it.unimi.dsi.fastutil.bytes.Byte2ReferenceAVLTreeMap Maven / Gradle / Ivy
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/*
* Copyright (C) 2002-2017 Sebastiano Vigna
*
* 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 it.unimi.dsi.fastutil.bytes;
import it.unimi.dsi.fastutil.objects.AbstractObjectSortedSet;
import it.unimi.dsi.fastutil.objects.ObjectBidirectionalIterator;
import it.unimi.dsi.fastutil.objects.ObjectListIterator;
import it.unimi.dsi.fastutil.objects.ObjectSortedSet;
import it.unimi.dsi.fastutil.objects.ReferenceCollection;
import it.unimi.dsi.fastutil.objects.AbstractReferenceCollection;
import it.unimi.dsi.fastutil.objects.ObjectIterator;
import java.util.Comparator;
import java.util.Iterator;
import java.util.Map;
import java.util.SortedMap;
import java.util.NoSuchElementException;
/**
* A type-specific AVL tree map with a fast, small-footprint implementation.
*
*
* The iterators provided by the views of this class are type-specific
* {@linkplain it.unimi.dsi.fastutil.BidirectionalIterator bidirectional
* iterators}. Moreover, the iterator returned by {@code iterator()} can be
* safely cast to a type-specific {@linkplain java.util.ListIterator list
* iterator}.
*/
public class Byte2ReferenceAVLTreeMap extends AbstractByte2ReferenceSortedMap
implements
java.io.Serializable,
Cloneable {
/** A reference to the root entry. */
protected transient Entry tree;
/** Number of entries in this map. */
protected int count;
/** The first key in this map. */
protected transient Entry firstEntry;
/** The last key in this map. */
protected transient Entry lastEntry;
/** Cached set of entries. */
protected transient ObjectSortedSet> entries;
/** Cached set of keys. */
protected transient ByteSortedSet keys;
/** Cached collection of values. */
protected transient ReferenceCollection values;
/**
* The value of this variable remembers, after a {@code put()} or a
* {@code remove()}, whether the domain of the map has been modified.
*/
protected transient boolean modified;
/** This map's comparator, as provided in the constructor. */
protected Comparator storedComparator;
/**
* This map's actual comparator; it may differ from {@link #storedComparator}
* because it is always a type-specific comparator, so it could be derived from
* the former by wrapping.
*/
protected transient ByteComparator actualComparator;
private static final long serialVersionUID = -7046029254386353129L;
{
allocatePaths();
}
/**
* Creates a new empty tree map.
*/
public Byte2ReferenceAVLTreeMap() {
tree = null;
count = 0;
}
/**
* Generates the comparator that will be actually used.
*
*
* When a given {@link Comparator} is specified and stored in
* {@link #storedComparator}, we must check whether it is type-specific. If it
* is so, we can used directly, and we store it in {@link #actualComparator}.
* Otherwise, we adapt it using a helper static method.
*/
private void setActualComparator() {
actualComparator = ByteComparators.asByteComparator(storedComparator);
}
/**
* Creates a new empty tree map with the given comparator.
*
* @param c
* a (possibly type-specific) comparator.
*/
public Byte2ReferenceAVLTreeMap(final Comparator c) {
this();
storedComparator = c;
setActualComparator();
}
/**
* Creates a new tree map copying a given map.
*
* @param m
* a {@link Map} to be copied into the new tree map.
*/
public Byte2ReferenceAVLTreeMap(final Map m) {
this();
putAll(m);
}
/**
* Creates a new tree map copying a given sorted map (and its
* {@link Comparator}).
*
* @param m
* a {@link SortedMap} to be copied into the new tree map.
*/
public Byte2ReferenceAVLTreeMap(final SortedMap m) {
this(m.comparator());
putAll(m);
}
/**
* Creates a new tree map copying a given map.
*
* @param m
* a type-specific map to be copied into the new tree map.
*/
public Byte2ReferenceAVLTreeMap(final Byte2ReferenceMap m) {
this();
putAll(m);
}
/**
* Creates a new tree map copying a given sorted map (and its
* {@link Comparator}).
*
* @param m
* a type-specific sorted map to be copied into the new tree map.
*/
public Byte2ReferenceAVLTreeMap(final Byte2ReferenceSortedMap m) {
this(m.comparator());
putAll(m);
}
/**
* Creates a new tree map using the elements of two parallel arrays and the
* given comparator.
*
* @param k
* the array of keys of the new tree map.
* @param v
* the array of corresponding values in the new tree map.
* @param c
* a (possibly type-specific) comparator.
* @throws IllegalArgumentException
* if {@code k} and {@code v} have different lengths.
*/
public Byte2ReferenceAVLTreeMap(final byte[] k, final V v[], final Comparator c) {
this(c);
if (k.length != v.length)
throw new IllegalArgumentException(
"The key array and the value array have different lengths (" + k.length + " and " + v.length + ")");
for (int i = 0; i < k.length; i++)
this.put(k[i], v[i]);
}
/**
* Creates a new tree map using the elements of two parallel arrays.
*
* @param k
* the array of keys of the new tree map.
* @param v
* the array of corresponding values in the new tree map.
* @throws IllegalArgumentException
* if {@code k} and {@code v} have different lengths.
*/
public Byte2ReferenceAVLTreeMap(final byte[] k, final V v[]) {
this(k, v, null);
}
/*
* The following methods implements some basic building blocks used by all
* accessors. They are (and should be maintained) identical to those used in
* AVLTreeSet.drv.
*
* The put()/remove() code is derived from Ben Pfaff's GNU libavl
* (http://www.msu.edu/~pfaffben/avl/). If you want to understand what's going
* on, you should have a look at the literate code contained therein first.
*/
/**
* Compares two keys in the right way.
*
*
* This method uses the {@link #actualComparator} if it is non-{@code null}.
* Otherwise, it resorts to primitive type comparisons or to
* {@link Comparable#compareTo(Object) compareTo()}.
