I don't think we should assume anything about the performance just because it uses reflection. Yes, traditionally reflection is computationally expensive, however, when used properly the penalty can be negligible. I don't think we have enough understanding of these libraries to know whether there is a concerning performance penalty.
As Dewayne said, create, update and delete actions represent a tiny fraction of the overall requests into TO. Given that the majority of these actions are performed by humans, I would be shocked if there was a perceptible performance difference with the reflection based validation in place. It's not like we're trying to validate enormous and complex objects here; we're talking 20 fields or so for any given post. I'm +1 on using validation libraries such as these even if they use reflection, provided that we do not see dramatic changes in performance. I think that's highly unlikely in this case. -- Thanks, Jeff On Thu, Jan 11, 2018 at 10:07 AM, Chris Lemmons <[email protected]> wrote: > True, but how many of those out-of-the-box checks are both useful and > relevantly complex? > > To me, the cool part of ozzo is the way it collects the output and > formats it. That's unfortunately also the computationally expensive > part. > > On Thu, Jan 11, 2018 at 9:49 AM, Dewayne Richardson <[email protected]> wrote: >> Please keep in mind that we do not Create/Update/Delete very often in >> Traffic Ops, so the performance penalty for Validation should be taken into >> consideration. I also don't want to re-invent all of those out-of-the-box >> field level checks by hand when I can just use them from here: >> https://github.com/asaskevich/govalidator#list-of-functions >> >> -Dew >> >> On Thu, Jan 11, 2018 at 9:24 AM, Chris Lemmons <[email protected]> wrote: >> >>> I like the output style, but I'm a bit concerned on the performance >>> front. ozzo appears to do all it's magic with heavy use of reflection, >>> which is often a slow spot in go. Most places, it wouldn't matter >>> much, but this will be called on every element of every API function, >>> so a nod toward performance may be in order. Have we done some >>> measurement to see whether this adds a relevant amount of overhead to >>> the calls? Or are the calls still dominated by the DB lookup? >>> >>> Relatedly, is this a major advantage over something like this: >>> >>> if ds.Active == nil { errMsgs = append(errMsgs, `"active" must be >>> provided`) } >>> >>> On Thu, Jan 11, 2018 at 8:49 AM, Dewayne Richardson <[email protected]> >>> wrote: >>> > We've been moving along with more functionality in the Golang proxy, >>> mostly >>> > the Read's up until now, comparatively TO does much fewer Create/Updates. >>> > Our current task is to circle back and start implementing the (C)reate, >>> > (U)pdate, and (D)eletes. One of the obvious needs for the this task are >>> > validation rules. I've been doing research to figure out the cleanest >>> and >>> > most maintainable way to rewrite the Perl validation rules in Go. >>> > >>> > TC Issue for tracking >>> > https://github.com/apache/incubator-trafficcontrol/issues/1756 >>> > >>> > These are the two dependencies I'd like to leverage and provide feedback: >>> > >>> > Both are MIT Licenses >>> > Uses normal programming constructs rather than error-prone struct tags to >>> > specify how data should be validated. >>> > https://github.com/go-ozzo/ozzo-validation >>> > https://github.com/go-ozzo/ozzo-validation/blob/master/LICENSE >>> > >>> > Core Validation library that the prior library uses that has a lot of >>> > useful convenience methods that I'd rather not re-invent >>> > https://github.com/asaskevich/govalidator >>> > https://github.com/asaskevich/govalidator#list-of-functions >>> > https://github.com/asaskevich/govalidator/blob/master/LICENSE >>> > >>> > And here is how I've used these as sample validation rules that I've >>> > implemented as a POC: >>> > >>> > https://github.com/dewrich/incubator-trafficcontrol/blob/ >>> tor-api-ds/traffic_ops/traffic_ops_golang/deliveryservice/ >>> deliveryservices.go#L93 >>> > >>> > Existing Mojo Perl Rules for comparison. >>> > https://github.com/apache/incubator-trafficcontrol/blob/ >>> master/traffic_ops/app/lib/API/Deliveryservice.pm#L1363 >>> > >>> > >>> > -Dew >>>
