I´m looking to implement a Cache solution in Scala to cache some Finagle services that I want to avoid create per request if the host and path are alike.
I've read several solutions, Guava, Memo patter of Scalaz, or even using Map.
Could you please give me any recommendation?
Regards
Guava Cache is an excellent library for this, and it is stable and high quality.
https://github.com/google/guava/wiki/CachesExplained
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I am considering rewriting a large project using Spray. I am unsure what is currently the best choice for accessing an RDBMS. I need to support Oracle and PosgreSQL and, as I am restricted to a free solution, Slick is rather not an option here.
I often use MyBatis in my Java projects, so I consider MyBatis-Scala as a possible solution, but this is just a wrapper for a Java library.
Which native Scala library fits best into Spray?
In my oppinion it is not the matter of "fitting" into Spray, but the matter of good strategic choice.
Please consider options of scala database frameworks. My personal preference is squeryl and sorm. Both of them provide pretty much nice DSL and are written in scala.
Also you can have a look at one more review of available scala frameworks (a bit outdated but well structured to give a basic idea).
Hope it helps.
Several links show that https://code.google.com/p/concurrentlinkedhashmap/ has been ported to Guava, but I can not find the corresponding API in Guava.
Can anybody show me an example to build a ConcurrentLinkedHashmap using Guava ?
Thanks!
ConcurrentLinkedHashmap API wasn't ported to Guava 1:1, but some solutions from CLHM were used in MapMaker and Cache (with CacheBuilder).
ConcurrentLinkedHashmap's author Ben Manes answers a question which may clarify your doubts: What does it mean that ConcurrentLinkedHashMap has been integrated into Guava?:
Guava is the long term replacement and most of the time you should use it. The history is that ConcurrentLinkedHashMap figured out the algorithms, Guava subsumed it, and then focused on adding features.
I think it's also important to note that he's currently writing another library which may suit your needs:
Caffeine is a Java 8 rewrite of Guava's cache. It tries to provide the best of ConcurrentLinkedHashMap and Guava, modernized with Java 8, and adopting the techniques that I've learned since those previous projects.
I'm looking for a socket.io client for Scala. I'm well aware of this, but I cringe at the idea of using it in Scala as it wouldn't feel quite natural nor would it allow for an idiomatic implementation. Does any of you, thus, have a suggestion as to where could I find a Scala client?
If so, just the lines for SBT and a link to the doc will suffice as an answer ;)
I'm afraid I don't know any already implemented libraries or apparent solutions for Scala. But I'll present two very simple approaches that should be very easy to use if you have the time to DIY :-)
But of course it really depends on what you want. As you probably already could imagine a plain WebSocket implementation of Java's standard library can be quite efficient if you need to process simple requests. I found one at scala-lang.org implementing a server calculating random numbers. If it is of interest there's also something brewing at the nightly build which might reveal some handy tricks.
If you want to go for simplicity and for pure Scala in all its might the Actors (in particular a RemoteActor) are immensly powerful. It requires Scala on both ends naturally, but it gives you a messaging-system almost instantly. This is a pretty good start-guide if you aren't already familiar with them.
Anyway. If no good library surfaces I hope this helped. Good luck.
What's the best way to use libpcap with Scala? I need to capture from live network devices, so it will most likely need a native binding.
I've found a couple like JPcap and JNetPcap but nothing particularly for Scala...
Any recommendations?
Since the libraries run on JVM already there is no need for an additional wrapper for Scala. Just pick the best library and pimp it to your needs.
JNetPcap seems like the most updated one here.
For a project I'm using both Scala and Riak (two things I have never worked with before ;) ).
Google searches seem to suggest using Riakki. However, it seems like that particular library hasn't been maintained since 2009 and doesn't even compile on my system. There is a more up-to-date fork on GitHub that does seem to work with more recent Scala versions. But Riakki seems to depend on Jiak, which has been deprecated since february of last year.
Seems like the only reasonable choice would be to use the official Riak Java-library from Scala. That's certainly possible, but I'd like to do things the Scala-way as I'm trying to learn the language. Having to interface with a Java-style API might ruin a bit of the fun. Writing my own wrapper sounds like it will be too much work.
tl;dr: I want to use Riak from Scala. What are other people using?
edit: just found Ryu (can't link to it - annoying limit on amount of hyperlinks per question for new users). Doesn't seem all that mature though.
Stackmob recently opensourced Scalariak.
Scaliak is a scala-ified version of the High-Level Riak Java Client w/
a Functional Twist. It is currently being used in production at
StackMob.
Scaliak is currently feature incomplete vs. the original High-Level
Riak Java Client. What is currently supported are mostly features
being used in production (there have been a few features implemented
and subsequently not used).
There is also Raiku which states that it is async.
I'm in the same bucket - excuse the bad pun - although I have some experience with Scala. I'm thinking of using the official Java client.
When you are toiling up a steep learning curve, you don't need to be dealing with incomplete and potentially wobbly API's. In my experience, using Java API's from Scala is minimally painful.
I think there'll be enough delight in playing with our new Raik toy that we'll forget about whatever un-Scala-ish foibles the Java API inflicts upon us. All the best.
I'm the author of yet another Scala Riak client, simply called riak-scala-client. It is based on Akka and Spray, it is not built on top of the existing Java client, and most importantly it is completely non-blocking.
Check it out at http://riak.scalapenos.com and let me know what you think.