/**
* Returns the current file cache.
*
* @param root root directory
* @return id, or {@code null} if newer file cache exists
* @throws InterruptedException interruption
*/
ProjectCache cache(final IOFile root) throws InterruptedException {
final ProjectCache pc = cache;
if (pc == null) {
// no file cache available: create and return new one
cache = new ProjectCache();
add(root, cache);
cache.finish();
} else {
// wait until file cache is initialized
while (!pc.valid()) {
Thread.yield();
// file cache was replaced with newer version
if (pc != cache) throw new InterruptedException();
}
}
// return existing file cache
return cache;
}
/**
* Recursively populates the cache.
*
* @param root root directory
* @param pc file cache
* @throws InterruptedException interruption
*/
void add(final IOFile root, final ProjectCache pc) throws InterruptedException {
// check if file cache was replaced or invalidated
if (pc != cache) throw new InterruptedException();
final IOFile[] files = root.children();
for (final IOFile file : files) {
if (file.name().equals(IO.IGNORESUFFIX)) return;
}
for (final IOFile file : files) {
if (file.isDir()) {
add(file, pc);
} else {
pc.add(file.path());
}
}
}