/*
 * Copyright (c) 2011-2017 Contributors to the Eclipse Foundation
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 * which is available at https://www.apache.org/licenses/LICENSE-2.0.
 *
 * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 */

package io.vertx.core.shareddata;

import io.vertx.codegen.annotations.GenIgnore;
import io.vertx.codegen.annotations.VertxGen;

import java.util.Collection;
import java.util.Map;
import java.util.Set;
import java.util.function.BiConsumer;
import java.util.function.BiFunction;
import java.util.function.Function;

Local maps can be used to share data safely in a single Vert.x instance.
 By default the map allows immutable keys and values. Custom keys and values should implement Shareable interface. The map returns their copies. 

This ensures there is no shared access to mutable state from different threads (e.g. different event loops) in the
Vert.x instance, and means you don't have to protect access to that state using synchronization or locks.
 Since the version 3.4, this class extends the Map interface. However some methods are only accessible in Java. 
Author:
Tim Fox
See Also:
Shareable/**
 * Local maps can be used to share data safely in a single Vert.x instance.
 * <p>
 * By default the map allows immutable keys and values.
 * Custom keys and values should implement {@link Shareable} interface. The map returns their copies.
 * <p>
 * This ensures there is no shared access to mutable state from different threads (e.g. different event loops) in the
 * Vert.x instance, and means you don't have to protect access to that state using synchronization or locks.
 * <p>
 *
 * Since the version 3.4, this class extends the {@link Map} interface. However some methods are only accessible in Java.
 *
 * @author <a href="http://tfox.org">Tim Fox</a>
 * @see Shareable
 */
@VertxGen
public interface LocalMap<K, V> extends Map<K, V> {

  
Get a value from the map
Params:
key – the key
Returns:
the value, or null if none/**
   * Get a value from the map
   *
   * @param key the key
   * @return the value, or null if none
   */
  V get(Object key);

  
Put an entry in the map
Params:
key –   the key
value – the value
Returns:
return the old value, or null if none/**
   * Put an entry in the map
   *
   * @param key   the key
   * @param value the value
   * @return return the old value, or null if none
   */
  V put(K key, V value);

  
Remove an entry from the map
Params:
key – the key
Returns:
the old value/**
   * Remove an entry from the map
   *
   * @param key the key
   * @return the old value
   */
  V remove(Object key);

  
Clear all entries in the map
/**
   * Clear all entries in the map
   */
  void clear();

  
Get the size of the map
Returns:
the number of entries in the map/**
   * Get the size of the map
   *
   * @return the number of entries in the map
   */
  int size();

  
Returns:
true if there are zero entries in the map/**
   * @return true if there are zero entries in the map
   */
  boolean isEmpty();

  
Put the entry only if there is no existing entry for that key
Params:
key –   the key
value – the value
Returns:
the old value or null, if none/**
   * Put the entry only if there is no existing entry for that key
   *
   * @param key   the key
   * @param value the value
   * @return the old value or null, if none
   */
  V putIfAbsent(K key, V value);

  
Remove the entry only if there is an entry with the specified key and value.
 This method is the poyglot version of remove(Object, Object). 
Params:
key –   the key
value – the value
Returns:
true if removed/**
   * Remove the entry only if there is an entry with the specified key and value.
   * <p>
   * This method is the poyglot version of {@link #remove(Object, Object)}.
   *
   * @param key   the key
   * @param value the value
   * @return true if removed
   */
  boolean removeIfPresent(K key, V value);

  
Replace the entry only if there is an existing entry with the specified key and value.
 This method is the polyglot version of replace(Object, Object, Object). 
Params:
key –      the key
oldValue – the old value
newValue – the new value
Returns:
true if removed/**
   * Replace the entry only if there is an existing entry with the specified key and value.
   * <p>
   * This method is the polyglot version of {@link #replace(Object, Object, Object)}.
   *
   * @param key      the key
   * @param oldValue the old value
   * @param newValue the new value
   * @return true if removed
   */
  boolean replaceIfPresent(K key, V oldValue, V newValue);

  
Replace the entry only if there is an existing entry with the key
Params:
key –   the key
value – the new value
Returns:
the old value/**
   * Replace the entry only if there is an existing entry with the key
   *
   * @param key   the key
   * @param value the new value
   * @return the old value
   */
  V replace(K key, V value);

  
Close and release the map
/**
   * Close and release the map
   */
  void close();

  
Returns:
the set of keys in the map/**
   * @return the set of keys in the map
   */
  @GenIgnore
  Set<K> keySet();

  
Returns:
the set of values in the map/**
   * @return the set of values in the map
   */
  @GenIgnore
  Collection<V> values();

