Skip to content

Instantly share code, notes, and snippets.

View vshabanov's full-sized avatar

Vladimir Shabanov vshabanov

55 followers · 0 following
View GitHub Profile
@vshabanov
vshabanov / OneBRC.hs
Last active March 21, 2024 22:19
One billion lines challenge
{-# LANGUAGE GHC2021, LambdaCase, PatternSynonyms, RecordWildCards,
ViewPatterns, OverloadedStrings, GADTs, NoMonoLocalBinds,
UnboxedTuples, MagicHash #-}
{-# OPTIONS_GHC -O2 -fspec-constr-count=100 -fllvm #-}
-- need at least 8 to completely remove all allocations
-- (I don't know what change lead to it)
{-# OPTIONS_GHC -Wall -Wno-gadt-mono-local-binds -Wno-type-defaults #-}
@vshabanov
vshabanov / dnsutils.hs
Created October 2, 2017 12:53
Some utilities to work with dns package
resolveA :: DNSCache -> String -> IO (Either T.Text HostAddress)
resolveA c d =
handle Left $ checkDomain id d $ fmap errorStr $ resolve c (B.pack d)
resolveCachedA :: DNSCache -> String -> IO (Maybe (Either T.Text HostAddress))
resolveCachedA c d =
handle (Just . Left) $ checkDomain Just d $ fmap (fmap errorStr) $ resolveCache c (B.pack d)
handle f a = a `E.catch` handleError f
@vshabanov
vshabanov / list.hs
Created September 3, 2017 23:58
Полнофункциональные гетерогенные списки
{-# LANGUAGE GADTs #-}
class Clickable a where
click :: a -> String
class Renderable a where
render :: a -> String
data Interface a where
Clickable :: Clickable a => Interface a
Renderable :: Renderable a => Interface a
@vshabanov
vshabanov / AesonUnicodeTest.hs
Last active October 19, 2016 23:32
import qualified Data.ByteString.Lazy.Char8 as B
import qualified Data.Text.Lazy as T
import qualified Data.Text.Lazy.Encoding as T
import qualified Data.Aeson as JSON
import Data.Char
import Text.Printf
import Control.Monad
-- wget http://www.unicode.org/Public/9.0.0/ucd/UnicodeData.txt
@vshabanov
vshabanov / gc
Created May 16, 2014 17:40
Лог GC
/home/volodya/bazqux/reader +RTS -N6 -T -A64m -I0 -M15G -Sgc.log
Alloc Copied Live GC GC TOT TOT Page Flts
bytes bytes bytes user elap user elap
...
200204936 11385664 4462860272 0.07 0.01 220.24 712.22 0 0 (Gen: 0)
125044568 14154720 4466342848 0.05 0.01 220.38 713.54 0 0 (Gen: 0)
143563344 28353016 4485534120 0.11 0.02 220.58 713.96 0 0 (Gen: 0)
111524720 2261676760 2517120536 3.88 0.65 224.51 714.69 0 0 (Gen: 1)
213486648 31853152 2547183104 0.14 0.02 224.86 715.83 0 0 (Gen: 0)
148648432 25858736 2548365176 0.11 0.02 225.08 716.76 0 0 (Gen: 0)
@vshabanov
vshabanov / gist:5768546
Created June 12, 2013 19:55
Riak Segmentation Fault in eleveldb.so
Core was generated by `/tank/riak-1.3.1/erts-5.9.1/bin/beam.smp -K true -A 64 -W w -- -root /tank/riak'.
Program terminated with signal 11, Segmentation fault.
#0 0x00007f162547fa30 in MurmurHash64A(void const*, int, unsigned int) ()
from /tank/riak-1.3.1/lib/eleveldb-1.3.0/priv/eleveldb.so
(gdb) bt
#0 0x00007f162547fa30 in MurmurHash64A(void const*, int, unsigned int) ()
from /tank/riak-1.3.1/lib/eleveldb-1.3.0/priv/eleveldb.so
#1 0x00007f162547833c in leveldb::(anonymous namespace)::BloomFilterPolicy2::CreateFilter(leveldb::Slice const*, int, std::string*) const ()
from /tank/riak-1.3.1/lib/eleveldb-1.3.0/priv/eleveldb.so
@vshabanov
vshabanov / XMLParser.hs
Created January 10, 2012 08:23
Более шустрый парсер для tagsoup (где-то раз в 200 быстрее)
{-# LANGUAGE OverloadedStrings, BangPatterns, FlexibleInstances #-}
-- | Тупейший (и, надеюсь, быстрый) парсер xml -> теги.
--
-- Выдает где-то от 40МБ/сек (а где-то и 80 и 200)
--
-- Все теги и атрибуты возвращаются в lowercase (строка меняется INPLACE,
-- для уменьшения числа аллокаций и фрагментации)
--
-- После профилирования выяснилось,
-- что TagSoup отжирает 75% памяти и >50% времени. Более того,