[performance] PackageFragmentRoot.getRawClasspathEntry() has bad impact on startup performance

[laeubi]

While looking at a problem here I noticed that PackageFragmentRoot.getRawClasspathEntry() has a very bad impact on startup performance because it calls project.getResolvedClasspath()

eclipse.jdt.core/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/PackageFragmentRoot.java

Line 616 in 17fc318

project.getResolvedClasspath(); // force the reverse rawEntry cache to be populated

this leads to a resolve operation of all classpath containers (that actually should happen in a background thread!) in the main UI thread whenever one has an open Java Editor + Package Explorer open. This even blocks the whole UI startup of eclipse.

This is sadly not the only place where this could happen... but the other places are more UI related.

[srikanth-sankaran]

Jay, thanks for taking a look

[laeubi]

Especially calling "Raw" ClasspathEntry would indicate for me it is actually not resolved as there is also

eclipse.jdt.core/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/PackageFragmentRoot.java

Line 630 in 17fc318

public IClasspathEntry getResolvedClasspathEntry() throws JavaModelException {