| /* |
| * 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 com.google.common.collect; |
| |
| import com.google.common.annotations.GwtCompatible; |
| import com.google.common.base.Objects; |
| |
| import java.util.Collection; |
| import java.util.Map; |
| import java.util.Set; |
| |
| import javax.annotation.Nullable; |
| |
| /** |
| * A collection that associates an ordered pair of keys, called a row key and a |
| * column key, with a single value. A table may be sparse, with only a small |
| * fraction of row key / column key pairs possessing a corresponding value. |
| * |
| * <p>The mappings corresponding to a given row key may be viewed as a {@link |
| * Map} whose keys are the columns. The reverse is also available, associating a |
| * column with a row key / value map. Note that, in some implementations, data |
| * access by column key may have fewer supported operations or worse performance |
| * than data access by row key. |
| * |
| * <p>The methods returning collections or maps always return views of the |
| * underlying table. Updating the table can change the contents of those |
| * collections, and updating the collections will change the table. |
| * |
| * <p>All methods that modify the table are optional, and the views returned by |
| * the table may or may not be modifiable. When modification isn't supported, |
| * those methods will throw an {@link UnsupportedOperationException}. |
| * |
| * <p>See the Guava User Guide article on <a href= |
| * "http://code.google.com/p/guava-libraries/wiki/NewCollectionTypesExplained#Table"> |
| * {@code Table}</a>. |
| * |
| * @author Jared Levy |
| * @param <R> the type of the table row keys |
| * @param <C> the type of the table column keys |
| * @param <V> the type of the mapped values |
| * @since 7.0 |
| */ |
| @GwtCompatible |
| public interface Table<R, C, V> { |
| // TODO(jlevy): Consider adding methods similar to ConcurrentMap methods. |
| |
| // Accessors |
| |
| /** |
| * Returns {@code true} if the table contains a mapping with the specified |
| * row and column keys. |
| * |
| * @param rowKey key of row to search for |
| * @param columnKey key of column to search for |
| */ |
| boolean contains(@Nullable Object rowKey, @Nullable Object columnKey); |
| |
| /** |
| * Returns {@code true} if the table contains a mapping with the specified |
| * row key. |
| * |
| * @param rowKey key of row to search for |
| */ |
| boolean containsRow(@Nullable Object rowKey); |
| |
| /** |
| * Returns {@code true} if the table contains a mapping with the specified |
| * column. |
| * |
| * @param columnKey key of column to search for |
| */ |
| boolean containsColumn(@Nullable Object columnKey); |
| |
| /** |
| * Returns {@code true} if the table contains a mapping with the specified |
| * value. |
| * |
| * @param value value to search for |
| */ |
| boolean containsValue(@Nullable Object value); |
| |
| /** |
| * Returns the value corresponding to the given row and column keys, or |
| * {@code null} if no such mapping exists. |
| * |
| * @param rowKey key of row to search for |
| * @param columnKey key of column to search for |
| */ |
| V get(@Nullable Object rowKey, @Nullable Object columnKey); |
| |
| /** Returns {@code true} if the table contains no mappings. */ |
| boolean isEmpty(); |
| |
| /** |
| * Returns the number of row key / column key / value mappings in the table. |
| */ |
| int size(); |
| |
| /** |
| * Compares the specified object with this table for equality. Two tables are |
| * equal when their cell views, as returned by {@link #cellSet}, are equal. |
| */ |
| @Override |
| boolean equals(@Nullable Object obj); |
| |
| /** |
| * Returns the hash code for this table. The hash code of a table is defined |
| * as the hash code of its cell view, as returned by {@link #cellSet}. |
| */ |
| @Override |
| int hashCode(); |
| |
| // Mutators |
| |
| /** Removes all mappings from the table. */ |
| void clear(); |
| |
| /** |
| * Associates the specified value with the specified keys. If the table |
| * already contained a mapping for those keys, the old value is replaced with |
| * the specified value. |
| * |
| * @param rowKey row key that the value should be associated with |
| * @param columnKey column key that the value should be associated with |
| * @param value value to be associated with the specified keys |
| * @return the value previously associated with the keys, or {@code null} if |
| * no mapping existed for the keys |
| */ |
| V put(R rowKey, C columnKey, V value); |
| |
| /** |
| * Copies all mappings from the specified table to this table. The effect is |
| * equivalent to calling {@link #put} with each row key / column key / value |
| * mapping in {@code table}. |
| * |
| * @param table the table to add to this table |
| */ |
| void putAll(Table<? extends R, ? extends C, ? extends V> table); |
