软件体系结构之质量属性.ppt

RuntimeTacticsMaintainamodelofthesystem.维护系统模型Inthiscase,themodelmaintainedisthatofthesystem.Itdeterminestheexpectedsystembehaviorsothatappropriatefeedbackcanbegiventotheuser.Thesystemmodelpredictsitemssuchasthetimeneededtocompletecurrentactivity.Design-timeTacticsSeparatetheuserinterfacefromtherestoftheapplication.从应用中分离用户接口Localizingexpectedchangesistherationaleforsemanticcoherence.Sincetheuserinterfaceisexpectedtochangefrequentlybothduringthedevelopmentandafterdeployment,maintainingtheuserinterfacecodeseparatelywilllocalizechangestoit.Model-View-ControllerPresentation-Abstraction-ControlSeeheimArch/SlinkySummaryofruntimeusabilitytacticshowthearchitectrealizesparticularqualityattributerequirements.01thetacticsusedbythearchitecttocreateadesignusingarchitecturalpatternsandstrategies.02TacticsSummaryPreventRippleEffects–tacticsUseanintermediary.使用中间物IfBhasanytypeofdependencyonAotherthansemantic,itispossibletoinsertanintermediarybetweenBandAthatmanagesactivitiesassociatedwiththedependency.Theintermediaryare:data(syntax).Repositories(bothblackboardandpassive)actasintermediariesbetweentheproducerandconsumerofdata.service(syntax).Thefacade,bridge,mediator,strategy,proxy,andfactorypatternsallprovideintermediariesthatconvertthesyntaxofaservicefromoneformintoanother.若B对A有任何非语义的依赖，在B和A之间插入一个中间物来管理与依赖相关的活动是可能的。中间物可以是：数据（语法）。仓储是数据的生产者和消费者之间的中间物。服务。把服务从一种形式转换为另一种形式的语法。PreventRippleEffects-tacticsidentityofaninterfaceofA.Abrokerpatterncanbeusedtomaskchangesintheidentityofaninterface.IfBdependsontheidentityofaninterfaceofAandthatidentitychanges,byaddingthatidentitytothebrokerandhavingthebrokermaketheconnectiontothenewidentityofA,Bcanremainunchanged.locationofA(runtime).Anameserverena