Re: scoping and speed
In theory, yes, as ColdFusion will have to hunt through the various scopes to find the exact variable that you're referencing. Whether it's noticeable or not.. hard to say. From the CF8 docs ( http://livedocs.adobe.com/coldfusion/8/htmldocs/help.html?content=Variables_32.html ): Because ColdFusion must search for variables when you do not specify the scope, you can improve performance by specifying the scope for all variables. I do actually recall hearing that on Railo, it was faster to -not- scope local variables. Not sure if that still holds true or not. On Thu, Dec 10, 2009 at 7:13 AM, Chad Gray cg...@careyweb.com wrote: If you don't scope your local variables does the page run slower? IE. #variables.foo# vs. #foo# ~| Want to reach the ColdFusion community with something they want? Let them know on the House of Fusion mailing lists Archive: http://www.houseoffusion.com/groups/cf-talk/message.cfm/messageid:329047 Subscription: http://www.houseoffusion.com/groups/cf-talk/subscribe.cfm Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4
RE: scoping and speed
Funny thing is, even when I have specified scope for all my variables, I've still seen ColdFusion stack traces hunting around for scopes. However, please note this was a very intense script trying to calculate all prime numbers between 0 and 10,000,000. For the other 99.% of ColdFusion code out there, do what creates the most manageable, self-documenting code. The performance results will most likely be negligible. ~Brad Original Message Subject: Re: scoping and speed From: Charlie Griefer charlie.grie...@gmail.com Date: Thu, December 10, 2009 9:59 am To: cf-talk cf-talk@houseoffusion.com Because ColdFusion must search for variables when you do not specify the scope, you can improve performance by specifying the scope for all variables. ~| Want to reach the ColdFusion community with something they want? Let them know on the House of Fusion mailing lists Archive: http://www.houseoffusion.com/groups/cf-talk/message.cfm/messageid:329054 Subscription: http://www.houseoffusion.com/groups/cf-talk/subscribe.cfm Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4
Re: scoping and speed
Out of curiosity Gert, why would Railo be slower finding #variables.foo# than finding #foo# if variable cascading is on? Is it checking for the existence of a struct named variables before checking the actual scope or something? Judah On Thu, Dec 10, 2009 at 8:40 AM, Gert Franz gert.fr...@railo.ch wrote: Yes... that's true. If you even scope the variables from the variables scope (EXCEPT in components, since they have their own variables scope) CF is around 4 times slower than addressing a variable from there without the prefix variables. But this execution isn't very significant when your website is quite slow. It is 4 times faster not to scope variables from the variables scope, but in reality you won't notice that much improvement since accessing variables in comparison to querying a database is really a matter of order of magnitudes (So maybe variables.whatever executes in 12 nano seconds, where as whatever executes in 3 nano seconds, whereas a query will take 1ms which is 1000 nano seconds). In Railo you can enable a setting that actually forces you to scope your variables from the various scopes. So for instance if you do something like this: cfoutput#id#/cfoutput and ID is in the URL scope Railo will complain that it doesn't know the variable ID (if this setting is turned on) and throw an error. So you HAVE TO write it like this: cfoutput#url.id#/cfoutput Then Railo processes the page without error. Once you have scoped all your variables the system will be somewhat faster. Just imagine it like this: You are searching for a Peter (a variable) in a school (CF memory). You enter every classroom (scope) and check whether a pupil named Peter is sitting in it. If you find it, thats your variable. But if you know that Peter is sitting in the classroom number 55 then you go directly there and look for Peter. With the scope cascading disabled, Railo will not allow you to look for a Peter in the school without the classroom number. Hope that helps a little. Greetings from Switzerland Gert Fran ~| Want to reach the ColdFusion community with something they want? Let them know on the House of Fusion mailing lists Archive: http://www.houseoffusion.com/groups/cf-talk/message.cfm/messageid:329071 Subscription: http://www.houseoffusion.com/groups/cf-talk/subscribe.cfm Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4
Re: scoping and speed
