After discussing further with Scott, there's probably a better way to solve this one. Closing this review and retooling.....
It turns out this does result in a significant savings in practice, for projects with lots of ClientBundles with resources outside of the module space. So this approach will serve as an example solution for a concrete problem. But the solution should not alter the global ResourceOracle shared by other unrelated generators. However, question is whether keeping a local resource oracle for use only by ClientBundles would not incur significant overhead, since it would imply adding a mechanism for maintaining extra framework for handling per-generator resource oracles, and refreshing them, etc. Toby's longer term proposal of adding a custom a indexing classloader implementation is a more promising approach here, since circumventing a slow class loader lookup would no longer be necessary, and things would just work (assuming the classloader can be kept up to date successfully). http://gwt-code-reviews.appspot.com/1356801/diff/1/4 File dev/core/src/com/google/gwt/dev/resource/impl/ExpandableResourceOracleImpl.java (right): http://gwt-code-reviews.appspot.com/1356801/diff/1/4#newcode28 dev/core/src/com/google/gwt/dev/resource/impl/ExpandableResourceOracleImpl.java:28: public class ExpandableResourceOracleImpl extends ResourceOracleImpl well, getPathPrefixes is public on ResourcesOracleImpl (but not ResourcesOracle), so currently, generators don't have access to it. http://gwt-code-reviews.appspot.com/1356801/diff/1/5 File user/src/com/google/gwt/resources/ext/ResourceGeneratorUtil.java (right): http://gwt-code-reviews.appspot.com/1356801/diff/1/5#newcode570 user/src/com/google/gwt/resources/ext/ResourceGeneratorUtil.java:570: if (((GeneratorContextExt) genContext).isProdMode()) { It's only dev mode, since the optimization depends on the initial generator run discovering resource paths that caused a fallback to the class loader, and then subsequent generator runs being able to take advantage of the expanded resource oracle. Generators don't run multiple times for a given moduleSpace's ResourceOracle, in prodMode. http://gwt-code-reviews.appspot.com/1356801/show -- http://groups.google.com/group/Google-Web-Toolkit-Contributors