*
* @param k1
* the first key.
* @param k2
* the second key.
* @return a number smaller than, equal to or greater than 0, as usual (i.e.,
* when k1 < k2, k1 = k2 or k1 > k2, respectively).
*/
final int compare(final byte k1, final byte k2) {
return actualComparator == null ? (Byte.compare((k1), (k2))) : actualComparator.compare(k1, k2);
}
/**
* Returns the entry corresponding to the given key, if it is in the tree;
* {@code null}, otherwise.
*
* @param k
* the key to search for.
* @return the corresponding entry, or {@code null} if no entry with the given
* key exists.
*/
final Entry findKey(final byte k) {
Entry e = tree;
int cmp;
while (e != null && (cmp = compare(k, e.key)) != 0)
e = cmp < 0 ? e.left() : e.right();
return e;
}
/**
* Locates a key.
*
* @param k
* a key.
* @return the last entry on a search for the given key; this will be the given
* key, if it present; otherwise, it will be either the smallest greater
* key or the greatest smaller key.
*/
final Entry locateKey(final byte k) {
Entry e = tree, last = tree;
int cmp = 0;
while (e != null && (cmp = compare(k, e.key)) != 0) {
last = e;
e = cmp < 0 ? e.left() : e.right();
}
return cmp == 0 ? e : last;
}
/**
* This vector remembers the directions followed during the current insertion.
* It suffices for about 232 entries.
*/
private transient boolean dirPath[];
private void allocatePaths() {
dirPath = new boolean[48];
}
@Override
public V put(final byte k, final V v) {
Entry e = add(k);
final V oldValue = e.value;
e.value = v;
return oldValue;
}
/**
* Returns a node with key k in the balanced tree, creating one with defRetValue
* if necessary.
*
* @param k
* the key
* @return a node with key k. If a node with key k already exists, then that
* node is returned, otherwise a new node with defRetValue is created
* ensuring that the tree is balanced after creation of the node.
*/
private Entry add(final byte k) {
/*
* After execution of this method, modified is true iff a new entry has been
* inserted.
*/
modified = false;
Entry e = null;
if (tree == null) { // The case of the empty tree is treated separately.
count++;
e = tree = lastEntry = firstEntry = new Entry<>(k, defRetValue);
modified = true;
} else {
Entry p = tree, q = null, y = tree, z = null, w = null;
int cmp, i = 0;
while (true) {
if ((cmp = compare(k, p.key)) == 0) {
return p;
}
if (p.balance() != 0) {
i = 0;
z = q;
y = p;
}
if (dirPath[i++] = cmp > 0) {
if (p.succ()) {
count++;
e = new Entry<>(k, defRetValue);
modified = true;
if (p.right == null)
lastEntry = e;
e.left = p;
e.right = p.right;
p.right(e);
break;
}
q = p;
p = p.right;
} else {
if (p.pred()) {
count++;
e = new Entry<>(k, defRetValue);
modified = true;
if (p.left == null)
firstEntry = e;
e.right = p;
e.left = p.left;
p.left(e);
break;
}
q = p;
p = p.left;
}
}
p = y;
i = 0;
while (p != e) {
if (dirPath[i])
p.incBalance();
else
p.decBalance();
p = dirPath[i++] ? p.right : p.left;
}
if (y.balance() == -2) {
Entry x = y.left;
if (x.balance() == -1) {
w = x;
if (x.succ()) {
x.succ(false);
y.pred(x);
} else
y.left = x.right;
x.right = y;
x.balance(0);
y.balance(0);
} else {
assert x.balance() == 1;
w = x.right;
x.right = w.left;
w.left = x;
y.left = w.right;
w.right = y;
if (w.balance() == -1) {
x.balance(0);
y.balance(1);
} else if (w.balance() == 0) {
x.balance(0);
y.balance(0);
} else {
x.balance(-1);
y.balance(0);
}
w.balance(0);
if (w.pred()) {
x.succ(w);
w.pred(false);
}
if (w.succ()) {
y.pred(w);
w.succ(false);
}
}
} else if (y.balance() == +2) {
Entry x = y.right;
if (x.balance() == 1) {
w = x;
if (x.pred()) {
x.pred(false);
y.succ(x);
} else
y.right = x.left;
x.left = y;
x.balance(0);
y.balance(0);
} else {
assert x.balance() == -1;
w = x.left;
x.left = w.right;
w.right = x;
y.right = w.left;
w.left = y;
if (w.balance() == 1) {
x.balance(0);
y.balance(-1);
} else if (w.balance() == 0) {
x.balance(0);
y.balance(0);
} else {
x.balance(1);
y.balance(0);
}
w.balance(0);
if (w.pred()) {
y.succ(w);
w.pred(false);
}
if (w.succ()) {
x.pred(w);
w.succ(false);
}
}
} else
return e;
if (z == null)
tree = w;
else {
if (z.left == y)
z.left = w;
else
z.right = w;
}
}
return e;
}
/**
* Finds the parent of an entry.
*
* @param e
* a node of the tree.
* @return the parent of the given node, or {@code null} for the root.
*/
private Entry parent(final Entry e) {
if (e == tree)
return null;
Entry x, y, p;
x = y = e;
while (true) {
if (y.succ()) {
p = y.right;
if (p == null || p.left != e) {
while (!x.pred())
x = x.left;
p = x.left;
}
return p;
} else if (x.pred()) {
p = x.left;
if (p == null || p.right != e) {
while (!y.succ())
y = y.right;
p = y.right;
}
return p;
}
x = x.left;
y = y.right;
}
}
/*
* After execution of this method, {@link #modified} is true iff an entry has
* been deleted.
