@Test
public void testLockMissing_TempIndex() throws Exception {
final File idx = new File(db.getDirectory(), "tmp_index");
final File lck = new File(db.getDirectory(), "tmp_index.lock");
assertFalse(idx.exists());
assertFalse(lck.exists());
final DirCache dc = DirCache.lock(idx, db.getFS());
assertNotNull(dc);
assertFalse(idx.exists());
assertTrue(lck.exists());
assertEquals(0, dc.getEntryCount());
dc.unlock();
assertFalse(idx.exists());
assertFalse(lck.exists());
}
/**
* Create a new in-core index representation, lock it, and read from disk.
*
* <p>The new index will be locked and then read before it is returned to the caller. Read
* failures are reported as exceptions and therefore prevent the method from returning a partially
* populated index. On read failure, the lock is released.
*
* @param indexLocation location of the index file on disk.
* @param fs the file system abstraction which will be necessary to perform certain file system
* operations.
* @return a cache representing the contents of the specified index file (if it exists) or an
* empty cache if the file does not exist.
* @throws IOException the index file is present but could not be read, or the lock could not be
* obtained.
* @throws CorruptObjectException the index file is using a format or extension that this library
* does not support.
*/
public static DirCache lock(final File indexLocation, final FS fs)
throws CorruptObjectException, IOException {
final DirCache c = new DirCache(indexLocation, fs);
if (!c.lock()) throw new LockFailedException(indexLocation);
try {
c.read();
} catch (IOException e) {
c.unlock();
throw e;
} catch (RuntimeException e) {
c.unlock();
throw e;
} catch (Error e) {
c.unlock();
throw e;
}
return c;
}
