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@bvaughn
bvaughn / infinite-lists-and-reflow.md
Last active December 27, 2023 18:51
Infinite lists and reflow

Infinite lists and reflow

In my experience, infinite lists use two basic layout strategies. The first uses absolute positioning to control where visible items are rendered. The second uses relative positioning (with top/left padding to offset for unrendered items).

In both cases, the list abstraction caches some metadata about the size of items once they have been rendered– so that it knows where to position the items that come after them.

Both of these strategies need to handle reflow. For example, changing the width of a list often affects the height of its itesm. Generally speaking, only the "window" of rendered (visible) items are remeasured in this case (because it would be too slow to rerender and remeasure all of the items before). But once a user scrolls backwards (up/left)– the list needs to account for the reflowed sizes. If it didn't, items would appear to jump up or down (depending on the delta between the previous, cached sizes and the new/reflowed sizes).

How the list deals with new sizes

@akehrer
akehrer / sqlite_to_json.sql
Created January 9, 2018 19:58
SQLite Results as JSON using the SQLite JSON1 extension
-- When SQLite is compiled with the JSON1 extensions it provides builtin tools
-- for manipulating JSON data stored in the database.
-- This is a gist showing SQLite return query data as a JSON object.
-- https://www.sqlite.org/json1.html
-- An example table with some data
CREATE TABLE users (
id INTEGER PRIMARY KEY NOT NULL,
full_name TEXT NOT NULL,
email TEXT NOT NULL,
@bvaughn
bvaughn / react-virtualized-framerate-test.js
Last active December 9, 2024 14:14
Quick demonstration of a way to measure scrolling performance for react-virtualized in an automated way
/** Measures framerate for the time between start() and stop() calls */
function FramerateMeasurer () {
this.start = () => {
this._beginTime = ( performance || Date ).now()
this._frames = 0
this._animationFrameId = requestAnimationFrame(this._loop)
}
this.stop = () => {
const endTime = ( performance || Date ).now()
@carlessanagustin
carlessanagustin / Nginx_Cheat_Sheet.md
Last active April 21, 2025 02:32
Nginx Cheat Sheet
@PurpleBooth
PurpleBooth / README-Template.md
Last active April 29, 2025 02:22
A template to make good README.md

Project Title

One Paragraph of project description goes here

Getting Started

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes. See deployment for notes on how to deploy the project on a live system.

Prerequisites

@tsiege
tsiege / The Technical Interview Cheat Sheet.md
Last active April 26, 2025 08:09
This is my technical interview cheat sheet. Feel free to fork it or do whatever you want with it. PLEASE let me know if there are any errors or if anything crucial is missing. I will add more links soon.

ANNOUNCEMENT

I have moved this over to the Tech Interview Cheat Sheet Repo and has been expanded and even has code challenges you can run and practice against!






\

@matthewlehner
matthewlehner / autopgsqlbackup
Created July 11, 2012 16:10
Auto PostgreSQL backup script.
#!/bin/bash
#
# PostgreSQL Backup Script Ver 1.0
# http://autopgsqlbackup.frozenpc.net
# Copyright (c) 2005 Aaron Axelsen <[email protected]>
#
# This script is based of the AutoMySQLBackup Script Ver 2.2
# It can be found at http://sourceforge.net/projects/automysqlbackup/
#
# The PostgreSQL changes are based on a patch agaisnt AutoMySQLBackup 1.9
@hellerbarde
hellerbarde / latency.markdown
Created May 31, 2012 13:16 — forked from jboner/latency.txt
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

@bartoszmajsak
bartoszmajsak / prepare-commit-msg.sh
Last active January 22, 2025 09:31
How to automatically prepend git commit with a branch name
#!/bin/bash
# This way you can customize which branches should be skipped when
# prepending commit message.
if [ -z "$BRANCHES_TO_SKIP" ]; then
BRANCHES_TO_SKIP=(master develop test)
fi
BRANCH_NAME=$(git symbolic-ref --short HEAD)
BRANCH_NAME="${BRANCH_NAME##*/}"