*/
@Override
public V remove(final byte k) {
modified = false;
if (tree == null)
return defRetValue;
int cmp;
Entry p = tree, q = null;
boolean dir = false;
final byte kk = k;
while (true) {
if ((cmp = compare(kk, p.key)) == 0)
break;
else if (dir = cmp > 0) {
q = p;
if ((p = p.right()) == null)
return defRetValue;
} else {
q = p;
if ((p = p.left()) == null)
return defRetValue;
}
}
if (p.left == null)
firstEntry = p.next();
if (p.right == null)
lastEntry = p.prev();
if (p.succ()) {
if (p.pred()) {
if (q != null) {
if (dir)
q.succ(p.right);
else
q.pred(p.left);
} else
tree = dir ? p.right : p.left;
} else {
p.prev().right = p.right;
if (q != null) {
if (dir)
q.right = p.left;
else
q.left = p.left;
} else
tree = p.left;
}
} else {
Entry r = p.right;
if (r.pred()) {
r.left = p.left;
r.pred(p.pred());
if (!r.pred())
r.prev().right = r;
if (q != null) {
if (dir)
q.right = r;
else
q.left = r;
} else
tree = r;
r.balance(p.balance());
q = r;
dir = true;
} else {
Entry s;
while (true) {
s = r.left;
if (s.pred())
break;
r = s;
}
if (s.succ())
r.pred(s);
else
r.left = s.right;
s.left = p.left;
if (!p.pred()) {
p.prev().right = s;
s.pred(false);
}
s.right = p.right;
s.succ(false);
if (q != null) {
if (dir)
q.right = s;
else
q.left = s;
} else
tree = s;
s.balance(p.balance());
q = r;
dir = false;
}
}
Entry y;
while (q != null) {
y = q;
q = parent(y);
if (!dir) {
dir = q != null && q.left != y;
y.incBalance();
if (y.balance() == 1)
break;
else if (y.balance() == 2) {
Entry x = y.right;
assert x != null;
if (x.balance() == -1) {
Entry w;
assert x.balance() == -1;
w = x.left;
x.left = w.right;
w.right = x;
y.right = w.left;
w.left = y;
if (w.balance() == 1) {
x.balance(0);
y.balance(-1);
} else if (w.balance() == 0) {
x.balance(0);
y.balance(0);
} else {
assert w.balance() == -1;
x.balance(1);
y.balance(0);
}
w.balance(0);
if (w.pred()) {
y.succ(w);
w.pred(false);
}
if (w.succ()) {
x.pred(w);
w.succ(false);
}
if (q != null) {
if (dir)
q.right = w;
else
q.left = w;
} else
tree = w;
} else {
if (q != null) {
if (dir)
q.right = x;
else
q.left = x;
} else
tree = x;
if (x.balance() == 0) {
y.right = x.left;
x.left = y;
x.balance(-1);
y.balance(+1);
break;
}
assert x.balance() == 1;
if (x.pred()) {
y.succ(true);
x.pred(false);
} else
y.right = x.left;
x.left = y;
y.balance(0);
x.balance(0);
}
}
} else {
dir = q != null && q.left != y;
y.decBalance();
if (y.balance() == -1)
break;
else if (y.balance() == -2) {
Entry x = y.left;
assert x != null;
if (x.balance() == 1) {
Entry w;
assert x.balance() == 1;
w = x.right;
x.right = w.left;
w.left = x;
y.left = w.right;
w.right = y;
if (w.balance() == -1) {
x.balance(0);
y.balance(1);
} else if (w.balance() == 0) {
x.balance(0);
y.balance(0);
} else {
assert w.balance() == 1;
x.balance(-1);
y.balance(0);
}
w.balance(0);
if (w.pred()) {
x.succ(w);
w.pred(false);
}
if (w.succ()) {
y.pred(w);
w.succ(false);
}
if (q != null) {
if (dir)
q.right = w;
else
q.left = w;
} else
tree = w;
} else {
if (q != null) {
if (dir)
q.right = x;
else
q.left = x;
} else
tree = x;
if (x.balance() == 0) {
y.left = x.right;
x.right = y;
x.balance(+1);
y.balance(-1);
break;
}
assert x.balance() == -1;
if (x.succ()) {
y.pred(true);
x.succ(false);
} else
y.left = x.right;
x.right = y;
y.balance(0);
x.balance(0);
}
}
}
}
modified = true;
count--;
return p.value;
}
@Override
public boolean containsValue(final Object v) {
final ValueIterator i = new ValueIterator();
V ev;
int j = count;
while (j-- != 0) {
ev = i.next();
if (((ev) == (v)))
return true;
}
return false;
}
@Override
public void clear() {
count = 0;
tree = null;
entries = null;
values = null;
keys = null;
firstEntry = lastEntry = null;
}
/**
* This class represent an entry in a tree map.
*
*
* We use the only "metadata", i.e., {@link Entry#info}, to store information
* about balance, predecessor status and successor status.
*
*
* Note that since the class is recursive, it can be considered equivalently a
* tree.
*/
private static final class Entry extends AbstractByte2ReferenceMap.BasicEntry implements Cloneable {
/** If the bit in this mask is true, {@link #right} points to a successor. */
private static final int SUCC_MASK = 1 << 31;
/** If the bit in this mask is true, {@link #left} points to a predecessor. */
private static final int PRED_MASK = 1 << 30;
/**
* The bits in this mask hold the node balance info. You can get it just by
* casting to byte.
*/
private static final int BALANCE_MASK = 0xFF;
/** The pointers to the left and right subtrees. */
Entry left, right;
/**
* This integers holds different information in different bits (see
* {@link #SUCC_MASK}, {@link #PRED_MASK} and {@link #BALANCE_MASK}).
*/
int info;
Entry() {
super(((byte) 0), (null));
}
/**
* Creates a new entry with the given key and value.
*
* @param k
* a key.
* @param v
* a value.
*/
Entry(final byte k, final V v) {
super(k, v);
info = SUCC_MASK | PRED_MASK;
}
/**
* Returns the left subtree.
*
* @return the left subtree ({@code null} if the left subtree is empty).
*/
Entry left() {
return (info & PRED_MASK) != 0 ? null : left;
}
/**
* Returns the right subtree.