According to Adobe, Yes. http://www.adobe.com/devnet/coldfusion/articles/coldfusion_performance_04.html Thanks, Eric Cobb http://www.cfgears.com Chad Gray wrote: If you don't scope your local variables does the page run slower? IE. #variables.foo# vs. #foo# ~| Want to reach the ColdFusion community with something they want? Let them know on the House of Fusion mailing lists Archive: http://www.houseoffusion.com/groups/cf-talk/message.cfm/messageid:329072 Subscription: http://www.houseoffusion.com/groups/cf-talk/subscribe.cfm Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4
Re: scoping and speed
Actually I think that was my bad. I had mentioned that I heard #foo# evaluates faster than #variables.foo# on Railo. Guess I heard (or remembered) incorrectly :) Sorry 'bout that. On Thu, Dec 10, 2009 at 1:11 PM, Gert Franz gert.fr...@railo.ch wrote: Judah, you got me wrong. For Railo there is no difference if searching #variables.foo# instead of #foo#. It is only a difference for Adobe CF. Here ACF checks whether there is a struct called variables in the variables scope and if not it will check the variables scope. If you only have foo it will check the variables scope instantly since there is no . in the variable addressing and hence it's faster. In Railo variables.foo is identical to foo. This is one reason why we do not support dots in variable names like ACF if you use something like this: cfset variables[susi.peter] = 5 cfoutput#susi.peter#/cfoutput --- this works in ACF but not in Railo. Railo throws an error saying that there is no key named peter in the struct susi. ACF assumes first the same and in case of an error it checks the variables scope for a variable with the key susi.peter. In Railo you have to write: cfoutput#variables[susi.peter]#/cfoutput Since we do not allow the first notation, when you have something like variables.foo Railo knows that it will check the variables scope at compile time. ACF does not! Hope that clarifies things a little. Greetings from Switzerland Gert Franz Railo Technologies Professional Open Source skype: gert.franz g...@getrailo.com +41 76 5680 231 www.getrailo.com -Ursprüngliche Nachricht- Von: Judah McAuley [mailto:ju...@wiredotter.com] Gesendet: Donnerstag, 10. Dezember 2009 20:16 An: cf-talk Betreff: Re: scoping and speed Out of curiosity Gert, why would Railo be slower finding #variables.foo# than finding #foo# if variable cascading is on? Is it checking for the existence of a struct named variables before checking the actual scope or something? Judah On Thu, Dec 10, 2009 at 8:40 AM, Gert Franz gert.fr...@railo.ch wrote: Yes... that's true. If you even scope the variables from the variables scope (EXCEPT in components, since they have their own variables scope) CF is around 4 times slower than addressing a variable from there without the prefix variables. But this execution isn't very significant when your website is quite slow. It is 4 times faster not to scope variables from the variables scope, but in reality you won't notice that much improvement since accessing variables in comparison to querying a database is really a matter of order of magnitudes (So maybe variables.whatever executes in 12 nano seconds, where as whatever executes in 3 nano seconds, whereas a query will take 1ms which is 1000 nano seconds). In Railo you can enable a setting that actually forces you to scope your variables from the various scopes. So for instance if you do something like this: cfoutput#id#/cfoutput and ID is in the URL scope Railo will complain that it doesn't know the variable ID (if this setting is turned on) and throw an error. So you HAVE TO write it like this: cfoutput#url.id#/cfoutput Then Railo processes the page without error. Once you have scoped all your variables the system will be somewhat faster. Just imagine it like this: You are searching for a Peter (a variable) in a school (CF memory). You enter every classroom (scope) and check whether a pupil named Peter is sitting in it. If you find it, thats your variable. But if you know that Peter is sitting in the classroom number 55 then you go directly there and look for Peter. With the scope cascading disabled, Railo will not allow you to look for a Peter in the school without the classroom number. Hope that helps a little. Greetings from Switzerland Gert Fran ~| Want to reach the ColdFusion community with something they want? Let them know on the House of Fusion mailing lists Archive: http://www.houseoffusion.com/groups/cf-talk/message.cfm/messageid:329075 Subscription: http://www.houseoffusion.com/groups/cf-talk/subscribe.cfm Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4
