--- /dev/null
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ * Copyright (C) 2012 Google Inc.
+ *
+ * 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.gson.internal;
+
+import java.io.ObjectStreamException;
+import java.io.Serializable;
+import java.util.AbstractMap;
+import java.util.AbstractSet;
+import java.util.Comparator;
+import java.util.ConcurrentModificationException;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.NoSuchElementException;
+import java.util.Set;
+
+/**
+ * A map of comparable keys to values. Unlike {@code TreeMap}, this class uses
+ * insertion order for iteration order. Comparison order is only used as an
+ * optimization for efficient insertion and removal.
+ *
+ * <p>This implementation was derived from Android 4.1's TreeMap class.
+ */
+public final class LinkedTreeMap<K, V> extends AbstractMap<K, V> implements Serializable {
+ @SuppressWarnings({ "unchecked", "rawtypes" }) // to avoid Comparable<Comparable<Comparable<...>>>
+ private static final Comparator<Comparable> NATURAL_ORDER = new Comparator<Comparable>() {
+ public int compare(Comparable a, Comparable b) {
+ return a.compareTo(b);
+ }
+ };
+
+ Comparator<? super K> comparator;
+ Node<K, V> root;
+ int size = 0;
+ int modCount = 0;
+
+ // Used to preserve iteration order
+ final Node<K, V> header = new Node<K, V>();
+
+ /**
+ * Create a natural order, empty tree map whose keys must be mutually
+ * comparable and non-null.
+ */
+ @SuppressWarnings("unchecked") // unsafe! this assumes K is comparable
+ public LinkedTreeMap() {
+ this((Comparator<? super K>) NATURAL_ORDER);
+ }
+
+ /**
+ * Create a tree map ordered by {@code comparator}. This map's keys may only
+ * be null if {@code comparator} permits.
+ *
+ * @param comparator the comparator to order elements with, or {@code null} to
+ * use the natural ordering.
+ */
+ @SuppressWarnings({ "unchecked", "rawtypes" }) // unsafe! if comparator is null, this assumes K is comparable
+ public LinkedTreeMap(Comparator<? super K> comparator) {
+ this.comparator = comparator != null
+ ? comparator
+ : (Comparator) NATURAL_ORDER;
+ }
+
+ @Override public int size() {
+ return size;
+ }
+
+ @Override public V get(Object key) {
+ Node<K, V> node = findByObject(key);
+ return node != null ? node.value : null;
+ }
+
+ @Override public boolean containsKey(Object key) {
+ return findByObject(key) != null;
+ }
+
+ @Override public V put(K key, V value) {
+ if (key == null) {
+ throw new NullPointerException("key == null");
+ }
+ Node<K, V> created = find(key, true);
+ V result = created.value;
+ created.value = value;
+ return result;
+ }
+
+ @Override public void clear() {
+ root = null;
+ size = 0;
+ modCount++;
+
+ // Clear iteration order
+ Node<K, V> header = this.header;
+ header.next = header.prev = header;
+ }
+
+ @Override public V remove(Object key) {
+ Node<K, V> node = removeInternalByKey(key);
+ return node != null ? node.value : null;
+ }
+
+ /**
+ * Returns the node at or adjacent to the given key, creating it if requested.
+ *
+ * @throws ClassCastException if {@code key} and the tree's keys aren't
+ * mutually comparable.
+ */
+ Node<K, V> find(K key, boolean create) {
+ Comparator<? super K> comparator = this.comparator;
+ Node<K, V> nearest = root;
+ int comparison = 0;
+
+ if (nearest != null) {
+ // Micro-optimization: avoid polymorphic calls to Comparator.compare().
+ @SuppressWarnings("unchecked") // Throws a ClassCastException below if there's trouble.
+ Comparable<Object> comparableKey = (comparator == NATURAL_ORDER)
+ ? (Comparable<Object>) key
+ : null;
+
+ while (true) {
+ comparison = (comparableKey != null)
+ ? comparableKey.compareTo(nearest.key)
+ : comparator.compare(key, nearest.key);
+
+ // We found the requested key.
+ if (comparison == 0) {
+ return nearest;
+ }
+
+ // If it exists, the key is in a subtree. Go deeper.
+ Node<K, V> child = (comparison < 0) ? nearest.left : nearest.right;
+ if (child == null) {
+ break;
+ }
+
+ nearest = child;
+ }
+ }
+
+ // The key doesn't exist in this tree.
+ if (!create) {
+ return null;
+ }
+
+ // Create the node and add it to the tree or the table.
+ Node<K, V> header = this.header;
+ Node<K, V> created;
+ if (nearest == null) {
+ // Check that the value is comparable if we didn't do any comparisons.