  
Attempts to compute a mapping for the specified key and its current mapped value (or null if there is no current mapping). 
 If the function returns null, the mapping is removed (or remains absent if initially absent). If the function itself throws an (unchecked) exception, the exception is rethrown, and the current mapping is left unchanged. 
Params:
key –               key with which the specified value is to be associated
remappingFunction – the function to compute a value
Returns:
the new value associated with the specified key, or null if none/**
   * Attempts to compute a mapping for the specified key and its current
   * mapped value (or {@code null} if there is no current mapping).
   * <p>
   * If the function returns {@code null}, the mapping is removed (or
   * remains absent if initially absent).  If the function itself throws an
   * (unchecked) exception, the exception is rethrown, and the current mapping
   * is left unchanged.
   *
   * @param key               key with which the specified value is to be associated
   * @param remappingFunction the function to compute a value
   * @return the new value associated with the specified key, or null if none
   **/
  @GenIgnore
  @Override
  V compute(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction);

  
If the specified key is not already associated with a value (or is mapped to null), attempts to compute its value using the given mapping function and enters it into this map unless null. 
 If the function returns null no mapping is recorded. If the function itself throws an (unchecked) exception, the exception is rethrown, and no mapping is recorded. 
Params:
key –             key with which the specified value is to be associated
mappingFunction – the function to compute a value
Returns:
the current (existing or computed) value associated with
the specified key, or null if the computed value is null/**
   * If the specified key is not already associated with a value (or is mapped
   * to {@code null}), attempts to compute its value using the given mapping
   * function and enters it into this map unless {@code null}.
   * <p>
   * If the function returns {@code null} no mapping is recorded. If
   * the function itself throws an (unchecked) exception, the
   * exception is rethrown, and no mapping is recorded.
   *
   * @param key             key with which the specified value is to be associated
   * @param mappingFunction the function to compute a value
   * @return the current (existing or computed) value associated with
   * the specified key, or null if the computed value is null
   */
  @GenIgnore
  @Override
  V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction);

  
If the value for the specified key is present and non-null, attempts to
compute a new mapping given the key and its current mapped value.
 If the function returns null, the mapping is removed. If the function itself throws an (unchecked) exception, the exception is rethrown, and the current mapping is left unchanged. 
Params:
key –               key with which the specified value is to be associated
remappingFunction – the function to compute a value
Returns:
the new value associated with the specified key, or null if none/**
   * If the value for the specified key is present and non-null, attempts to
   * compute a new mapping given the key and its current mapped value.
   * <p>
   * If the function returns {@code null}, the mapping is removed.  If the
   * function itself throws an (unchecked) exception, the exception is
   * rethrown, and the current mapping is left unchanged.
   *
   * @param key               key with which the specified value is to be associated
   * @param remappingFunction the function to compute a value
   * @return the new value associated with the specified key, or null if none
   */
  @GenIgnore
  @Override
  V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction);


  
Returns true if this map contains a mapping for the specified key. 
Params:
key – key whose presence in this map is to be tested
Returns:
true if this map contains a mapping for the specified key/**
   * Returns {@code true} if this map contains a mapping for the specified
   * key.
   *
   * @param key key whose presence in this map is to be tested
   * @return {@code true} if this map contains a mapping for the specified key
   */
  @Override
  boolean containsKey(Object key);

  
Returns @{code true} if this map maps one or more keys to the
specified value.
Params:
value – value whose presence in this map is to be tested
Returns:
@{code true} if this map maps one or more keys to the specified value/**
   * Returns @{code true} if this map maps one or more keys to the
   * specified value.
   *
   * @param value value whose presence in this map is to be tested
   * @return @{code true} if this map maps one or more keys to the specified value
   */
  @Override
  boolean containsValue(Object value);

  
Returns a Set view of the mappings contained in this map. 
 Unlike the default Map implementation, the set is not backed by the map. So changes made to the map are not reflected in the set. Entries added or remove to the set are not reflected to the map. In addition, the entries are not modifiable (Entry.setValue(Object) is not supported). 
Returns:
a set view of the mappings contained in this map/**
   * Returns a {@link Set} view of the mappings contained in this map.
   * <p>
   * Unlike the default {@link Map} implementation, the set is <strong>not</strong> backed by the map. So changes
   * made to the map are not reflected in the set. Entries added or remove to the set are not reflected to the map.
   * In addition, the entries are not modifiable ({@link java.util.Map.Entry#setValue(Object)} is not supported).
   *
   * @return a set view of the mappings contained in this map
   */
  @GenIgnore
  @Override
  Set<Entry<K, V>> entrySet();

  
Performs the given action for each entry in this map until all entries
have been processed or the action throws an exception.

