vlsi.utils.CompactHashMapClass Maven / Gradle / Ivy
/*
* Copyright (c) 2011
*
* This file is part of CompactMap
*
* CompactMap is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* CompactMap is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with CompactMap. If not, see {
public static final CompactHashMapClass EMPTY = new CompactHashMapClassEmptyDefaults(
new com.github.andrewoma.dexx.collection.HashMap());
final com.github.andrewoma.dexx.collection.Map key2slot; // Immutable
// This value is used as a marker of deleted object
// "new String" is required to avoid clashing with regular strings
public static final String REMOVED_OBJECT = new String("Non existing mapping value");
public CompactHashMapClass(com.github.andrewoma.dexx.collection.Map key2slot) {
this.key2slot = key2slot;
}
protected Map getDefaultValues() {
return Collections.emptyMap();
}
protected abstract CompactHashMapClassEmptyDefaults getMapWithEmptyDefaults();
public V get(CompactHashMap map, K key) {
Object result = getInternal(map, key);
return result != REMOVED_OBJECT ? (V) result : null;
}
private Object getInternal(CompactHashMap map, Object key) {
final Integer slot = key2slot.get((K) key);
if (slot == null)
return getDefaultValues().get(key);
return getValueFromSlot(map, slot);
}
protected static Object getValueFromSlot(CompactHashMap map, int slot) {
switch (slot) {
case -1:
return map.v1;
case -2:
return map.v2;
case -3:
return map.v3;
}
return ((Object[]) map.v1)[slot];
}
public V put(CompactHashMap map, K key, Object value) {
Integer slot = key2slot.get(key);
Object prevValue = REMOVED_OBJECT;
if (slot == null) {
prevValue = getDefaultValues().get(key);
// Try put value as "default"
Map newDef = CompactHashMapDefaultValues.getNewDefaultValues(getDefaultValues(), key, value);
if (newDef != null) {
map.klass = getMapWithEmptyDefaults().getNewDefaultClass(newDef);
return (V) prevValue;
}
if (value == REMOVED_OBJECT)
return (V) prevValue;
// The value is not default -- put using regular way
slot = createNewSlot(map, key);
}
switch (slot) {
case -1:
if (prevValue == REMOVED_OBJECT)
prevValue = map.v1;
map.v1 = value;
break;
case -2:
if (prevValue == REMOVED_OBJECT)
prevValue = map.v2;
map.v2 = value;
break;
case -3:
if (prevValue == REMOVED_OBJECT)
prevValue = map.v3;
map.v3 = value;
break;
default:
Object[] array = (Object[]) map.v1;
if (prevValue == REMOVED_OBJECT)
prevValue = array[slot];
array[slot] = value;
break;
}
return (V) prevValue;
}
private Integer createNewSlot(CompactHashMap map, K key) {
final CompactHashMapClass nextKlass = getMapWithEmptyDefaults().getNextKlass(key, getDefaultValues());
map.klass = nextKlass;
int prevSize = key2slot.size();
if (prevSize == 3) {
// Array length should be odd to play well with 8 byte alignment of object size
// 1.5 refs (object header) + 1 int (array length) + n*length refs (contents)
Object[] array = new Object[4];
array[0] = map.v1;
map.v1 = array;
} else if (prevSize > 3) {
Object[] array = (Object[]) map.v1;
if (array.length < prevSize - 1) {
int newSize = array.length * 3 / 2;
newSize += newSize & 1; // If odd, round to next even
Object[] newArray = new Object[newSize];
System.arraycopy(array, 0, newArray, 0, array.length);
map.v1 = newArray;
}
}
return nextKlass.key2slot.get(key);
}
public int size(CompactHashMap map) {
return key2slot.size() + getDefaultValues().size() - removedSlotsCount(map);
}
private int removedSlotsCount(CompactHashMap map) {
int emptySlots = 0;
switch (key2slot.size()) {
default: // more than 3
for (Object o : (Object[]) map.v1) {
if (o == REMOVED_OBJECT) emptySlots++;
}
/* fall through */
case 3: // v1 is filled after v2
if (map.v1 == REMOVED_OBJECT) emptySlots++;
/* fall through */
case 2: // v2 is filled after v3
if (map.v2 == REMOVED_OBJECT) emptySlots++;
/* fall through */
case 1: // v3 is filled the first
if (map.v3 == REMOVED_OBJECT) emptySlots++;
case 0:
}
return emptySlots;
}
public boolean containsKey(CompactHashMap map, Object key) {
// We cannot use plain getInternal here since we will be unable to distinguish
// existing, but null default value
final Integer slot = key2slot.get((K) key);
if (slot == null)
return getDefaultValues().containsKey(key);
return getValueFromSlot(map, slot) != REMOVED_OBJECT;
}
public Set keySet(CompactHashMap map) {
return new CompactHashMapClass.KeySet(map);
}
public Set values(CompactHashMap map) {
return new CompactHashMapClass.Values(map);
}
public Set> entrySet(CompactHashMap map) {
return new CompactHashMapClass.EntrySet(map);
}
public void serialize(final CompactHashMap map, final ObjectOutputStream s) throws IOException {
// We serialize default and non default values separately
