计算属性是基于它们的响应式依赖进行缓存的。只在相关响应式依赖发生改变时它们才会重新求值。这就意味着只要 message 还没有发生改变，多次访问 reversedMessage 计算属性会立即返回之前的计算结果，而不必再次执行函数

缓存技术蕴含的是空间换时间的思想；压缩体现的是时间换空间的思想；分布式思想也最初体现在 CPU 的设计和实现上

普通磁盘的寻道时间是 10ms 左右，而相比于磁盘寻道花费的时间，CPU 执行指令和内存寻址的时间都在是 ns（纳秒）级别，从千兆网卡上读取数据的时间是在μs（微秒）级别

某些层次负责的是对下层不同实现的抽象，从而对上层屏蔽实现细节。比方说 VFS 对上层（系统调用层）来说提供了统一的调用接口，同时对下层中不同的文件系统规约了实现模型，当新增一种文件系统实现的时候，只需要按照这种模型来设计，就可以无缝插入到 Linux 文件系统中

分层架构可以让我们更容易做横向扩展。如果系统没有分层，当流量增加时我们需要针对整体系统来做扩展。但是，如果我们按照上面提到的三层架构将系统分层后，那么我们就可以针对具体的问题来做细致的扩展

分层架构需要考虑的另一个因素，是层次之间一定是相邻层互相依赖，数据的流转也只能在相邻的两层之间流转

Happens-Before 并不是说前面一个操作发生在后续操作的前面，它真正要表达的是：前面一个操作的结果对后续操作是可见的

导致可见性的原因是缓存，导致有序性的原因是编译优化，那解决可见性、有序性最直接的办法就是禁用缓存和编译优化

Java 内存模型在 1.5 版本对 volatile 语义进行了增强。怎么增强的呢？答案是一项 Happens-Before 规则

Java 内存模型规范了 JVM 如何提供按需禁用缓存和编译优化的方法

final 修饰变量时，初衷是告诉编译器：这个变量生而不变，可以可劲儿优化

“同一时刻只有一个线程执行”这个条件非常重要，我们称之为互斥。如果我们能够保证对共享变量的修改是互斥的，那么，无论是单核 CPU 还是多核 CPU，就都能保证原子性了。

一个或者多个操作在 CPU 执行的过程中不被中断的特性，称为“原子性”

使用 watch 选项允许我们执行异步操作 (访问一个 API)，限制我们执行该操作的频率，并在我们得到最终结果前，设置中间状态。这些都是计算属性无法做到的

如果 <navigation-link> 没有包含一个 <slot> 元素，则该组件起始标签和结束标签之间的任何内容都会被抛弃。

组件是可复用的 Vue 实例，所以它们与 new Vue 接收相同的选项，例如 data、computed、watch、methods 以及生命周期钩子等。仅有的例外是像 el 这样根实例特有的选项

I'm old enough to have friends and contemporaries who have long since retired, and that's their prerogative - enough is enough; it doesn't mean a thing to me. But I haven't got any money, so, you know, I just keep on working.

I was bartending when I recorded 'Same Love,' and when it was on the radio, too. I remember overhearing people talking about the song while I was making them drinks.

The flow of people into the United States into slavery, it follows the other types of immigration into the United States, so people who are trying to build new lives, trying to build a better life.

It takes both courage and talent to stand up in front of fellow human beings and make them crack a smile, and at the same time keep it clean.

What is Champions League level? I saw a lot of rubbish games at Champions League level.

But once you are in that field, emotional intelligence emerges as a much stronger predictor of who will be most successful, because it is how we handle ourselves in our relationships that determines how well we do once we are in a given job.

Waiting in line for something mundane is very boring. Waiting for my doctor to see me and waiting for my dentist to see me, yes, that is boring.

I'd like to live as a poor man with lots of money.

The first decent building I did with my own practice was a chapel in Taiwan.

In India, you're taught that there are certain qualities that make you a divine human being.

You find when you pursue a life of greater health and happiness, you then treat the body you have with dignity, respect, and absolute care.

I don't sleep much. I'm on the go. My mind is racing. My wife says my mind is like the rolling dials on a slot machine. So, yeah, I think about everything.

Hollywood films have become a cesspool of formula and it's up to us to try to change it... I feel like a preacher! But it's really true. I feel personally responsible for the future of American cinema. Me personally.

It all started when I went to this model search in Charlotte when I was 18. That's when I met all these agents and realized I could do it, and I won! I met a photographer at the competition who persuaded me to sign with a different agency than the one that was offered to me. So, I started with a small agency and eventually moved up to IMG.

People in the Middle East may consider the U.S. an evil hegemony that has tainted their culture, but when I look at the growth of racial and ethnic tolerance and understanding in my generation in the U.S., and see those sentiments make it around the world, it makes me feel proud.

Contentment has been worn as a crown by no end of sleepy heads.

If you find something helpful to give you a hand allow it to assist you hands down

Everybody is promoting something.

One of the nice things about a second book is that your readers already have so much of the introductions on board, they don't have to put all their attention into figuring out the world and can more easily let that play out as a background to the other things you want to do.

No cowboy songs, no hoedowns. It's a more serious piece. Yet every bar of 'Appalachian Spring' is clear, clean, tonal, intelligible - great music that anyone can grasp at first hearing.

I'm exhausted trying to stay healthy.

My parents always encouraged me to do creative stuff, to do weird stuff.

Water and sanitation has not had the same kind of champion that global health, and even education, have had.

As a decathlete, you take pride in saying, 'The elements, I'm not going to let them affect me. It's just the 11th event. Another thing you have to fight through.'