Isibali sekhodi sehashi Fowler-Noll-Vo FNV1-64

Umsebenzi we-FNV-1 64-bit hash uyingxenye yomndeni we-Fowler–Noll–Vo (FNV) yemisebenzi ye-hashi, eklanyelwe ukusheshisa ukushesha kuyilapho kugcinwa ukusatshalaliswa okuhle kwamavelu e-hashi. Ivamise ukusetshenziswa ezinhlelweni ezifana namathebula e-hashi, ama-checksums, nokubheka idatha. Ikhiqiza ikhodi ye-hashi engu-64 bit (8 byte), evame ukumelwa njengenombolo ye-hexadecimal enezinhlamvu ezingu-16.

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-Fowler-Noll-Vo FNV-1 64 bit Hash Algorithm

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

Okokuqala, ake sicabange nge-algorithm ye-FNV-1 njengeresiphi yokwenza i-smoothie ekhethekile. Isithako ngasinye osingezayo (njengezithelo, ubisi, noma uju) simele ucezu lwedatha - njengezinhlamvu, izinombolo, noma ifayela lonke.

Manje, umgomo uwukuxuba lezi zithako ngendlela eqondile kakhulu ukuze ngisho noshintsho oluncane kakhulu lweresiphi (njengokwengeza i-blueberry eyodwa eyengeziwe) lenze ukunambitheka kwe-smoothie kuhluke ngokuphelele. Isebenza kanjalo imisebenzi ye-hash - idala "i-flavour" eyingqayizivele (noma inani le-hashi) layo yonke isethi eyingqayizivele yezithako (noma idatha yokufaka).

Indlela i-algorithm ye-FNV-1 eyenza ngayo lokhu inqubo enezinyathelo eziningi:

Isinyathelo 1: Qala Ngesisekelo (Isisekelo Se-Offset)

Cabanga ngalokhu njengokuthela isisekelo esikhethekile se-smoothie ku-blender yakho. Lesi sisekelo sihlala sifana, kungakhathaliseki ukuthi yiziphi izithako ongezayo. Ku-FNV-1, lokhu kubizwa ngokuthi "isisekelo se-offset" - inombolo yokuqala yokuqala.

Isinyathelo sesi-2: Engeza Izithako Ngazo Zonke (Ukucubungula Idatha)

Manje usuqala ukwengeza izithako zakho, esisodwa ngesikhathi - ake sithi i-sitrobheli, bese kuba ubhanana, bese kuba noju. Ngayinye yalezi imele ibhayithi yedatha.

Isinyathelo sesi-3: Hlanganisa ne-Secret Multiplier (I-FNV Prime)

Ngemva kokwengeza isithako ngasinye, ucindezela inkinobho yokuhlanganisa, kodwa nakhu ukusonta: i-blender iphindaphinda yonke into "ngenombolo yomlingo" eyimfihlo ebizwa ngokuthi i-FNV prime. Lokhu kusiza ukuhlanganisa izinto kahle.

Isinyathelo sesi-4: Engeza i-Dash of Magic (Ukusebenza kwe-XOR)

Ngaphambi kokwengeza isithako esilandelayo, ufafaza othulini oluncane lomlingo (lokhu umsebenzi we-XOR). Kufana nokuphenyisisa ukunambitheka ngezindlela ezingalindelekile, ukuqinisekisa ukuthi ngisho nezinguquko ezincane zenza umehluko omkhulu.

Isinyathelo sesi-5: Phinda kuze kube yilapho usuqedile

Ulokhu uhlanganisa futhi ufafaza umlingo ngemva kwesithako esisha ngasinye kuze kube yilapho usucubungule yonke into.

Isinyathelo sesi-6: I-Final Smoothie (Inani likaHashi)

Uma usuqedile, uthela i-smoothie. Ukunambitheka kokugcina (inani le-hashi) kuyingqayizivele kuleyo nhlanganisela yezithako. Ukube ubungeze ijikijolo elilodwa elengeziwe, linganambitha ngendlela ehluke ngokuphelele.

Inguqulo evezwe lapha inguqulo yokuqala ye-FNV-1 64 bit. Kukhona futhi inguqulo ethuthukisiwe ye-FNV-1a 64 bit etholakalayo: Isibali sekhodi sehashi Fowler-Noll-Vo FNV1a-64