| |
| /** |
| * Removes the mapping, if any, associated with the given keys. |
| * |
| * @param rowKey row key of mapping to be removed |
| * @param columnKey column key of mapping to be removed |
| * @return the value previously associated with the keys, or {@code null} if |
| * no such value existed |
| */ |
| V remove(@Nullable Object rowKey, @Nullable Object columnKey); |
| |
| // Views |
| |
| /** |
| * Returns a view of all mappings that have the given row key. For each row |
| * key / column key / value mapping in the table with that row key, the |
| * returned map associates the column key with the value. If no mappings in |
| * the table have the provided row key, an empty map is returned. |
| * |
| * <p>Changes to the returned map will update the underlying table, and vice |
| * versa. |
| * |
| * @param rowKey key of row to search for in the table |
| * @return the corresponding map from column keys to values |
| */ |
| Map<C, V> row(R rowKey); |
| |
| /** |
| * Returns a view of all mappings that have the given column key. For each row |
| * key / column key / value mapping in the table with that column key, the |
| * returned map associates the row key with the value. If no mappings in the |
| * table have the provided column key, an empty map is returned. |
| * |
| * <p>Changes to the returned map will update the underlying table, and vice |
| * versa. |
| * |
| * @param columnKey key of column to search for in the table |
| * @return the corresponding map from row keys to values |
| */ |
| Map<R, V> column(C columnKey); |
| |
| /** |
| * Returns a set of all row key / column key / value triplets. Changes to the |
| * returned set will update the underlying table, and vice versa. The cell set |
| * does not support the {@code add} or {@code addAll} methods. |
| * |
| * @return set of table cells consisting of row key / column key / value |
| * triplets |
| */ |
| Set<Cell<R, C, V>> cellSet(); |
| |
| /** |
| * Returns a set of row keys that have one or more values in the table. |
| * Changes to the set will update the underlying table, and vice versa. |
| * |
| * @return set of row keys |
| */ |
| Set<R> rowKeySet(); |
| |
| /** |
| * Returns a set of column keys that have one or more values in the table. |
| * Changes to the set will update the underlying table, and vice versa. |
| * |
| * @return set of column keys |
| */ |
| Set<C> columnKeySet(); |
| |
| /** |
| * Returns a collection of all values, which may contain duplicates. Changes |
| * to the returned collection will update the underlying table, and vice |
| * versa. |
| * |
| * @return collection of values |
| */ |
| Collection<V> values(); |
| |
| /** |
| * Returns a view that associates each row key with the corresponding map from |
| * column keys to values. Changes to the returned map will update this table. |
| * The returned map does not support {@code put()} or {@code putAll()}, or |
| * {@code setValue()} on its entries. |
| * |
| * <p>In contrast, the maps returned by {@code rowMap().get()} have the same |
| * behavior as those returned by {@link #row}. Those maps may support {@code |
| * setValue()}, {@code put()}, and {@code putAll()}. |
| * |
| * @return a map view from each row key to a secondary map from column keys to |
| * values |
| */ |
| Map<R, Map<C, V>> rowMap(); |
| |
| /** |
| * Returns a view that associates each column key with the corresponding map |
| * from row keys to values. Changes to the returned map will update this |
| * table. The returned map does not support {@code put()} or {@code putAll()}, |
| * or {@code setValue()} on its entries. |
| * |
| * <p>In contrast, the maps returned by {@code columnMap().get()} have the |
| * same behavior as those returned by {@link #column}. Those maps may support |
| * {@code setValue()}, {@code put()}, and {@code putAll()}. |
| * |
| * @return a map view from each column key to a secondary map from row keys to |
| * values |
| */ |
| Map<C, Map<R, V>> columnMap(); |
| |
| /** |
| * Row key / column key / value triplet corresponding to a mapping in a table. |
| * |
| * @since 7.0 |
| */ |
| interface Cell<R, C, V> { |
| /** |
| * Returns the row key of this cell. |
| */ |
| R getRowKey(); |
| |
| /** |
| * Returns the column key of this cell. |
| */ |
| C getColumnKey(); |
| |
| /** |
| * Returns the value of this cell. |
| */ |
| V getValue(); |
| |
| /** |
| * Compares the specified object with this cell for equality. Two cells are |
| * equal when they have equal row keys, column keys, and values. |
| */ |
| @Override |
| boolean equals(@Nullable Object obj); |
| |
| /** |
| * Returns the hash code of this cell. |
| * |
| * <p>The hash code of a table cell is equal to {@link |
| * Objects#hashCode}{@code (e.getRowKey(), e.getColumnKey(), e.getValue())}. |
| */ |
| @Override |
| int hashCode(); |
| } |
| } |