/** Converts the flat map data to a map. */
private void convertToMap() {
delegateMap = createDelegateMap();
switch (size) { // drop through
case 3:
delegateMap.put(key3, value3);
case 2:
delegateMap.put(key2, value2);
case 1:
delegateMap.put(key1, value1);
}
size = 0;
hash1 = hash2 = hash3 = 0;
key1 = key2 = key3 = null;
value1 = value2 = value3 = null;
}
/**
* Checks whether the map contains the specified key.
*
* @param key the key to search for
* @return true if the map contains the key
*/
public boolean containsKey(Object key) {
if (delegateMap != null) {
return delegateMap.containsKey(key);
}
if (key == null) {
switch (size) { // drop through
case 3:
if (key3 == null) return true;
case 2:
if (key2 == null) return true;
case 1:
if (key1 == null) return true;
}
} else {
if (size > 0) {
int hashCode = key.hashCode();
switch (size) { // drop through
case 3:
if (hash3 == hashCode && key.equals(key3)) return true;
case 2:
if (hash2 == hashCode && key.equals(key2)) return true;
case 1:
if (hash1 == hashCode && key.equals(key1)) return true;
}
}
}
return false;
}
/**
* Checks whether the map contains the specified value.
*
* @param value the value to search for
* @return true if the map contains the key
*/
public boolean containsValue(Object value) {
if (delegateMap != null) {
return delegateMap.containsValue(value);
}
if (value == null) { // drop through
switch (size) {
case 3:
if (value3 == null) return true;
case 2:
if (value2 == null) return true;
case 1:
if (value1 == null) return true;
}
} else {
switch (size) { // drop through
case 3:
if (value.equals(value3)) return true;
case 2:
if (value.equals(value2)) return true;
case 1:
if (value.equals(value1)) return true;
}
}
return false;
}
/**
* Gets the value mapped to the key specified.
*
* @param key the key
* @return the mapped value, null if no match
*/
public Object get(Object key) {
if (delegateMap != null) {
return delegateMap.get(key);
}
if (key == null) {
switch (size) {
// drop through
case 3:
if (key3 == null) return value3;
case 2:
if (key2 == null) return value2;
case 1:
if (key1 == null) return value1;
}
} else {
if (size > 0) {
int hashCode = key.hashCode();
switch (size) {
// drop through
case 3:
if (hash3 == hashCode && key.equals(key3)) return value3;
case 2:
if (hash2 == hashCode && key.equals(key2)) return value2;
case 1:
if (hash1 == hashCode && key.equals(key1)) return value1;
}
}
}
return null;
}
/**
* Gets the map as a String.
*
* @return a string version of the map
*/
public String toString() {
if (delegateMap != null) {
return delegateMap.toString();
}
if (size == 0) {
return "{}";
}
StringBuffer buf = new StringBuffer(128);
buf.append('{');
switch (size) { // drop through
case 3:
buf.append((key3 == this ? "(this Map)" : key3));
buf.append('=');
buf.append((value3 == this ? "(this Map)" : value3));
buf.append(',');
case 2:
buf.append((key2 == this ? "(this Map)" : key2));
buf.append('=');
buf.append((value2 == this ? "(this Map)" : value2));
buf.append(',');
case 1:
buf.append((key1 == this ? "(this Map)" : key1));
buf.append('=');
buf.append((value1 == this ? "(this Map)" : value1));
}
buf.append('}');
return buf.toString();
}
/**
* Gets an iterator over the map. Changes made to the iterator affect this map.
*
* <p>A MapIterator returns the keys in the map. It also provides convenient methods to get the
* key and value, and set the value. It avoids the need to create an entrySet/keySet/values
* object. It also avoids creating the Map Entry object.
*
* @return the map iterator
*/
public MapIterator mapIterator() {
if (delegateMap != null) {
return delegateMap.mapIterator();
}
if (size == 0) {
return EmptyMapIterator.INSTANCE;
}
return new FlatMapIterator(this);
}
/**
* Puts all the values from the specified map into this map.
