it.unimi.dsi.fastutil.chars.Char2ByteArrayMap Maven / Gradle / Ivy
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/*
* Copyright (C) 2007-2017 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.chars;
import java.util.Map;
import java.util.NoSuchElementException;
import it.unimi.dsi.fastutil.objects.AbstractObjectIterator;
import it.unimi.dsi.fastutil.objects.AbstractObjectSet;
import it.unimi.dsi.fastutil.objects.ObjectIterator;
import it.unimi.dsi.fastutil.bytes.ByteCollection;
import it.unimi.dsi.fastutil.bytes.ByteCollections;
import it.unimi.dsi.fastutil.bytes.ByteArraySet;
import it.unimi.dsi.fastutil.bytes.ByteArrays;
/** A simple, brute-force implementation of a map based on two parallel backing arrays.
*
* The main purpose of this
* implementation is that of wrapping cleanly the brute-force approach to the storage of a very
* small number of pairs: just put them into two parallel arrays and scan linearly to find an item.
*/
public class Char2ByteArrayMap extends AbstractChar2ByteMap implements java.io.Serializable, Cloneable {
private static final long serialVersionUID = 1L;
/** The keys (valid up to {@link #size}, excluded). */
private transient char[] key;
/** The values (parallel to {@link #key}). */
private transient byte[] value;
/** The number of valid entries in {@link #key} and {@link #value}. */
private int size;
/** Creates a new empty array map with given key and value backing arrays. The resulting map will have as many entries as the given arrays.
*
*
It is responsibility of the caller that the elements of key are distinct.
*
* @param key the key array.
* @param value the value array (it must have the same length as key).
*/
public Char2ByteArrayMap(final char[] key, final byte[] value) {
this.key = key;
this.value = value;
size = key.length;
if(key.length != value.length) throw new IllegalArgumentException("Keys and values have different lengths (" + key.length + ", " + value.length + ")");
}
/** Creates a new empty array map.
*/
public Char2ByteArrayMap() {
this.key = CharArrays.EMPTY_ARRAY;
this.value = ByteArrays.EMPTY_ARRAY;
}
/** Creates a new empty array map of given capacity.
*
* @param capacity the initial capacity.
*/
public Char2ByteArrayMap(final int capacity) {
this.key = new char[capacity];
this.value = new byte[capacity];
}
/** Creates a new empty array map copying the entries of a given map.
*
* @param m a map.
*/
public Char2ByteArrayMap(final Char2ByteMap m) {
this(m.size());
putAll(m);
}
/** Creates a new empty array map copying the entries of a given map.
*
* @param m a map.
*/
public Char2ByteArrayMap(final Map m) {
this(m.size());
putAll(m);
}
/** Creates a new array map with given key and value backing arrays, using the given number of elements.
*
*
It is responsibility of the caller that the first size elements of key are distinct.
*
* @param key the key array.
* @param value the value array (it must have the same length as key).
* @param size the number of valid elements in key and value.
*/
public Char2ByteArrayMap(final char[] key, final byte[] value, final int size) {
this.key = key;
this.value = value;
this.size = size;
if(key.length != value.length) throw new IllegalArgumentException("Keys and values have different lengths (" + key.length + ", " + value.length + ")");
if (size > key.length) throw new IllegalArgumentException("The provided size (" + size + ") is larger than or equal to the backing-arrays size (" + key.length + ")");
}
private final class EntrySet extends AbstractObjectSet implements FastEntrySet {
@Override
public ObjectIterator iterator() {
return new AbstractObjectIterator() {
int curr = -1, next = 0;
@Override
public boolean hasNext() {
return next < size;
}
@Override
public Entry next() {
if (! hasNext()) throw new NoSuchElementException();
return new AbstractChar2ByteMap.BasicEntry ( key[curr = next], value[next++]);
}
@Override
public void remove() {
if (curr == -1) throw new IllegalStateException();
curr = -1;
final int tail = size-- - next--;
System.arraycopy(key, next + 1, key, next, tail);
System.arraycopy(value, next + 1, value, next, tail);
}
};
}
@Override
public ObjectIterator fastIterator() {
return new AbstractObjectIterator() {
int next = 0, curr = -1;
final BasicEntry entry = new BasicEntry (((char)0), ((byte)0));
@Override
public boolean hasNext() {