*
* @return the right subtree ({@code null} if the right subtree is empty).
*/
Entry right() {
return (info & SUCC_MASK) != 0 ? null : right;
}
/**
* Checks whether the left pointer is really a predecessor.
*
* @return true if the left pointer is a predecessor.
*/
boolean pred() {
return (info & PRED_MASK) != 0;
}
/**
* Checks whether the right pointer is really a successor.
*
* @return true if the right pointer is a successor.
*/
boolean succ() {
return (info & SUCC_MASK) != 0;
}
/**
* Sets whether the left pointer is really a predecessor.
*
* @param pred
* if true then the left pointer will be considered a predecessor.
*/
void pred(final boolean pred) {
if (pred)
info |= PRED_MASK;
else
info &= ~PRED_MASK;
}
/**
* Sets whether the right pointer is really a successor.
*
* @param succ
* if true then the right pointer will be considered a successor.
*/
void succ(final boolean succ) {
if (succ)
info |= SUCC_MASK;
else
info &= ~SUCC_MASK;
}
/**
* Sets the left pointer to a predecessor.
*
* @param pred
* the predecessr.
*/
void pred(final Entry pred) {
info |= PRED_MASK;
left = pred;
}
/**
* Sets the right pointer to a successor.
*
* @param succ
* the successor.
*/
void succ(final Entry succ) {
info |= SUCC_MASK;
right = succ;
}
/**
* Sets the left pointer to the given subtree.
*
* @param left
* the new left subtree.
*/
void left(final Entry left) {
info &= ~PRED_MASK;
this.left = left;
}
/**
* Sets the right pointer to the given subtree.
*
* @param right
* the new right subtree.
*/
void right(final Entry right) {
info &= ~SUCC_MASK;
this.right = right;
}
/**
* Returns the current level of the node.
*
* @return the current level of this node.
*/
int balance() {
return (byte) info;
}
/**
* Sets the level of this node.
*
* @param level
* the new level of this node.
*/
void balance(int level) {
info &= ~BALANCE_MASK;
info |= (level & BALANCE_MASK);
}
/** Increments the level of this node. */
void incBalance() {
info = info & ~BALANCE_MASK | ((byte) info + 1) & 0xFF;
}
/** Decrements the level of this node. */
protected void decBalance() {
info = info & ~BALANCE_MASK | ((byte) info - 1) & 0xFF;
}
/**
* Computes the next entry in the set order.
*
* @return the next entry ({@code null}) if this is the last entry).
*/
Entry next() {
Entry next = this.right;
if ((info & SUCC_MASK) == 0)
while ((next.info & PRED_MASK) == 0)
next = next.left;
return next;
}
/**
* Computes the previous entry in the set order.
*
* @return the previous entry ({@code null}) if this is the first entry).
*/
Entry prev() {
Entry prev = this.left;
if ((info & PRED_MASK) == 0)
while ((prev.info & SUCC_MASK) == 0)
prev = prev.right;
return prev;
}
@Override
public V setValue(final V value) {
final V oldValue = this.value;
this.value = value;
return oldValue;
}
@Override
@SuppressWarnings("unchecked")
public Entry clone() {
Entry c;
try {
c = (Entry) super.clone();
} catch (CloneNotSupportedException cantHappen) {
throw new InternalError();
}
c.key = key;
c.value = value;
c.info = info;
return c;
}
@Override
@SuppressWarnings("unchecked")
public boolean equals(final Object o) {
if (!(o instanceof Map.Entry))
return false;
Map.Entry e = (Map.Entry) o;
return ((key) == ((e.getKey()).byteValue())) && ((value) == ((e.getValue())));
}
@Override
public int hashCode() {
return (key) ^ ((value) == null ? 0 : System.identityHashCode(value));
}
@Override
public String toString() {
return key + "=>" + value;
}
/*
* public void prettyPrint() { prettyPrint(0); }
*
* public void prettyPrint(int level) { if (pred()) { for (int i = 0; i < level;
* i++) System.err.print(" "); System.err.println("pred: " + left); } else if
* (left != null) left.prettyPrint(level +1); for (int i = 0; i < level; i++)
* System.err.print(" "); System.err.println(key + "=" + value + " (" +
* balance() + ")"); if (succ()) { for (int i = 0; i < level; i++)
* System.err.print(" "); System.err.println("succ: " + right); } else if
* (right != null) right.prettyPrint(level + 1); }
*/
}
/*
* public void prettyPrint() { System.err.println("size: " + count); if (tree !=
* null) tree.prettyPrint(); }
*/
@Override
public boolean containsKey(final byte k) {
return findKey(k) != null;
}
@Override
public int size() {
return count;
}
@Override
public boolean isEmpty() {
return count == 0;
}
@Override
public V get(final byte k) {
final Entry e = findKey(k);
return e == null ? defRetValue : e.value;
}
@Override
public byte firstByteKey() {
if (tree == null)
throw new NoSuchElementException();
return firstEntry.key;
}
@Override
public byte lastByteKey() {
if (tree == null)
throw new NoSuchElementException();
return lastEntry.key;
}
/**
* An abstract iterator on the whole range.
*
*
* This class can iterate in both directions on a threaded tree.
*/
private class TreeIterator {
/**
* The entry that will be returned by the next call to
* {@link java.util.ListIterator#previous()} (or {@code null} if no previous
* entry exists).
*/
Entry prev;
/**
* The entry that will be returned by the next call to
* {@link java.util.ListIterator#next()} (or {@code null} if no next entry
* exists).
*/
Entry next;
/**
* The last entry that was returned (or {@code null} if we did not iterate or
* used {@link #remove()}).
*/
Entry curr;
/**
* The current index (in the sense of a {@link java.util.ListIterator}). Note
* that this value is not meaningful when this {@link TreeIterator} has been
* created using the nonempty constructor.
