ASP缓存类(ASP缓存技术总结)

‘ 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

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 ========================

Class Cls_Cache
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

‘========================
‘clsCache.asp
‘========================
‘== begin : 2004-6-26 21:51:47
‘== copyright : slightboy (C)1998-2004
‘== email : slightboy@msn.com
‘========================

Class JayCache

‘========================
‘ 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

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