+ if (comparator == NATURAL_ORDER && !(key instanceof Comparable)) {
+ throw new ClassCastException(key.getClass().getName() + " is not Comparable");
+ }
+ created = new Node<K, V>(nearest, key, header, header.prev);
+ root = created;
+ } else {
+ created = new Node<K, V>(nearest, key, header, header.prev);
+ if (comparison < 0) { // nearest.key is higher
+ nearest.left = created;
+ } else { // comparison > 0, nearest.key is lower
+ nearest.right = created;
+ }
+ rebalance(nearest, true);
+ }
+ size++;
+ modCount++;
+
+ return created;
+ }
+
+ @SuppressWarnings("unchecked")
+ Node<K, V> findByObject(Object key) {
+ try {
+ return key != null ? find((K) key, false) : null;
+ } catch (ClassCastException e) {
+ return null;
+ }
+ }
+
+ /**
+ * Returns this map's entry that has the same key and value as {@code
+ * entry}, or null if this map has no such entry.
+ *
+ * <p>This method uses the comparator for key equality rather than {@code
+ * equals}. If this map's comparator isn't consistent with equals (such as
+ * {@code String.CASE_INSENSITIVE_ORDER}), then {@code remove()} and {@code
+ * contains()} will violate the collections API.
+ */
+ Node<K, V> findByEntry(Entry<?, ?> entry) {
+ Node<K, V> mine = findByObject(entry.getKey());
+ boolean valuesEqual = mine != null && equal(mine.value, entry.getValue());
+ return valuesEqual ? mine : null;
+ }
+
+ private boolean equal(Object a, Object b) {
+ return a == b || (a != null && a.equals(b));
+ }
+
+ /**
+ * Removes {@code node} from this tree, rearranging the tree's structure as
+ * necessary.
+ *
+ * @param unlink true to also unlink this node from the iteration linked list.
+ */
+ void removeInternal(Node<K, V> node, boolean unlink) {
+ if (unlink) {
+ node.prev.next = node.next;
+ node.next.prev = node.prev;
+ }
+
+ Node<K, V> left = node.left;
+ Node<K, V> right = node.right;
+ Node<K, V> originalParent = node.parent;
+ if (left != null && right != null) {
+
+ /*
+ * To remove a node with both left and right subtrees, move an
+ * adjacent node from one of those subtrees into this node's place.
+ *
+ * Removing the adjacent node may change this node's subtrees. This
+ * node may no longer have two subtrees once the adjacent node is
+ * gone!
+ */
+
+ Node<K, V> adjacent = (left.height > right.height) ? left.last() : right.first();
+ removeInternal(adjacent, false); // takes care of rebalance and size--
+
+ int leftHeight = 0;
+ left = node.left;
+ if (left != null) {
+ leftHeight = left.height;
+ adjacent.left = left;
+ left.parent = adjacent;
+ node.left = null;
+ }
+
+ int rightHeight = 0;
+ right = node.right;
+ if (right != null) {
+ rightHeight = right.height;
+ adjacent.right = right;
+ right.parent = adjacent;
+ node.right = null;
+ }
+
+ adjacent.height = Math.max(leftHeight, rightHeight) + 1;
+ replaceInParent(node, adjacent);
+ return;
+ } else if (left != null) {
+ replaceInParent(node, left);
+ node.left = null;
+ } else if (right != null) {
+ replaceInParent(node, right);
+ node.right = null;
+ } else {
+ replaceInParent(node, null);
+ }
+
+ rebalance(originalParent, false);
+ size--;
+ modCount++;
+ }
+
+ Node<K, V> removeInternalByKey(Object key) {
+ Node<K, V> node = findByObject(key);
+ if (node != null) {
+ removeInternal(node, true);
+ }
+ return node;
+ }
+
+ private void replaceInParent(Node<K, V> node, Node<K, V> replacement) {
+ Node<K, V> parent = node.parent;
+ node.parent = null;
+ if (replacement != null) {
+ replacement.parent = parent;
+ }
+
+ if (parent != null) {
+ if (parent.left == node) {
+ parent.left = replacement;
+ } else {
+ assert (parent.right == node);
+ parent.right = replacement;
+ }
+ } else {
+ root = replacement;
+ }
+ }
+
+ /**
+ * Rebalances the tree by making any AVL rotations necessary between the
+ * newly-unbalanced node and the tree's root.
+ *
+ * @param insert true if the node was unbalanced by an insert; false if it
+ * was by a removal.
