http://hsqldb.org: HSQLDB - Lightweight 100% Java SQL Database Engine
(The HSQL Development Group)
- Blaine Simpson
/* Copyright (c) 2001-2019, The HSQL Development Group
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the HSQL Development Group nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.hsqldb.map;
import org.hsqldb.types.TimestampData;
/*
* implementation notes:
*
* NB: As of this version this class cannot be used for mixed object types
* It is relatively easy to support this by adding an 'instanceof' test inside
* each getOrAddXxxx method before casting the Set values to the target type
* for comparison purposes.
*
* superclass is used as an Object Set
* getOrAddXxxx methods are implemented directly for speed
* the superclass infrastructure is otherwise used
*/
Subclass of BaseHashMap for maintaining a pool of objects. Supports a
range of java.lang.* objects.
Author: Fred Toussi (fredt@users dot sourceforge.net) Version: 2.4.1 Since: 1.7.2
/**
* Subclass of BaseHashMap for maintaining a pool of objects. Supports a
* range of java.lang.* objects.
*
* @author Fred Toussi (fredt@users dot sourceforge.net)
* @version 2.4.1
* @since 1.7.2
*
*/
public class ValuePoolHashMap extends BaseHashMap {
long hits;
public ValuePoolHashMap(int initialCapacity, int maxCapacity,
int purgePolicy) throws IllegalArgumentException {
super(initialCapacity, BaseHashMap.objectKeyOrValue,
BaseHashMap.noKeyOrValue, true);
this.maxCapacity = maxCapacity;
this.purgePolicy = purgePolicy;
}
protected Integer getOrAddInteger(int intKey) {
Integer testValue;
int index = hashIndex.getHashIndex(intKey);
int lookup = hashIndex.hashTable[index];
int lastLookup = -1;
for (; lookup >= 0;
lastLookup = lookup,
lookup = hashIndex.getNextLookup(lookup)) {
testValue = (Integer) objectKeyTable[lookup];
int keyValue = testValue.intValue();
if (keyValue == intKey) {
if (accessCount > ACCESS_MAX) {
resetAccessCount();
}
accessTable[lookup] = accessCount++;
hits++;
return testValue;
} else if (keyValue > intKey) {
break;
}
}
if (hashIndex.elementCount >= threshold) {
reset();
return getOrAddInteger(intKey);
}
lookup = hashIndex.linkNode(index, lastLookup);
testValue = Integer.valueOf(intKey);
objectKeyTable[lookup] = testValue;
if (accessCount > ACCESS_MAX) {
resetAccessCount();
}
accessTable[lookup] = accessCount++;
return testValue;
}
protected Long getOrAddLong(long longKey) {
Long testValue;
int index = hashIndex.getHashIndex((int) (longKey ^ (longKey >>> 32)));
int lookup = hashIndex.hashTable[index];
int lastLookup = -1;
for (; lookup >= 0;
lastLookup = lookup,
lookup = hashIndex.getNextLookup(lookup)) {
testValue = (Long) objectKeyTable[lookup];
long keyValue = testValue.longValue();
if (keyValue == longKey) {
if (accessCount > ACCESS_MAX) {
resetAccessCount();
}
accessTable[lookup] = accessCount++;
return testValue;
} else if (keyValue > longKey) {
break;
}
}
if (hashIndex.elementCount >= threshold) {
reset();
return getOrAddLong(longKey);
}
lookup = hashIndex.linkNode(index, lastLookup);
testValue = Long.valueOf(longKey);
objectKeyTable[lookup] = testValue;
if (accessCount > ACCESS_MAX) {
resetAccessCount();
}
accessTable[lookup] = accessCount++;
return testValue;
}
This is dissimilar to normal hash map get() methods. The key Object
should have an equals(String) method which should return true if the
key.toString().equals(String) is true. Also the key.hashCode() method
must return the same value as key.toString.hashCode().
The above is always true when the key is a String. But it means it is
possible to submit special keys that fulfill the contract. For example
a wrapper around a byte[] can be submitted as key to retrieve either
a new String, which is the result of the toString() method of the
wrapper, or return an existing String which would be equal to the result
of toString().
Params: - key – String or other Object with compatible equals(String)
and hashCode().
Returns: String from map or a new String
/**
* This is dissimilar to normal hash map get() methods. The key Object
* should have an equals(String) method which should return true if the
* key.toString().equals(String) is true. Also the key.hashCode() method
* must return the same value as key.toString.hashCode().<p>
*
* The above is always true when the key is a String. But it means it is
* possible to submit special keys that fulfill the contract. For example
* a wrapper around a byte[] can be submitted as key to retrieve either
* a new String, which is the result of the toString() method of the
* wrapper, or return an existing String which would be equal to the result
* of toString().
*
* @param key String or other Object with compatible equals(String)
* and hashCode().
