[ANN] RubyDNS 0.7.0 - Using Fiber for improved DSL

ruby-talk
1

Hi Everyone,

I wouldn't normally share an incremental release, but I thought that the
way I used Fibers in the latest version of RubyDNS might be interesting to
others.

Previously, RubyDNS used EventMachine deferrables for managing "sequential"
event based processing. The code to wire up sequential events was fairly
unintuitive and for clients using the RubyDNS DSL, it was even more
buggy/confusing.

Enter Fibers. Now deferred and sequential processing follow the same
pathway. For each transaction (incoming DNS request) a Fiber is created.
Once the Fiber terminates, the result is returned to the client. By
default, the execution is linear, but if the user wants to pass the DNS
request upstream, the fiber is suspended until the request is done (or
fails).

When I first started looking at fibers, I didn't realise how powerful they
are because they avoid tangled event driven code for the user and for the
most part hide the implementation details regarding what might take time to
complete. Now, I feel confident that RubyDNS has improved both the
intuitive nature of the DSL, and also the actual implementation is easier
to follow/test.

For more details, please see the RubyDNS project page:
http://www.codeotaku.com/projects/rubydns/index.en or browse the latest
source code:
https://github.com/ioquatix/rubydns/blob/master/lib/rubydns/server.rb#L75-L94

Here is the code, pre-fiberization:

Fiber is a really nice feature, looking forward to using it in more
projects.

Kind regards,
Samuel

2

Very nice. So, next time I see a chain of lambdas, I'll try to replace it with a fiber.

Very OT, but it reminded me of this example from SimPy:

http://simpy.readthedocs.org/en/latest/examples/gas_station_refuel.html

This uses (python) generators to preserve the imperative flow of an actor, while also allowing interaction with the simulation.
(Python's generators seem to be more or less fibers, but I know little python.)

···

On 02/02/2014 06:27 AM, Samuel Williams wrote:

For more details, please see the RubyDNS project page:
RubyDNS or browse the latest
source code:
https://github.com/ioquatix/rubydns/blob/master/lib/rubydns/server.rb#L75-L94

Here is the code, pre-fiberization:
rubydns/lib/rubydns/server.rb at 0505d52f6078919eceb5e0599f8b225f9a54dffb · socketry/rubydns · GitHub

3

Be sure to check out Celluloid if you're interested in these sorts of
patterns:

···

On Tue, Feb 4, 2014 at 12:18 PM, Joel VanderWerf <joelvanderwerf@gmail.com>wrote:

On 02/02/2014 06:27 AM, Samuel Williams wrote:

For more details, please see the RubyDNS project page:
RubyDNS or browse the latest
source code:
rubydns/lib at master · socketry/rubydns · GitHub
rubydns/server.rb#L75-L94

Here is the code, pre-fiberization:
GitHub - socketry/rubydns at 0505d52f6078919eceb5e0599f8b225f9a54dffb
5f9a54dffb/lib/rubydns/server.rb#L189-L238

Very nice. So, next time I see a chain of lambdas, I'll try to replace it
with a fiber.

Very OT, but it reminded me of this example from SimPy:

Gas Station Refueling — SimPy 4.1.1 documentation

This uses (python) generators to preserve the imperative flow of an actor,
while also allowing interaction with the simulation.
(Python's generators seem to be more or less fibers, but I know little
python.)

--
Tony Arcieri