Binary compatibility and finding compiled classes

Wed Oct 13 15:32:00 GMT 2004

Bryce McKinlay writes:
 > >
 > Exactly, the code generated by the compiler already knows which otable 
 > slot to use. The hashtable would be used to speed up the look-up of 
 > methods when the runtime is filling out the tables when linking a class. 
 > Currently, to go from a {ClassName,MethodName,Signature} to a _Jv_Method 
 > requires linear searching through the class hierarchy. This would speed 
 > up method lookups in reflection and JNI, too. Personally, I'm not 100% 
 > sure that the gains from hash look-ups will outweigh the cost and extra 
 > memory of generating the hash tables, but its definitely something we 
 > need to keep an eye on - linking needs to be as efficient as possible.
I'm not sure these are comparable, because the hash tables for class
and method lookups can be generated at compile time and don't need to
occupy significantly more memory than the linear lists we have at the
moment. As far as I can tell, except for the time taken to write the
code this is a win-win.
Andrew.