// That makes serialized representation more compact when several maps share defaults
int size = key2slot.size() - removedSlotsCount(map);
s.writeInt(size);
if (size > 0)
for (Pair entry : key2slot) {
Object value = getValueFromSlot(map, entry.component2());
if (value == REMOVED_OBJECT) continue;
s.writeObject(entry.component1());
s.writeObject(value);
}
// Serialize default values as separate map
s.writeObject(getDefaultValues());
}
public static void deserialize(CompactHashMap map, ObjectInputStream s) throws IOException, ClassNotFoundException {
int size = s.readInt();
map.klass = CompactHashMapClass.EMPTY;
for (int i = 0; i < size; i++) {
K key = (K) s.readObject();
V value = (V) s.readObject();
map.put(key, value);
}
Map defaults = (Map) s.readObject();
// TODO: optimize to CompactHashMapClassEmptyDefaults.getNewDefaultClass
// Current implementation of getNewDefaultClass relies on identity equality, thus it does not fit
for (Map.Entry entry : defaults.entrySet()) {
map.put(entry.getKey(), entry.getValue());
}
}
static class KeySet extends AbstractSet {
private final CompactHashMap map;
public KeySet(CompactHashMap map) {
this.map = map;
}
@Override
public int size() {
return map.size();
}
@Override
public boolean contains(Object o) {
return map.containsKey(o);
}
@Override
public boolean remove(Object o) {
return map.remove(o) != null; // TODO: support null as "previous" value
}
@Override
public Iterator iterator() {
return new KeyIterator(map);
}
@Override
public void clear() {
map.clear();
}
}
static class Values extends AbstractSet {
private final CompactHashMap map;
public Values(CompactHashMap map) {
this.map = map;
}
@Override
public int size() {
return map.size();
}
@Override
public boolean contains(Object o) {
return map.containsValue(o);
}
@Override
public Iterator iterator() {
return new ValueIterator(map);
}
@Override
public void clear() {
map.clear();
}
}
static class EntrySet extends AbstractSet> {
private final CompactHashMap map;
public EntrySet(CompactHashMap map) {
this.map = map;
}
@Override
public Iterator> iterator() {
return new EntryIterator(map);
}
@Override
public boolean contains(Object o) {
if (!(o instanceof Map.Entry))
return false;
Map.Entry e = (Map.Entry) o;
Object mapValue = map.get(e.getKey());
return mapValue == e.getValue() || mapValue != null && mapValue.equals(e.getValue());
}
@Override
public boolean remove(Object o) {
if (!(o instanceof Map.Entry))
return false;
Map.Entry e = (Map.Entry) o;
return map.remove(e.getKey()) != null; // TODO: support "return true" when value was null
}
@Override
public int size() {
return map.size();
}
@Override
public void clear() {
map.clear();
}
}
static abstract class HashIterator implements Iterator {
boolean defValues = true;
private final CompactHashMap map;
Iterator it;
Map.Entry current, next;
public HashIterator(CompactHashMap map) {
this.map = map;
if (map.isEmpty()) return;
this.it = map.klass.getDefaultValues().entrySet().iterator();
advance();
}
private void advance() {
if (!it.hasNext() && defValues) {
defValues = false;
it = map.klass.key2slot.asMap().entrySet().iterator();
}
if (!it.hasNext()) {
next = null;
return;
}
while (it.hasNext()) {
Map.Entry entry = (Map.Entry) it.next();
V value;
if (defValues)
value = (V) entry.getValue();
else {
value = (V) getValueFromSlot(map, (Integer) entry.getValue());
if (value == REMOVED_OBJECT) continue;
}
next = new SimpleEntry(map, (K) entry.getKey(), value);
return;
}
next = null;
}
public boolean hasNext() {
return next != null;
}
public Map.Entry nextEntry() {
if (next == null)
throw new NoSuchElementException();
current = next;
advance();
return current;
}
public void remove() {
map.remove(current.getKey());
}
}
static class KeyIterator extends HashIterator {
public KeyIterator(CompactHashMap kvCompactMap) {
super(kvCompactMap);
}
public K next() {
return nextEntry().getKey();
}
}
static class ValueIterator extends HashIterator {
public ValueIterator(CompactHashMap kvCompactMap) {
super(kvCompactMap);
}
public V next() {
return nextEntry().getValue();
}
}
static class EntryIterator extends HashIterator> {
public EntryIterator(CompactHashMap kvCompactMap) {
super(kvCompactMap);
}
public Map.Entry next() {
return nextEntry();
}
}
static class SimpleEntry implements Map.Entry {
final K key;
V value;
private final CompactHashMap map;
public SimpleEntry(CompactHashMap map, K key, V value) {
this.map = map;
this.key = key;
this.value = value;
}
public K getKey() {
return key;
}
public V getValue() {
return value;
}
public V setValue(V value) {
this.value = value;
return map.put(key, value);
}
}
}
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