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isyufu / emacs-doom-clojure-install.md
Created September 11, 2023 11:30
Emacs Doom + Clojure install

install Doom Emacs + Clojure

install apt install

But before you doom yourself, here are some things you should know:

@isyufu
isyufu / ParquetUtils.kt
Last active January 26, 2022 10:00
Read write parqet file in kotlin\java
package com.my.helpers
import io.github.serpro69.kfaker.faker
import mu.KLogging
import org.apache.avro.SchemaBuilder
import org.apache.avro.generic.GenericData
import org.apache.avro.generic.GenericRecord
import org.apache.avro.reflect.ReflectData
import org.apache.parquet.avro.AvroParquetWriter
import org.apache.parquet.hadoop.ParquetFileReader
@isyufu
isyufu / parallel_execution_by_key.java
Created July 26, 2021 01:43
java reactor parallel execution by key
import java.util.Arrays;
import reactor.core.publisher.Flux;
import reactor.core.scheduler.Schedulers;
Flux.fromIterable(Arrays.asList(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20))
.groupBy(x -> x.hashCode() % 5)
.parallel(10)
.runOn(Schedulers.parallel())
.flatMap(g -> g.collectMap(y -> {log.info(" g: "+g.key()+" y: "+ y); return y;}).log("subscr"))
.subscribe();
@isyufu
isyufu / scylldba_notes.md
Last active May 6, 2020 15:27
scylldba notes

data-modeling

docker run --name scyllaU -d scylladb/scylla:3.0.10
docker exec -it scyllaU nodetool status
docker exec -it scyllaU cqlsh

CREATE KEYSPACE Pets_Clinic WITH replication = {'class': 'SimpleStrategy', 'replication_factor' : 1};
use Pets_Clinic; 

CREATE TABLE heartrate_v1 (
@isyufu
isyufu / combineInterfaces.kt
Created January 17, 2019 00:28
kt getUserFromDatabase getOrElse FromNetwork
interface DaoOperationsSyntax {
val dao: DaoDatabase
fun User.queryUser() =
dao.query("SELECT * from Users where userId = ${this.id}")
fun Company.queryCompany() =
dao.query("SELECT * from Companies where companyId = ${this.id}")
}
@isyufu
isyufu / Latency Comparison Numbers
Created December 25, 2018 23:43
Latency Comparison Numbers
Latency Comparison Numbers
--------------------------
L1 cache reference 0.5 ns
Branch mispredict 5 ns
L2 cache reference 7 ns 14x L1 cache
Mutex lock/unlock 25 ns
Main memory reference 100 ns 20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy 3,000 ns 3 us
Send 1K bytes over 1 Gbps network 10,000 ns 10 us
Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD
@isyufu
isyufu / SendMessageToAkkaStream.scala
Created June 26, 2018 08:26
Send message to AkkaStream
import akka.actor.{ActorSystem, Props}
import akka.stream.{ActorMaterializer, OverflowStrategy}
import akka.stream.scaladsl.{Flow, Sink, Source}
import com.typesafe.config.ConfigFactory
import jetbrains.exodus.entitystore.{PersistentEntityStoreImpl, PersistentEntityStores}
import jetbrains.exodus.env.{Environments, Store}
import org.apache.commons.lang3.SerializationUtils
import collection.JavaConverters._
@isyufu
isyufu / TryXodus.scala
Created June 21, 2018 00:39
JetBrains Xodus is a Java transactional schema-less embedded database
/* "org.jetbrains.xodus" % "xodus-openAPI" % "1.2.3",
"org.jetbrains.xodus" % "xodus-entity-store" % "1.2.3",
*/
object XodusApp extends App {
import jetbrains.exodus.bindings.StringBinding.{entryToString, stringToEntry}
import jetbrains.exodus.env.StoreConfig.WITHOUT_DUPLICATES
val env = Environments.newInstance("data")
@isyufu
isyufu / TryDoobie.scala
Created June 16, 2018 03:02
Doobie with SQLite
/* library dependecies
"org.xerial" % "sqlite-jdbc" % "3.23.1",
"org.tpolecat" %% "doobie-core" % "0.5.3",
"org.tpolecat" %% "doobie-hikari" % "0.5.3", // HikariCP transactor.
"org.tpolecat" %% "doobie-specs2" % "0.5.3", // Specs2 support for typechecking statements.
"org.tpolecat" %% "doobie-scalatest" % "0.5.3", // ScalaTest support for typechecking statements.
*/
object TryDoobie extends App {
import doobie._
@isyufu
isyufu / grep.sh
Created October 16, 2017 03:45
grep cheat sheet
#!/bin/sh
#http://www.thegeekstuff.com/2011/01/advanced-regular-expressions-in-grep-command-with-10-examples-%E2%80%93-part-ii/
# GENERAL
# print lines begining with range of letters
grep ^[A-D] table.txt
# REGEX