+ */
+ private void rebalance(Node<K, V> unbalanced, boolean insert) {
+ for (Node<K, V> node = unbalanced; node != null; node = node.parent) {
+ Node<K, V> left = node.left;
+ Node<K, V> right = node.right;
+ int leftHeight = left != null ? left.height : 0;
+ int rightHeight = right != null ? right.height : 0;
+
+ int delta = leftHeight - rightHeight;
+ if (delta == -2) {
+ Node<K, V> rightLeft = right.left;
+ Node<K, V> rightRight = right.right;
+ int rightRightHeight = rightRight != null ? rightRight.height : 0;
+ int rightLeftHeight = rightLeft != null ? rightLeft.height : 0;
+
+ int rightDelta = rightLeftHeight - rightRightHeight;
+ if (rightDelta == -1 || (rightDelta == 0 && !insert)) {
+ rotateLeft(node); // AVL right right
+ } else {
+ assert (rightDelta == 1);
+ rotateRight(right); // AVL right left
+ rotateLeft(node);
+ }
+ if (insert) {
+ break; // no further rotations will be necessary
+ }
+
+ } else if (delta == 2) {
+ Node<K, V> leftLeft = left.left;
+ Node<K, V> leftRight = left.right;
+ int leftRightHeight = leftRight != null ? leftRight.height : 0;
+ int leftLeftHeight = leftLeft != null ? leftLeft.height : 0;
+
+ int leftDelta = leftLeftHeight - leftRightHeight;
+ if (leftDelta == 1 || (leftDelta == 0 && !insert)) {
+ rotateRight(node); // AVL left left
+ } else {
+ assert (leftDelta == -1);
+ rotateLeft(left); // AVL left right
+ rotateRight(node);
+ }
+ if (insert) {
+ break; // no further rotations will be necessary
+ }
+
+ } else if (delta == 0) {
+ node.height = leftHeight + 1; // leftHeight == rightHeight
+ if (insert) {
+ break; // the insert caused balance, so rebalancing is done!
+ }
+
+ } else {
+ assert (delta == -1 || delta == 1);
+ node.height = Math.max(leftHeight, rightHeight) + 1;
+ if (!insert) {
+ break; // the height hasn't changed, so rebalancing is done!
+ }
+ }
+ }
+ }
+
+ /**
+ * Rotates the subtree so that its root's right child is the new root.
+ */
+ private void rotateLeft(Node<K, V> root) {
+ Node<K, V> left = root.left;
+ Node<K, V> pivot = root.right;
+ Node<K, V> pivotLeft = pivot.left;
+ Node<K, V> pivotRight = pivot.right;
+
+ // move the pivot's left child to the root's right
+ root.right = pivotLeft;
+ if (pivotLeft != null) {
+ pivotLeft.parent = root;
+ }
+
+ replaceInParent(root, pivot);
+
+ // move the root to the pivot's left
+ pivot.left = root;
+ root.parent = pivot;
+
+ // fix heights
+ root.height = Math.max(left != null ? left.height : 0,
+ pivotLeft != null ? pivotLeft.height : 0) + 1;
+ pivot.height = Math.max(root.height,
+ pivotRight != null ? pivotRight.height : 0) + 1;
+ }
+
+ /**
+ * Rotates the subtree so that its root's left child is the new root.
+ */
+ private void rotateRight(Node<K, V> root) {
+ Node<K, V> pivot = root.left;
+ Node<K, V> right = root.right;
+ Node<K, V> pivotLeft = pivot.left;
+ Node<K, V> pivotRight = pivot.right;
+
+ // move the pivot's right child to the root's left
+ root.left = pivotRight;
+ if (pivotRight != null) {
+ pivotRight.parent = root;
+ }
+
+ replaceInParent(root, pivot);
+
+ // move the root to the pivot's right
+ pivot.right = root;
+ root.parent = pivot;
+
+ // fixup heights
+ root.height = Math.max(right != null ? right.height : 0,
+ pivotRight != null ? pivotRight.height : 0) + 1;
+ pivot.height = Math.max(root.height,
+ pivotLeft != null ? pivotLeft.height : 0) + 1;
+ }
+
+ private EntrySet entrySet;
+ private KeySet keySet;
+
+ @Override public Set<Entry<K, V>> entrySet() {
+ EntrySet result = entrySet;
+ return result != null ? result : (entrySet = new EntrySet());
+ }
+
+ @Override public Set<K> keySet() {
+ KeySet result = keySet;
+ return result != null ? result : (keySet = new KeySet());
+ }
+
+ static final class Node<K, V> implements Entry<K, V> {
+ Node<K, V> parent;
+ Node<K, V> left;
+ Node<K, V> right;
+ Node<K, V> next;
+ Node<K, V> prev;
+ final K key;
+ V value;
+ int height;
+
+ /** Create the header entry */
+ Node() {
+ key = null;
+ next = prev = this;
+ }
+
+ /** Create a regular entry */
+ Node(Node<K, V> parent, K key, Node<K, V> next, Node<K, V> prev) {
+ this.parent = parent;
+ this.key = key;
+ this.height = 1;
+ this.next = next;
+ this.prev = prev;
+ prev.next = this;
+ next.prev = this;
+ }
+
+ public K getKey() {
+ return key;
+ }
+
+ public V getValue() {
+ return value;
+ }
+
+ public V setValue(V value) {
+ V oldValue = this.value;
+ this.value = value;
+ return oldValue;
+ }
+
+ @SuppressWarnings("rawtypes")
+ @Override public boolean equals(Object o) {
+ if (o instanceof Entry) {
+ Entry other = (Entry) o;
+ return (key == null ? other.getKey() == null : key.equals(other.getKey()))
+ && (value == null ? other.getValue() == null : value.equals(other.getValue()));
+ }
+ return false;
+ }
+
+ @Override public int hashCode() {
+ return (key == null ? 0 : key.hashCode())
+ ^ (value == null ? 0 : value.hashCode());
+ }
+
+ @Override public String toString() {
+ return key + "=" + value;
+ }
+
+ /**
+ * Returns the first node in this subtree.
