ASP缓存类含调用演示

6/4/2009来源:ASP技巧人气:5617

程序代码
<%
    'by xilou,www.chinacms.org,20090115
    '最后更新:20090115
    '修改记录:无
   
    CONST CACHEPREFIX = "CACHE_" '缓存前缀,不能为空

    '说明:
    '        1,缓存的格式为application(CACHEPREFIX & key) = array("缓存key","缓存时间","缓存内容","缓存说明","到期时间")
    '          2,缓存key不区分大小写
   
   
   
    '添加缓存,不检查缓存是否存在,如果存在则相当于更新缓存
    'varAry :  参数,格式为:array("缓存key","缓存时间","缓存内容","缓存说明")
    '           缓存key :application()格式相同
    '           缓存时间:单位秒,可以为负数,表示立即过期,可以为空,空或不是数字则默认为20分钟过期
    '          缓存内容:缓存数据,不支持对对象的缓存
    '           缓存说明:缓存描述说明
    Function AddCache(varAry)
        Dim c,ary(4)
        If Not IsArray(varAry) Then
            Response.Write "Error:AddCache(varAry)参数错误,参数不是数组"
            Response.End()
        End If
        If UBound(varAry) <> 3 Then
            Response.Write "Error:AddCache(varAry)参数错误,数组长度错误"
            Response.End()
        End If
        If varAry(0) = "" Then
            Response.Write "Error:AddCache(varAry)错误,key不能为空"
            Response.End()
        End If
        If varAry(1) = "" or Not IsNumeric(varAry(1)) Then varAry(1) = 1200
        Application.Lock()
        Application(CACHEPREFIX & varAry(0)) = array(varAry(0),varAry(1),varAry(2),varAry(3),DateAdd("s",varAry(1),Now()))
        Application.UnLock()
    End Function
   
    '检查某个缓存是否存在,存在返回True否则返回False
    'key : 缓存key
    Function CheckCache(key)
        Dim k
        For Each k In Application.Contents
            If LCase(k) = LCase(CACHEPREFIX & key) Then CheckCache = True : Exit Function
        Next
        CheckCache = False
    End Function
   
    '获取缓存
    '返回数组,格式为:array("缓存key","缓存时间","缓存内容","缓存说明","到期时间",是否过期True|False)
    '如果不存在则出错,所以获取之前先用CheckCache(key)检查
    Function GetCache(key)
        Dim app,isExp
        app = Application(CACHEPREFIX & key)
        isExp = False
        If DateDiff("s",Now(),app(4)) <= 0 Then isExp = True
        GetCache = Array(app(0),app(1),app(2),app(3),app(4),isExp)
    End Function
   
    '清除缓存
    Function RemoveCache(key)
        Application.Lock()
        Application.Contents.Remove(CACHEPREFIX & key)
        Application.UnLock()
    End Function
   
    '更新缓存,如果缓存不存在则出错,所以更新之前先用CheckCache(key)检查
    'varAry :  参数,格式为:array("缓存key","缓存时间","缓存内容","缓存说明")
    '           缓存key :application()格式相同
    '           缓存时间:单位秒,可以为负数,表示立即过期,可以为空,空或不是数字则默认为20分钟过期
    '          缓存内容:缓存数据,不支持对对象的缓存
    '           缓存说明:缓存描述说明
    '注意   : 如果不更新varAry某个值则设置该值为null即可,
    '           如UpdateCache(array("key",null,"内容",null)),就是不更新过期时间和说明
    Function UpdateCache(varAry)
        Dim app
        app = GetCache(varAry(0))
        If Not IsNull(varAry(1)) Then app(1) = varAry(1)
        If Not IsNull(varAry(2)) Then app(2) = varAry(2)
        If Not IsNull(varAry(3)) Then app(3) = varAry(3)
        If app(1) = "" or Not IsNumeric(app(1)) Then app(1) = 1200
        Application.Lock()
        Application(CACHEPREFIX & app(0)) = array(app(0),app(1),app(2),app(3),DateAdd("s",app(1),Now()))
        Application.UnLock()
    End Function
    'www.knowsky.com
    '打印cache,做调试用
    Function PrintCache(key)
        Dim app,i,t
        If CheckCache(key) Then
            app = GetCache(key)
            Response.Write "<pre>{"&chr(10)
            Response.Write chr(32) & "缓存名称" & chr(32) & ":" & chr(32) & CACHEPREFIX & app(0) & chr(10)
            Response.Write chr(32) & "缓存key " & chr(32) & ":" & chr(32) & app(0) & chr(10)
            Response.Write chr(32) & "缓存时间" & chr(32) & ":" & chr(32) & app(1) & chr(10)
            Response.Write chr(32) & "到期时间" & chr(32) & ":" & chr(32) & app(4) & chr(10)
            Response.Write chr(32) & "是否到期" & chr(32) & ":" & chr(32) & app(5) & chr(10)
            Response.Write chr(32) & "缓存说明" & chr(32) & ":" & chr(32) & app(3) & chr(10)
            '内容
            Response.Write chr(32) & "缓存内容" & chr(32) & ":" & chr(32)
            t = VarType(app(2))
            If InStr(",0,1,2,3,4,5,6,7,8,11,",","&t&",") > 0 Then
                Response.Write app(2)
            Else
                Response.Write TypeName(app(2))
            End If
            Response.Write chr(10)
           
            Response.Write "}</pre>"&chr(10)
        Else
            Response.Write "不存在该缓存"
        End If
    End Function
   
   
   '-----------demo

    Sub br(str)
        Response.Write str & "<br />" & vbcrlf
    End Sub
   
    'RemoveCache "xilou"
    'AddCache Array("xilou","",array("数据内容"),"缓存说明")
    br CheckCache("xilou")
    PrintCache "xilou"
   
    Dim app
    If CheckCache("xilou") Then
        app = GetCache("xilou") '获取
        UpdateCache array(app(0),null,"testsfsfsf",null)'更新
    Else
        AddCache array("xilou","","内容","说明")
    End If
    'Dim k
    'For Each k In Application.Contents
        'br k
    'Next
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