*/
int index = 0;
TreeIterator() {
next = firstEntry;
}
TreeIterator(final byte k) {
if ((next = locateKey(k)) != null) {
if (compare(next.key, k) <= 0) {
prev = next;
next = next.next();
} else
prev = next.prev();
}
}
public boolean hasNext() {
return next != null;
}
public boolean hasPrevious() {
return prev != null;
}
void updateNext() {
next = next.next();
}
Entry nextEntry() {
if (!hasNext())
throw new NoSuchElementException();
curr = prev = next;
index++;
updateNext();
return curr;
}
void updatePrevious() {
prev = prev.prev();
}
Entry previousEntry() {
if (!hasPrevious())
throw new NoSuchElementException();
curr = next = prev;
index--;
updatePrevious();
return curr;
}
public int nextIndex() {
return index;
}
public int previousIndex() {
return index - 1;
}
public void remove() {
if (curr == null)
throw new IllegalStateException();
/*
* If the last operation was a next(), we are removing an entry that preceeds
* the current index, and thus we must decrement it.
*/
if (curr == prev)
index--;
next = prev = curr;
updatePrevious();
updateNext();
Byte2ReferenceAVLTreeMap.this.remove(curr.key);
curr = null;
}
public int skip(final int n) {
int i = n;
while (i-- != 0 && hasNext())
nextEntry();
return n - i - 1;
}
public int back(final int n) {
int i = n;
while (i-- != 0 && hasPrevious())
previousEntry();
return n - i - 1;
}
}
/**
* An iterator on the whole range.
*
*
* This class can iterate in both directions on a threaded tree.
*/
private class EntryIterator extends TreeIterator implements ObjectListIterator> {
EntryIterator() {
}
EntryIterator(final byte k) {
super(k);
}
@Override
public Byte2ReferenceMap.Entry next() {
return nextEntry();
}
@Override
public Byte2ReferenceMap.Entry previous() {
return previousEntry();
}
@Override
public void set(Byte2ReferenceMap.Entry ok) {
throw new UnsupportedOperationException();
}
@Override
public void add(Byte2ReferenceMap.Entry ok) {
throw new UnsupportedOperationException();
}
}
@Override
public ObjectSortedSet> byte2ReferenceEntrySet() {
if (entries == null)
entries = new AbstractObjectSortedSet>() {
final Comparator> comparator = (Comparator>) (
x, y) -> Byte2ReferenceAVLTreeMap.this.actualComparator.compare(x.getByteKey(), y.getByteKey());
@Override
public Comparator> comparator() {
return comparator;
}
@Override
public ObjectBidirectionalIterator> iterator() {
return new EntryIterator();
}
@Override
public ObjectBidirectionalIterator> iterator(
final Byte2ReferenceMap.Entry from) {
return new EntryIterator(from.getByteKey());
}
@Override
public boolean contains(final Object o) {
if (!(o instanceof Map.Entry))
return false;
final Map.Entry e = (Map.Entry) o;
if (e.getKey() == null || !(e.getKey() instanceof Byte))
return false;
final Entry f = findKey(((Byte) (e.getKey())).byteValue());
return e.equals(f);
}
@Override
public boolean remove(final Object o) {
if (!(o instanceof Map.Entry))
return false;
final Map.Entry e = (Map.Entry) o;
if (e.getKey() == null || !(e.getKey() instanceof Byte))
return false;
final Entry f = findKey(((Byte) (e.getKey())).byteValue());
if (f == null || !((f.getValue()) == ((e.getValue()))))
return false;
Byte2ReferenceAVLTreeMap.this.remove(f.key);
return true;
}
@Override
public int size() {
return count;
}
@Override
public void clear() {
Byte2ReferenceAVLTreeMap.this.clear();
}
@Override
public Byte2ReferenceMap.Entry first() {
return firstEntry;
}
@Override
public Byte2ReferenceMap.Entry last() {
return lastEntry;
}
@Override
public ObjectSortedSet> subSet(Byte2ReferenceMap.Entry from,
Byte2ReferenceMap.Entry to) {
return subMap(from.getByteKey(), to.getByteKey()).byte2ReferenceEntrySet();
}
@Override
public ObjectSortedSet> headSet(Byte2ReferenceMap.Entry to) {
return headMap(to.getByteKey()).byte2ReferenceEntrySet();
}
@Override
public ObjectSortedSet> tailSet(Byte2ReferenceMap.Entry from) {
return tailMap(from.getByteKey()).byte2ReferenceEntrySet();
}
};
return entries;
}
/**
* An iterator on the whole range of keys.
*
*
* This class can iterate in both directions on the keys of a threaded tree. We
* simply override the
* {@link java.util.ListIterator#next()}/{@link java.util.ListIterator#previous()}
* methods (and possibly their type-specific counterparts) so that they return
* keys instead of entries.
*/
private final class KeyIterator extends TreeIterator implements ByteListIterator {
public KeyIterator() {
}
public KeyIterator(final byte k) {
super(k);
}
@Override
public byte nextByte() {
return nextEntry().key;
}
@Override
public byte previousByte() {
return previousEntry().key;
}
}
/** A keyset implementation using a more direct implementation for iterators. */
private class KeySet extends AbstractByte2ReferenceSortedMap.KeySet {
@Override
public ByteBidirectionalIterator iterator() {
return new KeyIterator();
}
@Override
public ByteBidirectionalIterator iterator(final byte from) {
return new KeyIterator(from);
}
}
/**
* Returns a type-specific sorted set view of the keys contained in this map.
*
*
* In addition to the semantics of {@link java.util.Map#keySet()}, you can
* safely cast the set returned by this call to a type-specific sorted set
* interface.
*
* @return a type-specific sorted set view of the keys contained in this map.
*/
@Override
public ByteSortedSet keySet() {
if (keys == null)
keys = new KeySet();
return keys;
}
/**
* An iterator on the whole range of values.
*
*
* This class can iterate in both directions on the values of a threaded tree.
* We simply override the
* {@link java.util.ListIterator#next()}/{@link java.util.ListIterator#previous()}
* methods (and possibly their type-specific counterparts) so that they return
* values instead of entries.
