#!/usr/bin/env python
# -*- coding:utf-8 -*-
#
#  Author :  cold
#  E-mail :  wh_linux@126.com
#  Date  :  13/01/14 09:57:31
#  Desc  :  
#
import config
import pylibmc
from tornado.web import RequestHandler
#### 省略Cache类定义 #####

class Memcached(object):
  _mc = pylibmc.client.Client(config.CACHE_HOST, binary = True)

  def __enter__(self):
    if config.CACHED:
      return Memcached
    else:
      return Cache()

  def __exit__(self, exc_type, exc_val, exc_tb):
    pass

  @classmethod
  def get_cache(cls):
    return cls._mc

  @classmethod
  def get(cls, key, default = None):
    r = cls._mc.get(key)
    if not r:
      r = default
    return r

  @classmethod
  def set(cls, key, value, timeout = 0):
    timeout = timeout if timeout else config.CACHE_TIMEOUT
    return cls._mc.set(key, value, timeout)

  @classmethod
  def delete(cls, key):
    return cls._mc.delete(key)

  @classmethod
  def flush(cls):
    return cls._mc.flush_all()

  def __getattr__(self, key):
    return Memcached.get(key)

  def __setattr__(self, key, value):
    return Memcached.set(key, value)


class BaseHandler(RequestHandler):
  """ 继承tornado请求基类,重写 prepare和on_finish方法 """
  cache = Memcached

  def render(self, template_path, *args, **kwargs):
    """ 渲染模板 """
    # 省略渲染模板代码
    content = ''   # 渲染模板后的内容
    if self.request.method == "GET" and CACHED and \
      not self.request.path.startswith("/admin"):
      self.cache.set(self.request.uri, content) # 将渲染后的内容缓存起来
    self.write(content)

  def prepare(self):
    super(BaseHandler, self).prepare()
    # 如果请求是GET方法,而且不是请求后台
    if self.request.method == "GET" and CACHED and \
      not self.request.path.startswith("/admin"):

      # 尝试获取当前页面的缓存
      cache = self.cache.get(self.request.uri)
      # 获取缓存则输出页面,结束请求
      if cache:
        return self.finish(cache)

  def on_finish(self):
    """ 重写结束请求前的方法函数 """
    if self.request.method == "POST":
      # 如果遇到POST提交则清空缓存
      self.cache.flush()

$ webbench -c 500 -t 30 http://www.linuxzen.com/
Webbench - Simple Web Benchmark 1.5
Copyright (c) Radim Kolar 1997-2004, GPL Open Source Software.

Benchmarking: GET http://www.linuxzen.com/
500 clients, running 30 sec.

Speed=54 pages/min, 38160 bytes/sec.
Requests: 27 susceed, 0 failed.

$ webbench -c 500 -t 30 http://www.linuxzen.com/
Webbench - Simple Web Benchmark 1.5
Copyright (c) Radim Kolar 1997-2004, GPL Open Source Software.

Benchmarking: GET http://www.linuxzen.com/
500 clients, running 30 sec.

Speed=256 pages/min, 238544 bytes/sec.
Requests: 128 susceed, 0 failed.