jm42

Flashback Logging

NOTE: Post-writing, I discovered a similar concept named Ring Buffer Logging. What sets Flashback Logging apart is its approach to handling the buffer. When a log event matches the standard log level threshold, such as 'INFO', the buffer is cleared. This behavior is based on the rationale that such a log event indicates the system's return to normal operations, eliminating the need to keep previously buffered entries.

Introduction

Flashback Logging is a design pattern in the logging and debugging domain. Its primary goal is to reduce the time spent on debugging by making verbose logs readily available during error occurrences without the storage overhead of always keeping verbose logs.

`$HOME`, Not So Sweet `$HOME`

Preface
1 What is $HOME to you?
2 Setup
- 2.1 Linux
2.1.4 xdg-user-dirs

macOS Internals

Understand your Mac and iPhone more deeply by tracing the evolution of Mac OS X from prelease to Swift. John Siracusa delivers the details.

Starting Points

How to use this gist

You've got two main options:

year	population (M)	time	pop.avg (M)	years lived (B)	total years lived (B)	% years lived
-190000	0
-50000	2	140000	1	140	140	6.45
-8000	5	42000	3.5	147	287	13.21
-7000	7	1000	6	6	293	13.49
-6000	14	1000	10.5	11	304	14
-5000	27	1000	20.5	21	325	14.96
-4000	50	1000	38.5	39	364	16.76
-3000	100	1000	75	75	439	20.21

🐘 Postgres Standalone

Why?

Localize your database into one single folder of your choosing.
No sudo / root requirement.
Run multiple Postgres at the same time on the same machine- Full bare metal performance.
Postgres is a great starter before moving to "slow single machine but horizontal scale": CockroachDB, ScyllaDB, etc.

Compile

Random numbers in bash et al

There is a variable $RANDOM than you can read in bash or zsh to get a random number beteen 0 and 32767. Here in zsh on my (old) mac:

% echo $RANDOM
13757
% echo $RANDOM
16896

	/* wide */
	.wide .markdown-preview-sizer {
	max-width: unset !important;
	}

	.life-calendar p a.internal-link {
	display: inline-block;
	}

	import { writeFileSync } from "node:fs"

	// data from https://en.wikipedia.org/wiki/Estimates_of_historical_world_population PRB column
	// and https://www.prb.org/articles/how-many-people-have-ever-lived-on-earth
	const data = `
	-190000 0
	-50000 2M
	-8000 5M
	0 300M
	1200 450M

	//SPDX-License-Identifier: MIT
	pragma solidity >=0.8.0 <0.9.0;

	abstract contract Registry {
	function resolver(bytes32 node) external view virtual returns (address);
	}

	abstract contract Resolver {
	function addr(bytes32 node) external view virtual returns (address);
	}

	$ grep -P "^[ABCDEFabcdefOoIi]{6,6}$" /usr/share/dict/words \| tr 'OoIi' '0011' \| tr '[:lower:]' '[:upper:]' \| awk '{print "#" $0}'
	#ACAD1A
	#B0BB1E
	#DEBB1E
	#AB1DED
	#ACAC1A
	#ACCEDE
	#AC1D1C
	#BAB1ED
	#BA0BAB