DO NOT REPLY TO THIS EMAIL, BUT PLEASE POST YOUR BUG RELATED COMMENTS THROUGH THE WEB INTERFACE AVAILABLE AT <http://nagoya.apache.org/bugzilla/show_bug.cgi?id=26503>. ANY REPLY MADE TO THIS MESSAGE WILL NOT BE COLLECTED AND INSERTED IN THE BUG DATABASE.
http://nagoya.apache.org/bugzilla/show_bug.cgi?id=26503 New feature: Extend ReferenceMap with IdentityMap functionality (WeakIdentityHashMap) Summary: New feature: Extend ReferenceMap with IdentityMap functionality (WeakIdentityHashMap) Product: Commons Version: unspecified Platform: All URL: http://developer.java.sun.com/developer/bugParade/bugs/4 809420.html OS/Version: All Status: NEW Severity: Normal Priority: Other Component: Collections AssignedTo: [EMAIL PROTECTED] ReportedBy: [EMAIL PROTECTED] Hello All, I would like to ask your opinion on providing IdentityMap features to ReferenceMap. (I am particularly interested in WeakIdentityHashMap) Object cache is often implemented using ReferenceMap (WeakHashMap). This class delegates decision on when to de-cache an objects on Java GC. In many systems Java objects that represent database instances use database identity: methods Object.equals(Object) and Object.hashCode() are redefined to use database identity (identity defined in terms of object table + object primary keys). When traditional java.util.Map is used to implement database caches different instances of the same database objects present a problem: instances override each other. Class java.util.IdentityHashMap (Apache Collections 3.0: IdentityMap) can be used to solve this problem - this approach uses System.identityHashCode() to obtain reference hashCode and Java comparison operator to compare keys (and values). What I need is functionality of IdentityMap combined with WeakReference-based keys. Is it possible to extend ReferenceMap with an ability to use reference identity instead of object identity? I can send you my prototype if you are interested (it adds about ten lines of code to ReferenceMap). Here are some links to Sun's bug parade pages that describe similar feature request for Java's java.util.WeakHashMap: http://developer.java.sun.com/developer/bugParade/bugs/4809420.html http://developer.java.sun.com/developer/bugParade/bugs/4500542.html P.S. There is a need for this feature in Apache DB-OJB project. All the Best, Andy --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
