| ⌘T | go to file |
| ⌘⌃P | go to project |
| ⌘R | go to methods |
| ⌃G | go to line |
| ⌘KB | toggle side bar |
| ⌘⇧P | command prompt |
megayu megayu
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| # 30 minutes Lisp in Ruby | |
| # Hong Minhee <http://dahlia.kr/> | |
| # | |
| # This Lisp implementation does not provide a s-expression reader. | |
| # Instead, it uses Ruby syntax like following code: | |
| # | |
| # [:def, :factorial, | |
| # [:lambda, [:n], | |
| # [:if, [:"=", :n, 1], | |
| # 1, |
msackman
/ QueueingConsumerCoDel.java
Created
May 11, 2012 10:00
QueueingConsumer extended with the CoDel algorithm
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| // The contents of this file are subject to the Mozilla Public License | |
| // Version 1.1 (the "License"); you may not use this file except in | |
| // compliance with the License. You may obtain a copy of the License | |
| // at http://www.mozilla.org/MPL/ | |
| // | |
| // Software distributed under the License is distributed on an "AS IS" | |
| // basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See | |
| // the License for the specific language governing rights and | |
| // limitations under the License. | |
| // |
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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 |
jordansissel
/ RESULTS.md
Created
September 21, 2012 07:41
screenshot + code showing how to query logstash/elasticsearch with a graphite function.
Operation: Decouple whisper from graphite.
Method: Create a graphite function that does a date histogram facet query against elasticsearch for a given query string for the time period viewed in the current graph.
Reason: graphite has some awesome math functions. Wouldn't it be cool if we could use those on logstash results?
The screenshot below is using logstash to watch the twitter stream of keywords "iphone" "apple" and "samsung" - then I graph them each, so we get an idea of popularity. As a bonus, I also do a movingAverage() on the iphone curve to show you why this is awesome.
pbailis
/ rapgenius-balancing.md
Last active
July 23, 2019 12:57
Randomized load balancing comparison
RapGenius has an interesting post about Heroku's randomized load balancing, complaining about how random placement degrades performance compared to prior omniscient approaches. RapGenius ran some simulations, including an experiments with a "Choice of Two" method:
Choice of two routing is the naive method from before, with the twist that when you assign a request to a random dyno, if that dyno is already busy then you reassign the request to a second random dyno, with no regard for whether the second dyno is busy
This differs subtly but substantially from the standard "Power of Two Choices" randomized load balancing:
each [request] is placed in the least loaded of d >= 2 [Dynos] chosen independently and uniformly at random
Take a look at the difference in queue lengths below, for 200 Dynos, 100
aras-p
/ preprocessor_fun.h
Last active
July 16, 2024 02:50
Things to commit just before leaving your job
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| // Just before switching jobs: | |
| // Add one of these. | |
| // Preferably into the same commit where you do a large merge. | |
| // | |
| // This started as a tweet with a joke of "C++ pro-tip: #define private public", | |
| // and then it quickly escalated into more and more evil suggestions. | |
| // I've tried to capture interesting suggestions here. | |
| // | |
| // Contributors: @r2d2rigo, @joeldevahl, @msinilo, @_Humus_, | |
| // @YuriyODonnell, @rygorous, @cmuratori, @mike_acton, @grumpygiant, |
staltz
/ introrx.md
Last active
July 22, 2024 09:31
The introduction to Reactive Programming you've been missing
(by @andrestaltz)
If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.
由于路由管控系统的建立，实时动态黑洞路由已成为最有效的封锁手段，TCP连接重置和DNS污染成为次要手段，利用漏洞的穿墙方法已不再具有普遍意义。对此应对方法是多样化协议的VPN来抵抗识别。这里介绍一种太简单、有时很朴素的“穷人VPN”。
朴素VPN只需要一次内核配置（Linux内核），即可永久稳定运行，不需要任何用户态守护进程。所有流量转换和加密全部由内核完成，原生性能，开销几乎没有。静态配置，避免动态握手和参数协商产生指纹特征导致被识别。并且支持NAT，移动的内网用户可以使用此方法。支持广泛，基于L2TPv3标准，Linux内核3.2+都有支持，其他操作系统原则上也能支持。但有两个局限：需要root权限；一个隧道只支持一个用户。
朴素VPN利用UDP封装的静态L2TP隧道实现VPN，内核XFRM实现静态IPsec。实际上IP-in-IP隧道即可实现VPN，但是这种协议无法穿越NAT，因此必须利用UDP封装。内核3.18将支持Foo-over-UDP，在UDP里面直接封装IP，与静态的L2TP-over-UDP很类似。
wincent
/ gist:598fa75e22bdfa44cf47
Last active
April 2, 2024 18:21
2015-01-29 Unofficial Relay FAQ
Compilation of questions and answers about Relay from React.js Conf.
Disclaimer: I work on Relay at Facebook. Relay is a complex system on which we're iterating aggressively. I'll do my best here to provide accurate, useful answers, but the details are subject to change. I may also be wrong. Feedback and additional questions are welcome.
Relay is a new framework from Facebook that provides data-fetching functionality for React applications. It was announced at React.js Conf (January 2015).
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