Exceptions thrown by the action are relayed to the caller.
Params:
action – The action to be performed for each entry/**
   * Performs the given action for each entry in this map until all entries
   * have been processed or the action throws an exception.
   * <p>
   * Exceptions thrown by the action are relayed to the caller.
   *
   * @param action The action to be performed for each entry
   */
  @GenIgnore
  @Override
  void forEach(BiConsumer<? super K, ? super V> action);

  
Returns the value to which the specified key is mapped, or defaultValue if this map contains no mapping for the key. 
Params:
key –          the key whose associated value is to be returned
defaultValue – the default mapping of the key
Returns:
the value to which the specified key is mapped, or defaultValue if this map contains no mapping for the key/**
   * Returns the value to which the specified key is mapped, or
   * {@code defaultValue} if this map contains no mapping for the key.
   *
   * @param key          the key whose associated value is to be returned
   * @param defaultValue the default mapping of the key
   * @return the value to which the specified key is mapped, or {@code defaultValue} if this map contains no mapping
   * for the key
   */
  @Override
  V getOrDefault(Object key, V defaultValue);

  
If the specified key is not already associated with a value or is associated with null, associates it with the given non-null value. Otherwise, replaces the associated value with the results of the given remapping function, or removes if the result is null. This method may be of use when combining multiple mapped values for a key. 
Params:
key –               key with which the resulting value is to be associated
value –             the non-null value to be merged with the existing value
                         associated with the key or, if no existing value or a null value
                         is associated with the key, to be associated with the key
remappingFunction – the function to recompute a value if present
Returns:
the new value associated with the specified key, or null if no
value is associated with the key/**
   * If the specified key is not already associated with a value or is
   * associated with null, associates it with the given non-null value.
   * Otherwise, replaces the associated value with the results of the given
   * remapping function, or removes if the result is {@code null}. This
   * method may be of use when combining multiple mapped values for a key.
   *
   * @param key               key with which the resulting value is to be associated
   * @param value             the non-null value to be merged with the existing value
   *                          associated with the key or, if no existing value or a null value
   *                          is associated with the key, to be associated with the key
   * @param remappingFunction the function to recompute a value if present
   * @return the new value associated with the specified key, or null if no
   * value is associated with the key
   */
  @GenIgnore
  @Override
  V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction);

  
Copies all of the mappings from the specified map to this map. The effect of this call is equivalent to that of calling put(k, v) on this map once for each mapping from key k to value v in the specified map. The behavior of this operation is undefined if the specified map is modified while the operation is in progress. 
Params:
m – mappings to be stored in this map/**
   * Copies all of the mappings from the specified map to this map.  The effect of this call is equivalent to that
   * of calling {@link #put(Object, Object) put(k, v)} on this map once for each mapping from key {@code k} to value
   * {@code v} in the specified map.  The behavior of this operation is undefined if the specified map is modified
   * while the operation is in progress.
   *
   * @param m mappings to be stored in this map
   */
  @GenIgnore
  @Override
  void putAll(Map<? extends K, ? extends V> m);

  
Removes the entry for the specified key only if it is currently
mapped to the specified value.
Params:
key –   key with which the specified value is associated
value – value expected to be associated with the specified key
Returns:
true if the value was removed/**
   * Removes the entry for the specified key only if it is currently
   * mapped to the specified value.
   *
   * @param key   key with which the specified value is associated
   * @param value value expected to be associated with the specified key
   * @return {@code true} if the value was removed
   */
  @Override
  @GenIgnore
  boolean remove(Object key, Object value);

  
Replaces the entry for the specified key only if currently
mapped to the specified value.
Params:
key –      key with which the specified value is associated
oldValue – value expected to be associated with the specified key
newValue – value to be associated with the specified key
Returns:
true if the value was replaced/**
   * Replaces the entry for the specified key only if currently
   * mapped to the specified value.
   *
   * @param key      key with which the specified value is associated
   * @param oldValue value expected to be associated with the specified key
   * @param newValue value to be associated with the specified key
   * @return {@code true} if the value was replaced
   */
  @Override
  @GenIgnore
  boolean replace(K key, V oldValue, V newValue);

  
Replaces each entry's value with the result of invoking the given
function on that entry until all entries have been processed or the
function throws an exception.  Exceptions thrown by the function are
relayed to the caller.
Params:
function – the function to apply to each entry/**
   * Replaces each entry's value with the result of invoking the given
   * function on that entry until all entries have been processed or the
   * function throws an exception.  Exceptions thrown by the function are
   * relayed to the caller.
   *
   * @param function the function to apply to each entry
   */
  @GenIgnore
  @Override
  void replaceAll(BiFunction<? super K, ? super V, ? extends V> function);
}