<%
'**********************************************
'vbs Cache类
' 属性valid，是否可用，取值前判断
' 属性name，cache名，新建对象后赋值
' 方法add(值,到期时间)，设置cache内容
' 属性value，返回cache内容
' 属性blempty，是否未设置值
' 方法makeEmpty，释放内存，测试用
' 方法equal(变量1)，判断cache值是否和变量1相同
' 方法expires(time)，修改过期时间为time
' 木鸟写的缓存类
'**********************************************
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 'uri
private sub class_initialize()
path=request.servervariables("url")
path=left(path,instrRev(path,"/"))
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)<now then
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)<now then
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
dim content,myCache
Set myCache = new Cache
myCache.name="sofoisndoffo" '定义缓存名称
if myCache.valid then '如果缓存有效
content=myCache.value '读取缓存内容
else
content="sosuo8.com测试" '大量内容，可以是非常耗时大量数据库查询记录集
myCache.add content,dateadd("n",1000,now) '将内容赋值给缓存，并设置缓存有效期是当前时间＋1000分钟
end if
Response.Write(content)
'myCache.makeEmpty()
set clsCache=nothing '释放对象
%>