code: void renameCache(Path oldhdfsPath, Path newhdfsPath,
      Path localPath) throws IOException {
      CacheEntry found = cacheMap.remove(oldhdfsPath);
      if (found == null) {
        String msg = "LookasideCache error renaming path: " + oldhdfsPath +
                     " to: " + newhdfsPath +
                     " Path " + newhdfsPath +
                     " because it does not exists in the cache.";
        LOG.warn(msg);
        return;
      }
      // Update its timestamp and localPath
      found.hdfsPath = newhdfsPath;
      found.setGenstamp(globalStamp.incrementAndGet());
      found.localPath = localPath;
  
      // add it back to the cache
      CacheEntry empty = cacheMap.putIfAbsent(newhdfsPath, found);
      if (empty != null) {
        String msg = "LookasideCache error renaming path: " + oldhdfsPath +
                     " to: " + newhdfsPath +
                     " Path " + newhdfsPath +
                     " already exists in the cache.";
        LOG.warn(msg);
        throw new IOException(msg);
      }
      localMetrics.numRename++;
      if (LOG.isDebugEnabled()) {
        LOG.debug("LookasideCache renamed path:" + oldhdfsPath +
                  " to:" + newhdfsPath +
                  " cachedPath: " + localPath);
      }
    }
docs: Change the localPath in the cache. The size remains the
  same. The accesstime is updated.