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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 jakarta.faces.component;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import jakarta.el.ValueExpression;
import jakarta.faces.context.FacesContext;
import java.util.function.Supplier;

/**
 * A delta enabled state holder implementing the StateHolder Interface. 
 * 

* Components implementing the PartalStateHolder interface have an initial state * and delta states, the initial state is the one holding all root values * and deltas store differences to the initial states *

*

* For components not implementing partial state saving only the initial states are * of importance, everything is stored and restored continously there *

*

* The state helper seems to have three internal storage mechanisms: * one being a list which stores plain values, * one being a key value pair which stores key values in maps * add serves the plain list type while put serves the * key value type, * the third is the value which has to be stored plainly as is! *

* In other words, this map can be seen as a composite map. It has two maps: * initial state map and delta map. *

* If delta map is used (method component.initialStateMarked() ), * base or initial state map cannot be changed, since all changes * should be tracked on delta map. *

*

* The intention of this class is just hold property values * and do a clean separation between initial state and delta. *

*

* The context from this class comes and that should be taken into account * is this: *

*

* First request: *

*
    *
  • A new template is created (using * jakarta.faces.view.ViewDeclarationLanguage.buildView method) * and component.markInitialState is called from its related TagHandler classes * (see jakarta.faces.view.facelets.ComponentHandler ). * When this method is executed, the component tree was populated from the values * set in the facelet abstract syntax tree (or in other words composition of * facelets templates).
  • *
  • From this point all updates on the variables are considered "delta".
  • *
  • SaveState, if initialStateMarked is true, only delta is saved.
  • *
*

* Second request (and next ones) *

*
    *
  • A new template is created and component.markInitialState is called from * its related TagHandler classes again. In this way, components like c:forEach * or c:if, that add or remove components could notify about this and handle * them properly (see jakarta.faces.view.StateManagementStrategy). Note that a * component restored using this method is no different as the same component * at the first request at the same time.
  • *
  • A call for restoreState is done, passing the delta as object value. If no * delta, the state is complete and no call is triggered.
  • *
  • Lifecycle occur, changing the necessary stuff.
  • *
  • SaveState, if initialStateMarked is true, only delta is saved.
  • *
*

* From the previous analysis, the following conclusions arise: *

    *
  • This class only needs to keep track of delta changes, so when * restoreState/saveState is called, the right objects are passed.
  • *
  • UIComponent.clearInitialState is used to reset the partial * state holder to a non delta state, so the state to be saved by * saveState is no longer a delta instead is a full state. If a call * to clearInitialState occur it is not expected a call for * UIComponent.markInitialState occur on the current request.
  • *
  • The state is handled in the same way on UIData, so components * inside UIData share its state on all rows. There is no way to save * delta per row.
  • *
  • The map backed by method put(Serializable,String,Object) is * a replacement of UIComponentBase.attributesMap and UIComponent.bindings map. * Note that on jsf 1.2, instances saved on attributesMap should not be * StateHolder, but on jsf 2.0 it is possible to have it. PartialStateHolder * instances are not handled in this map, or in other words delta state is not * handled in this classes (markInitialState and clearInitialState is not propagated).
  • *
  • The list backed by method add(Serializable,Object) should be (is not) a * replacement of UIComponentBase.facesListeners, but note that StateHelper * does not implement PartialStateHolder, and facesListener could have instances * of that class that needs to be notified when UIComponent.markInitialState or * UIComponent.clearInitialState is called, or in other words facesListeners * should deal with PartialStateHolder instances.
  • *
  • The list backed by method add(Serializable,Object) is * a replacement of UIViewRoot.phaseListeners list. Note that instances of * PhaseListener are not expected to implement StateHolder or PartialStateHolder.
  • *
*

*

* NOTE: The current implementation of StateHelper on RI does not handle * stateHolder values internally. To prevent problems when developers create * custom components we should do this too. But anyway, the code that * handle this case should be let here as comment, if some day this feature * is provided. Note than stateHolder aware properties like converter, * validator or listeners should deal with StateHolder or PartialStateHolder * on component classes. * *

