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/*
 * Copyright (C) 2009 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 com.google.common.collect;

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Objects;

import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import javax.annotation.Nullable;

/**
 * An immutable {@link Table} with reliable user-specified iteration order.
 * Does not permit null keys or values.
 *
 * 

Note: Although this class is not final, it cannot be subclassed as * it has no public or protected constructors. Thus, instances of this class are * guaranteed to be immutable. * *

See the Guava User Guide article on * immutable collections. * * @author Gregory Kick * @since 11.0 */ @GwtCompatible // TODO(gak): make serializable public abstract class ImmutableTable extends AbstractTable { private static final ImmutableTable EMPTY = new SparseImmutableTable( ImmutableList.>of(), ImmutableSet.of(), ImmutableSet.of()); /** Returns an empty immutable table. */ @SuppressWarnings("unchecked") public static ImmutableTable of() { return (ImmutableTable) EMPTY; } /** Returns an immutable table containing a single cell. */ public static ImmutableTable of(R rowKey, C columnKey, V value) { return new SingletonImmutableTable(rowKey, columnKey, value); } /** * Returns an immutable copy of the provided table. * *

The {@link Table#cellSet()} iteration order of the provided table * determines the iteration ordering of all views in the returned table. Note * that some views of the original table and the copied table may have * different iteration orders. For more control over the ordering, create a * {@link Builder} and call {@link Builder#orderRowsBy}, * {@link Builder#orderColumnsBy}, and {@link Builder#putAll} * *

Despite the method name, this method attempts to avoid actually copying * the data when it is safe to do so. The exact circumstances under which a * copy will or will not be performed are undocumented and subject to change. */ public static ImmutableTable copyOf( Table table) { if (table instanceof ImmutableTable) { @SuppressWarnings("unchecked") ImmutableTable parameterizedTable = (ImmutableTable) table; return parameterizedTable; } else { int size = table.size(); switch (size) { case 0: return of(); case 1: Cell onlyCell = Iterables.getOnlyElement(table.cellSet()); return ImmutableTable.of(onlyCell.getRowKey(), onlyCell.getColumnKey(), onlyCell.getValue()); default: ImmutableSet.Builder> cellSetBuilder = ImmutableSet.builder(); for (Cell cell : table.cellSet()) { /* * Must cast to be able to create a Cell rather than a * Cell */ cellSetBuilder.add(cellOf((R) cell.getRowKey(), (C) cell.getColumnKey(), (V) cell.getValue())); } return RegularImmutableTable.forCells(cellSetBuilder.build()); } } } /** * Returns a new builder. The generated builder is equivalent to the builder * created by the {@link Builder#ImmutableTable.Builder()} constructor. */ public static Builder builder() { return new Builder(); } /** * Verifies that {@code rowKey}, {@code columnKey} and {@code value} are * non-null, and returns a new entry with those values. */ static Cell cellOf(R rowKey, C columnKey, V value) { return Tables.immutableCell(checkNotNull(rowKey), checkNotNull(columnKey), checkNotNull(value)); } /** * A builder for creating immutable table instances, especially {@code public * static final} tables ("constant tables"). Example:

   {@code
   *
   *   static final ImmutableTable SPREADSHEET =
   *       new ImmutableTable.Builder()
   *           .put(1, 'A', "foo")
   *           .put(1, 'B', "bar")
   *           .put(2, 'A', "baz")
   *           .build();}
* *

By default, the order in which cells are added to the builder determines * the iteration ordering of all views in the returned table, with {@link * #putAll} following the {@link Table#cellSet()} iteration order. However, if * {@link #orderRowsBy} or {@link #orderColumnsBy} is called, the views are * sorted by the supplied comparators. * * For empty or single-cell immutable tables, {@link #of()} and * {@link #of(Object, Object, Object)} are even more convenient. * *

