org.h2.util.ValueHashMap Maven / Gradle / Ivy
/*
* Copyright 2004-2014 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (http://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.util;
import java.util.ArrayList;
import org.h2.message.DbException;
import org.h2.value.Value;
import org.h2.value.ValueNull;
/**
* This hash map supports keys of type Value.
*
* @param the value type
*/
public class ValueHashMap extends HashBase {
private Value[] keys;
private V[] values;
/**
* Create a new value hash map.
*
* @return the object
*/
public static ValueHashMap newInstance() {
return new ValueHashMap();
}
@Override
@SuppressWarnings("unchecked")
protected void reset(int newLevel) {
super.reset(newLevel);
keys = new Value[len];
values = (V[]) new Object[len];
}
@Override
protected void rehash(int newLevel) {
Value[] oldKeys = keys;
V[] oldValues = values;
reset(newLevel);
int len = oldKeys.length;
for (int i = 0; i < len; i++) {
Value k = oldKeys[i];
if (k != null && k != ValueNull.DELETED) {
// skip the checkSizePut so we don't end up
// accidentally recursing
internalPut(k, oldValues[i]);
}
}
}
private int getIndex(Value key) {
return key.hashCode() & mask;
}
/**
* Add or update a key value pair.
*
* @param key the key
* @param value the new value
*/
public void put(Value key, V value) {
checkSizePut();
internalPut(key, value);
}
private void internalPut(Value key, V value) {
int index = getIndex(key);
int plus = 1;
int deleted = -1;
do {
Value k = keys[index];
if (k == null) {
// found an empty record
if (deleted >= 0) {
index = deleted;
deletedCount--;
}
size++;
keys[index] = key;
values[index] = value;
return;
} else if (k == ValueNull.DELETED) {
// found a deleted record
if (deleted < 0) {
deleted = index;
}
} else if (k.equals(key)) {
// update existing
values[index] = value;
return;
}
index = (index + plus++) & mask;
} while (plus <= len);
// no space
DbException.throwInternalError("hashmap is full");
}
/**
* Remove a key value pair.
*
* @param key the key
*/
public void remove(Value key) {
checkSizeRemove();
int index = getIndex(key);
int plus = 1;
do {
Value k = keys[index];
if (k == null) {
// found an empty record
return;
} else if (k == ValueNull.DELETED) {
// found a deleted record
} else if (k.equals(key)) {
// found the record
keys[index] = ValueNull.DELETED;
values[index] = null;
deletedCount++;
size--;
return;
}
index = (index + plus++) & mask;
} while (plus <= len);
// not found
}
/**
* Get the value for this key. This method returns null if the key was not
* found.
*
* @param key the key
* @return the value for the given key
*/
public V get(Value key) {
int index = getIndex(key);
int plus = 1;
do {
Value k = keys[index];
if (k == null) {
// found an empty record
return null;
} else if (k == ValueNull.DELETED) {
// found a deleted record
} else if (k.equals(key)) {
// found it
return values[index];
}
index = (index + plus++) & mask;
} while (plus <= len);
return null;
}
/**
* Get the list of keys.
*
* @return all keys
*/
public ArrayList keys() {
ArrayList list = New.arrayList(size);
for (Value k : keys) {
if (k != null && k != ValueNull.DELETED) {
list.add(k);
}
}
return list;
}
/**
* Get the list of values.
*
* @return all values
*/
public ArrayList values() {
ArrayList list = New.arrayList(size);
int len = keys.length;
for (int i = 0; i < len; i++) {
Value k = keys[i];
if (k != null && k != ValueNull.DELETED) {
list.add(values[i]);
}
}
return list;
}
}