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/*
* Copyright (C) 2008 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.weakref.jmx.internal.guava.collect;
import static org.weakref.jmx.internal.guava.base.Preconditions.checkNotNull;
import static org.weakref.jmx.internal.guava.base.Predicates.alwaysTrue;
import static org.weakref.jmx.internal.guava.base.Predicates.equalTo;
import static org.weakref.jmx.internal.guava.base.Predicates.in;
import static org.weakref.jmx.internal.guava.base.Predicates.not;
import static org.weakref.jmx.internal.guava.collect.Maps.safeContainsKey;
import static org.weakref.jmx.internal.guava.collect.Maps.safeGet;
import org.weakref.jmx.internal.guava.annotations.GwtCompatible;
import org.weakref.jmx.internal.guava.base.Function;
import org.weakref.jmx.internal.guava.base.Predicate;
import org.weakref.jmx.internal.guava.base.Supplier;
import org.weakref.jmx.internal.guava.collect.Maps.ImprovedAbstractMap;
import org.weakref.jmx.internal.guava.collect.Sets.ImprovedAbstractSet;
import java.io.Serializable;
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import javax.annotation.Nullable;
/**
* {@link Table} implementation backed by a map that associates row keys with
* column key / value secondary maps. This class provides rapid access to
* records by the row key alone or by both keys, but not by just the column key.
*
* The views returned by {@link #column}, {@link #columnKeySet()}, and {@link
* #columnMap()} have iterators that don't support {@code remove()}. Otherwise,
* all optional operations are supported. Null row keys, columns keys, and
* values are not supported.
*
*
Lookups by row key are often faster than lookups by column key, because
* the data is stored in a {@code Map>}. A method call like {@code
* column(columnKey).get(rowKey)} still runs quickly, since the row key is
* provided. However, {@code column(columnKey).size()} takes longer, since an
* iteration across all row keys occurs.
*
* Note that this implementation is not synchronized. If multiple threads
* access this table concurrently and one of the threads modifies the table, it
* must be synchronized externally.
*
* @author Jared Levy
*/
@GwtCompatible
class StandardTable extends AbstractTable implements Serializable {
@GwtTransient final Map> backingMap;
@GwtTransient final Supplier extends Map> factory;
StandardTable(Map> backingMap,
Supplier extends Map> factory) {
this.backingMap = backingMap;
this.factory = factory;
}
// Accessors
@Override public boolean contains(
@Nullable Object rowKey, @Nullable Object columnKey) {
return rowKey != null && columnKey != null && super.contains(rowKey, columnKey);
}
@Override public boolean containsColumn(@Nullable Object columnKey) {
if (columnKey == null) {
return false;
}
for (Map map : backingMap.values()) {
if (safeContainsKey(map, columnKey)) {
return true;
}
}
return false;
}
@Override public boolean containsRow(@Nullable Object rowKey) {
return rowKey != null && safeContainsKey(backingMap, rowKey);
}
@Override public boolean containsValue(@Nullable Object value) {
return value != null && super.containsValue(value);
}
@Override public V get(@Nullable Object rowKey, @Nullable Object columnKey) {
return (rowKey == null || columnKey == null)
? null
: super.get(rowKey, columnKey);
}
@Override public boolean isEmpty() {
return backingMap.isEmpty();
}
@Override public int size() {
int size = 0;
for (Map map : backingMap.values()) {
size += map.size();
}
return size;
}
// Mutators
@Override public void clear() {
backingMap.clear();
}
private Map getOrCreate(R rowKey) {
Map map = backingMap.get(rowKey);
if (map == null) {
map = factory.get();
backingMap.put(rowKey, map);
}
return map;
}
@Override public V put(R rowKey, C columnKey, V value) {
checkNotNull(rowKey);
checkNotNull(columnKey);
checkNotNull(value);
return getOrCreate(rowKey).put(columnKey, value);
}
@Override public V remove(
@Nullable Object rowKey, @Nullable Object columnKey) {
if ((rowKey == null) || (columnKey == null)) {
return null;
}
Map map = safeGet(backingMap, rowKey);
if (map == null) {
return null;
}
V value = map.remove(columnKey);
if (map.isEmpty()) {
backingMap.remove(rowKey);
}
return value;
}
private Map removeColumn(Object column) {
Map output = new LinkedHashMap();
Iterator>> iterator
= backingMap.entrySet().iterator();
while (iterator.hasNext()) {
Entry> entry = iterator.next();
V value = entry.getValue().remove(column);
if (value != null) {
output.put(entry.getKey(), value);
if (entry.getValue().isEmpty()) {
iterator.remove();
}
}
}
return output;
}
private boolean containsMapping(
Object rowKey, Object columnKey, Object value) {
return value != null && value.equals(get(rowKey, columnKey));
}
/** Remove a row key / column key / value mapping, if present. */
private boolean removeMapping(Object rowKey, Object columnKey, Object value) {
if (containsMapping(rowKey, columnKey, value)) {
remove(rowKey, columnKey);
return true;
}
return false;
}
// Views
/**
* Abstract set whose {@code isEmpty()} returns whether the table is empty and
* whose {@code clear()} clears all table mappings.