*/
private final class ValueIterator extends TreeIterator implements ObjectListIterator {
@Override
public V next() {
return nextEntry().value;
}
@Override
public V previous() {
return previousEntry().value;
}
}
/**
* Returns a type-specific collection view of the values contained in this map.
*
*
* In addition to the semantics of {@link java.util.Map#values()}, you can
* safely cast the collection returned by this call to a type-specific
* collection interface.
*
* @return a type-specific collection view of the values contained in this map.
*/
@Override
public ReferenceCollection values() {
if (values == null)
values = new AbstractReferenceCollection() {
@Override
public ObjectIterator iterator() {
return new ValueIterator();
}
@Override
public boolean contains(final Object k) {
return containsValue(k);
}
@Override
public int size() {
return count;
}
@Override
public void clear() {
Byte2ReferenceAVLTreeMap.this.clear();
}
};
return values;
}
@Override
public ByteComparator comparator() {
return actualComparator;
}
@Override
public Byte2ReferenceSortedMap headMap(byte to) {
return new Submap(((byte) 0), true, to, false);
}
@Override
public Byte2ReferenceSortedMap tailMap(byte from) {
return new Submap(from, false, ((byte) 0), true);
}
@Override
public Byte2ReferenceSortedMap subMap(byte from, byte to) {
return new Submap(from, false, to, false);
}
/**
* A submap with given range.
*
*
* This class represents a submap. One has to specify the left/right limits
* (which can be set to -∞ or ∞). Since the submap is a view on the
* map, at a given moment it could happen that the limits of the range are not
* any longer in the main map. Thus, things such as
* {@link java.util.SortedMap#firstKey()} or {@link java.util.Collection#size()}
* must be always computed on-the-fly.
*/
private final class Submap extends AbstractByte2ReferenceSortedMap implements java.io.Serializable {
private static final long serialVersionUID = -7046029254386353129L;
/** The start of the submap range, unless {@link #bottom} is true. */
byte from;
/** The end of the submap range, unless {@link #top} is true. */
byte to;
/** If true, the submap range starts from -∞. */
boolean bottom;
/** If true, the submap range goes to ∞. */
boolean top;
/** Cached set of entries. */
protected transient ObjectSortedSet> entries;
/** Cached set of keys. */
protected transient ByteSortedSet keys;
/** Cached collection of values. */
protected transient ReferenceCollection values;
/**
* Creates a new submap with given key range.
*
* @param from
* the start of the submap range.
* @param bottom
* if true, the first parameter is ignored and the range starts from
* -∞.
* @param to
* the end of the submap range.
* @param top
* if true, the third parameter is ignored and the range goes to
* ∞.
*/
public Submap(final byte from, final boolean bottom, final byte to, final boolean top) {
if (!bottom && !top && Byte2ReferenceAVLTreeMap.this.compare(from, to) > 0)
throw new IllegalArgumentException("Start key (" + from + ") is larger than end key (" + to + ")");
this.from = from;
this.bottom = bottom;
this.to = to;
this.top = top;
this.defRetValue = Byte2ReferenceAVLTreeMap.this.defRetValue;
}
@Override
public void clear() {
final SubmapIterator i = new SubmapIterator();
while (i.hasNext()) {
i.nextEntry();
i.remove();
}
}
/**
* Checks whether a key is in the submap range.
*
* @param k
* a key.
* @return true if is the key is in the submap range.
*/
final boolean in(final byte k) {
return (bottom || Byte2ReferenceAVLTreeMap.this.compare(k, from) >= 0)
&& (top || Byte2ReferenceAVLTreeMap.this.compare(k, to) < 0);
}
@Override
public ObjectSortedSet> byte2ReferenceEntrySet() {
if (entries == null)
entries = new AbstractObjectSortedSet>() {
@Override
public ObjectBidirectionalIterator> iterator() {
return new SubmapEntryIterator();
}
@Override
public ObjectBidirectionalIterator> iterator(
final Byte2ReferenceMap.Entry from) {
return new SubmapEntryIterator(from.getByteKey());
}
@Override
public Comparator> comparator() {
return Byte2ReferenceAVLTreeMap.this.byte2ReferenceEntrySet().comparator();
}
@Override
public boolean contains(final Object o) {
if (!(o instanceof Map.Entry))
return false;
final Map.Entry e = (Map.Entry) o;
if (e.getKey() == null || !(e.getKey() instanceof Byte))
return false;
final Byte2ReferenceAVLTreeMap.Entry f = findKey(((Byte) (e.getKey())).byteValue());
return f != null && in(f.key) && e.equals(f);
}
@Override
public boolean remove(final Object o) {
if (!(o instanceof Map.Entry))
return false;
final Map.Entry e = (Map.Entry) o;
if (e.getKey() == null || !(e.getKey() instanceof Byte))
return false;
final Byte2ReferenceAVLTreeMap.Entry f = findKey(((Byte) (e.getKey())).byteValue());
if (f != null && in(f.key))
Submap.this.remove(f.key);
return f != null;
}
@Override
public int size() {
int c = 0;
for (Iterator i = iterator(); i.hasNext(); i.next())
c++;
return c;
}
@Override
public boolean isEmpty() {
return !new SubmapIterator().hasNext();
}
@Override
public void clear() {
Submap.this.clear();
}
@Override
public Byte2ReferenceMap.Entry first() {
return firstEntry();
}
@Override
public Byte2ReferenceMap.Entry last() {
return lastEntry();
}
@Override
public ObjectSortedSet> subSet(Byte2ReferenceMap.Entry from,
Byte2ReferenceMap.Entry to) {