*
* @param map the map to add
* @throws NullPointerException if the map is null
*/
public void putAll(Map map) {
int size = map.size();
if (size == 0) {
return;
}
if (delegateMap != null) {
delegateMap.putAll(map);
return;
}
if (size < 4) {
for (Iterator it = map.entrySet().iterator(); it.hasNext(); ) {
Map.Entry entry = (Map.Entry) it.next();
put(entry.getKey(), entry.getValue());
}
} else {
convertToMap();
delegateMap.putAll(map);
}
}
/**
* Clears the map, resetting the size to zero and nullifying references to avoid garbage
* collection issues.
*/
public void clear() {
if (delegateMap != null) {
delegateMap.clear(); // should aid gc
delegateMap = null; // switch back to flat mode
} else {
size = 0;
hash1 = hash2 = hash3 = 0;
key1 = key2 = key3 = null;
value1 = value2 = value3 = null;
}
}
/**
* Gets the standard Map hashCode.
*
* @return the hash code defined in the Map interface
*/
public int hashCode() {
if (delegateMap != null) {
return delegateMap.hashCode();
}
int total = 0;
switch (size) { // drop through
case 3:
total += (hash3 ^ (value3 == null ? 0 : value3.hashCode()));
case 2:
total += (hash2 ^ (value2 == null ? 0 : value2.hashCode()));
case 1:
total += (hash1 ^ (value1 == null ? 0 : value1.hashCode()));
}
return total;
}
/**
* Compares this map with another.
*
* @param obj the object to compare to
* @return true if equal
*/
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (delegateMap != null) {
return delegateMap.equals(obj);
}
if (obj instanceof Map == false) {
return false;
}
Map other = (Map) obj;
if (size != other.size()) {
return false;
}
if (size > 0) {
Object otherValue = null;
switch (size) { // drop through
case 3:
if (other.containsKey(key3) == false) {
return false;
}
otherValue = other.get(key3);
if (value3 == null ? otherValue != null : !value3.equals(otherValue)) {
return false;
}
case 2:
if (other.containsKey(key2) == false) {
return false;
}
otherValue = other.get(key2);
if (value2 == null ? otherValue != null : !value2.equals(otherValue)) {
return false;
}
case 1:
if (other.containsKey(key1) == false) {
return false;
}
otherValue = other.get(key1);
if (value1 == null ? otherValue != null : !value1.equals(otherValue)) {
return false;
}
}
}
return true;
}
/**
* Gets the values view of the map. Changes made to the view affect this map. To simply iterate
* through the values, use {@link #mapIterator()}.
*
* @return the values view
*/
public Collection values() {
if (delegateMap != null) {
return delegateMap.values();
}
return new Values(this);
}
/**
* Gets the keySet view of the map. Changes made to the view affect this map. To simply iterate
* through the keys, use {@link #mapIterator()}.
*
* @return the keySet view
*/
public Set keySet() {
if (delegateMap != null) {
return delegateMap.keySet();
}
return new KeySet(this);
}
/**
* Gets the entrySet view of the map. Changes made to the view affect this map. The Map Entry is
* not an independent object and changes as the iterator progresses. To simply iterate through the
* entries, use {@link #mapIterator()}.
*
* @return the entrySet view
*/
public Set entrySet() {
if (delegateMap != null) {
return delegateMap.entrySet();
}
return new EntrySet(this);
}
/**
* Removes the specified mapping from this map.
