coldfusion - Does VAR scope in function really get Garbage collected quickly if the reference is shared? -

-

if have function say

<cfcomponent name="details"> <cffunctiion  name="getdetails" access="public" returntype="struct"> <cfscript> var mydetails = {}; mydetails.fname='lilly'; mydetails.lname ='flower'; </cfscript> <cfreturn mydetails > </cffunction> </cfcomponent>

now call function , return session variable 

<cfset session.mydetails = details.getdetails()>

what here reference of structure mydetails (since complex object) function. believe reference point same memory location created when called function , variable created inside it.

so var scope garbage collected since have reference still pointing memory location through new session.mydetails variable!!!

when return value object, it's not returned reference. try this:

testcomponent.cfc

<cfcomponent name="details">      <cffunction  name="getdetails" access="public" returntype="struct">         <cfscript>             var mydetails = {};             mydetails.fname='lilly';             mydetails.lname ='flower';             mydetails.timestamp = gettickcount();         </cfscript>          <cfreturn mydetails />      </cffunction>  </cfcomponent>

test.cfm

<cfset myobject = createobject("component", "testcomponent") /> <cfset mydetails = myobject.getdetails() /> <cfdump var="#mydetails#" label="first request" /> <cfset otherdetails = myobject.getdetails() /> <cfdump var="#mydetails#" label="after second request" /> <cfdump var="#otherdetails#" label="otherdetails second request" />

you'll notice first , second dumps mydetails same, means second request, variable set "otherdetails" not change original value in "mydetails". means structure returned, , assigned variable, byvalue instead of byreference.

with being said, original local variable in component should garbage collected @ same time component instance itself, while struct sitting in session won't garbage collected until session does.


Comments

Post a Comment

Popular posts from this blog

Javascript line number mapping -

-
magically formatted comments change reported line number of javascript errors in browsers; this: //@line n "f" n line number , f file name. unfortunately, //@line appears ungoogleable. know there documentation on feature, , browsers support it? (i found references here , here .) from can find available in mozilla based browsers. it using js_setoptions command can turn these options on or off depending on values passed. https://developer.mozilla.org/en/js_setoptions
Read more

c# - Is it possible to remove an existing registration from Autofac container builder? -

-
something along lines: builder.registertype<mytype>().as<itype>(); builder.registertype<mytype2>().as<itype>(); builder.deregistertype<mytype>().as<itype>() var container = builder.build(); var types = container.resolve<ienumerable<itype>>(); assert.istrue(types.count == 1); assert.istrue(types[0].gettype == typeof(mytype2)); scenario: go through bunch of assemblies , go register types want make sure have 1 implementation of given type. need before create container. track on own nice if autofac me bit. this cannot done directly using containerbuilder , unless start on new one. mind you, having first built container should able construct new container filtering away unwanted types , reusing registrations first container. this: ... var container = builder.build(); builder = new containerbuilder(); var components = container.componentregistry.registrations .where(cr => cr.activator.limittype != typ...
Read more

php - Mysql PK and FK char(36) vs int(10) -

-
i have read mysql can handle indexes , searches better if tables keys integers rather char(36) uuid's. is worth converting int(10)? note: use 1 server , have have plans use multiple databases concurrently therefore removing 1 of big reasons using uuid. our tables innodb if makes difference. thanks in advance. usually rdbms can handle integer keys pk more efficient, other datatypes. reason how build index column, yes: long dont require string (or other typed) keys, should use integers. however: char(36) , int(10) far away being equal, because int(10) much smaller, char(36). dont know, if require many different keys, should keep in mind. update, complete last paragraph: int(10) 32-bit, char(36) 36 - ^byte^ (= 288-bit). not mean, int consumes less space, means, char(36) has 4 times more different keys.
Read more