Inkampani ye-Facebook mayelana nokuqaliswa komthombo ovulekile wamathebula we-hashi , elungiselelwe ukusetshenziswa kahle kwenkumbulo. I-F14 isetshenziswa kungqalasizinda ye-Facebook njengokungena esikhundleni sezinhlobo eziningi zamatafula e-hashi futhi inganciphisa ukusetshenziswa kwememori ngaphandle kokudela ukusebenza. I-F14 idlula ngokuphawulekayo amathebula e-hash e-google::sparse_hash_map, kuze kube manje athathwa njengasebenza kahle kakhulu mayelana nokusetshenziswa kwenkumbulo. Ikhodi yephrojekthi ibhalwe ku-C++ futhi ifakiwe kulabhulali .
I-F14 ibhekisela kuma-algorithms anohlelo lokuxazulula ukushayisana olusekelwe ku-hashing ephindwe kabili eno-14 (uchungechunge lwezikhala eziyi-14 lugcinwa kuseli yetafula le-hashi eyodwa, futhi isikhawu phakathi kwamaseli sibalwa kusetshenziswa umsebenzi we-hashi osizayo). Ukuze kusheshiswe ukusebenza kokuhlunga kwamaseli, ukuqaliswa kusebenzisa imiyalelo ye-vector SSE2 yezinhlelo ze-x86_64 kanye ne-NEON ye-Aarch64, evumela ukufana kokwenziwa kwemisebenzi yokukhetha izikhala ezinamaketanga okhiye nokuhlunga okhiye ngaphakathi kweketango. Amabhulokhi wezikhala eziyi-14 acutshungulwa ngesikhathi, okuyibhalansi efanele phakathi kokusebenza kahle kokusebenzisa inqolobane yokucubungula kanye nenani lokushayisana.
Isici esikhethekile se-F14 yikhono lokukhetha amasu ahlukene okugcina idatha:
- I-F14NodeMap - isebenzisa inkumbulo encane yokhiye abakhulu nabamaphakathi. Iqinisekisa ukuthi izakhi zigcinwa ngokungaqondile ngocingo oluya ku-malloc ekufakweni ngakunye;
- I-F14ValueMap - inikeza ukusetshenziswa kwememori okuncane kokhiye abancane. Ama-elementi agcinwa kumaseli ngokwawo (emgqeni). Okhiye abaphakathi nendawo nabakhulu, le ndlela iholela ekhanda elibonakalayo lenkumbulo;
- I-F14VectorMap - isebenza ngokushesha kumatafula amakhulu nokhiye abayinkimbinkimbi, kodwa ihamba kancane kokhiye abalula namathebula amancane. Ama-elementi apakishwe ohlwini oluqhubekayo olunabantu abaningi futhi aqondiswe yisikhombisi senkomba esingu-32-bit;
- I-F14FastMap isu elihlanganisiwe. Uma ukhiye ungaphansi kwamabhayithi angu-24, kuzobe sekukhethwa i-F14ValueMap, futhi uma ngaphezulu, kukhethwa i-F14VectorMap.
Source: opennet.ru