tangyumeng

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

tangyumeng

Hello World in React

A Pen by Dan Abramov on CodePen.

License.

tangyumeng

#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <libproc.h>
#include <mach/mach.h>
#include <CoreFoundation/CoreFoundation.h>


int main(void)
{

tangyumeng

blog

https://blog.csdn.net/bjrxyz/article/details/73435407 ⭐️⭐️⭐️⭐️⭐️

https://github.com/CivelXu/iOS-Lame-Audio-transcoding ⭐️⭐️⭐️⭐️

https://juejin.im/entry/5c70b2936fb9a049e12ad3f5 ⭐️⭐️⭐️

https://keyj.emphy.de/lame-weirdness/ ⭐️⭐️⭐️

tangyumeng

#!/bin/sh
PROJ=`find . -name '*.xib' -o -name '*.[mh]'`

for png in `find . -name '*.png'`
do
    name=`basename $png`
    if ! grep -q $name $PROJ; then
        echo "$png is not referenced"
    fi
done

tangyumeng

extension Sequence where Element: Hashable {
    func unique() -> [Element] {
        var seen: Set<Element> = []
        return filter { (element) -> Bool in
            if (seen.contains(element)) {
                return false
            } else {
                seen.insert(element)
                return true
            }

tangyumeng

extension Array {
    func split(where condation: (Element, Element) -> Bool) -> [[Element]] {
        var result: [[Element]] = self.isEmpty ? [] : [[self[0]]]
        for (previous, current) in zip(self, self.dropFirst()) {
            if (condation(previous, current)) {
                result.append([current])
            } else {
                result[result.endIndex - 1].append(current)
            }
        }

tangyumeng

//  Created by Vasily Ulianov on 09.02.17, updated in 2019.
//  License: MIT

import Foundation

/// Subclass of `Operation` that adds support of asynchronous operations.
/// 1. Call `super.main()` when override `main` method.
/// 2. When operation is finished or cancelled set `state = .finished` or `finish()`
open class AsynchronousOperation: Operation {
    public override var isAsynchronous: Bool {

tangyumeng

//  Created by Vasily Ulianov on 09.02.17, updated in 2019.
//  License: MIT

import Foundation

/// Subclass of `Operation` that adds support of asynchronous operations.
/// 1. Call `super.main()` when override `main` method.
/// 2. When operation is finished or cancelled set `state = .finished` or `finish()`
open class AsynchronousOperation: Operation {
    public override var isAsynchronous: Bool {

tangyumeng

public class ReverseLinkedList {
	public static void main(String[] args) {
	    ListNode head = new ListNode(2);
	    head.next = new ListNode(4);
	    head.next.next = new ListNode(6);
	    head.next.next.next = new ListNode(8);
	    head.next.next.next.next = new ListNode(10);

	    ListNode result = ReverseLinkedList.reverse2(head);
	    System.out.print("Nodes of the reversed LinkedList are: ");