/**
  * Remove an existing mapping from the cache.
  *
  * @param parentPathId The parent's path (directory) ID number.
  * @param childPathName The name of the path within the parent's directory
  */
 public void remove(int parentPathId, String childPathName) {
   PathNameCacheKey key = new PathNameCacheKey(parentPathId, childPathName);
   map.remove(key);
 }
 /**
  * Given a parent Path ID number and the child's path name look up the value in the cache.
  *
  * @param parentPathId The parent's path (directory) ID number.
  * @param childPathName The name of the path within the parent's directory
  * @return a PathNameCacheValue object containing the cache mapping, or null if the mapping isn't
  *     in the cache.
  */
 public PathNameCacheValue get(int parentPathId, String childPathName) {
   PathNameCacheKey key = new PathNameCacheKey(parentPathId, childPathName);
   return map.get(key);
 }
 /**
  * Add a new mapping to the cache.
  *
  * @param parentPathId The parent's path ID (actually, a directory ID).
  * @param childPathName The name of the path within that parent's directory.
  * @param childPathId The child's path ID to be used as the target of the mapping.
  * @param childType What type is the child (file, directory, etc), to be used as the target of the
  *     mapping.
  */
 public void put(int parentPathId, String childPathName, int childPathId, int childType) {
   PathNameCacheKey key = new PathNameCacheKey(parentPathId, childPathName);
   PathNameCacheValue value = new PathNameCacheValue(childPathId, childType);
   map.put(key, value);
 }
 /** Clear the cache, removing all stored items and reseting the size to 0. */
 public void clear() {
   map.clear();
 }