asp 缓存实现教程代码

<%
class Cache
 private obj   'cache内容
 private expireTime  '过期时间
 private expireTimeName '过期时间application名
 private cacheName  'cache内容application名
 private path   'url
 
 private sub class_initialize()
  path=request.servervariables("url")
  path=left(path,instrRev(path,"/top/cache/"))
 end sub
 
 private sub class_terminate()
 end sub
 
 public property get blEmpty
  '是否为空
  if isempty(obj) then
   blEmpty=true
  else
   blEmpty=false
  end if
 end property
 
 public property get valid
  '是否可用(过期)
  if isempty(obj) or not isDate(expireTime) then
   valid=false
  elseif CDate(expireTime)     valid=false
  else
   valid=true
  end if
 end property
 
 public property let name(str)
  '设置cache名
  cacheName=str & path
  obj=application(cacheName)
  expireTimeName=str & "expires" & path
  expireTime=application(expireTimeName)
 end property
 
 public property let expires(tm)
  '重设置过期时间
  expireTime=tm
  application.lock
  application(expireTimeName)=expireTime
  application.unlock
 end property
 
 public sub add(var,expire)
  '赋值
  if isempty(var) or not isDate(expire) then
   exit sub
  end if
  obj=var
  expireTime=expire
  application.lock
  application(cacheName)=obj
  application(expireTimeName)=expireTime
  application.unlock
 end sub
 
 public property get value
  '取值
  if isempty(obj) or not isDate(expireTime) then
   value=null
  elseif CDate(expireTime)    value=null
  else
   value=obj
  end if
 end property
 
 public sub makeEmpty()
  '释放application
  application.lock
  application(cacheName)=empty
  application(expireTimeName)=empty
  application.unlock
  obj=empty
  expireTime=empty
 end sub
 
 public function equal(var2)
  '比较
  if typename(obj)<>typename(var2) then
   equal=false
  elseif typename(obj)="Object" then
   if obj is var2 then
    equal=true
   else
    equal=false
   end if
  elseif typename(obj)="Variant()" then
   if join(obj,"^")=join(var2,"^") then
    equal=true
   else
    equal=false
   end if
  else
   if obj=var2 then
    equal=true
   else
    equal=false
   end if
  end if
 end function
end class
%>