/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 2000-2003
* Sleepycat Software. All rights reserved.
*
* $Id: StoredSortedValueSet.java,v 1.10 2003/10/22 14:28:40 mhayes Exp $
*/
package com.sleepycat.bdb.collection;
import com.sleepycat.bdb.bind.DataBinding;
import com.sleepycat.bdb.bind.EntityBinding;
import com.sleepycat.bdb.DataIndex;
import com.sleepycat.bdb.DataStore;
import com.sleepycat.bdb.DataView;
import com.sleepycat.db.DbException;
import java.util.Comparator;
import java.util.SortedSet;
/**
* The SortedSet returned by Map.values() and which can also be constructed
* directly if a Map is not needed.
* Although this collection is a set it may contain duplicate values. Only if
* an entity value binding is used are all elements guaranteed to be unique.
*
* <p>In addition to the standard SortedSet methods, this class provides the
* following methods for stored sorted value sets only. Note that the use of
* these methods is not compatible with the standard Java collections
* interface.</p>
* <ul>
* <li>{@link #headSet(Object, boolean)}</li>
* <li>{@link #tailSet(Object, boolean)}</li>
* <li>{@link #subSet(Object, boolean, Object, boolean)}</li>
* </ul>
*
* @author Mark Hayes
*/
public class StoredSortedValueSet extends StoredValueSet implements SortedSet {
// no non-indexed valueBinding ctor is possible since key cannot be derived
/**
* Creates a sorted value set entity view of a {@link DataStore}.
*
* @param store is the DataStore underlying the new collection.
*
* @param valueEntityBinding is the binding used to translate between
* key/value buffers and entity value objects.
*
* @param writeAllowed is true to create a read-write collection or false
* to create a read-only collection.
*
* @throws IllegalArgumentException if formats are not consistently
* defined or a parameter is invalid.
*
* @throws RuntimeExceptionWrapper if a {@link DbException} is thrown.
*/
public StoredSortedValueSet(DataStore store,
EntityBinding valueEntityBinding,
boolean writeAllowed) {
super(new DataView(store, null, null, null,
valueEntityBinding, writeAllowed));
checkKeyDerivation();
}
/**
* Creates a sorted value set view of a {@link DataIndex}.
*
* @param index is the DataIndex underlying the new collection.
*
* @param valueBinding is the binding used to translate between value
* buffers and value objects.
*
* @param writeAllowed is true to create a read-write collection or false
* to create a read-only collection.
*
* @throws IllegalArgumentException if formats are not consistently
* defined or a parameter is invalid.
*
* @throws RuntimeExceptionWrapper if a {@link DbException} is thrown.
*/
public StoredSortedValueSet(DataIndex index,
DataBinding valueBinding,
boolean writeAllowed) {
super(new DataView(null, index, null, valueBinding,
null, writeAllowed));
checkKeyDerivation();
}
/**
* Creates a sorted value set entity view of a {@link DataIndex}.
*
* @param index is the DataIndex underlying the new collection.
*
* @param valueEntityBinding is the binding used to translate between
* key/value buffers and entity value objects.
*
* @param writeAllowed is true to create a read-write collection or false
* to create a read-only collection.
*
* @throws IllegalArgumentException if formats are not consistently
* defined or a parameter is invalid.
*
* @throws RuntimeExceptionWrapper if a {@link DbException} is thrown.
*/
public StoredSortedValueSet(DataIndex index,
EntityBinding valueEntityBinding,
boolean writeAllowed) {
super(new DataView(null, index, null, null,
valueEntityBinding, writeAllowed));
checkKeyDerivation();
}
StoredSortedValueSet(DataView valueSetView) {
super(valueSetView);
checkKeyDerivation();
}
private void checkKeyDerivation() {
if (!view.canDeriveKeyFromValue()) {
throw new IllegalArgumentException("Cannot derive key from value");
}
}
/**
* Returns null since comparators are not supported. The natural ordering
* of a stored collection is data byte order, whether the data classes
* implement the {@link java.lang.Comparable} interface or not.
