Hacker News: thurston

New comment by thurston in "Details of the Cloudflare outage on July 2, 2019"

thurston — Wed, 17 Jul 2019 16:12:16 +0000

Sorry I didn't see the parent you were responding too, so my point is actually the same as you already made. Thanks.

New comment by thurston in "Details of the Cloudflare outage on July 2, 2019"

thurston — Wed, 17 Jul 2019 16:10:40 +0000

Ragel has the advantage that CPU blowups happen at compile time, rather than run-time. Other risks aside, they would have avoided this problem had they been using ragel or something similar to pre-compile their patterns into deterministic machines.

New comment by thurston in "Rust at CloudFlare"

thurston — Sat, 19 May 2018 17:13:09 +0000

What rarely gets discussed in this case was that old, working code was modified in a critical way in order to accommodate new code when that didn't need to be done at all. It was actually a failure in the software development process.

New comment by thurston in "Additional Target Languages Return to Ragel 7"

thurston — Fri, 18 May 2018 19:01:57 +0000

Initial list:

C, C++, Objective-C, Objective-C++, ASM, Crack, C#, D, Go, Java, JavaScript, Julia, OCaml, Ruby, Rust

Others can be added.

Additional Target Languages Return to Ragel 7

thurston — Fri, 18 May 2018 18:57:41 +0000

Article URL: https://www.colm.net/news/2018/05/18/new-target-langs.html

Comments URL: https://news.ycombinator.com/item?id=17104003

Points: 2

# Comments: 1

Changes to Ragel in Response to the CloudFlare Incident

thurston — Tue, 28 Feb 2017 07:13:46 +0000

Article URL: http://colm.net/news/2017/02/28/changes-to-ragel-cloudflare.html

Comments URL: https://news.ycombinator.com/item?id=13751918

Points: 4

# Comments: 0

New comment by thurston in "Cloudflare Reverse Proxies Are Dumping Uninitialized Memory"

thurston — Fri, 24 Feb 2017 11:53:20 +0000

Well doing that would mean ragel would incorrectly read one character, rather than run off forever. Personally I'd rather have the latter. Much easier to catch with memory checkers. Eventually you try to read some thing you're not allowed to read, or blow something else up, instead of just read the first byte of the int following the buffer, or whatever.

There would have to be an additional bounds check when issuing a goto in an error action, but doing that is contrary to the simple execution model that ragel users have come to rely on.

Gotta ask the question, where was the testing when they altered 7 year old code without the involvement of the original developer?

New comment by thurston in "Cloudflare Reverse Proxies Are Dumping Uninitialized Memory"

thurston — Fri, 24 Feb 2017 06:50:11 +0000

Author of Ragel here.

An experienced Ragel programmer would know that when you start setting the EOF pointer you are enabling code paths that never executed before. Like, potentially buggy ones. Eek!

New comment by thurston in "Ragel State Machine Compiler"

thurston — Tue, 17 Nov 2015 15:47:07 +0000

Thanks!

New comment by thurston in "Ragel State Machine Compiler"

thurston — Tue, 17 Nov 2015 15:46:43 +0000

WRT Lua, not at this time, but it is one I would like to support. Won't be too much work to add it.

New comment by thurston in "Ragel State Machine Compiler"

thurston — Tue, 17 Nov 2015 15:44:57 +0000

Keep using them is how you overcome this ;)

New comment by thurston in "Ragel State Machine Compiler"

thurston — Tue, 17 Nov 2015 15:43:17 +0000

At their core they target different language classes. Ragel deals with regular, whereas LPeg deals with context-free grammars.

New comment by thurston in "Ragel State Machine Compiler"

thurston — Mon, 16 Nov 2015 20:46:41 +0000

My pleasure, thank you for the note!

New comment by thurston in "Ragel State Machine Compiler"

thurston — Mon, 16 Nov 2015 20:46:20 +0000

Not at this time. But yes Ragel 7 will make it much easier. The first round of new languages I added helped me polish the technique. Once 7 is out and vetted it will make sense to add more.

New comment by thurston in "Ragel State Machine Compiler"

thurston — Mon, 16 Nov 2015 18:11:28 +0000

Same reason you would want to use yacc to write a parser. A grammar annotated with code is a nice way to express a parser. If the language happens to be regular, you can use ragel to generate a directly executable deterministic state machine. The code is simple and fast.

New comment by thurston in "Ragel State Machine Compiler"

thurston — Mon, 16 Nov 2015 14:30:17 +0000

Ragel allows embedding actions into the subexpressions of a regular expression. This allows one to compose a parser using a single regular expression.

New comment by thurston in "Open letter to FB from protest leaders in macedonia."

thurston — Sat, 18 Jun 2011 00:39:42 +0000

help me!

http://www.complang.org/dsnp/

New comment by thurston in "Colm programming language released: best parser-writer ever"

thurston — Wed, 18 May 2011 20:35:43 +0000

Just plain old text as it came in. I see now that is not what you were referring to. You're talking about JSON, XML, etc I now think.

There is also a print_xml function, which puts the tree into XML, but it's mostly used for debugging at this point, not export to other systems. I'm hoping that with time these kinds of features will crop up.

New comment by thurston in "Colm programming language released: best parser-writer ever"

thurston — Wed, 18 May 2011 20:33:04 +0000

They are related systems. DMS is much more mature.

New comment by thurston in "Colm programming language released: best parser-writer ever"

thurston — Wed, 18 May 2011 20:30:27 +0000

Ya it's currently hard to find. http://d-cent.org/fsw2011/

I need help from people like you actually. What I've done.

1. defined the protocol

2. implmented it in a C++ daemon that

   a) talks to other daemons

   b) serves the content managers (frontend UIs)

3. written a (crappy) example content manager.

What needs to happen next is step 3 needs to be repeated by other people who know what they are doing. They don't need to understand the details of the protocol, they just need to understand the basic model, which is just message broadcast, distributed agreement, etc.

Email me for more details, will get back to you later tonight.