*/ class _DeltaStateHelper implements StateHelper, TransientStateHelper, TransientStateHolder { /** * We need to hold a component instance because: * * - The component is the one who knows if we are on initial or delta mode * - eval assume calls to component.ValueExpression */ private UIComponent _component; /** * This map holds the full current state */ private Map _fullState; /** * This map only keep track of delta changes to be saved */ private Map _deltas; private Map _transientState; private Object[] _initialState; private boolean _transient = false; /** * This is a copy-on-write map of the full state after markInitialState() * was called, but before any delta is written that is not part of * the initial state (value, localValueSet, submittedValue, valid). * The intention is allow to reset the StateHelper when copyFullInitialState * is set to true. */ private Map _initialFullState; /** * Indicates if a copy-on-write map is created to allow reset the state * of this StateHelper. */ private boolean _copyFullInitialState; public _DeltaStateHelper(UIComponent component) { super(); this._component = component; _fullState = new HashMap(); _deltas = null; _transientState = null; _initialFullState = null; _copyFullInitialState = false; } /** * Used to create delta map on demand * * @return */ private boolean _createDeltas(Serializable key) { if (isInitialStateMarked()) { if (_copyFullInitialState && _initialFullState == null) { if (_initialState == null) { // Copy it directly _initialFullState = new HashMap(); copyMap(_component.getFacesContext(), _fullState, _initialFullState); } else { // Create only if the passed key is not part of the defined initial state boolean keyInInitialState = false; for (int i = 0; i < _initialState.length; i+=2) { Serializable key2 = (Serializable) _initialState[i]; if (key.equals(key2)) { keyInInitialState = true; break; } } if (!keyInInitialState) { // Copy it directly, but note in this case if the initialFullState map // contains some key already defined in initialState, this key must be // overriden. It is better to do in that way, because it is possible // to skip resetState() if the view cannot be recycled. _initialFullState = new HashMap(); copyMap(_component.getFacesContext(), _fullState, _initialFullState); } } } if (_deltas == null) { _deltas = new HashMap(2); } return true; } return false; } void setCopyFullInitialState(boolean value) { _copyFullInitialState = value; } private static void copyMap(FacesContext context, Map sourceMap, Map targetMap) { Map serializableMap = sourceMap; Map.Entry entry; Iterator> it = serializableMap.entrySet().iterator(); while (it.hasNext()) { entry = it.next(); Serializable key = entry.getKey(); Object value = entry.getValue(); // The condition in which the call to saveAttachedState // is to handle List, StateHolder or non Serializable instances. // we check it here, to prevent unnecessary calls. if (value instanceof StateHolder || value instanceof List || !(value instanceof Serializable)) { Object savedValue = UIComponentBase.saveAttachedState(context, value); targetMap.put(key, UIComponentBase.restoreAttachedState(context, savedValue)); } else if (!(value instanceof Serializable)) { Object newInstance; try { newInstance = entry.getValue().getClass().newInstance(); } catch (InstantiationException e) { throw new RuntimeException("Could not restore StateHolder of type " + entry.getValue().getClass().getName() + " (missing no-args constructor?)", e); } catch (IllegalAccessException e) { throw new RuntimeException(e); } targetMap.put(key, newInstance); } else { targetMap.put(key, value); } } } protected boolean isInitialStateMarked() { return _component.initialStateMarked(); } @Override public void add(Serializable key, Object value) { if (_createDeltas(key)) { //Track delta case Map deltaListMapValues = (Map) _deltas.get(key); if (deltaListMapValues == null) { deltaListMapValues = new InternalDeltaListMap<>(3); _deltas.put(key, deltaListMapValues); } deltaListMapValues.put(value, Boolean.TRUE); } //Handle change on full map List fullListValues = (List) _fullState.get(key); if (fullListValues == null) { fullListValues = new InternalList<>(3); _fullState.put(key, fullListValues); } fullListValues.add(value); } @Override public Object eval(Serializable key) { Object returnValue = _fullState.get(key); if (returnValue != null) { return returnValue; } ValueExpression expression = _component.getValueExpression(key.toString()); if (expression != null) { return expression.getValue(_component.getFacesContext().getELContext()); } return null; } @Override public Object eval(Serializable key, Object defaultValue) { Object