Lero tikufuna kulankhula za zosintha zaposachedwa kwambiri za Sherlock system [ichi ndi gulu lapamwamba kwambiri ku yunivesite ya Stanford - pafupifupi. trans.], zomwe zimafulumizitsa kwambiri kusanja mafayilo mumakanema okhala ndi zolembera zambiri.
Mosiyana ndi zolemba zanthawi zonse, ili ndi lipoti lamkati la momwe timagwirira ntchito pafupipafupi pa Sherlock kuti iziyenda bwino kwa ogwiritsa ntchito. Tikuyembekeza kufalitsa nkhani zambiri ngati izi mtsogolomu.
Kulemba mafayilo ambiri kumatenga nthawi
Zonse zinayamba ndi funso lothandizira luso kuchokera kwa wogwiritsa ntchito. Iye anafotokoza vuto kuti kuphedwa ls zimatenga mphindi zochepa mu bukhu lokhala ndi zolembera zopitilira 15 $SCRATCH [chilolezo cha mafayilo osakhalitsa - pafupifupi. njira].
Mafayilo masauzande ambiri mu bukhu limodzi nthawi zambiri amakhala olemetsa pamafayilo ndipo sizovomerezeka. Wogwiritsa adadziwa izi ndipo adavomereza kuti sizinali zabwino, koma adanena kuti mndandandawo unali wofulumira nthawi 1000 pa laputopu yake kuposa Sherlock. Ndithudi, zimenezi zinatipweteka. Kotero ife tinayang'ana mozama.
Chifukwa ndikuwoneka bwino
Tinayang'ana zomwe imachita ls polemba ndandanda, ndi chifukwa chake ndondomekoyi imatenga nthawi yayitali. Pa zogawa zamakono zambiri ls mwachisawawa imayenda ngati ls --color=auto, chifukwa aliyense amakonda mitundu.
Koma mitundu yokongola imabwera pamtengo: pa fayilo iliyonse ls ayenera kupeza zambiri za mtundu wa fayilo, zilolezo zake, mbendera, mawonekedwe owonjezera ndi zina zotero kuti asankhe mtundu woyenera.
Njira imodzi yosavuta yothetsera vutoli ndikuyimitsa mtundu mu ls palimodzi, koma taganizirani kukwiya kwa ogwiritsa ntchito. Mulimonsemo musachotse zotulutsa zamtundu, sitiri zilombo.
Kotero ife tinayang'ana mozama. ls zolemba zamitundu kudzera pazosintha zachilengedwe LS_COLORS, yomwe yakhazikitsidwa dircolors(1) kutengera fayilo yosinthira dir_colors(5)... Inde, (ndipo ngati simukudziwa za mafayilo (chitani), ndiye dir_colors , Ngakhale zilizonse).
Tiyeni tione bwinobwino
Kuti tiwone mtundu wamtundu womwe umayambitsa kuchepa, tidapanga malo oyesera:
$ mkdir $SCRATCH/dont
$ touch $SCRATCH/dont/{1..10000} # don't try this at home!
$ time ls --color=always $SCRATCH/dont | wc -l
10000
real 0m12.758s
user 0m0.104s
sys 0m0.699sMasekondi 12,7 kwa mafayilo 10, osati abwino kwambiri.
Mwa njira, tikufuna mbendera
--color=always: ngakhale amatembenukira kwals --color=auto, komalsimazindikira ngati sichinalumikizidwe ndi cholumikizira (mwachitsanzo ndi chitoliro kapena ndi njira yoloweranso) ndikuyimitsa utoto ngati yakhazikitsidwaauto. Munthu wochenjera.
Ndiye chikutenga nthawi yayitali bwanji? Tinayang'ana ndi strace:
$ strace -c ls --color=always $SCRATCH/dont | wc -l
10000
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
44.21 0.186617 19 10000 lstat
42.60 0.179807 18 10000 10000 getxattr
12.19 0.051438 5 10000 capget
0.71 0.003002 38 80 getdents
0.07 0.000305 10 30 mmap
0.05 0.000217 12 18 mprotect
0.03 0.000135 14 10 read
0.03 0.000123 11 11 open
0.02 0.000082 6 14 close
[...]
Uwu: mafoni 10 lstat(), mafoni 10 getxattr() (zomwe zonse zimalephera chifukwa chilengedwe chathu chilibe zomwe ls akufuna), mafoni 10 capget().
Ndithudi izi zikhoza kukonzedwa bwino.
