hellerbarde

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

albans

import static org.mockito.Matchers.any;

import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

import java.lang.reflect.InvocationTargetException;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;

jackrusher

The venerable master Qc Na was walking with his student, Anton. Hoping to prompt the master into a discussion, Anton said "Master, I have heard that objects are a very good thing - is this true?" Qc Na looked pityingly at his student and replied, "Foolish pupil - objects are merely a poor man's closures."

Chastised, Anton took his leave from his master and returned to his cell, intent on studying closures. He carefully read the entire "Lambda: The Ultimate..." series of papers and its cousins, and implemented a small Scheme interpreter with a closure-based object system. He learned much, and

leonardofed

A curated list of AWS resources to prepare for the AWS Certifications

A curated list of awesome AWS resources you need to prepare for the all 5 AWS Certifications. This gist will include: open source repos, blogs & blogposts, ebooks, PDF, whitepapers, video courses, free lecture, slides, sample test and many other resources.

---

sibelius

let start = 0;
const limit = 10;

items.slice(start, limit).forEach(subset =>
    await Promise.all(subset.map(async (item) => {
        // do async work with a single item
    }))
        .then(() => (start += limit)
);

antirez

# LVDB - LLOOGG Memory DB
# Copyriht (C) 2009 Salvatore Sanfilippo <[email protected]>
# All Rights Reserved

# TODO
# - cron with cleanup of timedout clients, automatic dump
# - the dump should use array startsearch to write it line by line
#   and may just use gets to read element by element and load the whole state.
# - 'help','stopserver','saveandstopserver','save','load','reset','keys' commands.
# - ttl with milliseconds resolution 'ttl a 1000'. Check ttl in dump!

jFransham

Achieving warp speed with Rust

Contents:

• Number one optimization tip: don't
• Never optimize blindly
• Don't bother optimizing one-time costs
• Improve your algorithms
• CPU architecture primer
• Keep as much as possible in cache
• Keep as much as possible in registers

amiyasahu

import com.google.common.base.Defaults;
import com.google.common.collect.Sets;

import javax.annotation.Nonnull;
import java.beans.BeanInfo;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Set;

beginor

CREATE SEQUENCE public.global_id_seq;
ALTER SEQUENCE public.global_id_seq OWNER TO postgres;

CREATE OR REPLACE FUNCTION public.id_generator()
    RETURNS bigint
    LANGUAGE 'plpgsql'
AS $BODY$
DECLARE
    our_epoch bigint := 1314220021721;
    seq_id bigint;

mikepruett3

<#
.SYNOPSIS
    Script to Initialize my custom powershell setup.
.DESCRIPTION
    Script uses scoop
.NOTES
    **NOTE** Will configure the Execution Policy for the "CurrentUser" to Unrestricted.

    Author: Mike Pruett
    Date: October 18th, 2018