daniel-j-h

# Instrument binaries, pgo data to /data/pgo, serial make is important to not confuse the pgo generator
env CXXFLAGS='-march=native -fprofile-dir=/data/pgo -fprofile-generate=/data/pgo' cmake .. -DCMAKE_BUILD_TYPE=Release                   
make -j 1

# Run instrumented program, generate and write pgo data
./runIt

# Use profile data and feed into gcc, correct for threading counter noise, serial make is important to not confuse the pgo generator
env CXXFLAGS='-march=native -fprofile-dir=/data/pgo -fprofile-use=/data/pgo -fprofile-correction' cmake .. -DCMAKE_BUILD_TYPE=Release                   
make -j 1

daniel-j-h

update-alternatives --install "/usr/bin/ld" "ld" "/usr/bin/ld.gold" 20
update-alternatives --install "/usr/bin/ld" "ld" "/usr/bin/ld.bfd" 10

update-alternatives --config ld

ld --version
GNU gold

export CPP=cpp-5 gcc-5 g++-5
env CXXFLAGS='-march=native -flto -fuse-linker-plugin' cmake .. -DCMAKE_BUILD_TYPE=Release

daniel-j-h

package com.example.view

import androidx.compose.runtime.*
import androidx.compose.ui.Modifier
import androidx.compose.ui.platform.LocalContext
import androidx.compose.ui.platform.LocalLifecycleOwner
import androidx.compose.ui.viewinterop.AndroidView
import androidx.lifecycle.Lifecycle
import androidx.lifecycle.LifecycleEventObserver
import com.mapbox.geojson.Point

daniel-j-h

#!/usr/bin/env python3

import sys
import csv
import json
import argparse
from pathlib import Path


def main(args):

daniel-j-h

# Nix skeleton for compiler, cmake, boost.
# Dependencies (boost and others you specify) are getting built with selectec compiler (for ABI compatibility).
# Examples:
#   nix-shell --argstr compiler gcc5 --run 'mkdir build && cd build && cmake .. && cmake --build .'
#   nix-shell --argstr compiler gcc6 --run 'mkdir build && cd build && cmake .. && cmake --build .'
#   nix-shell --argstr compiler clang_38 --run 'mkdir build && cd build && cmake .. && cmake --build .'

{ nixpkgs ? import <nixpkgs> {}, compiler ? "gcc6" }:

let

daniel-j-h

On Logic Solvers

From SAT to SMT and back.

There is a Gist, see references [@gist].

Satisfiability (SAT)

Is a given formula (i.e. $\lnot A \land (B \lor C)$) satisfiable?

daniel-j-h

#include <stdexcept>
#include <utility>

class Str {
public:

  template <std::size_t N>
  constexpr Str(const char(&a)[N]) : p(a), s(N - 1) {}

  constexpr char operator[](std::size_t n) const {

daniel-j-h

Re-key your encrypted volumes

When you encrypt volumes like your laptop's SSD or USB sticks on Linux there's a high chance you're using Linux Unified Key Setup (LUKS) in the background. To decrypt volumes, LUKS uses your secret passphrase and puts it through a function to derive the actual volume decryption key. The key derivation function is supposed to be expensive to compute so that brute-force attacks are hard to pull off.

There are three problems with the LUKS setup in practice

1. The key derivation function gets benchmarked and tuned to your system to keep the decryption process short e.g. below a second because no one wants to wait too long
2. Therefore, if you encrypt volumes with a weak device like a laptop, the key derivation function will we weak
3. If you encrypted a device in the past and are still using its volume, you will not benefit from more recent key derivation function algorithms which have stronger guarantees against brute force attacks e.g. using GPUs

That's why you should re-key y

daniel-j-h

#!/usr/bin/env python2
# -*- coding: utf-8 -*-

# http://docs.sqlalchemy.org/en/latest/orm/self_referential.html

import json

from sqlalchemy import create_engine, Column, Integer, String, ForeignKey, CheckConstraint
from sqlalchemy.orm import sessionmaker, relationship, backref
from sqlalchemy.ext.declarative import declarative_base

daniel-j-h

#!/usr/bin/env python3

'''
pip install tqdm numpy pillow mercantile 'rasterio==1.0b1' 'rio-tiler==1.0a7'
'''

import os

import argparse