是些很简单的句子,相信有四级英语就可以毫不费力的看明白。下面把文章的引文放这里,供大家参考,你可以看看适不适合你的需要:
Okay, let me get something straight. I’m not going to persuade you to use Cassandra. I just assume you have already chosen Cassandra as your storage solution. Maybe you know the basic things, the underneath mechanisms, about Cassandra or maybe not. Anyway, I assume you don’t care what makes Cassandra outstanding and you just want to use it. If that’s the case, this tutorial is going to help you, in these 3 aspects:
1) to set up the environment correctly,
2) to understand how to model you data in a Cassandra way,
3) to understand and use Twitter’s Cassandra Ruby client.
After reading this tutorial, you should have a working environment and can start your project with a good understanding of doing your job in a very Cassandra way. Here we go!
相关文档:
我们知道ruby中对于整数的[],[]=,<<,>>操作是针对于二进制的值来运算的。
我现在写一个针对十进制数操作的类,拥有整数的所有方法,如下:
class InterEx
def initialize(val=0)
@val=val
end
def to_s
@val.to_s
end
def [](idx)
self.to_s[idx].to_i
end
d ......
require 'curses'
module Curses
def self.program
main_scr=init_screen
noecho
cbreak
curs_set(0)
main_scr.keypad=true
yield main_scr
end
end
Curses.program do |scr|
max_x=scr.maxx
max_y=scr.maxy
100.times do
scr.setpos(rand(max_y),rand(max_x))
......
Ruby 类的继承
关键字: Ruby 类的继承
一、普通方式的继承
Ruby只支持单继承
ruby 代码
class
Child < Father
......
end
Object是所有类的始祖,并且Object的实例方法 ......
Ruport是一个免费的Ruby报表工具,它可以令到制作报表软件变得简单一些。Ruport支持从文件或者数据库获得数据,提供工具操作数据。额外地,Ruport支持高扩展的格式化软件,目前能够支援HTML、PDF、CSV和文本输出。
Ruport可能是Ruby目前唯一的报表工具,目前在持续开发中,更多的新特性正在添加。
安装方法:
gem instal ......
%{String} 用于创建一个使用双引号括起来的字符串
%Q{String} 用于创建一个使用双引号括起来的字符串
%Q!Some String of “Characters”! <==> ” Some String of \”Characters\” “
%q{String} 用于创建一个使用单引号括起来的字符串
%q!Som ......