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#
# This ProGuard configuration file illustrates how to process a program
# library, such that it remains usable as a library.
# Usage:
#     java -jar proguard.jar @library.pro
#

# Save the obfuscation mapping to a file, so we can de-obfuscate any stack
# traces later on. Keep a fixed source file attribute and all line number
# tables to get line numbers in the stack traces.

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buildscript {
    repositories {
        mavenCentral()
        maven {
            url 'https://oss.sonatype.org/content/repositories/snapshots/'
        }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:0.9.+'
        classpath 'com.squareup.gradle:gradle-android-test-plugin:0.9.1-SNAPSHOT'

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Analyze & Manage Memory on Android Like a Boss

This Blog is all about memory management in Android. It provides information about how you can analyze & reduce memory usage while developing an Android app.

Memory management is a complex field of computer science and there are many techniques being developed to make it more efficient. This guide is designed to introduce you to some of the basic memory management issues that programmers face.

Memory Management in Android

Android is a Linux based operating system. It uses native open source C libraries which power Linux machines. All the basic operating system operations like I/O, memory management and so on are handled by the Linux kernel. Like Java and .NET, Android uses its own run time and virtual machine to manage application memory. Unlike either of these frameworks, the Android run time also manages the lifetime processes. Each Android application runs in a separate process within its own Dalvik instance, relinquishing all responsibility for memo

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Summary of book "Clean Architecture" by Robert C. Martin

Uncle Bob, the well known author of Clean Code, is coming back to us with a new book called Clean Architecture which wants to take a larger view on how to create software.

Even if Clean Code is one of the major book around OOP and code design (mainly by presenting the SOLID principles), I was not totally impressed by the book.

Clean Architecture leaves me with the same feeling, even if it's pushing the development world to do better, has some good stories and present robust principles to build software.

The book is build around 34 chapters organised in chapters.

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Previous versions used homebrew to install the various versions. As suggested in the comments, it's better to use pyenv instead. If you are looking for the previous version of this document, see the revision history.

$ brew update
$ brew install pyenv
$ pyenv install 3.5.0
$ pyenv install 3.4.3
$ pyenv install 3.3.6
$ pyenv install 3.2.6
$ pyenv install 2.7.10

$ pyenv install 2.6.9

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openssl

Install

Install the OpenSSL on Debian based systems

sudo apt-get install openssl

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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

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struct ComposeTransformer<T, R> {
    let transformer: (Observable<T>) -> Observable<R>
    init(transformer: @escaping (Observable<T>) -> Observable<R>) {
        self.transformer = transformer
    }
    
    func call(_ observable: Observable<T>) -> Observable<R> {
        return transformer(observable)
    }
}

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Async/Await for Swift

• Proposal: SE-XXXX
• Authors: Chris Lattner, Joe Groff

Introduction

Modern Cocoa development involves a lot of asynchronous programming using closures and completion handlers, but these APIs are hard to use. This gets particularly problematic when many asynchronous operations are used, error handling is required, or control flow between asynchronous calls gets complicated. This proposal describes a language extension to make this a lot more natural and less error prone.

This paper introduces a first class Coroutine model to Swift. Functions can opt into to being async, allowing the programmer to compose complex logic involving asynchronous operations, leaving the compiler in charge of producing the necessary closures and state machines to implement that logic.

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Swift Concurrency Manifesto

Author: Chris Lattner

Chinese Translation by Jason Yu

Contents

• Introduction
• Overall Vision