return subMap(from.getByteKey(), to.getByteKey()).byte2ReferenceEntrySet();
}
@Override
public ObjectSortedSet> headSet(Byte2ReferenceMap.Entry to) {
return headMap(to.getByteKey()).byte2ReferenceEntrySet();
}
@Override
public ObjectSortedSet> tailSet(Byte2ReferenceMap.Entry from) {
return tailMap(from.getByteKey()).byte2ReferenceEntrySet();
}
};
return entries;
}
private class KeySet extends AbstractByte2ReferenceSortedMap.KeySet {
@Override
public ByteBidirectionalIterator iterator() {
return new SubmapKeyIterator();
}
@Override
public ByteBidirectionalIterator iterator(final byte from) {
return new SubmapKeyIterator(from);
}
}
@Override
public ByteSortedSet keySet() {
if (keys == null)
keys = new KeySet();
return keys;
}
@Override
public ReferenceCollection values() {
if (values == null)
values = new AbstractReferenceCollection() {
@Override
public ObjectIterator iterator() {
return new SubmapValueIterator();
}
@Override
public boolean contains(final Object k) {
return containsValue(k);
}
@Override
public int size() {
return Submap.this.size();
}
@Override
public void clear() {
Submap.this.clear();
}
};
return values;
}
@Override
public boolean containsKey(final byte k) {
return in(k) && Byte2ReferenceAVLTreeMap.this.containsKey(k);
}
@Override
public boolean containsValue(final Object v) {
final SubmapIterator i = new SubmapIterator();
Object ev;
while (i.hasNext()) {
ev = i.nextEntry().value;
if (((ev) == (v)))
return true;
}
return false;
}
@Override
public V get(final byte k) {
final Byte2ReferenceAVLTreeMap.Entry e;
final byte kk = k;
return in(kk) && (e = findKey(kk)) != null ? e.value : this.defRetValue;
}
@Override
public V put(final byte k, final V v) {
modified = false;
if (!in(k))
throw new IllegalArgumentException("Key (" + k + ") out of range ["
+ (bottom ? "-" : String.valueOf(from)) + ", " + (top ? "-" : String.valueOf(to)) + ")");
final V oldValue = Byte2ReferenceAVLTreeMap.this.put(k, v);
return modified ? this.defRetValue : oldValue;
}
@Override
public V remove(final byte k) {
modified = false;
if (!in(k))
return this.defRetValue;
final V oldValue = Byte2ReferenceAVLTreeMap.this.remove(k);
return modified ? oldValue : this.defRetValue;
}
@Override
public int size() {
final SubmapIterator i = new SubmapIterator();
int n = 0;
while (i.hasNext()) {
n++;
i.nextEntry();
}
return n;
}
@Override
public boolean isEmpty() {
return !new SubmapIterator().hasNext();
}
@Override
public ByteComparator comparator() {
return actualComparator;
}
@Override
public Byte2ReferenceSortedMap headMap(final byte to) {
if (top)
return new Submap(from, bottom, to, false);
return compare(to, this.to) < 0 ? new Submap(from, bottom, to, false) : this;
}
@Override
public Byte2ReferenceSortedMap tailMap(final byte from) {
if (bottom)
return new Submap(from, false, to, top);
return compare(from, this.from) > 0 ? new Submap(from, false, to, top) : this;
}
@Override
public Byte2ReferenceSortedMap subMap(byte from, byte to) {
if (top && bottom)
return new Submap(from, false, to, false);
if (!top)
to = compare(to, this.to) < 0 ? to : this.to;
if (!bottom)
from = compare(from, this.from) > 0 ? from : this.from;
if (!top && !bottom && from == this.from && to == this.to)
return this;
return new Submap(from, false, to, false);
}
/**
* Locates the first entry.
*
* @return the first entry of this submap, or {@code null} if the submap is
* empty.
*/
public Byte2ReferenceAVLTreeMap.Entry firstEntry() {
if (tree == null)
return null;
// If this submap goes to -infinity, we return the main map first entry;
// otherwise, we locate the start of the map.
Byte2ReferenceAVLTreeMap.Entry e;
if (bottom)
e = firstEntry;
else {
e = locateKey(from);
// If we find either the start or something greater we're OK.
if (compare(e.key, from) < 0)
e = e.next();
}
// Finally, if this subset doesn't go to infinity, we check that the resulting
// key isn't greater than the end.
if (e == null || !top && compare(e.key, to) >= 0)
return null;
return e;
}
/**
* Locates the last entry.
*
* @return the last entry of this submap, or {@code null} if the submap is
* empty.
*/
public Byte2ReferenceAVLTreeMap.Entry lastEntry() {
if (tree == null)
return null;
// If this submap goes to infinity, we return the main map last entry;
// otherwise, we locate the end of the map.
Byte2ReferenceAVLTreeMap.Entry e;
if (top)
e = lastEntry;
else {
e = locateKey(to);
// If we find something smaller than the end we're OK.
if (compare(e.key, to) >= 0)
e = e.prev();
}
// Finally, if this subset doesn't go to -infinity, we check that the resulting
// key isn't smaller than the start.
if (e == null || !bottom && compare(e.key, from) < 0)
return null;
return e;
}
@Override
public byte firstByteKey() {
Byte2ReferenceAVLTreeMap.Entry e = firstEntry();
if (e == null)
throw new NoSuchElementException();
return e.key;
}
@Override
public byte lastByteKey() {
Byte2ReferenceAVLTreeMap.Entry e = lastEntry();
if (e == null)
throw new NoSuchElementException();
return e.key;
}
/**
* An iterator for subranges.
*
*
* This class inherits from {@link TreeIterator}, but overrides the methods that
* update the pointer after a {@link java.util.ListIterator#next()} or
* {@link java.util.ListIterator#previous()}. If we would move out of the range
* of the submap we just overwrite the next or previous entry with {@code null}.