* This method does not conform to the {@link SortedSet#comparator}
* interface.
*
* @return null.
*/
public Comparator comparator() {
return null;
}
/**
* Returns the first (lowest) element currently in this sorted set.
* This method conforms to the {@link SortedSet#first} interface.
*
* @return the first element.
*
* @throws RuntimeExceptionWrapper if a {@link DbException} is thrown.
*/
public Object first() {
return getFirstOrLast(true);
}
/**
* Returns the last (highest) element currently in this sorted set.
* This method conforms to the {@link SortedSet#last} interface.
*
* @return the last element.
*
* @throws RuntimeExceptionWrapper if a {@link DbException} is thrown.
*/
public Object last() {
return getFirstOrLast(false);
}
/**
* Returns a view of the portion of this sorted set whose elements are
* strictly less than toValue.
* This method conforms to the {@link SortedSet#headSet} interface.
*
* @param toValue the upper bound.
*
* @return the subset.
*
* @throws RuntimeExceptionWrapper if a {@link DbException} is thrown.
*/
public SortedSet headSet(Object toValue) {
return subSet(null, false, toValue, false);
}
/**
* Returns a view of the portion of this sorted set whose elements are
* strictly less than toValue, optionally including toValue.
* This method does not exist in the standard {@link SortedSet} interface.
*
* @param toValue is the upper bound.
*
* @param toInclusive is true to include toValue.
*
* @return the subset.
*
* @throws RuntimeExceptionWrapper if a {@link DbException} is thrown.
*/
public SortedSet headSet(Object toValue, boolean toInclusive) {
return subSet(null, false, toValue, toInclusive);
}
/**
* Returns a view of the portion of this sorted set whose elements are
* greater than or equal to fromValue.
* This method conforms to the {@link SortedSet#tailSet} interface.
*
* @param fromValue is the lower bound.
*
* @return the subset.
*
* @throws RuntimeExceptionWrapper if a {@link DbException} is thrown.
*/
public SortedSet tailSet(Object fromValue) {
return subSet(fromValue, true, null, false);
}
/**
* Returns a view of the portion of this sorted set whose elements are
* strictly greater than fromValue, optionally including fromValue.
* This method does not exist in the standard {@link SortedSet} interface.
*
* @param fromValue is the lower bound.
*
* @param fromInclusive is true to include fromValue.
*
* @return the subset.
*
* @throws RuntimeExceptionWrapper if a {@link DbException} is thrown.
*/
public SortedSet tailSet(Object fromValue, boolean fromInclusive) {
return subSet(fromValue, fromInclusive, null, false);
}
/**
* Returns a view of the portion of this sorted set whose elements range
* from fromValue, inclusive, to toValue, exclusive.
* This method conforms to the {@link SortedSet#subSet} interface.
*
* @param fromValue is the lower bound.
*
* @param toValue is the upper bound.
*
* @return the subset.
*
* @throws RuntimeExceptionWrapper if a {@link DbException} is thrown.
*/
public SortedSet subSet(Object fromValue, Object toValue) {
return subSet(fromValue, true, toValue, false);
}
/**
* Returns a view of the portion of this sorted set whose elements are
* strictly greater than fromValue and strictly less than toValue,
* optionally including fromValue and toValue.
* This method does not exist in the standard {@link SortedSet} interface.
*
* @param fromValue is the lower bound.
*
* @param fromInclusive is true to include fromValue.
*
* @param toValue is the upper bound.
*
* @param toInclusive is true to include toValue.
*
* @return the subset.
*
* @throws RuntimeExceptionWrapper if a {@link DbException} is thrown.
*/
public SortedSet subSet(Object fromValue, boolean fromInclusive,
Object toValue, boolean toInclusive) {
try {
return new StoredSortedValueSet(
view.subView(fromValue, fromInclusive, toValue, toInclusive,
null));
} catch (Exception e) {
throw StoredContainer.convertException(e);
}
}
}