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hackape / latency.markdown
Created July 3, 2022 20:53 — forked from hellerbarde/latency.markdown
Latency numbers every programmer should know

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

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hackape / explanation.md
Created January 21, 2022 03:23 — forked from masak/explanation.md
How is git commit sha1 formed

Ok, I geeked out, and this is probably more information than you need. But it completely answers the question. Sorry. ☺

Locally, I'm at this commit:

$ git show
commit d6cd1e2bd19e03a81132a23b2025920577f84e37
Author: jnthn <jnthn@jnthn.net>
Date:   Sun Apr 15 16:35:03 2012 +0200

When I added FIRST/NEXT/LAST, it was idiomatic but not quite so fast. This makes it faster. Another little bit of masak++'s program.

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hackape / crypto-aes-gcm.js
Created March 24, 2021 09:02 — forked from chrisveness/crypto-aes-gcm.js
Uses the SubtleCrypto interface of the Web Cryptography API to encrypt and decrypt text using AES-GCM (AES Galois counter mode).
/**
* Encrypts plaintext using AES-GCM with supplied password, for decryption with aesGcmDecrypt().
* (c) Chris Veness MIT Licence
*
* @param {String} plaintext - Plaintext to be encrypted.
* @param {String} password - Password to use to encrypt plaintext.
* @returns {String} Encrypted ciphertext.
*
* @example
* const ciphertext = await aesGcmEncrypt('my secret text', 'pw');