*/
private class SubmapIterator extends TreeIterator {
SubmapIterator() {
next = firstEntry();
}
SubmapIterator(final byte k) {
this();
if (next != null) {
if (!bottom && compare(k, next.key) < 0)
prev = null;
else if (!top && compare(k, (prev = lastEntry()).key) >= 0)
next = null;
else {
next = locateKey(k);
if (compare(next.key, k) <= 0) {
prev = next;
next = next.next();
} else
prev = next.prev();
}
}
}
@Override
void updatePrevious() {
prev = prev.prev();
if (!bottom && prev != null && Byte2ReferenceAVLTreeMap.this.compare(prev.key, from) < 0)
prev = null;
}
@Override
void updateNext() {
next = next.next();
if (!top && next != null && Byte2ReferenceAVLTreeMap.this.compare(next.key, to) >= 0)
next = null;
}
}
private class SubmapEntryIterator extends SubmapIterator
implements
ObjectListIterator> {
SubmapEntryIterator() {
}
SubmapEntryIterator(final byte k) {
super(k);
}
@Override
public Byte2ReferenceMap.Entry next() {
return nextEntry();
}
@Override
public Byte2ReferenceMap.Entry previous() {
return previousEntry();
}
}
/**
* An iterator on a subrange of keys.
*
*
* This class can iterate in both directions on a subrange of the keys of a
* threaded tree. We simply override the
* {@link java.util.ListIterator#next()}/{@link java.util.ListIterator#previous()}
* methods (and possibly their type-specific counterparts) so that they return
* keys instead of entries.
*/
private final class SubmapKeyIterator extends SubmapIterator implements ByteListIterator {
public SubmapKeyIterator() {
super();
}
public SubmapKeyIterator(byte from) {
super(from);
}
@Override
public byte nextByte() {
return nextEntry().key;
}
@Override
public byte previousByte() {
return previousEntry().key;
}
};
/**
* An iterator on a subrange of values.
*
*
* This class can iterate in both directions on the values of a subrange of the
* keys of a threaded tree. We simply override the
* {@link java.util.ListIterator#next()}/{@link java.util.ListIterator#previous()}
* methods (and possibly their type-specific counterparts) so that they return
* values instead of entries.
*/
private final class SubmapValueIterator extends SubmapIterator implements ObjectListIterator {
@Override
public V next() {
return nextEntry().value;
}
@Override
public V previous() {
return previousEntry().value;
}
};
}
/**
* Returns a deep copy of this tree map.
*
*
* This method performs a deep copy of this tree map; the data stored in the
* set, however, is not cloned. Note that this makes a difference only for
* object keys.
*
* @return a deep copy of this tree map.
*/
@Override
@SuppressWarnings("unchecked")
public Byte2ReferenceAVLTreeMap clone() {
Byte2ReferenceAVLTreeMap c;
try {
c = (Byte2ReferenceAVLTreeMap) super.clone();
} catch (CloneNotSupportedException cantHappen) {
throw new InternalError();
}
c.keys = null;
c.values = null;
c.entries = null;
c.allocatePaths();
if (count != 0) {
// Also this apparently unfathomable code is derived from GNU libavl.
Entry e, p, q, rp = new Entry<>(), rq = new Entry<>();
p = rp;
rp.left(tree);
q = rq;
rq.pred(null);
while (true) {
if (!p.pred()) {
e = p.left.clone();
e.pred(q.left);
e.succ(q);
q.left(e);
p = p.left;
q = q.left;
} else {
while (p.succ()) {
p = p.right;
if (p == null) {
q.right = null;
c.tree = rq.left;
c.firstEntry = c.tree;
while (c.firstEntry.left != null)
c.firstEntry = c.firstEntry.left;
c.lastEntry = c.tree;
while (c.lastEntry.right != null)
c.lastEntry = c.lastEntry.right;
return c;
}
q = q.right;
}
p = p.right;
q = q.right;
}
if (!p.succ()) {
e = p.right.clone();
e.succ(q.right);
e.pred(q);
q.right(e);
}
}
}
return c;
}
private void writeObject(java.io.ObjectOutputStream s) throws java.io.IOException {
int n = count;
EntryIterator i = new EntryIterator();
Entry e;
s.defaultWriteObject();
while (n-- != 0) {
e = i.nextEntry();
s.writeByte(e.key);
s.writeObject(e.value);
}
}
/**
* Reads the given number of entries from the input stream, returning the
* corresponding tree.
*
* @param s
* the input stream.
* @param n
* the (positive) number of entries to read.
* @param pred
* the entry containing the key that preceeds the first key in the
* tree.
* @param succ
* the entry containing the key that follows the last key in the
* tree.
*/
@SuppressWarnings("unchecked")
private Entry readTree(final java.io.ObjectInputStream s, final int n, final Entry pred, final Entry succ)
throws java.io.IOException, ClassNotFoundException {
if (n == 1) {
final Entry top = new Entry<>(s.readByte(), (V) s.readObject());
top.pred(pred);
top.succ(succ);
return top;
}
if (n == 2) {
/*
* We handle separately this case so that recursion will always* be on nonempty
* subtrees.
*/
final Entry top = new Entry<>(s.readByte(), (V) s.readObject());
top.right(new Entry<>(s.readByte(), (V) s.readObject()));
top.right.pred(top);
top.balance(1);
top.pred(pred);
top.right.succ(succ);
return top;
}
// The right subtree is the largest one.
final int rightN = n / 2, leftN = n - rightN - 1;
final Entry top = new Entry<>();
top.left(readTree(s, leftN, pred, top));
top.key = s.readByte();
top.value = (V) s.readObject();
top.right(readTree(s, rightN, top, succ));
if (n == (n & -n))
top.balance(1); // Quick test for determining whether n is a power of 2.
return top;
}
private void readObject(java.io.ObjectInputStream s) throws java.io.IOException, ClassNotFoundException {
s.defaultReadObject();
/*
* The storedComparator is now correctly set, but we must restore on-the-fly the
* actualComparator.
*/
setActualComparator();
allocatePaths();
if (count != 0) {
tree = readTree(s, count, null, null);
Entry e;
e = tree;
while (e.left() != null)
e = e.left();
firstEntry = e;
e = tree;
while (e.right() != null)
e = e.right();
lastEntry = e;
}
}
}