Sanarwar a browser - abin da yake da shi?

Mutane da yawa Internet masu amfani da ake yi mamaki: "Sanarwar na mai browser - abin da yake da shi?" Yana nuna wani style of igiyar ruwa da yanar-gizo, inda wani request ga wani fatauci qaddamar da wani tsakiyar uwar garke. Wannan ya saba da gaban shugabanci na bayanai, inda request domin canja wuri na bayanai da aka qaddamar da mai karɓar ko abokin ciniki.

Domin sanarwar da sabis sukan dogara ne a kan bayanai da zaɓin bayyana a gaba. Wannan shi ne tsarin biyan zuwa ɗaba'ar. Client "ya rubuta cewa" ya daban-daban bayanai "tashoshi" bayar da uwar garke. A duk lokacin da sabon abun ciki shi ne samuwa a kan daya daga cikin wadanda tashoshi, da uwar garken aika da wannan bayani don shi. Sanarwar a browser wani lokacin emulates wani binciken da dabara, musamman a cikin yanayi inda da real tambaya ba zai yiwu - misali, a kan yanar ta tsanani tsaro manufofin da cewa bukatar da kin amincewa da shigowa HTTP / S buƙatun.

manufa na aiki

Synchronous gudanar da taro da kuma saƙon nan-take ne na hali misalai na abin da ya kama da Manzanci. Mene ne shi da kuma yadda yake aiki? Saƙonnin taɗi da kuma wani lokacin fayilolin tura zuwa ga mai amfani da zaran sun ake samu ta hanyar saƙon sabis. Dukansu rarraba tsara-to-LVS da Karkasa shirye-shirye (kamar IRC ko XMPP) da damar "da tura" fayiloli. Wannan yana nufin cewa sunan na aikawa fara canja wurin bayanai maimakon da mai karɓa.

E-mail kuma iya aiki tare da sanarwar - SMTP yarjejeniya ne, a ainihi, "tura". Duk da haka, na karshe "mataki" daga mail server a kwamfuta yawanci aikata wani Pull-yarjejeniya kamar POP3 ko IMAP. A IMAP yarjejeniya hada da rago-umurnin, wanda damar da uwar garke sanar da abokin ciniki kai saƙo mai shigowa. The asali BlackBerry shi ne na farko rare na'urar, inda sanarwar da aka rayayye aiki a browser. Mẽne ne a wadannan na'urori - za a iya gani a cikin e-mail address (ga mara waya).

Abin da shi ya kafin?

Wani misali shi ne PointCast Network wanda aka sani a shekarun 1990s. Yana bayar da labarai da kuma kasuwar jari data. Kuma Netscape, shi kuma aikace-aikace daga Microsoft ya hade da shi a cikin su software don kowane version na browser, amma shi ya ba ta kasance m, kuma daga baya ya bace gaba daya. Bincike baya maye gurbin wannan aiki a cikin 2000s zuwa RSS - biyan kuði tsarin, inda akwai wani karin ci-gaba sanarwar a browser. Mene ne wani data biyan - ya san kowane karatu na blogs.

Waɗansu amfãnõni sanarwar-sa yanar gizo da aikace-aikacen ya hada da bayani a kan kasuwar data (stock farashin), online chat da saƙon tsarin (WebChat), auctions, online betting da kuma wasanni, wasanni betting, sa idanu Consoles da kuma kama.

Sanarwar da browser - cewa shi ne a yau?

Sanarwar via IEFT ne mai sauki yarjejeniya da cewa yana amfani da HTTP / 2 ya sadar da take sanarwar (for kira mai shigowa da kuma saƙonnin). A yarjejeniya hadawa duk real-lokaci events in guda zaman, wanda damar domin mafi ingantaccen amfani da cibiyar sadarwa da watsa rediyo albarkatu. Daya tsayawa sabis hadawa duk abubuwan da rarraba su aikace-aikace kamar yadda suka zama akwai. Wannan na bukatar daya kawai zaman, ta haka ne guje da ɓata lokaci da kuma zirga-zirga.

Sanarwar a browser - shi ne daga wani fasaha ra'ayi?

HTTP-sanarwar (kuma aka sani da streaming HTTP) ne inji domin aikawa da bayanai daga browser da Web uwar garke. Yana za a iya cimma ta da wani da dama sunadaran. Yawanci, da sabar yanar gizo ba žare dangane bayan da sanarwa da aka aika zuwa ga abokin ciniki. A da sabar yanar gizo bar dangane bude, kuma a cikin taron na wani sabon taron (misali, canza data aika a sakon) aka nuna nan take. In ba haka ba, taron zai yi jerin gwano har sai na gaba abokin ciniki request ne karbi.

Mai sabobin yanar gizo bayar da wannan siffa ta amfani da CGI (misali, Non-parsed BBC rubutun a kan Apache). Muhimmi inji wannan m ne block watsa coding. A classic misali ne sanarwar da browser "mãtan aure". Mẽne ne a kan wannan shafin? Na farko shi ne bayani game da sakonni masu shigowa da kuma alamomi "Like".

madadin sunadaran

Wani inji ake dangantawa da wani musamman irin MIME, wanda ake kira da Multi-bangaren sauyawa. An farko gabatar a 1995, da Netscape, da browser "a kan gardama" musanya daftarin aiki a duk lokacin da wani sabon version a kan uwar garke aka samu. Kuma har yanzu yana goyon a Firefox, Opera, Safari, da kuma a yau, amma ba a Internet Explorer. Wannan inji za a iya amfani da su HTML-takardun da ma don yawo hotuna a webcam aikace-aikace.