Builder instances can be reused - it is safe to call {@link #build} * multiple times to build multiple tables in series. Each table is a superset * of the tables created before it. * * @since 11.0 */ public static final class Builder { private final List> cells = Lists.newArrayList(); private Comparator rowComparator; private Comparator columnComparator; /** * Creates a new builder. The returned builder is equivalent to the builder * generated by {@link ImmutableTable#builder}. */ public Builder() {} /** * Specifies the ordering of the generated table's rows. */ public Builder orderRowsBy(Comparator rowComparator) { this.rowComparator = checkNotNull(rowComparator); return this; } /** * Specifies the ordering of the generated table's columns. */ public Builder orderColumnsBy( Comparator columnComparator) { this.columnComparator = checkNotNull(columnComparator); return this; } /** * Associates the ({@code rowKey}, {@code columnKey}) pair with {@code * value} in the built table. Duplicate key pairs are not allowed and will * cause {@link #build} to fail. */ public Builder put(R rowKey, C columnKey, V value) { cells.add(cellOf(rowKey, columnKey, value)); return this; } /** * Adds the given {@code cell} to the table, making it immutable if * necessary. Duplicate key pairs are not allowed and will cause {@link * #build} to fail. */ public Builder put( Cell cell) { if (cell instanceof Tables.ImmutableCell) { checkNotNull(cell.getRowKey()); checkNotNull(cell.getColumnKey()); checkNotNull(cell.getValue()); @SuppressWarnings("unchecked") // all supported methods are covariant Cell immutableCell = (Cell) cell; cells.add(immutableCell); } else { put(cell.getRowKey(), cell.getColumnKey(), cell.getValue()); } return this; } /** * Associates all of the given table's keys and values in the built table. * Duplicate row key column key pairs are not allowed, and will cause * {@link #build} to fail. * * @throws NullPointerException if any key or value in {@code table} is null */ public Builder putAll( Table table) { for (Cell cell : table.cellSet()) { put(cell); } return this; } /** * Returns a newly-created immutable table. * * @throws IllegalArgumentException if duplicate key pairs were added */ public ImmutableTable build() { int size = cells.size(); switch (size) { case 0: return of(); case 1: return new SingletonImmutableTable( Iterables.getOnlyElement(cells)); default: return RegularImmutableTable.forCells( cells, rowComparator, columnComparator); } } } ImmutableTable() {} @Override public ImmutableSet> cellSet() { return (ImmutableSet>) super.cellSet(); } @Override abstract ImmutableSet> createCellSet(); @Override final UnmodifiableIterator> cellIterator() { throw new AssertionError("should never be called"); } @Override public ImmutableCollection values() { return (ImmutableCollection) super.values(); } @Override abstract ImmutableCollection createValues(); @Override final Iterator valuesIterator() { throw new AssertionError("should never be called"); } /** * {@inheritDoc} * * @throws NullPointerException if {@code columnKey} is {@code null} */ @Override public ImmutableMap column(C columnKey) { checkNotNull(columnKey); return Objects.firstNonNull( (ImmutableMap) columnMap().get(columnKey), ImmutableMap.of()); } @Override public ImmutableSet columnKeySet() { return columnMap().keySet(); } /** * {@inheritDoc} * *

The value {@code Map} instances in the returned map are * {@link ImmutableMap} instances as well. */ @Override public abstract ImmutableMap> columnMap(); /** * {@inheritDoc} * * @throws NullPointerException if {@code rowKey} is {@code null} */ @Override public ImmutableMap row(R rowKey) { checkNotNull(rowKey); return Objects.firstNonNull( (ImmutableMap) rowMap().get(rowKey), ImmutableMap.of()); } @Override public ImmutableSet rowKeySet() { return rowMap().keySet(); } /** * {@inheritDoc} * *

The value {@code Map} instances in the returned map are * {@link ImmutableMap} instances as well. */ @Override public abstract ImmutableMap> rowMap(); @Override public boolean contains(@Nullable Object rowKey, @Nullable Object columnKey) { return get(rowKey, columnKey) != null; } @Override public boolean containsValue(@Nullable Object value) { return values().contains(value); } /** * Guaranteed to throw an exception and leave the table unmodified. * * @throws UnsupportedOperationException always * @deprecated Unsupported operation. */ @Deprecated @Override public final void clear() { throw new UnsupportedOperationException(); } /** * Guaranteed to throw an exception and leave the table unmodified. * * @throws UnsupportedOperationException always * @deprecated Unsupported operation. */ @Deprecated @Override public final V put(R rowKey, C columnKey, V value) { throw new UnsupportedOperationException(); } /** * Guaranteed to throw an exception and leave the table unmodified. * * @throws UnsupportedOperationException always * @deprecated Unsupported operation. */ @Deprecated @Override public final void putAll( Table table) { throw new UnsupportedOperationException(); } /** * Guaranteed to throw an exception and leave the table unmodified. * * @throws UnsupportedOperationException always * @deprecated Unsupported operation. */ @Deprecated @Override public final V remove(Object rowKey, Object columnKey) { throw new UnsupportedOperationException(); } }





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