return next < size;
}
@Override
public Entry next() {
if (! hasNext()) throw new NoSuchElementException();
entry.key = key[curr = next];
entry.value = value[next++];
return entry;
}
@Override
public void remove() {
if (curr == -1) throw new IllegalStateException();
curr = -1;
final int tail = size-- - next--;
System.arraycopy(key, next + 1, key, next, tail);
System.arraycopy(value, next + 1, value, next, tail);
}
};
}
@Override
public int size() {
return size;
}
@Override
public boolean contains(Object o) {
if (! (o instanceof Map.Entry)) return false;
final Map.Entry e = (Map.Entry)o;
if (e.getKey() == null || ! (e.getKey() instanceof Character)) return false;
if (e.getValue() == null || ! (e.getValue() instanceof Byte)) return false;
final char k = ((((Character)( e.getKey())).charValue()));
return Char2ByteArrayMap.this.containsKey(k) && ( (Char2ByteArrayMap.this.get(k)) == (((((Byte)(e.getValue())).byteValue()))) );
}
@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 Character)) return false;
if (e.getValue() == null || ! (e.getValue() instanceof Byte)) return false;
final char k = ((((Character)( e.getKey())).charValue()));
final byte v = ((((Byte)( e.getValue())).byteValue()));
final int oldPos = Char2ByteArrayMap.this.findKey(k);
if (oldPos == -1 || ! ( (v) == (Char2ByteArrayMap.this.value[oldPos]) )) return false;
final int tail = size - oldPos - 1;
System.arraycopy(Char2ByteArrayMap.this.key, oldPos + 1, Char2ByteArrayMap.this.key, oldPos, tail);
System.arraycopy(Char2ByteArrayMap.this.value, oldPos + 1, Char2ByteArrayMap.this.value, oldPos, tail);
Char2ByteArrayMap.this.size--;
return true;
}
}
@Override
public FastEntrySet char2ByteEntrySet() {
return new EntrySet();
}
private int findKey(final char k) {
final char[] key = this.key;
for(int i = size; i-- != 0;) if (( (key[i]) == (k) )) return i;
return -1;
}
@Override
public byte get(final char k) {
final char[] key = this.key;
for(int i = size; i-- != 0;) if (( (key[i]) == (k) )) return value[i];
return defRetValue;
}
@Override
public int size() {
return size;
}
@Override
public void clear() {
size = 0;
}
@Override
public boolean containsKey(final char k) {
return findKey(k) != -1;
}
@Override
public boolean containsValue(byte v) {
for(int i = size; i-- != 0;) if (( (value[i]) == (v) )) return true;
return false;
}
@Override
public boolean isEmpty() {
return size == 0;
}
@Override
public byte put(char k, byte v) {
final int oldKey = findKey(k);
if (oldKey != -1) {
final byte oldValue = value[oldKey];
value[oldKey] = v;
return oldValue;
}
if (size == key.length) {
final char[] newKey = new char[size == 0 ? 2 : size * 2];
final byte[] newValue = new byte[size == 0 ? 2 : size * 2];
for(int i = size; i-- != 0;) {
newKey[i] = key[i];
newValue[i] = value[i];
}
key = newKey;
value = newValue;
}
key[size] = k;
value[size] = v;
size++;
return defRetValue;
}
@Override
public byte remove(final char k) {
final int oldPos = findKey(k);
if (oldPos == -1) return defRetValue;
final byte oldValue = value[oldPos];
final int tail = size - oldPos - 1;
System.arraycopy(key, oldPos + 1, key, oldPos, tail);
System.arraycopy(value, oldPos + 1, value, oldPos, tail);
size--;
return oldValue;
}
@Override
public CharSet keySet() {
return new CharArraySet (key, size);
}
@Override
public ByteCollection values() {
return ByteCollections.unmodifiable(new ByteArraySet (value, size));
}
/** Returns a deep copy of this map.
*
* This method performs a deep copy of this hash map; the data stored in the
* map, however, is not cloned. Note that this makes a difference only for object keys.
*
* @return a deep copy of this map.
*/
@Override
public Char2ByteArrayMap clone() {
Char2ByteArrayMap c;
try {
c = (Char2ByteArrayMap )super.clone();
}
catch(CloneNotSupportedException cantHappen) {
throw new InternalError();
}
c.key = key.clone();
c.value = value.clone();
return c;
}
private void writeObject(java.io.ObjectOutputStream s) throws java.io.IOException {
s.defaultWriteObject();
for(int i = 0; i < size; i++) {
s.writeChar(key[i]);
s.writeByte(value[i]);
}
}
private void readObject(java.io.ObjectInputStream s) throws java.io.IOException, ClassNotFoundException {
s.defaultReadObject();
key = new char[size];
value = new byte[size];
for(int i = 0; i < size; i++) {
key[i] = s.readChar();
value[i] = s.readByte();
}
}
}