/*
* Copyright 2015 the original author or authors.
* @https://github.com/scouter-project/scouter
*
* 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.
*
* The initial idea for this class is from "org.apache.commons.lang.IntHashMap";
* http://commons.apache.org/commons-lang-2.6-src.zip
*
*/
package scouter.util;
import java.util.Arrays;
import java.util.NoSuchElementException;
/**
* @author Paul Kim (sjkim@whatap.io)
*/
public class StringLinkedSet {
private static final int DEFAULT_CAPACITY = 101;
private static final float DEFAULT_LOAD_FACTOR = 0.75f;
private StringLinkedSetry table[];
private StringLinkedSetry header;
private int count;
private int threshold;
private float loadFactor;
public StringLinkedSet(int initCapacity, float loadFactor) {
if (initCapacity < 0)
throw new RuntimeException("Capacity Error: " + initCapacity);
if (loadFactor <= 0)
throw new RuntimeException("Load Count Error: " + loadFactor);
if (initCapacity == 0)
initCapacity = 1;
this.loadFactor = loadFactor;
this.table = new StringLinkedSetry[initCapacity];
this.header = new StringLinkedSetry(null, null);
this.header.link_next = header.link_prev = header;
threshold = (int) (initCapacity * loadFactor);
}
public StringLinkedSet() {
this(DEFAULT_CAPACITY, DEFAULT_LOAD_FACTOR);
}
public int size() {
return count;
}
public String[] getArray() {
String[] _keys = new String[this.size()];
StringEnumer en = this.elements();
for (int i = 0; i < _keys.length; i++)
_keys[i] = en.nextString();
return _keys;
}
public synchronized StringEnumer elements() {
return new Enumer();
}
public synchronized boolean contains(String key) {
if (key == null)
return false;
StringLinkedSetry tab[] = table;
int index = hash(key) % tab.length;
for (StringLinkedSetry e = tab[index]; e != null; e = e.next) {
if (CompareUtil.equals(e.key, key)) {
return true;
}
}
return false;
}
public synchronized String getFirst() {
return this.header.link_next.key;
}
public synchronized String getLast() {
return this.header.link_prev.key;
}
private int hash(String key) {
return key.hashCode() & Integer.MAX_VALUE;
}
protected void rehash() {
int oldCapacity = table.length;
StringLinkedSetry oldMap[] = table;
int newCapacity = oldCapacity * 2 + 1;
StringLinkedSetry newMap[] = new StringLinkedSetry[newCapacity];
threshold = (int) (newCapacity * loadFactor);
table = newMap;
for (int i = oldCapacity; i-- > 0;) {
StringLinkedSetry old = oldMap[i];
while (old != null) {
StringLinkedSetry e = old;
old = old.next;
String key = e.key;
int index = hash(key) % newCapacity;
e.next = newMap[index];
newMap[index] = e;
}
}
}
private int max;
public StringLinkedSet setMax(int max) {
this.max = max;
return this;
}
private static enum MODE {
FORCE_FIRST, FORCE_LAST, FIRST, LAST
};
public String put(String key) {
return _put(key, MODE.LAST);
}
public String putLast(String key) {
return _put(key, MODE.FORCE_LAST);
}
public String putFirst(String key) {
return _put(key, MODE.FORCE_FIRST);
}
private synchronized String _put(String key, MODE m) {
StringLinkedSetry tab[] = table;
int index = hash(key) % tab.length;
for (StringLinkedSetry e = tab[index]; e != null; e = e.next) {
if (CompareUtil.equals(e.key, key)) {
switch (m) {
case FORCE_FIRST:
if (header.link_next != e) {
unchain(e);
chain(header, header.link_next, e);
}
break;
case FORCE_LAST:
if (header.link_prev != e) {
unchain(e);
chain(header.link_prev, header, e);
}
break;
}
return e.key;
}
}
if (max > 0) {
switch (m) {
case FORCE_FIRST:
case FIRST:
while (count >= max) {
String v = header.link_prev.key;
remove(v);
overflowed(v);
}
break;
case FORCE_LAST:
case LAST:
while (count >= max) {
