至于缓存的作用，我想我也不用再多说了，它的作用已经很明显，特别是对于信息量非常大或是全数据库页面的网站，他能很好地利用主机的内存资源，加速ASP的执行效率，减轻服务器的负担，而动网在这一方面做得是最突出的，像他现在的dvbbs7.1.0版，更是在缓存的利用上更上一层楼，前后台大多的操作都和缓存有关，而现在动网里用的也就是迷城浪子的缓存类，下面列出动网的三大高手写的ASP缓存类
木鸟写的
＇**********************************************
＇ 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 2002.12.24
＇ http://www.aspsky.net/
＇**********************************************
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
木鸟 类例子 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，
＇ 方法DelCahe ,删除内存
＇ 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
＇ 用法
set myCache=New Cache
myCache.name="BoardJumpList" ＇定义缓存名
if myCache.valid then ＇判断是否可用(包括过期，与是否为空值)
response.write myCache.value ＇输出
else
................
BoardJumpList=xxx
myCache.add BoardJumpList,dateadd("n",60,now) ＇写入缓存 xxx.add 内容,过期时间
response.write BoardJumpList ＇输出
end if
myCache.makeEmpty() 释放内存
mycache.DelCahe() 删除缓存
迷城浪子写的
Class Cls_Cache
Rem ==================使用说明====================
Rem = 本类模块是动网先锋原创，作者：迷城浪子。如采用本类模块，请不要去掉这个说明。这段注释不会影响执行的速度。
Rem = 作用：缓存和缓存管理类
Rem = 公有变量：Reloadtime 过期时间（单位为分钟）缺省值为14400
Rem = MaxCount 缓存对象的最大值，超过则自动删除使用次数少的对象。缺省值为300
Rem = CacheName 缓存组的总名称，缺省值为"Dvbbs",如果一个站点中有超过一个缓存组，则需要外部改变这个值。
Rem = 属性:Name 定义缓存对象名称，只写属性。
Rem = 属性:value 读取和写入缓存数据。
Rem = 函数：ObjIsEmpty()判断当前缓存是否过期。
Rem = 方法：DelCahe(MyCaheName)手工删除一个缓存对象，参数是缓存对象的名称。
Rem ========================
Public Reloadtime,MaxCount,CacheName
Private LocalCacheName,CacheData,DelCount
Private Sub Class_Initialize()
Reloadtime=14400
CacheName="Dvbbs"
End Sub
Private Sub SetCache(SetName,NewValue)
Application.Lock
Application(SetName) = NewValue
Application.unLock
End Sub
Private Sub makeEmpty(SetName)
Application.Lock
Application(SetName) = Empty
Application.unLock
End Sub
Public Property Let Name(ByVal vNewValue)
LocalCacheName=LCase(vNewValue)
End Property
Public Property Let Value(ByVal vNewValue)
If LocalCacheName<>"" Then
CacheData=Application(CacheName&"_"&LocalCacheName)
If IsArray(CacheData) Then
CacheData(0)=vNewValue
CacheData(1)=Now()
Else
ReDim CacheData(2)
CacheData(0)=vNewValue
CacheData(1)=Now()
End If
SetCache CacheName&"_"&LocalCacheName,CacheData
Else
Err.Raise vbObjectError + 1, "DvbbsCacheServer", " please change the CacheName."
End If
End Property
Public Property Get Value()
If LocalCacheName<>"" Then
CacheData=Application(CacheName&"_"&LocalCacheName)
If IsArray(CacheData) Then
Value=CacheData(0)
Else
Err.Raise vbObjectError + 1, "DvbbsCacheServer", " The CacheData Is Empty."
End If
Else
Err.Raise vbObjectError + 1, "DvbbsCacheServer", " please change the CacheName."
End If
End Property
Public Function ObjIsEmpty()
ObjIsEmpty=True
CacheData=Application(CacheName&"_"&LocalCacheName)
If Not IsArray(CacheData) Then Exit Function
If Not IsDate(CacheData(1)) Then Exit Function
If DateDiff("s",CDate(CacheData(1)),Now()) < 60*Reloadtime Then
ObjIsEmpty=False
End If
End Function
Public Sub DelCahe(MyCaheName)
makeEmpty(CacheName&"_"&MyCaheName)
End Sub
End Class
迷城浪子 类例子
Set WydCache=New Cls_Cache
WydCache.Reloadtime=0.5 ＇定义过期时间 (以分钟为单会)
WydCache.CacheName="pages" ＇定义缓存名
IF WydCache.ObjIsEmpty() Then ＇＇判断是否可用(包括过期，与是否为空值)
Response.write WydCache.Value
Else
..................