Kuthekera? Ayi
Kutsatira malangizo , tinayesa kuletsa kuyang'ana mawonekedwe :
$ eval $(dircolors -b | sed s/ca=[^:]*:/ca=:/)
$ time strace -c ls --color=always $SCRATCH/dont | wc -l
10000
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
98.95 0.423443 42 10000 lstat
0.78 0.003353 42 80 getdents
0.04 0.000188 10 18 mprotect
0.04 0.000181 6 30 mmap
0.02 0.000085 9 10 read
0.02 0.000084 28 3 mremap
0.02 0.000077 7 11 open
0.02 0.000066 5 14 close
[...]
------ ----------- ----------- --------- --------- ----------------
100.00 0.427920 10221 6 total
real 0m8.160s
user 0m0.115s
sys 0m0.961s
Wow, mpaka 8 masekondi othamanga! Tinachotsa mafoni onse okwera mtengowo getxattr(), ndi zovuta capget() zinasowanso, kwambiri.
Koma pali mafoni okwiyitsa awa lstat(), Ngakhaleβ¦
Mukufuna maluwa angati?
Choncho, tinayang'anitsitsa LS_COLORS.
Choyamba tidangoyimitsa kusinthaku:
$ echo $LS_COLORS rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:su=37;41:sg=30;43:ca=:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arc=01;31:*.arj=01;31:*.taz=01;31:*.lha=01;31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.tzo=01;31:*.t7z=01;31:*.zip=01;31:*.z=01;31:*.Z=01;31:*.dz=01;31:*.gz=01;31:*.lrz=01;31:*.lz=01;31:*.lzo=01;31:*.xz=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.alz=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.cab=01;31:*.jpg=01;35:*.jpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.axv=01;35:*.anx=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.au=00;36:*.flac=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.axa=00;36:*.oga=00;36:*.spx=00;36:*.xspf=00;36: $ unset LS_COLORS $ echo $LS_COLORS $ time ls --color=always $SCRATCH/dont | wc -l 10000 real 0m13.037s user 0m0.077s sys 0m1.092s
Chani!?! Padakali 13 seconds?
Iwo likukhalira kuti pamene chilengedwe variable LS_COLORS chimodzi chokha mwa zinthu zake sichinafotokozedwe kapena chikusowa <type>=color:, imagwiritsa ntchito nkhokwe zomangidwa mwachisawawa ndipo imagwiritsabe ntchito mitundu. Chifukwa chake ngati mukufuna kuletsa mitundu yamtundu wina wa fayilo, muyenera kuyisintha <type>=: kapena <type> 00 mu file DIR_COLORS.
Pambuyo poyesa ndi zolakwika zambiri, tinachepetsa kusaka kwathu mpaka izi:
EXEC 00
SETUID 00
SETGID 00
CAPABILITY 00chomwe chalembedwa ngati
LS_COLORS='ex=00:su=00:sg=00:ca=00:'
Izi zikutanthauza kuti: osasankha mafayilo potengera mawonekedwe. , koma pang'onopang'ono , pa .
Timafulumira ls
Ndipo ngati simuchita chilichonse mwa macheke awa, imbani lstat() kutha, ndipo tsopano ndi nkhani yosiyana kwambiri:
$ export LS_COLORS='ex=00:su=00:sg=00:ca=00:'
$ time strace -c ls --color=always $SCRATCH/dont | wc -l
10000
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
63.02 0.002865 36 80 getdents
8.10 0.000368 12 30 mmap
5.72 0.000260 14 18 mprotect
3.72 0.000169 15 11 open
2.79 0.000127 13 10 read
[...]
------ ----------- ----------- --------- --------- ----------------
100.00 0.004546 221 6 total
real 0m0.337s
user 0m0.032s
sys 0m0.029sMasekondi 0,3 pamndandanda wamafayilo 10, mbiri.
Kupanga Sherlock
Kuyambira masekondi 13 okhala ndi zosintha zosasintha mpaka masekondi 0,3 ndi zosintha zazing'ono LS_COLORS kumatanthauza kuthamangitsidwa kwa 40 chifukwa cha kusakhalapo setuid / setgid ndi mafayilo osinthika amitundu. Osati kutaya kwakukulu chotero.
Zachidziwikire, izi zakhazikitsidwa ku Sherlock kwa aliyense wogwiritsa ntchito.
Koma ngati mukufuna kubweza utoto, mutha kubwereranso kumakonzedwe osasintha:
$ unset LS_COLORS
Koma pamakalozera omwe ali ndi mafayilo ambiri, onetsetsani kuti mwapanga khofi ikugwira ntchito ls.
Source: www.habr.com