Johdanto
Theso-calledmodulereferstoarelativelyindependentcollectionofprogramobjectssuchasdatadescriptionsandexecutionstatements.Eachmoduleintheprogramneedstobenamedseparately,andaccesstothespecifiedmodulecanberealizedthroughthename.Inhigh-levellanguages,modulesareembodiedasfunctions,subroutines,procedures,etc.Amodulehasfourcharacteristics:input/output(interface),function,internaldata,andprogramcode.Theinput/outputisusedtorealizethedatatransmissionbetweenthemoduleandothermodules,thatis,theoriginaldatarequiredbythemoduleistransferredandtheresultdataisobtainedfromthemodule.Functionreferstotheworkdonebythemodule.Theinput/outputandfunctionsofthemoduleconstitutetheexternalcharacteristicsofthemodule.Internaldatareferstoalocalquantitythatcanonlybeusedinsidethemodule.
Someprogramshaveasingle-modulestructure,andsomehaveamulti-modulestructure.Thesemodulesareinseparableinthelogicoftheprogram,canbewrittenindifferentprogramminglanguages,canberespectivelycompiledbythecorrespondingcompiler,canbecombinedwithotherprogramunitsandloadedintothecomputertorun.Duetotheneedtowritelargeprogramsandmodulescanbeusedmultipletimes,modularizationisagoodmethod.Alargeprogramcomposedofasetofmodulescanhavethreestructures,namelysequentialstructure,concurrentstructureanddistributedstructure.Theprogramofsequentialstructureistheoldest,andtheprogramminglanguageusedissequentialprogramminglanguage,suchasALGOL,FORTRAN,Candsoon.Theprogramoftheconcurrentstructureiscomposedofseveralmodulesthatcanbeexecutedatthesametime.Thesemodulescanbeexecutedinparallelonmultipleprocessors,ortheycanbecross-executedonthesameprocessor.Theprogramminglanguageusedisaconcurrentprogramminglanguage,suchasconcurrentPASCAL,Modula-2,etc.Theprogramofthedistributedstructureiscomposedofseveralmodulesthatcanberunindependently.Thesemodulescanbedistributedinadistributedsystemandrunonseveralcomputersatthesametime.Theprogramminglanguageusedisthedistributedprogramminglanguage.Forlargeprograms,itcanalsobeamixtureofthesethreestructures.
WEB-ohjelmistorakenteen periaatteet
Ohjelmistorakenteen suunnittelun heuristiset säännöt
(1)Moduulin toimintojen parantaminen
PerformprescribedfunctionsPart;errorhandlingpart;whendataneedstobereturnedtothecaller,returnthecorrectendflag.
(2) Eliminoitu monistustoiminto
(3)Limittheinfluenceofthemodulewithinthecontrolrangeofthemodule
(4) Syvyys, leveys, tuulettimen ulostulo Kohtalainen ja tuuletin sisään
(5)Kohtalainen moduulikoko
Moduleistoolarge:comprehensibilityisreduced.Themoduleistoosmall:thecostismorecomplexthantheeffectiveoperatingsysteminterface.
(6)Vähennä moduuliliitännän monimutkaisuutta
Theinterfacetransmissioninformationshouldbesimpleandconsistentwiththemodulefunction.
(7)Moduulin toiminta on ennakoitavissa
Themoduleisregardedasablackbox,thesameinputproducesthesameoutput,anditsfunctionispredictable.Thefunctionofthemodulewithinternalstatemaybeunpredictable.Difficulttounderstand,difficulttotest,anddifficulttomaintain.
(8) Vältä kytköksissä olevia moduuleja
Preventbranchesorreferencesinthemiddleofmodules(forcontentcoupling).
(9)Thesoftwaremustbepackagedaccordingtodesignconstraintsandportability
Packagingreferstothetechnologyusedtoassemblesoftwareforaspecificenvironment.
Hakemistorakenne on selvä
Hakemistorakenne on selvä,nottoodeeporcomplicated.Itisbettertousearelativeaddressforthepath.