* @return String from map or a new String
*/
protected String getOrAddString(Object key) {
String testValue;
int index = hashIndex.getHashIndex(key.hashCode());
int lookup = hashIndex.hashTable[index];
int lastLookup = -1;
for (; lookup >= 0;
lastLookup = lookup,
lookup = hashIndex.getNextLookup(lookup)) {
testValue = (String) objectKeyTable[lookup];
if (key.equals(testValue)) {
if (accessCount > ACCESS_MAX) {
resetAccessCount();
}
accessTable[lookup] = accessCount++;
return testValue;
}
}
if (hashIndex.elementCount >= threshold) {
reset();
return getOrAddString(key);
}
testValue = key.toString();
lookup = hashIndex.linkNode(index, lastLookup);
objectKeyTable[lookup] = testValue;
if (accessCount > ACCESS_MAX) {
resetAccessCount();
}
accessTable[lookup] = accessCount++;
return testValue;
}
protected String getOrAddSubString(String key, int from, int limit) {
// to improve
key = key.substring(from, limit);
String testValue;
int index = hashIndex.getHashIndex(key.hashCode());
int lookup = hashIndex.hashTable[index];
int lastLookup = -1;
for (; lookup >= 0;
lastLookup = lookup,
lookup = hashIndex.getNextLookup(lookup)) {
testValue = (String) objectKeyTable[lookup];
if (key.equals(testValue)) {
if (accessCount > ACCESS_MAX) {
resetAccessCount();
}
accessTable[lookup] = accessCount++;
return testValue;
}
}
if (hashIndex.elementCount >= threshold) {
reset();
return getOrAddString(key);
}
testValue = new String(key.toCharArray());
lookup = hashIndex.linkNode(index, lastLookup);
objectKeyTable[lookup] = testValue;
if (accessCount > ACCESS_MAX) {
resetAccessCount();
}
accessTable[lookup] = accessCount++;
return testValue;
}
protected TimestampData getOrAddDate(long longKey) {
TimestampData testValue;
int hash = (int) longKey ^ (int) (longKey >>> 32);
int index = hashIndex.getHashIndex(hash);
int lookup = hashIndex.hashTable[index];
int lastLookup = -1;
for (; lookup >= 0;
lastLookup = lookup,
lookup = hashIndex.getNextLookup(lookup)) {
testValue = (TimestampData) objectKeyTable[lookup];
if (testValue.getSeconds() == longKey) {
if (accessCount > ACCESS_MAX) {
resetAccessCount();
}
accessTable[lookup] = accessCount++;
return testValue;
}
}
if (hashIndex.elementCount >= threshold) {
reset();
return getOrAddDate(longKey);
}
lookup = hashIndex.linkNode(index, lastLookup);
testValue = new TimestampData(longKey);
objectKeyTable[lookup] = testValue;
if (accessCount > ACCESS_MAX) {
resetAccessCount();
}
accessTable[lookup] = accessCount++;
return testValue;
}
protected Double getOrAddDouble(long longKey) {
Double testValue;
int index = hashIndex.getHashIndex((int) (longKey ^ (longKey >>> 32)));
int lookup = hashIndex.hashTable[index];
int lastLookup = -1;
for (; lookup >= 0;
lastLookup = lookup,
lookup = hashIndex.getNextLookup(lookup)) {
testValue = (Double) objectKeyTable[lookup];
if (Double.doubleToLongBits(testValue.doubleValue()) == longKey) {
if (accessCount > ACCESS_MAX) {
resetAccessCount();
}
accessTable[lookup] = accessCount++;
return testValue;
}
}
if (hashIndex.elementCount >= threshold) {
reset();
return getOrAddDouble(longKey);
}
lookup = hashIndex.linkNode(index, lastLookup);
testValue = Double.valueOf(Double.longBitsToDouble(longKey));
objectKeyTable[lookup] = testValue;
if (accessCount > ACCESS_MAX) {
resetAccessCount();
}
accessTable[lookup] = accessCount++;
return testValue;
}
protected Object getOrAddObject(Object key) {
Object testValue;
int index = hashIndex.getHashIndex(key.hashCode());
int lookup = hashIndex.hashTable[index];
int lastLookup = -1;
for (; lookup >= 0;
lastLookup = lookup,
lookup = hashIndex.getNextLookup(lookup)) {
testValue = objectKeyTable[lookup];
if (testValue.equals(key)) {
if (accessCount > ACCESS_MAX) {
resetAccessCount();
}
accessTable[lookup] = accessCount++;
return testValue;
}
}
if (hashIndex.elementCount >= threshold) {
reset();
return getOrAddObject(key);
}
lookup = hashIndex.linkNode(index, lastLookup);
objectKeyTable[lookup] = key;
if (accessCount > ACCESS_MAX) {
resetAccessCount();
}
accessTable[lookup] = accessCount++;
return key;
}
}