javier javiermon

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Learning Rust

The following is a list of resources for learning Rust as well as tips and tricks for learning the language faster.

Warning

Rust is not C or C++ so the way your accustomed to do things in those languages might not work in Rust. The best way to learn Rust is to embrace its best practices and see where that takes you.

The generally recommended path is to start by reading the books, and doing small coding exercises until the rules around borrow checking become intuitive. Once this happens, then you can expand to more real world projects. If you find yourself struggling hard with the borrow checker, seek help. It very well could be that you're trying to solve your problem in a way that goes against how Rust wants you to work.

Here's a list of mildly interesting things about the C language that I learned mostly by consuming Clang's ASTs. Although surprises are getting sparser, I might continue to update this document over time.

There are many more mildly interesting features of C++, but the language is literally known for being weird, whereas C is usually considered smaller and simpler, so this is (almost) only about C.

1. Combined type and variable/field declaration, inside a struct scope [https://godbolt.org/g/Rh94Go]

struct foo {
   struct bar {
 int x;

Tuning Intel Skylake and beyond for optimal performance and feature level support on Linux:

Note that on Skylake, Kabylake (and the now cancelled "Broxton") SKUs, functionality such as power saving, GPU scheduling and HDMI audio have been moved onto binary-only firmware, and as such, the GuC and the HuC blobs must be loaded at run-time to access this functionality.

Enabling GuC and HuC on Skylake and above requires a few extra parameters be passed to the kernel before boot.

Instructions provided for both Fedora and Ubuntu (including Debian):

Note that the firmware for these GPUs is often packaged by your distributor, and as such, you can confirm the firmware blob's availability by running:

How to recover lost Python source code if it's still resident in-memory

I screwed up using git ("git checkout --" on the wrong file) and managed to delete the code I had just written... but it was still running in a process in a docker container. Here's how I got it back, using https://pypi.python.org/pypi/pyrasite/ and https://pypi.python.org/pypi/uncompyle6

Attach a shell to the docker container

Install GDB (needed by pyrasite)

apt-get update && apt-get install gdb

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

Clarify and agree on the scope of the system

User cases (description of sequences of events that, taken together, lead to a system doing something useful)
- Who is going to use it?
- How are they going to use it?

emacs --daemon to run in the background. emacsclient.emacs24 <filename/dirname> to open in terminal

NOTE: "M-m and SPC can be used interchangeably".

Undo - C-/
Redo - C-?
Change case: 1. Camel Case : M-c 2. Upper Case : M-u

Lower Case : M-l

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

	#! /usr/bin/env ruby

	# NOTE: Requires Ruby 2.1 or greater.

	# This script can be used to parse and dump the information from
	# the 'html/contact_info.htm' file in a Facebook user data ZIP download.
	#
	# It prints all cell phone call + SMS message + MMS records, plus a summary of each.
	#
	# It also dumps all of the records into CSV files inside a 'CSV' folder, that is created

	#!/usr/bin/python
	# -- coding: utf-8 --

	import subprocess


	__all__ = ["transform"]
	__version__ = '0.3'
	__author__ = 'Christoph Burgmer <[email protected]>'
	__url__ = 'http://github.com/cburgmer/upsidedown'