jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

hellerbarde

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

jdamcd

SUBSYSTEM=="usb", ATTR{idVendor}=="0502", MODE="0666", GROUP="plugdev" #Acer
SUBSYSTEM=="usb", ATTR{idVendor}=="0b05", MODE="0666", GROUP="plugdev" #ASUS
SUBSYSTEM=="usb", ATTR{idVendor}=="413c", MODE="0666", GROUP="plugdev" #Dell
SUBSYSTEM=="usb", ATTR{idVendor}=="0489", MODE="0666", GROUP="plugdev" #Foxconn
SUBSYSTEM=="usb", ATTR{idVendor}=="04c5", MODE="0666", GROUP="plugdev" #Fujitsu
SUBSYSTEM=="usb", ATTR{idVendor}=="04c5", MODE="0666", GROUP="plugdev" #Fujitsu Toshiba
SUBSYSTEM=="usb", ATTR{idVendor}=="091e", MODE="0666", GROUP="plugdev" #Garmin-Asus
SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", MODE="0666", GROUP="plugdev" #Google
SUBSYSTEM=="usb", ATTR{idVendor}=="201E", MODE="0666", GROUP="plugdev" #Haier
SUBSYSTEM=="usb", ATTR{idVendor}=="109b", MODE="0666", GROUP="plugdev" #Hisense

chrisbanes

/*
 * Copyright (C) 2006 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software

JakeWharton

import android.text.SpannableStringBuilder;
import java.util.ArrayDeque;
import java.util.Deque;

import static android.text.Spanned.SPAN_INCLUSIVE_EXCLUSIVE;

/** A {@link SpannableStringBuilder} wrapper whose API doesn't make me want to stab my eyes out. */
public class Truss {
  private final SpannableStringBuilder builder;
  private final Deque<Span> stack;

JakeWharton

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;

public class ForegroundImageView extends ImageView {
  private Drawable foreground;

hkurokawa

#! /bin/bash

## This script is for taking a screen shot of an Android device.
## If possible, it tries to resize the image file and then copy to the clipboard.
##
## Note the script generates screenshot_yyyyMMddHHmmss.png and screenshot_yyyyMMddHHmmss_s.png
## under /sdcard on the device (you can specify another location with '-t' option)
## and copies it to the current working directory.
## 
## The script passes unrecognized arguments to adb command, which means you can specify "-e" or "-d"

dlew

public static Action1<Throwable> crashOnError() {
    final Throwable checkpoint = new Throwable();
    return throwable -> {
        StackTraceElement[] stackTrace = checkpoint.getStackTrace();
        StackTraceElement element = stackTrace[1]; // First element after `crashOnError()`
        String msg = String.format("onError() crash from subscribe() in %s.%s(%s:%s)",
            element.getClassName(),
            element.getMethodName(),
            element.getFileName(),
            element.getLineNumber());

bkase

Production-Ready(?) Native Single-Atom-State Purely Functional Reactive Composable UI Components, or PRNSAASPFRUICC

The native UI toolkits on Android and iOS are frustratingly imperative. Unfortunately, there has been little architecture evolution (unlike the web). However, nothing(ish) is stopping us from bolting something "nice" on top. By nice I mean single-atom-state purely functional reactive composable UI components. In this post, I'll explain what this title means, the inspiration behind the design of the framework, an example component, and dive a little into the framework's implementation.

Right now, there only exists a Kotlin (Android) implementation, but a Swift port will be relatively straightforward and will happen soon.

Let's break down the title:

• "Production-Ready"

nickbutcher

<?xml version="1.0" encoding="utf-8"?>
<!--
  Copyright 2016 Google Inc.

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0