returnValue = _fullState.get(key); if (returnValue == null) { ValueExpression expression = _component.getValueExpression(key.toString()); if (expression != null) { returnValue = expression.getValue(_component.getFacesContext().getELContext()); } } if (returnValue == null) { returnValue = defaultValue; } return returnValue; } /** * * @param key * @param defaultValueSupplier * @return * * @since 4.0 */ @Override public Object eval(Serializable key, Supplier defaultValueSupplier) { Object returnValue = _fullState.get(key); if (returnValue == null) { ValueExpression expression = _component.getValueExpression(key.toString()); if (expression != null) { returnValue = expression.getValue(_component.getFacesContext().getELContext()); } } if (returnValue == null && defaultValueSupplier != null) { returnValue = defaultValueSupplier.get(); } return returnValue; } @Override public Object get(Serializable key) { return _fullState.get(key); } @Override public Object put(Serializable key, Object value) { Object returnValue = null; if (_createDeltas(key)) { if (_deltas.containsKey(key)) { returnValue = _deltas.put(key, value); _fullState.put(key, value); } else if (value == null && !_fullState.containsKey(key)) { returnValue = null; } else { _deltas.put(key, value); returnValue = _fullState.put(key, value); } } else { returnValue = _fullState.put(key, value); } return returnValue; } @Override public Object put(Serializable key, String mapKey, Object value) { boolean returnSet = false; Object returnValue = null; if (_createDeltas(key)) { //Track delta case Map mapValues = (Map) _deltas.get(key); if (mapValues == null) { mapValues = new InternalMap<>(); _deltas.put(key, mapValues); } if (mapValues.containsKey(mapKey)) { returnValue = mapValues.put(mapKey, value); returnSet = true; } else { mapValues.put(mapKey, value); } } //Handle change on full map Map mapValues = (Map) _fullState.get(key); if (mapValues == null) { mapValues = new InternalMap<>(); _fullState.put(key, mapValues); } if (returnSet) { mapValues.put(mapKey, value); } else { returnValue = mapValues.put(mapKey, value); } return returnValue; } @Override public Object remove(Serializable key) { Object returnValue = null; if (_createDeltas(key)) { if (_deltas.containsKey(key)) { // Keep track of the removed values using key/null pair on the delta map returnValue = _deltas.put(key, null); _fullState.remove(key); } else { // Keep track of the removed values using key/null pair on the delta map _deltas.put(key, null); returnValue = _fullState.remove(key); } } else { returnValue = _fullState.remove(key); } return returnValue; } @Override public Object remove(Serializable key, Object valueOrKey) { // Comment by lu4242 : The spec javadoc says if it is a Collection // or Map deal with it. But the intention of this method is work // with add(?,?) and put(?,?,?), this ones return instances of // InternalMap and InternalList to prevent mixing, so to be // consistent we'll cast to those classes here. Object collectionOrMap = _fullState.get(key); Object returnValue = null; if (collectionOrMap instanceof InternalMap) { if (_createDeltas(key)) { returnValue = _removeValueOrKeyFromMap(_deltas, key, valueOrKey, true); _removeValueOrKeyFromMap(_fullState, key, valueOrKey, false); } else { returnValue = _removeValueOrKeyFromMap(_fullState, key, valueOrKey, false); } } else if (collectionOrMap instanceof InternalList) { if (_createDeltas(key)) { returnValue = _removeValueOrKeyFromCollectionDelta(_deltas, key, valueOrKey); _removeValueOrKeyFromCollection(_fullState, key, valueOrKey); } else { returnValue = _removeValueOrKeyFromCollection(_fullState, key, valueOrKey); } } return returnValue; } private static Object _removeValueOrKeyFromCollectionDelta( Map stateMap, Serializable key, Object valueOrKey) { Object returnValue = null; Map c = (Map) stateMap.get(key); if (c != null) { if (c.containsKey(valueOrKey)) { returnValue = valueOrKey; } c.put(valueOrKey, Boolean.FALSE); } return returnValue; } private static Object _removeValueOrKeyFromCollection( Map stateMap, Serializable key, Object valueOrKey) { Object returnValue = null; Collection c = (Collection) stateMap.get(key); if (c != null) { if (c.remove(valueOrKey)) { returnValue = valueOrKey; } if (c.isEmpty()) { stateMap.remove(key); } } return returnValue; } private static Object _removeValueOrKeyFromMap( Map stateMap, Serializable key, Object valueOrKey, boolean delta) { if (valueOrKey == null) { return null; } Object returnValue = null; Map map = (Map) stateMap.get(key); if (map != null) { if (delta) { // Keep track of the removed values using key/null pair on the delta map returnValue = map.put((String) valueOrKey, null); } else { returnValue = map.remove(valueOrKey); } if (map.isEmpty()) { //stateMap.remove(key); stateMap.put(key, null); } } return returnValue; } @Override public boolean isTransient() { return _transient; } /** * Serializing cod * the serialized data structure consists of key value pairs unless the value itself is an internal array * or a map in case of an internal array or map the value itself is another array with its initial value * myfaces.InternalArray, myfaces.internalMap * * the internal Array is then mapped to another array * * the internal Map again is then mapped to a map with key value pairs * * */ @Override public Object saveState(FacesContext context) { Map serializableMap = (isInitialStateMarked()) ? _deltas : _fullState; if (_initialState != null && _deltas != null && !_deltas.isEmpty() && isInitialStateMarked()) { // Before save the state, check if the property was changed from the // initial state value. If the property was changed but it has the // same value from the one in the initial state, we can remove it // from delta, because when the view is built again, it will be // restored to the same state. This check suppose some additional // map.get() calls when saving the state, but using it only in properties // that are expected to change over lifecycle (value, localValueSet, // submittedValue, valid), is worth to do it, because those ones // always generated delta changes. for (int i = 0; i < _initialState.length; i+=2) { Serializable key = (Serializable) _initialState[i]; Object defaultValue = _initialState[i+1]; // Check only if there is delta state for that property, in other // case it is not necessary. Remember it is possible to have // null values inside the Map. if (_deltas.containsKey(key)) { Object deltaValue = _deltas.get(key); if (deltaValue == null && defaultValue == null) { _deltas.remove(key); if (_deltas.isEmpty()) { break; } } if (deltaValue != null && deltaValue.equals(defaultValue)) { _deltas.remove(key); if (_deltas.isEmpty()) { break; } } } } } if (serializableMap == null || serializableMap.isEmpty()) { return null; } Map.Entry entry; Object[] retArr = new Object[serializableMap.entrySet().size() * 2]; Iterator> it = serializableMap.entrySet().iterator(); int cnt = 0; while (it.hasNext()) { entry = it.next(); retArr[cnt] = entry.getKey(); Object value = entry.getValue(); // The condition in which the call to saveAttachedState // is to handle List, StateHolder or non Serializable instances. // we check it here, to prevent unnecessary calls. if (value instanceof StateHolder || value instanceof List || !(value instanceof Serializable)) { Object savedValue = UIComponentBase.saveAttachedState(context, value); retArr[cnt + 1] = savedValue; } else { retArr[cnt + 1] = value; } cnt += 2; } return retArr; } @Override public void restoreState(FacesContext context, Object state) { if (state == null) { return; } Object[] serializedState = (Object[]) state; if (!isInitialStateMarked() && !_fullState.isEmpty()) { _fullState.clear(); if(_deltas != null) { _deltas.clear(); } } for (int cnt = 0; cnt < serializedState.length; cnt += 2) { Serializable key = (Serializable) serializedState[cnt]; Object savedValue = UIComponentBase.restoreAttachedState(context, serializedState[cnt + 1]); if (isInitialStateMarked()) { if (savedValue instanceof InternalDeltaListMap) { for (Map.Entry mapEntry : ((Map) savedValue).entrySet()) { boolean addOrRemove = mapEntry.getValue(); if (addOrRemove) { //add this.add(key, mapEntry.getKey()); } else { //remove this.remove(key, mapEntry.getKey()); } } } else if (savedValue instanceof InternalMap) { for (Map.Entry mapEntry : ((Map) savedValue).entrySet()) { this.put(key, mapEntry.getKey(), mapEntry.getValue()); } } else { put(key, savedValue); } } else { put(key, savedValue); } } } /** * Try to reset the state and then check if the reset was succesful or not, * calling saveState(). */ public Object resetHardState(FacesContext context) { if (_transientState != null) { _transientState.clear(); } if (_deltas != null && !