jFransham

Achieving warp speed with Rust

Contents:

• Number one optimization tip: don't
• Never optimize blindly
• Don't bother optimizing one-time costs
• Improve your algorithms
• CPU architecture primer
• Keep as much as possible in cache
• Keep as much as possible in registers

KodrAus

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.

saurabhshri

Install and use pip in a local directory without root/sudo access.

By: @saurabhshri

Why?

Many users when are given server access, do not have root (or sudo) privileges and can not simply do sudo apt-get install python-pip . Here's an easy way you can install and use pip without root (or sudo) access in a local directory. Note : This works without easy_install too.

How?

AtulKsol

psql: FATAL: Peer authentication failed for user “postgres” (or any user)

The connection failed because by default psql connects over UNIX sockets using peer authentication, that requires the current UNIX user to have the same user name as psql. So you will have to create the UNIX user postgres and then login as postgres or use sudo -u postgres psql database-name for accessing the database (and psql should not ask for a password).

If you cannot or do not want to create the UNIX user, like if you just want to connect to your database for ad hoc queries, forcing a socket connection using psql --host=localhost --dbname=database-name --username=postgres (as pointed out by @meyerson answer) will solve your immediate problem.

But if you intend to force password authentication over Unix sockets instead of the peer method, try changing the following pg_hba.conf* line:

from

vasanthk

System Design Cheatsheet

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

Basic Steps

1. 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?

karenyyng

Table Of Content

Skip to the relevant sections if needed.

• 2-min tutorial to do it the quick-and-dirty-way
• Concepts for resolving Git conflicts
• Setting up different editors / tool for using git mergetool
  • Finding out what mergetool editors are supported
• mergetool simple code example for vimdiff
  • Resolving conflict from a Git pull
• Other great references and tutorials

lolo32

CLang optimizations on Mac OSX

Version:

Apple LLVM version 6.0 (clang-600.0.57) (based on LLVM 3.5svn)
Target: x86_64-apple-darwin14.1.0
Thread model: posix

This was made with commands:

rain1024

PdfLatex is a tool that converts Latex sources into PDF. This is specifically very important for researchers, as they use it to publish their findings. It could be installed very easily using Linux terminal, though this seems an annoying task on Windows. Installation commands are given below.

• Install the TexLive base

sudo apt-get install texlive-latex-base

• Also install the recommended and extra fonts to avoid running into the error [1], when trying to use pdflatex on latex files with more fonts.

adamgreig

Embedded Rust on STM32F4

My notes from implementing Job Vranish's excellent guide.

Follow along with the guide above, getting rustc from rustup or similar:

rustc 1.0.0-nightly (dcaeb6aa2 2015-01-18 11:28:53 +0000)
binary: rustc
commit-hash: dcaeb6aa23ecba2dc2af870668a9239136d20fa3

commit-date: 2015-01-18 11:28:53 +0000

jackgris

# build with
#  docker build -t 'necrobious/haskell-ghc-7.8-64' .
 
FROM ubuntu:14.04
 
MAINTAINER [email protected]
ENV DEBIAN_FRONTEND noninteractive
 
####### Install Dependencies ###################################################
RUN apt-get -y update