BoardJumpList=xxx
WydCache.Value=BoardJumpList ＇写入内容
Response.write BoardJumpList
End if
mycache.DelCahe("缓存名") 删除缓存
slightboy 写的 ＇========================
＇clsCache.asp
＇========================
＇== begin : 2004-6-26 21:51:47
＇== copyright : slightboy (C)1998-2004
＇== email : [email protected]
＇========================
＇========================
＇ Dim Application(2)
＇ Application(0) Counter 计数器
＇ Application(1) dateTime 放置时间
＇ Application(2) Content 缓存内容
Public PREFIX
Public PREFIX_LENGTH
Private Sub Class_Initialize()
PREFIX = "Cached:"
PREFIX_LENGTH = 7
End Sub
Private Sub Class_Terminate
End Sub
＇ 设置变量
Public Property Let Cache(ByRef Key, ByRef Content)
Dim Item(2)
Item(0) = 0
Item(1) = Now()
IF (IsObject(Content)) Then
Set Item(2) = Content
Else
Item(2) = Content
End IF
Application.Unlock
Application(PREFIX & Key) = Item
Application.Lock
End Property
＇ 取出变量 计数器++
Public Property Get Cache(ByRef Key)
Dim Item
Item = Application(PREFIX & Key)
IF (IsArray(Item)) Then
IF (IsObject(Item)) Then
Set Cache = Item(2)
Else
Cache = Item(2)
End IF
Application(PREFIX & Key)(0) = Application(PREFIX & Key)(0) + 1
Else
Cache = Empty
End IF
End Property
＇ 检查缓存对象是否存在
Public Property Get Exists(ByRef Key)
Dim Item
Item = Application(PREFIX & Key)
IF (IsArray(Item)) Then
Exists = True
Else
Exists = False
End IF
End Property
＇ 得到计数器数值
Public Property Get Counter(ByRef Key)
Dim Item
Item = Application(PREFIX & Key)
IF (IsArray(Item)) Then
Counter = Item(0)
End IF
End Property
＇ 设置计数器时间
Public Property Let dateTime(ByRef Key, ByRef SetdateTime)
Dim Item
Item = Application(PREFIX & Key)
IF (IsArray(Item)) Then
Item(1) = SetdateTime
End IF
End Property
＇ 得到计数器时间
Public Property Get dateTime(ByRef Key)
Dim Item
Item = Application(PREFIX & Key)
IF (IsArray(Item)) Then
dateTime = Item(1)
End IF
End Property
＇ 重置计数器
Public Sub ResetCounter()
Dim Key
Dim Item
Application.Unlock
For Each Key in Application.Contents
IF (Left(Key, PREFIX_LENGTH) = PREFIX) Then
Item = Application(Key)
Item(0) = 0
Application(Key) = Item
End IF
Next
Application.Lock
End Sub
＇ 删除某以缓存
Public Sub Clear(ByRef Key)
Application.Contents.Remove(PREFIX & Key)
End Sub
＇ 清空没有使用的缓存
Public Sub ClearUnused()
Dim Key, Keys, KeyLength, KeyIndex
For Each Key in Application.Contents
IF (Left(Key, PREFIX_LENGTH) = PREFIX) Then
IF (Application(Key)(0) = 0) Then
Keys = Keys & VBNewLine & Key
End IF
End IF
Next
Keys = Split(Keys, VBNewLine)
KeyLength = UBound(Keys)
Application.Unlock
For KeyIndex = 1 To KeyLength
Application.Contents.Remove(Keys(KeyIndex))
Next
Application.Lock
End Sub
＇ 清空所有缓存
Public Sub ClearAll()
Dim Key, Keys, KeyLength, KeyIndex
For Each Key in Application.Contents
IF (Left(Key, PREFIX_LENGTH) = PREFIX) Then
Keys = Keys & VBNewLine & Key
End IF
Next
Keys = Split(Keys, VBNewLine)
KeyLength = UBound(Keys)
Application.Unlock
For KeyIndex = 1 To KeyLength
Application.Contents.Remove(Keys(KeyIndex))
Next
Application.Lock
End Sub
End Class
slightboyn 类例子 Set Wyd=New JayCache
Wyd.dateTime("Page")=时 间
If Wyd.Exists("Page") Then
Response.write Wyd.Cache("Page") ＇输出
Else
Wyd.Cache("Page")=xxx 写入
Responxe.write xxx
End IF
Wyd.Clear("page")＇删除缓存