*
* @param key the mapping to remove
* @return the value mapped to the removed key, null if key not in map
*/
public Object remove(Object key) {
if (delegateMap != null) {
return delegateMap.remove(key);
}
if (size == 0) {
return null;
}
if (key == null) {
switch (size) { // drop through
case 3:
if (key3 == null) {
Object old = value3;
hash3 = 0;
key3 = null;
value3 = null;
size = 2;
return old;
}
if (key2 == null) {
Object old = value3;
hash2 = hash3;
key2 = key3;
value2 = value3;
hash3 = 0;
key3 = null;
value3 = null;
size = 2;
return old;
}
if (key1 == null) {
Object old = value3;
hash1 = hash3;
key1 = key3;
value1 = value3;
hash3 = 0;
key3 = null;
value3 = null;
size = 2;
return old;
}
return null;
case 2:
if (key2 == null) {
Object old = value2;
hash2 = 0;
key2 = null;
value2 = null;
size = 1;
return old;
}
if (key1 == null) {
Object old = value2;
hash1 = hash2;
key1 = key2;
value1 = value2;
hash2 = 0;
key2 = null;
value2 = null;
size = 1;
return old;
}
return null;
case 1:
if (key1 == null) {
Object old = value1;
hash1 = 0;
key1 = null;
value1 = null;
size = 0;
return old;
}
}
} else {
if (size > 0) {
int hashCode = key.hashCode();
switch (size) { // drop through
case 3:
if (hash3 == hashCode && key.equals(key3)) {
Object old = value3;
hash3 = 0;
key3 = null;
value3 = null;
size = 2;
return old;
}
if (hash2 == hashCode && key.equals(key2)) {
Object old = value3;
hash2 = hash3;
key2 = key3;
value2 = value3;
hash3 = 0;
key3 = null;
value3 = null;
size = 2;
return old;
}
if (hash1 == hashCode && key.equals(key1)) {
Object old = value3;
hash1 = hash3;
key1 = key3;
value1 = value3;
hash3 = 0;
key3 = null;
value3 = null;
size = 2;
return old;
}
return null;
case 2:
if (hash2 == hashCode && key.equals(key2)) {
Object old = value2;
hash2 = 0;
key2 = null;
value2 = null;
size = 1;
return old;
}
if (hash1 == hashCode && key.equals(key1)) {
Object old = value2;
hash1 = hash2;
key1 = key2;
value1 = value2;
hash2 = 0;
key2 = null;
value2 = null;
size = 1;
return old;
}
return null;
case 1:
if (hash1 == hashCode && key.equals(key1)) {
Object old = value1;
hash1 = 0;
key1 = null;
value1 = null;
size = 0;
return old;
}
}
}
}
return null;
}
/**
* Puts a key-value mapping into this map.
*
* @param key the key to add
* @param value the value to add
* @return the value previously mapped to this key, null if none
*/
public Object put(Object key, Object value) {
if (delegateMap != null) {
return delegateMap.put(key, value);
}
// change existing mapping
if (key == null) {
switch (size) { // drop through
case 3:
if (key3 == null) {
Object old = value3;
value3 = value;
return old;
}
case 2:
if (key2 == null) {
Object old = value2;
value2 = value;
return old;
}
case 1:
if (key1 == null) {
Object old = value1;
value1 = value;
return old;
}
}
} else {
if (size > 0) {
int hashCode = key.hashCode();
switch (size) { // drop through
case 3:
if (hash3 == hashCode && key.equals(key3)) {
Object old = value3;
value3 = value;
return old;
}
case 2:
if (hash2 == hashCode && key.equals(key2)) {
Object old = value2;
value2 = value;
return old;
}
case 1:
if (hash1 == hashCode && key.equals(key1)) {
Object old = value1;
value1 = value;
return old;
}
}
}
}
// add new mapping
switch (size) {
default:
convertToMap();
delegateMap.put(key, value);
return null;
case 2:
hash3 = (key == null ? 0 : key.hashCode());
key3 = key;
value3 = value;
break;
case 1:
hash2 = (key == null ? 0 : key.hashCode());
key2 = key;
value2 = value;
break;
case 0:
hash1 = (key == null ? 0 : key.hashCode());
key1 = key;
value1 = value;
break;
}
size++;
return null;
}
/**
* Gets the size of the map.
*
* @return the size
*/
public int size() {
if (delegateMap != null) {
return delegateMap.size();
}
return size;
}