tclementdev

libdispatch efficiency tips

The libdispatch is one of the most misused API due to the way it was presented to us when it was introduced and for many years after that, and due to the confusing documentation and API. This page is a compilation of important things to know if you're going to use this library. Many references are available at the end of this document pointing to comments from Apple's very own libdispatch maintainer (Pierre Habouzit).

My take-aways are:

• You should create very few, long-lived, well-defined queues. These queues should be seen as execution contexts in your program (gui, background work, ...) that benefit from executing in parallel. An important thing to note is that if these queues are all active at once, you will get as many threads running. In most apps, you probably do not need to create more than 3 or 4 queues.

• Go serial first, and as you find performance bottle necks, measure why, and if concurrency helps, apply with care, always validating under system pressure. Reuse

smileyborg

// UICollectionView Objective-C example

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
        
    NSIndexPath *selectedIndexPath = [[self.collectionView indexPathsForSelectedItems] firstObject];
    if (selectedIndexPath != nil) {
        id<UIViewControllerTransitionCoordinator> coordinator = self.transitionCoordinator;
        if (coordinator != nil) {
            [coordinator animateAlongsideTransition:^(id<UIViewControllerTransitionCoordinatorContext> context) {

k06a

# Fetch
git clone https://github.com/username/reponame reponame
for b in `git branch -r | grep -v -- '->'`; do git branch --track ${b##origin/} $b; done

# Analyze
curl https://bootstrap.pypa.io/get-pip.py > get-pip.py && sudo python get-pip.py && rm get-pip.py
sudo pip install git-fat
git fat -a find 1000000

git ls-tree -r -t -l --full-name HEAD | sort -n -k 4

plumhead

extension String {
    func size(withAttributes attrs: [String:AnyObject], constrainedTo box: NSSize) -> NSRect {
        let storage = NSTextStorage(string: self)
        let container = NSTextContainer(containerSize: NSSize(width: box.width, height: box.height))
        let layout = NSLayoutManager()
        layout.addTextContainer(container)
        storage.addLayoutManager(layout)
        storage.addAttributes(attrs, range: NSMakeRange(0, storage.length))
        container.lineFragmentPadding = 0.0
        let _ = layout.glyphRangeForTextContainer(container)

sakrist

#!/bin/bash

#===============================================================================
#  Filename:  build_gmp.sh
#  Created by Volodymyr Boichentsov on 18/09/2015.
#  Copyright © 2015 3D4Medical. All rights reserved.
#  Property of 3D4Medical.
#===============================================================================

#-emit-obj -fembed-bitcode -disable-llvm-optzns -O3

mackuba

Here's my own list of the interesting stuff announced during this year's WWDC, collected from the keynotes, various Apple docs, blog posts and tweets.

If you're planning to watch the videos, I really recommend this Mac app that helps you download and watch them: https://github.com/insidegui/WWDC.

OS X El Capitan

http://www.apple.com/osx/elcapitan-preview/

• split view - two apps side by side on full screen

steipete

#import <Foundation/Foundation.h>

#if __IPHONE_OS_VERSION_MIN_REQUIRED < 80000

@interface NSString (PSPDFModernizer)

// Added in iOS 8, retrofitted for iOS 7
- (BOOL)containsString:(NSString *)aString;

@end

matej

//
//  CALayer+MBAnimationPersistence.h
//
//  Created by Matej Bukovinski on 19. 03. 14.
//  Copyright (c) 2014 Matej Bukovinski. All rights reserved.
//

#import <QuartzCore/QuartzCore.h>