akotlov

TextureView

You need to initialize TextureView before opening a camera. TextureView is for displaying the image from camera on the device. However, you cannot use it unless the texture is ready, either because the screen is currently off or it is initializing.

You should check mTextureView.isAvailable() before opening your camera. Else you will mTextureView.setSurfaceTextureListener(). And open your camera in the callback method onSurfaceTextureListener.

Camera

Before opening your camera you should check for a camera permission first.

akotlov

/**
 * Deep diff between two object, using lodash
 * @param  {Object} object Object compared
 * @param  {Object} base   Object to compare with
 * @return {Object}        Return a new object who represent the diff
 */
function difference(object, base) {
	function changes(object, base) {
		return _.transform(object, function(result, value, key) {
			if (!_.isEqual(value, base[key])) {

akotlov

CREATE OR REPLACE FUNCTION notify_trigger() RETURNS trigger AS $$
	DECLARE
		channel_name varchar DEFAULT (TG_TABLE_NAME || '_changes');
	BEGIN
		IF TG_OP = 'INSERT' THEN
			PERFORM pg_notify(channel_name, '{"id": "' || NEW.id || '"}');
			RETURN NEW;
		END IF;
		IF TG_OP = 'DELETE' THEN
			PERFORM pg_notify(channel_name, '{"id": "' || OLD.id || '"}');

akotlov

#!/usr/bin/env sh

##
# This is script with useful tips taken from:
#   https://github.com/mathiasbynens/dotfiles/blob/master/.osx
#
# install it:
#   curl -sL https://raw.github.com/gist/2263406/osx.sh | sh
#

akotlov

// For demonstration purposes
async function getHTML () {
  if (Math.random() > 0.5) {
    return 'Randomly succeeded'
  } else {
    throw new Error('Randomly failed')
  }
}

// Checks that an instance promise didn't resolve with an error,

akotlov

#!/bin/sh
#
# redis - this script starts and stops the redis daemon
#
# chkconfig:   - 85 15
# description:  Redis is an open source, BSD licensed, advanced \
#               key-value store. It is often referred to as a \
#               data structure server since keys can contain \
#               strings, hashes, lists, sets and sorted sets. 
# processname: redis

akotlov

1. Install Linux updates, set time zones, followed by GCC and Make

sudo yum -y update
sudo ln -sf /usr/share/zoneinfo/America/Indianapolis \
/etc/localtime
sudo yum -y install gcc make
 

2. Download, Untar and Make Redis 2.8 (check here http://redis.io/download)

akotlov

// Port, host and auth token of Redis server might be defined as environment
// variables. If not, fall back to defaults.
var redisPort = process.env.REDIS_PORT || 6379,
    redisHost = process.env.REDIS_HOST || '127.0.0.1',
    redisAuth = process.env.REDIS_AUTH || null,
    redis = require('redis');

// Since we are waiting for the error event, we don't have to check for errors
// individually after each Redis command.
var onError = function (error) {

akotlov

Redis

Redis stands for REmote DIctionary Server. By default, redis stores all data in memory. It's a key-structure database. redis-server is the actual datastore. redis-cli is the command line interface that performs any redis command. By default, redis binds to port 6379.

Starting the redis server

redis-server

While you can build a complete system using Redis only, I think most people will find that it supplements their more generic data solution - whether that be a traditional relational database, a document-oriented system, or something else. It’s the kind of solution you use to implement specific features.

akotlov

HTTP Streaming (or Chunked vs Store & Forward)

The standard way of understanding the HTTP protocol is via the request reply pattern. Each HTTP transaction consists of a finitely bounded HTTP request and a finitely bounded HTTP response.

However it's also possible for both parts of an HTTP 1.1 transaction to stream their possibly infinitely bounded data. The advantages is that the sender can send data that is beyond the sender's memory limit, and the receiver can act on