WHATWG Web aikace-aikacen kwamfuta 1.0 hada da wani inji cewa da nufin canza abinda ke ciki na abokin ciniki. Ya aka sani tun Satumba 1, 2006, a lokacin da Opera web browser aiwatar da wannan sabon gwaji tsarin kira Server-SentEvents. Ya halin yanzu daidaita matsayin wani ɓangare na HTML5. A wannan hanya, da uwar garken yana amfani da naci HTTP sadarwa, sakamakon wani martani ko da yaushe ya kasance "bude" (watau, da uwar garken bai tsaya a nan martani), yadda ya kamata "tricking" your browser. Saboda haka, aikace-aikace ko da yaushe ya kasance a cikin taya yanayin, bayan da page ya bude a full. A server sai lokaci-lokaci aika snippets na JavaScript sabunta cikin page content, game da shi kunna sanarwar. Amfani da wannan dabara, abokin ciniki ba ya bukatar Java applet ko wasu toshe-ins don ci gaba da wani bude haɗin sabar - abokin ciniki ta atomatik sami wani jawo hankali game da sabon events ya fito daga cikin uwar garke. Daya babbar hasara na wannan hanya, duk da haka, shi ne rashin iko da lokacin da browser uwar garke. Ana ɗaukaka a page ne ko da yaushe dole idan akwai wani timeout a bude page.

data memory

haddar dabara a kanta ba ta dace da Manzanci. Yana kawai ba ka damar koyi da sanarwar inji a cikin wani yanayi inda shi ne ba zai yiwu. Alal misali, a kan wani wuya tsaro manufofin shafukan da cewa bukatar kin amincewa daga mai shigowa HTTP / S buƙatun. Ba shi yiwuwa a sanarwar a browser (cewa shi ne, da kuma yadda yake aiki - ga sama). A wannan yanayin, abokin ciniki buƙatun bayanai daidai kamar yadda a cikin wani al'ada tambaya, amma saboda da tsammanin daga cikin uwar garke ba zai iya amsa nan da nan. Idan uwar garke ba ya da wani sabon bayanai ga abokin ciniki a lokacin da wani request ne karbi - maimakon ciwon aika wani komai a mayar da martani, da fatawar da ya rage bude, a lokacin da sabon bayani. Da zarar wannan data bayyana, shi nan da nan ta aika da HTTP / S martani ga abokin ciniki, kammala bude connection.

Bayan samun abokin ciniki sau da yawa nan da nan al'amurran da suka shafi wani request zuwa wani uwar garke martani. Kamar wancan ne, talakawan martani da bata lokaci lokaci (lokacin tsakanin lokacin da bayani ya zama samuwa, da kuma na gaba abokin ciniki request) hade da isowa daga buƙatun, shi ne cire.

XML Socket

Sanarwar a browser, aiki tare da taimako na wannan hanya, yi amfani da CBOX da kuma sauran aikace-aikace don Chatter. Yana amfani da XML Socket abubuwa a single-pixel fayiloli AdobeFlash. Karkashin iko na abokin ciniki JavaScript tabbatar da TCP dangane da unidirectional nodes a kan uwar garke. Request a cikin wannan yanayin da ya rage karantaba, maimakon, da kumburi aika abokin ciniki wani farɗan mai ganowa nan da nan. wani HTTP request ne sanya sa'an nan da sabar yanar gizo, wanda yana dauke da samu ganowa. A yanar gizo da aikace-aikacen iya sa'an nan fitowa da sako jawabi ga abokin ciniki a kan na gida dubawa gudun ba da sanda uwar garke, wanda watsa su via Flash. A amfani da wannan dabarar ne cewa shi yana amfani da na halitta jeri na bangaren na karanta-write.

Wannan shi ne hali da yawa yanar gizo na tushen aikace-aikace, ciki har da chat dakunan, kuma, kamar yadda wani sakamako, na tabbatar da high dace. Tun da ya ba yarda da bayanan a kan fita kwasfansu, da uwar garke ba a bukata don neman outbound TCP sadarwa, abin da ya sa yiwu kafa dubban lokaci daya sadarwa. Saboda haka akwai sanarwar a browser a kan "takwarorinsu" a wasu ayyuka na Site.

Samuwa sanarwar da sabis

Wannan yanayin ne samuwa a kan da yawa sabis cewa goyi bayan sama da aka ambata mahadi. Kamar yadda riga ya bayyana, sanarwar a browser - shi ne wata damar samun sakonni nan take da kuma sanarwar, ba tare da reloading da page. Services, inda wannan sabis ne samuwa, sun hada da:

• Apple Sanarwar Service.
• Google Cloud Saƙo.
• "Takwarorinsu".
• Facebook.
• Xtremepush.
• Amazon SNS.