/**
* Remove a pair from the mapping. This operation removes a (key,id) pair from the mapping.
*
* @param key is the key whose id is to be released
*/
public void dropPair(long key) {
int id = ht.lookup(key);
if (id == 0) return;
ht.remove(key);
ids.swap(id);
cnt--;
}
/**
* Create a String representation of the IdMap.
*
* @param s is the String in which the
*/
public String toString() {
String s = "{ ";
for (int i = firstId(); i != 0; i = nextId(i)) {
s += "(" + ht.getKey(i) + "," + i + ") ";
}
return s + "}";
}
/**
* Add a new key-id pair.
*
* @param key is the key for which an id is required
* @param id is the requested id that the key is to be mapped to
* @return the new id or 0 if the key is already mapped or the id is already in use or the
* operation fails
*/
public int addPair(long key, int id) {
if (validKey(key) || validId(id)) return 0;
if (!ht.insert(key, id)) return 0;
ids.swap(id);
cnt++;
return id;
}
/**
* Add a new key-id pair.
*
* @param key is the key for which an id is required
* @return the new id or 0 if the key is already mapped or the operation fails
*/
public int addPair(long key) {
if (validKey(key) || (ids.firstOut() == 0)) return 0;
int id = ids.firstOut();
if (!ht.insert(key, id)) return 0;
ids.swap(id);
cnt++;
return id;
}
/**
* Get the id for a given key.
*
* @param key is the key for which the id is required
* @return the corresponding id or 0 if the key is not mapped or the operation fails
*/
public int getId(long key) {
return ht.lookup(key);
}
/**
* Determine if a given key has been mapped to an identfier.
*
* @param key is the key to be checked
* @return true if the key has been mapped, else false
*/
public boolean validKey(long key) {
return (ht.lookup(key) != 0);
}
/**
* Get the key that was mapped to the given identifier
*
* @param id is the identifier whose key is to be returned
* @return the key that maps to id, or 0 if there is none
*/
public long getKey(int id) {
return (validId(id) ? ht.getKey(id) : 0);
}