String v = header.link_next.key;
remove(v);
overflowed(v);
}
break;
}
}
if (count >= threshold) {
rehash();
tab = table;
index = hash(key) % tab.length;
}
StringLinkedSetry e = new StringLinkedSetry(key, tab[index]);
tab[index] = e;
switch (m) {
case FORCE_FIRST:
case FIRST:
chain(header, header.link_next, e);
break;
case FORCE_LAST:
case LAST:
chain(header.link_prev, header, e);
break;
}
count++;
return null;
}
protected void overflowed(String value) {
}
public String unipoint(String key) {
String old = _put(key, MODE.LAST);
return old == null ? key : old;
}
public synchronized String remove(String key) {
if (key == null)
return null;
StringLinkedSetry tab[] = table;
int index = hash(key) % tab.length;
for (StringLinkedSetry e = tab[index], prev = null; e != null; prev = e, e = e.next) {
if (CompareUtil.equals(e.key, key)) {
if (prev != null) {
prev.next = e.next;
} else {
tab[index] = e.next;
}
count--;
//
unchain(e);
return key;
}
}
return null;
}
public synchronized String removeFirst() {
if (isEmpty())
return null;
return remove(header.link_next.key);
}
public synchronized String removeLast() {
if (isEmpty())
return null;
return remove(header.link_prev.key);
}
public boolean isEmpty() {
return size() == 0;
}
public synchronized void clear() {
StringLinkedSetry tab[] = table;
for (int index = tab.length; --index >= 0;)
tab[index] = null;
this.header.link_next = header.link_prev = header;
count = 0;
}
public String toString() {
StringBuffer buf = new StringBuffer();
StringEnumer it = elements();
buf.append("{");
while (it.hasMoreElements()) {
if (buf.length() > 1)
buf.append(",");
buf.append(it.nextString());
}
buf.append("}");
return buf.toString();
}
public static class StringLinkedSetry<V> {
String key;
StringLinkedSetry<V> next;
StringLinkedSetry<V> link_next, link_prev;
protected StringLinkedSetry(String key, StringLinkedSetry<V> next) {
this.key = key;
this.next = next;
}
protected Object clone() {
return new StringLinkedSetry(key, (next == null ? null : (StringLinkedSetry) next.clone()));
}
public String getKey() {
return key;
}
public boolean equals(Object o) {
if (!(o instanceof StringLinkedSetry))
return false;
StringLinkedSetry e = (StringLinkedSetry) o;
return CompareUtil.equals(e.key, key);
}
public int hashCode() {
return key.hashCode();
}
public String toString() {
return key;
}
}
private class Enumer implements StringEnumer {
StringLinkedSetry entry = StringLinkedSet.this.header.link_next;
public boolean hasMoreElements() {
return header != entry && entry != null;
}
public String nextString() {
if (hasMoreElements()) {
StringLinkedSetry e = entry;
entry = e.link_next;
return e.key;
}
throw new NoSuchElementException("no more next");
}
}
private void chain(StringLinkedSetry link_prev, StringLinkedSetry link_next, StringLinkedSetry e) {
e.link_prev = link_prev;
e.link_next = link_next;
link_prev.link_next = e;
link_next.link_prev = e;
}
private void unchain(StringLinkedSetry e) {
e.link_prev.link_next = e.link_next;
e.link_next.link_prev = e.link_prev;
e.link_prev = null;
e.link_next = null;
}
public synchronized void sort(boolean asc) {
if (this.size() <= 1)
return;
String[] list = new String[this.size()];
StringEnumer en = this.elements();
for (int i = 0; en.hasMoreElements(); i++) {
list[i] = en.nextString();
}
Arrays.sort(list);
this.clear();
if (asc) {
for (String n : list)
this.put(n);
} else {
for (int i = list.length - 1; i >= 0; i--) {
this.put(list[i]);
}
}
}
public static void main(String[] args) {
StringLinkedSet s = new StringLinkedSet();
s.put("aa");
s.put("bb");
s.put("00");
s.sort(true);
System.out.println(s);
s.sort(false);
System.out.println(s);
}
}