Isibali sekhodi sehashi MurmurHash3C

I-MurmurHash3 iwumsebenzi we-hashi ongabhalwanga phansi owaklanywa u-Austin Appleby ngonyaka ka-2008. Isetshenziswa kabanzi ukwenza i-hashing ngenjongo evamile ngenxa yesivinini sayo, ubulula, kanye nezakhiwo ezinhle zokusabalalisa. Imisebenzi ye-MurmurHash isebenza kahle kakhulu ezinhlakeni zedatha ezisekelwe ku-hash njengamathebula e-hashi, izihlungi ze-bloom, nezinhlelo zokuphindaphinda idatha.

Okuhlukile okwethulwa kuleli khasi okwehlukile kwe-3C, okuthuthukiselwe amasistimu angama-32 bit, okufana nokuhlukile kwe-3A. Nokho, ngokungafani nokuhluka kwe-3A, ikhiqiza amakhodi angu-128 bit (16 byte), ngokuvamile amelelwa njengenombolo ye-hexadecimal enamadijithi angu-32.

Ukudalulwa okuphelele: Angibhalanga ukusetshenziswa okuqondile komsebenzi we-hashi osetshenziswe kuleli khasi. Kungumsebenzi ojwayelekile ofakwe nolimi lokuhlela lwe-PHP. Ngenze isixhumi esibonakalayo sewebhu kuphela ukuze ngisenze sitholakale esidlangalaleni lapha ukuze kube lula.

Mayelana ne-MurmurHash3C Hash Algorithm

Angisona isazi sezibalo, kodwa ngizozama ukuchaza lo msebenzi we-hash ngisebenzisa isifaniso esingasiqonda ozakwethu abangezona izibalo. Uma ukhetha incazelo yezibalo elungile ngokwesayensi, egcwele, ngiyaqiniseka ukuthi ungayithola kwenye indawo ;-)

Manje, ake ucabange unebhokisi elikhulu lezitini ze-LEGO. Ngaso sonke isikhathi uma uzihlela ngendlela ethile, uthatha isithombe. Kungakhathaliseki ukuthi ilungiselelo likhulu noma linemibala kangakanani, ikhamera ihlale ikunikeza isithombe esincane, esinosayizi ongashintshi. Leso sithombe simele ukudalwa kwakho kwe-LEGO, kodwa ngendlela ehlangene.

I-MurmurHash3 yenza okufanayo ngedatha. Kuthatha noma yiluphi uhlobo lwedatha (umbhalo, izinombolo, amafayela) futhi inciphise ibe "inani leminwe" elincane, elingashintshi noma inani le-hashi. Lezi zigxivizo zeminwe zisiza amakhompyutha ukubona, ukuhlela, nokuqhathanisa idatha ngokushesha ngaphandle kokudinga ukubuka yonke into.

Esinye isifaniso singafana nokubhaka ikhekhe futhi i-MurmurHash3 iresiphi yokuguqula lelo khekhe libe yikhekhe elincane (i-hashi). Lokhu kungaba inqubo yezinyathelo ezintathu:

Isinyathelo 1: Sika ube Yizingcezu (Ukwephula Idatha)

• Okokuqala, i-MurmurHash3 isika idatha yakho ibe yizicucu ezilinganayo, njengokusika ikhekhe libe izikwele ezilinganayo.

Isinyathelo sesi-2: Hlanganisa Njengohlanya (Ukuxuba Izingcezu)

• Isiqephu ngasinye sihamba ngenqubo yokuhlanganisa yasendle:
  • Ukuphequlula: Njengokupheqa i-pancake, ihlela kabusha izingcezu.
  • Ukunyakazisa: Kwengeza izithako ezingahleliwe (ukusebenza kwezibalo) ukuze kuhlanganiswe izinto.
  • I-Squishing: Cindezela idatha ndawonye ukuze wenze isiqiniseko sokuthi akukho ucezu lwangempela olugqamayo.

Isinyathelo sesi-3: Ukuhlolwa Kokugcina Kokunambitha (Ukuphothula)

• Ngemuva kokuxuba zonke izingcezu, i-MurmurHash3 ikunikeza ukunyakazisa okokugcina ukuqinisekisa ukuthi ngisho nemvuthuluka encane yoshintsho kudatha yangempela ingashintsha ngokuphelele ukunambitheka (i-hashi).