+ */
+ public Node<K, V> first() {
+ Node<K, V> node = this;
+ Node<K, V> child = node.left;
+ while (child != null) {
+ node = child;
+ child = node.left;
+ }
+ return node;
+ }
+
+ /**
+ * Returns the last node in this subtree.
+ */
+ public Node<K, V> last() {
+ Node<K, V> node = this;
+ Node<K, V> child = node.right;
+ while (child != null) {
+ node = child;
+ child = node.right;
+ }
+ return node;
+ }
+ }
+
+ private abstract class LinkedTreeMapIterator<T> implements Iterator<T> {
+ Node<K, V> next = header.next;
+ Node<K, V> lastReturned = null;
+ int expectedModCount = modCount;
+
+ public final boolean hasNext() {
+ return next != header;
+ }
+
+ final Node<K, V> nextNode() {
+ Node<K, V> e = next;
+ if (e == header) {
+ throw new NoSuchElementException();
+ }
+ if (modCount != expectedModCount) {
+ throw new ConcurrentModificationException();
+ }
+ next = e.next;
+ return lastReturned = e;
+ }
+
+ public final void remove() {
+ if (lastReturned == null) {
+ throw new IllegalStateException();
+ }
+ removeInternal(lastReturned, true);
+ lastReturned = null;
+ expectedModCount = modCount;
+ }
+ }
+
+ class EntrySet extends AbstractSet<Entry<K, V>> {
+ @Override public int size() {
+ return size;
+ }
+
+ @Override public Iterator<Entry<K, V>> iterator() {
+ return new LinkedTreeMapIterator<Entry<K, V>>() {
+ public Entry<K, V> next() {
+ return nextNode();
+ }
+ };
+ }
+
+ @Override public boolean contains(Object o) {
+ return o instanceof Entry && findByEntry((Entry<?, ?>) o) != null;
+ }
+
+ @Override public boolean remove(Object o) {
+ if (!(o instanceof Entry)) {
+ return false;
+ }
+
+ Node<K, V> node = findByEntry((Entry<?, ?>) o);
+ if (node == null) {
+ return false;
+ }
+ removeInternal(node, true);
+ return true;
+ }
+
+ @Override public void clear() {
+ LinkedTreeMap.this.clear();
+ }
+ }
+
+ class KeySet extends AbstractSet<K> {
+ @Override public int size() {
+ return size;
+ }
+
+ @Override public Iterator<K> iterator() {
+ return new LinkedTreeMapIterator<K>() {
+ public K next() {
+ return nextNode().key;
+ }
+ };
+ }
+
+ @Override public boolean contains(Object o) {
+ return containsKey(o);
+ }
+
+ @Override public boolean remove(Object key) {
+ return removeInternalByKey(key) != null;
+ }
+
+ @Override public void clear() {
+ LinkedTreeMap.this.clear();
+ }
+ }
+
+ /**
+ * If somebody is unlucky enough to have to serialize one of these, serialize
+ * it as a LinkedHashMap so that they won't need Gson on the other side to
+ * deserialize it. Using serialization defeats our DoS defence, so most apps
+ * shouldn't use it.
+ */
+ private Object writeReplace() throws ObjectStreamException {
+ return new LinkedHashMap<K, V>(this);
+ }
+}
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projects / unical.git / blobdiff