*/
private abstract class TableSet extends ImprovedAbstractSet {
@Override public boolean isEmpty() {
return backingMap.isEmpty();
}
@Override public void clear() {
backingMap.clear();
}
}
/**
* {@inheritDoc}
*
* The set's iterator traverses the mappings for the first row, the
* mappings for the second row, and so on.
*
*
Each cell is an immutable snapshot of a row key / column key / value
* mapping, taken at the time the cell is returned by a method call to the
* set or its iterator.
*/
@Override public Set> cellSet() {
return super.cellSet();
}
@Override Iterator> cellIterator() {
return new CellIterator();
}
private class CellIterator implements Iterator> {
final Iterator>> rowIterator
= backingMap.entrySet().iterator();
Entry> rowEntry;
Iterator> columnIterator
= Iterators.emptyModifiableIterator();
@Override public boolean hasNext() {
return rowIterator.hasNext() || columnIterator.hasNext();
}
@Override public Cell next() {
if (!columnIterator.hasNext()) {
rowEntry = rowIterator.next();
columnIterator = rowEntry.getValue().entrySet().iterator();
}
Entry columnEntry = columnIterator.next();
return Tables.immutableCell(
rowEntry.getKey(), columnEntry.getKey(), columnEntry.getValue());
}
@Override public void remove() {
columnIterator.remove();
if (rowEntry.getValue().isEmpty()) {
rowIterator.remove();
}
}
}
@Override public Map row(R rowKey) {
return new Row(rowKey);
}
class Row extends ImprovedAbstractMap {
final R rowKey;
Row(R rowKey) {
this.rowKey = checkNotNull(rowKey);
}
Map backingRowMap;
Map backingRowMap() {
return (backingRowMap == null
|| (backingRowMap.isEmpty() && backingMap.containsKey(rowKey)))
? backingRowMap = computeBackingRowMap()
: backingRowMap;
}
Map computeBackingRowMap() {
return backingMap.get(rowKey);
}
// Call this every time we perform a removal.
void maintainEmptyInvariant() {
if (backingRowMap() != null && backingRowMap.isEmpty()) {
backingMap.remove(rowKey);
backingRowMap = null;
}
}
@Override
public boolean containsKey(Object key) {
Map backingRowMap = backingRowMap();
return (key != null && backingRowMap != null)
&& Maps.safeContainsKey(backingRowMap, key);
}
@Override
public V get(Object key) {
Map backingRowMap = backingRowMap();
return (key != null && backingRowMap != null)
? Maps.safeGet(backingRowMap, key)
: null;
}
@Override
public V put(C key, V value) {
checkNotNull(key);
checkNotNull(value);
if (backingRowMap != null && !backingRowMap.isEmpty()) {
return backingRowMap.put(key, value);
}
return StandardTable.this.put(rowKey, key, value);
}
@Override
public V remove(Object key) {
Map backingRowMap = backingRowMap();
if (backingRowMap == null) {
return null;
}
V result = Maps.safeRemove(backingRowMap, key);
maintainEmptyInvariant();
return result;
}
@Override
public void clear() {
Map backingRowMap = backingRowMap();
if (backingRowMap != null) {
backingRowMap.clear();
}
maintainEmptyInvariant();
}
@Override
protected Set> createEntrySet() {
return new RowEntrySet();
}
private final class RowEntrySet extends Maps.EntrySet {
@Override
Map map() {
return Row.this;
}
@Override
public int size() {
Map map = backingRowMap();
return (map == null) ? 0 : map.size();
}
@Override
public Iterator> iterator() {
final Map map = backingRowMap();
if (map == null) {
return Iterators.emptyModifiableIterator();
}
final Iterator> iterator = map.entrySet().iterator();
return new Iterator>() {
@Override public boolean hasNext() {
return iterator.hasNext();
}
@Override public Entry next() {
final Entry entry = iterator.next();
return new ForwardingMapEntry() {
@Override protected Entry delegate() {
return entry;
}
@Override public V setValue(V value) {
return super.setValue(checkNotNull(value));
}
@Override
public boolean equals(Object object) {
// TODO(user): identify why this affects GWT tests
return standardEquals(object);
}
};
}
@Override
public void remove() {
iterator.remove();
maintainEmptyInvariant();
}
};
}
}
}
/**
* {@inheritDoc}
*
* The returned map's views have iterators that don't support
* {@code remove()}.