_deltas.isEmpty() && isInitialStateMarked()) { clearFullStateMap(context); } return saveState(context); } /** * Execute a "soft reset", which means only remove all transient state. */ public Object resetSoftState(FacesContext context) { if (_transientState != null) { _transientState.clear(); } return null; } protected void clearFullStateMap(FacesContext context) { if (_deltas != null) { _deltas.clear(); } if (_initialFullState != null) { // If there is no delta, fullState is not required to be cleared. _fullState.clear(); copyMap(context, _initialFullState, _fullState); } if (_initialState != null) { // If initial state is defined, override properties in _initialFullState. for (int i = 0; i < _initialState.length; i+=2) { Serializable key2 = (Serializable) _initialState[i]; Object defaultValue = _initialState[i+1]; if (_fullState.containsKey(key2)) { _fullState.put(key2, defaultValue); } } } } @Override public void setTransient(boolean transientValue) { _transient = transientValue; } //We use our own data structures just to make sure //nothing gets mixed up internally static class InternalMap extends HashMap implements StateHolder { public InternalMap() { super(); } public InternalMap(int initialCapacity, float loadFactor) { super(initialCapacity, loadFactor); } public InternalMap(Map m) { super(m); } public InternalMap(int initialSize) { super(initialSize); } @Override public boolean isTransient() { return false; } @Override public void setTransient(boolean newTransientValue) { // No op } @Override public void restoreState(FacesContext context, Object state) { Object[] listAsMap = (Object[]) state; for (int cnt = 0; cnt < listAsMap.length; cnt += 2) { this.put((K) listAsMap[cnt], (V) UIComponentBase.restoreAttachedState(context, listAsMap[cnt + 1])); } } @Override public Object saveState(FacesContext context) { int cnt = 0; Object[] mapArr = new Object[this.size() * 2]; for (Map.Entry entry : this.entrySet()) { mapArr[cnt] = entry.getKey(); Object value = entry.getValue(); if (value instanceof StateHolder || value instanceof List || !(value instanceof Serializable)) { mapArr[cnt + 1] = UIComponentBase.saveAttachedState(context, value); } else { mapArr[cnt + 1] = value; } cnt += 2; } return mapArr; } } /** * Map used to keep track of list changes */ static class InternalDeltaListMap extends InternalMap { public InternalDeltaListMap() { super(); } public InternalDeltaListMap(int initialCapacity, float loadFactor) { super(initialCapacity, loadFactor); } public InternalDeltaListMap(int initialSize) { super(initialSize); } public InternalDeltaListMap(Map m) { super(m); } } static class InternalList extends ArrayList implements StateHolder { public InternalList() { super(); } public InternalList(Collection c) { super(c); } public InternalList(int initialSize) { super(initialSize); } @Override public boolean isTransient() { return false; } @Override public void setTransient(boolean newTransientValue) { } @Override public void restoreState(FacesContext context, Object state) { Object[] listAsArr = (Object[]) state; //since all other options would mean dual iteration //we have to do it the hard way for (Object elem : listAsArr) { add((T) UIComponentBase.restoreAttachedState(context, elem)); } } @Override public Object saveState(FacesContext context) { Object[] values = new Object[size()]; for (int i = 0; i < size(); i++) { Object value = get(i); if (value instanceof StateHolder || value instanceof List || !(value instanceof Serializable)) { values[i] = UIComponentBase.saveAttachedState(context, value); } else { values[i] = value; } } return values; } } @Override public Object getTransient(Object key) { return (_transientState == null) ? null : _transientState.get(key); } @Override public Object getTransient(Object key, Object defaultValue) { Object returnValue = _transientState == null ? null : _transientState.get(key); if (returnValue != null) { return returnValue; } return defaultValue; } @Override public Object putTransient(Object key, Object value) { if (_transientState == null) { _transientState = new HashMap(); } return _transientState.put(key, value); } @Override @SuppressWarnings("unchecked") public void restoreTransientState(FacesContext context, Object state) { _transientState = (Map) state; } @Override public Object saveTransientState(FacesContext context) { return _transientState; } public void markPropertyInInitialState(Object[] defaultInitialState) { // Check if in the fullState, one of the default properties were changed boolean canApplyDefaultInitialState = true; for (int i = 0; i < defaultInitialState.length; i+=2) { Serializable key = (Serializable) defaultInitialState[i]; if (_fullState.containsKey(key)) { canApplyDefaultInitialState = false; break; } } if (canApplyDefaultInitialState) { // Most of the times the defaultInitialState is used. _initialState = defaultInitialState; } else { // recalculate it Object[] initialState = new Object[defaultInitialState.length]; for (int i = 0; i < defaultInitialState.length; i+=2) { Serializable key = (Serializable) defaultInitialState[i]; initialState[i] = key; if (_fullState.containsKey(key)) { initialState[i+1] = _fullState.get(key); } else { initialState[i+1] = defaultInitialState[i+1]; } } _initialState = initialState; } } }