WhatkindofWhatkindofcontentisplacedinthedirectory,sothatitiseasytomanage,sothatthedirectorystructureoftheWEBprogramisclear,andyoucanknowwhatfunctionmodulesandcontentarestoredinacertainfolderataglance.Ifyoustoreitcasually,youwillneverknowwhatacertaindirectoryisforforalongtime.Forexample,executablefilesthatarefrequentlyusedshouldbestoredintherootdirectoryofthe(projectrootdirectory).Thisismainlytofacilitateunderstandingofitsfunction,andalsotoreducetheinputofaddresscharactersintheprogram.Thepicturesusedbytheprogramarestoreduniformlyintheimagesdirectoryundertherootdirectory.Iftheprojectislargerandhasmorebranches,youcancreateadirectorynamethatalsobranchestheprograminthedirectorytostoretherelevantpicturecontent.Theconfigurationfilesoftheprogramandcommoncommonfunctionlibraryareplacedintheincludedirectory,andtheextensionofthefunctionlibraryfilestoredinthisdirectoryshouldbenamed:.phpmustnotbenamed.inc.iniandotherfileswithextensions,Themainreasonistopreventthistypeoffilefrombeingavailableforuserstodownload,ortoconsultthesourcecodecontent,sothatitisconvenientandcleartocall.Thetemplatefilesshouldbestoredinthetemplatesdirectoryundertherootdirectorywiththeextension.html.Iftheprojectislargeandtherearemanycategories,thetemplatefilescanbestoredinthelowerdirectory.Temporaryfilesarestoredintherootdirectorytmpdirectory.Thisdirectoryisusuallysettobereadableandwritablebyanyone.Theuseofrelativeaddressesismainlytofacilitateprogramtransplantation.
Nimeäminen sopivasti
Thenamingisbestbasedonwhattheprogramisusedfor.Ifawordneedstobedescribed,uselowercasewordstonameit.Ifmorethanonewordcanbeusedtorepresentit,connectthelowercasewordswithanunderscore.Notethatthenameshouldnotbetoolong,whichisinconvenient.Althoughitcanexpressmoreclearly,itisdifficulttotype.Thefunctionnamingintheprogramcanalsobethesame.
Frequentlychangingcontentandinterfacemakethetemplatebetter
Frequentlychangingcontentandinterfaceusetemplatebetter,ifitismadeaccordingtothetraditionalproduction,theHTMLpagecontentisplacedintheprogramwhenprocessinginput,Itismoretroublesometochangetheprogram,whichmaycausegreaterinconvenience.
Julkisen tiedon yhtenäinen tallennus
Julkisen tiedon yhtenäinen tallennus,thisismainlyfortheconvenienceofthemostcommonfunctionsthatcanbecalledduringteamdevelopment,withouteverydeveloperhavingtocopyAcopyorwriteacopyofitandstoreitintheprogramfile.Thiswastesspaceandisnotveryefficient.
Sisällytä tiedostoja ei voida upottaa liikaa
Sisällytä tiedostoja ei voida upottaa liikaa.Thisisbecauseeverytimetheprogramincludesafile,itneedstobeopenedandread.ThisisIttakestime,andthatistosay,youmayencounterbugsthatarehardertofindwhenprocessingpaths.
Älä tallenna liikaa sisältötiedostoja hakemistoon
Ifthefilesarelargeandlarge,itisbesttodividethemintodirectoriesanddisks.
Tietorakenteet tulisi suunnitella järkevästi
Tietorakenteet tulisi suunnitella järkevästi,conciselyandconcisely.
Tietojen vahvistuksen tulisi olla palvelimen puolella
Tietojen vahvistuksen tulisi olla palvelimen puolella,butthishasitsdisadvantages,thatis,whentheamountofdataislarge,theserverwillloadRunningandauditingdataintegritycancosttimeandsystemresources.Ontheclientside,itwillnotoccupytoomanyresourcesoftheserver,becauseitoccupiestheresourcesoftheuser.
Connectingtothedatabaseislate,anddisconnectingisearly
Connectingaslateaspossibleanddisconnectingassoonaspossiblecanminimizetheuseofsystemresourcesandprovideconditionsforthenextconnection.
Käytä SESSIONia ja COOKIE:tä vähänmahdollisimman
Käytä SESSIONia ja COOKIE:tä vähänmahdollisimman,becausetheuseofSESSIONtakesupsystemresources,andSESSIONisstoredontheserverside,andeachreadinSESSIONThedataismoreexpensive.Althoughcookiesdonotoccupyserverresources,cookiesarenotverysafe.