chitchcock

Stevey's Google Platforms Rant

I was at Amazon for about six and a half years, and now I've been at Google for that long. One thing that struck me immediately about the two companies -- an impression that has been reinforced almost daily -- is that Amazon does everything wrong, and Google does everything right. Sure, it's a sweeping generalization, but a surprisingly accurate one. It's pretty crazy. There are probably a hundred or even two hundred different ways you can compare the two companies, and Google is superior in all but three of them, if I recall correctly. I actually did a spreadsheet at one point but Legal wouldn't let me show it to anyone, even though recruiting loved it.

I mean, just to give you a very brief taste: Amazon's recruiting process is fundamentally flawed by having teams hire for themselves, so their hiring bar is incredibly inconsistent across teams, despite various efforts they've made to level it out. And their operations are a mess; they don't real

jboner

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

hellerbarde

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

ms-tg

/**
 * ```
 * Does JDK8's Optional class satisfy the Monad laws?
 * =================================================
 *   1.  Left identity:  true
 *   2.  Right identity: true
 *   3.  Associativity:  true
 *
 * Yes, it does. 
 * ```

thaJeztah

Commit, clone a container

To 'clone' a container, you'll have to make an image of that container first, you can do so by "committing" the container. Docker will (by default) pause all processes running in the container during commit to preserve data-consistency.

For example;

docker commit --message="Snapshot of my container" my_container my_container_snapshot:yymmdd

arturotena

// How to have a not empty Optional of the type Void? You can't. But...
// Horrendus hack , I know. Please don't try this at home.

Optional<Optional<Void>> optionalVoidEmpty = Optional.empty();
Optional<Void> optionalVoid = Optional.empty();
Optional<Optional<Void>> optionalVoidNotEmpty = Optional.of(optionalVoid);

System.out.println(optionalVoidEmpty.isPresent());    // false
System.out.println(optionalVoid.isPresent());         // false
System.out.println(optionalVoidNotEmpty.isPresent()); // true

OlegIlyenko

In this gist I would like to describe an idea for GraphQL subscriptions. It was inspired by conversations about subscriptions in the GraphQL slack channel and different GH issues, like #89 and #411.

Conceptual Model

At the moment GraphQL allows 2 types of queries:

• query
• mutation

Reference implementation also adds the third type: subscription. It does not have any semantics yet, so here I would like to propose one possible semantics interpretation and the reasoning behind it.

eddieh

libevent vs libuv

Comparing libevent and libuv. My upfront biased: I want to like libevent. However, I want to objectively compare the two and make an informed decision.

What versions are we comparing?

• libevent 2.0.22 (Stable) [2014-01-05]
• libuv 1.8.0 (Stable) [2015-12-15]

JustinSDK

Prolog … 快速排序法 … 白話版… XD

/* 
 * [] 附加 Result 的 結果為 Result
 */
append([], Result, Result).

/*     
 *  Tail 附加 Other 的結果為 Subappend => [Head | Tail] 附加 Other 的結果為 [Head | Subappend]
 *       

addyosmani

Problem: How can we preprocess JavaScript (at build-time or on the server-side) so engines like V8 don't have to spend as much time in Parse? This is a topic that involves generating either bytecode or a bytecode-like-abstraction that an engine would need to accept. For folks that don't know, modern web apps typically spend a lot longer in Parsing & Compiling JS than you may think.

• Yoav: This can particularly be an issue on mobile. Same files getting parsed all the time for users. Theoretically if we moved the parsing work to the server-side, we would have to worry about it less.
• One angle to this problem is we all ship too much JavaScript. That's one perspective. We could also look at preprocessing.
• We've been talking about this topic over the last few weeks a bit with V8. There were three main options proposed.
• 1. Similar to what optimize-js does. Identify IIFEs and mark them as such so the browser and VMs heuristics will catch them and do a better job than today. optimize-js only tackles IIFE bu