LingFeng TheWaWaR

Problem

I have two Github accounts: oanhnn (personal) and superman (for work). I want to use both accounts on same computer (without typing password everytime, when doing git push or pull).

Solution

Use ssh keys and define host aliases in ssh config file (each alias for an account).

How to?

Generate ssh key pairs for accounts and add them to GitHub accounts.

The Problem

JoinMarket has a problem where it assumes different nicknames have different bitcoin wallets. This can be exploited by people running multiple yield generator bots from the same wallet, so they get a higher rate of profit at the expense of de-legitimizing the system for privacy.

Crypto primitive 1: Merkle Tree

A merkle tree is a way of producing a commitment to a set, which can later can prove that elements are contained within the set using only O(logN) data, and only revealing one other element in the set.

For example here is a merkle tree commiting to a set of numbers {6, 3, 9, 0, 8, 4, 7, 2}

Profiling performance

Using perf:

$ perf record -g binary
$ perf script | stackcollapse-perf.pl | rust-unmangle | flamegraph.pl > flame.svg

NOTE: See @GabrielMajeri's comments below about the -g option.

Achieving warp speed with Rust

1. Get LLVM 7 compiled with webassembly support.

You'll need LLVM to output to the WASM target. This has just been added by default in trunk, so if LLVM >7 is available, you might be able to just brew install llvm.

If you have wasm support already you should see:

$ llc --version

Memory profiling Rust code with heaptrack in 2019

I recently ran into a classic case of "our code is using way more memory than it should". So I took my first dive into memory profiling Rust code. I read several posts about this, including the following

	// To compile with gcc: (tested on Ubuntu 14.04 64bit):
	// g++ sdl2_opengl.cpp -lSDL2 -lGL
	// To compile with msvc: (tested on Windows 7 64bit)
	// cl sdl2_opengl.cpp /I C:\sdl2path\include /link C:\path\SDL2.lib C:\path\SDL2main.lib /SUBSYSTEM:CONSOLE /NODEFAULTLIB:libcmtd.lib opengl32.lib

	#include <stdio.h>
	#include <stdint.h>
	#include <assert.h>
	#include <SDL2/SDL.h>
	#include <SDL2/SDL_opengl.h>

	# In order for gpg to find gpg-agent, gpg-agent must be running, and there must be an env
	# variable pointing GPG to the gpg-agent socket. This little script, which must be sourced
	# in your shell's init script (ie, .bash_profile, .zshrc, whatever), will either start
	# gpg-agent or set up the GPG_AGENT_INFO variable if it's already running.

	# Add the following to your shell init to set up gpg-agent automatically for every shell
	if [ -f ~/.gnupg/.gpg-agent-info ] && [ -n "$(pgrep gpg-agent)" ]; then
	source ~/.gnupg/.gpg-agent-info
	export GPG_AGENT_INFO
	else

	const std = @import("std");
	const system = switch (std.builtin.os.tag) {
	.linux => std.os.linux,
	else => std.os.system,
	};

	const ThreadPool = @This();

	max_threads: u16,
	counter: u32 = 0,