*/
@Override public Map column(C columnKey) {
return new Column(columnKey);
}
private class Column extends ImprovedAbstractMap {
final C columnKey;
Column(C columnKey) {
this.columnKey = checkNotNull(columnKey);
}
@Override public V put(R key, V value) {
return StandardTable.this.put(key, columnKey, value);
}
@Override public V get(Object key) {
return StandardTable.this.get(key, columnKey);
}
@Override public boolean containsKey(Object key) {
return StandardTable.this.contains(key, columnKey);
}
@Override public V remove(Object key) {
return StandardTable.this.remove(key, columnKey);
}
/**
* Removes all {@code Column} mappings whose row key and value satisfy the
* given predicate.
*/
boolean removeFromColumnIf(Predicate super Entry> predicate) {
boolean changed = false;
Iterator>> iterator
= backingMap.entrySet().iterator();
while (iterator.hasNext()) {
Entry> entry = iterator.next();
Map map = entry.getValue();
V value = map.get(columnKey);
if (value != null
&& predicate.apply(Maps.immutableEntry(entry.getKey(), value))) {
map.remove(columnKey);
changed = true;
if (map.isEmpty()) {
iterator.remove();
}
}
}
return changed;
}
@Override Set> createEntrySet() {
return new EntrySet();
}
private class EntrySet extends ImprovedAbstractSet> {
@Override public Iterator> iterator() {
return new EntrySetIterator();
}
@Override public int size() {
int size = 0;
for (Map map : backingMap.values()) {
if (map.containsKey(columnKey)) {
size++;
}
}
return size;
}
@Override public boolean isEmpty() {
return !containsColumn(columnKey);
}
@Override public void clear() {
removeFromColumnIf(alwaysTrue());
}
@Override public boolean contains(Object o) {
if (o instanceof Entry) {
Entry, ?> entry = (Entry, ?>) o;
return containsMapping(entry.getKey(), columnKey, entry.getValue());
}
return false;
}
@Override public boolean remove(Object obj) {
if (obj instanceof Entry) {
Entry, ?> entry = (Entry, ?>) obj;
return removeMapping(entry.getKey(), columnKey, entry.getValue());
}
return false;
}
@Override public boolean retainAll(Collection> c) {
return removeFromColumnIf(not(in(c)));
}
}
private class EntrySetIterator extends AbstractIterator> {
final Iterator>> iterator
= backingMap.entrySet().iterator();
@Override protected Entry computeNext() {
while (iterator.hasNext()) {
final Entry> entry = iterator.next();
if (entry.getValue().containsKey(columnKey)) {
return new AbstractMapEntry() {
@Override public R getKey() {
return entry.getKey();
}
@Override public V getValue() {
return entry.getValue().get(columnKey);
}
@Override public V setValue(V value) {
return entry.getValue().put(columnKey, checkNotNull(value));
}
};
}
}
return endOfData();
}
}
@Override Set createKeySet() {
return new KeySet();
}
private class KeySet extends Maps.KeySet {
KeySet() {
super(Column.this);
}
@Override public boolean contains(Object obj) {
return StandardTable.this.contains(obj, columnKey);
}
@Override public boolean remove(Object obj) {
return StandardTable.this.remove(obj, columnKey) != null;
}
@Override public boolean retainAll(final Collection> c) {
return removeFromColumnIf(Maps.keyPredicateOnEntries(not(in(c))));
}
}
@Override
Collection createValues() {
return new Values();
}
private class Values extends Maps.Values {
Values() {
super(Column.this);
}
@Override public boolean remove(Object obj) {
return obj != null && removeFromColumnIf(Maps.valuePredicateOnEntries(equalTo(obj)));
}
@Override public boolean removeAll(final Collection> c) {
return removeFromColumnIf(Maps.valuePredicateOnEntries(in(c)));
}
@Override public boolean retainAll(final Collection> c) {
return removeFromColumnIf(Maps.valuePredicateOnEntries(not(in(c))));
}
}
}
@Override public Set rowKeySet() {
return rowMap().keySet();
}
private transient Set columnKeySet;
/**
* {@inheritDoc}
*
* The returned set has an iterator that does not support {@code remove()}.
*
* The set's iterator traverses the columns of the first row, the
* columns of the second row, etc., skipping any columns that have
* appeared previously.
*/
@Override
public Set columnKeySet() {
Set result = columnKeySet;
return (result == null) ? columnKeySet = new ColumnKeySet() : result;
}
private class ColumnKeySet extends TableSet {
@Override public Iterator iterator() {
return createColumnKeyIterator();
}
@Override public int size() {
return Iterators.size(iterator());
}
@Override public boolean remove(Object obj) {
if (obj == null) {
return false;
}
boolean changed = false;
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