/*
* 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.Enumeration;
import java.util.NoSuchElementException;
/**
* @author Paul Kim (sjkim@whatap.io)
*/
public class StringKeyLinkedMap<V> {
private static final int DEFAULT_CAPACITY = 101;
private static final float DEFAULT_LOAD_FACTOR = 0.75f;
private StringKeyLinkedEntry<V> table[];
private StringKeyLinkedEntry<V> header;
private int count;
private int threshold;
private float loadFactor;
public StringKeyLinkedMap(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 StringKeyLinkedEntry[initCapacity];
this.header = new StringKeyLinkedEntry(null, null, null);
this.header.link_next = header.link_prev = header;
threshold = (int) (initCapacity * loadFactor);
}
public StringKeyLinkedMap() {
this(DEFAULT_CAPACITY, DEFAULT_LOAD_FACTOR);
}
public int size() {
return count;
}
public String[] keyArray() {
String[] _keys = new String[this.size()];
StringEnumer en = this.keys();
for (int i = 0; i < _keys.length; i++)
_keys[i] = en.nextString();
return _keys;
}
public synchronized StringEnumer keys() {
return new Enumer(TYPE.KEYS);
}
public synchronized Enumeration<V> values() {
return new Enumer(TYPE.VALUES);
}
public synchronized Enumeration<StringKeyLinkedEntry<V>> entries() {
return new Enumer(TYPE.ENTRIES);
}
public synchronized boolean containsValue(V value) {
StringKeyLinkedEntry tab[] = table;
int i = tab.length;
while (i-- > 0) {
for (StringKeyLinkedEntry<V> e = tab[i]; e != null; e = e.next) {
if (CompareUtil.equals(e.value, value)) {
return true;
}
}
}
return false;
}
public synchronized boolean containsKey(String key) {
StringKeyLinkedEntry tab[] = table;
int index = hash(key) % tab.length;
for (StringKeyLinkedEntry e = tab[index]; e != null; e = e.next) {
if (CompareUtil.equals(e.key, key)) {
return true;
}
}
return false;
}
public synchronized V get(String key) {
if (key == null)
return null;
StringKeyLinkedEntry tab[] = table;
int index = hash(key) % tab.length;
for (StringKeyLinkedEntry<V> e = tab[index]; e != null; e = e.next) {
if (CompareUtil.equals(e.key, key)) {
return e.value;
}
}
return null;
}
public synchronized Object getFirst() {
if (isEmpty())
return null;
return this.header.link_next.value;
}
public synchronized Object getLast() {
if (isEmpty())
return null;
return this.header.link_prev.value;
}
private int hash(String key) {
return key.hashCode() & Integer.MAX_VALUE;
}
protected void rehash() {
int oldCapacity = table.length;
StringKeyLinkedEntry oldMap[] = table;
int newCapacity = oldCapacity * 2 + 1;
StringKeyLinkedEntry newMap[] = new StringKeyLinkedEntry[newCapacity];
threshold = (int) (newCapacity * loadFactor);
table = newMap;
for (int i = oldCapacity; i-- > 0;) {
StringKeyLinkedEntry old = oldMap[i];
while (old != null) {
StringKeyLinkedEntry 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 StringKeyLinkedMap<V> setMax(int max) {
this.max = max;
return this;
}
private static enum MODE {
FORCE_FIRST, FORCE_LAST, FIRST, LAST
};
public V put(String key, V value) {
return _put(key, value, MODE.LAST);
}
public V putLast(String key, V value) {
return _put(key, value, MODE.FORCE_LAST);
}
public V putFirst(String key, V value) {
return _put(key, value, MODE.FORCE_FIRST);
}
private synchronized V _put(String key, V value, MODE m) {
if (key == null)
return null;
StringKeyLinkedEntry tab[] = table;
int index = hash(key) % tab.length;
for (StringKeyLinkedEntry<V> e = tab[index]; e != null; e = e.next) {
if (CompareUtil.equals(e.getKey(), key)) {
V old = e.value;
e.value = value;
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 old;
}
}
if (max > 0) {
switch (m) {
case FORCE_FIRST:
case FIRST:
while (count >= max) {
//removeLast();
String k = header.link_prev.key;
V v = remove(k);
overflowed(k, v);
}
break;
case FORCE_LAST:
case LAST:
while (count >= max) {
//removeFirst();
String k = header.link_next.key;
V v = remove(k);
overflowed(k, v);
}
break;
}
}
if (count >= threshold) {
rehash();
tab = table;
index = hash(key) % tab.length;
}
StringKeyLinkedEntry e = new StringKeyLinkedEntry(key, value, 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;
}
public V intern(String key) {
return _intern(key, MODE.LAST);
}
private synchronized V _intern(String key, MODE m) {
if (key == null)
return null;
StringKeyLinkedEntry tab[] = table;
int index = hash(key) % tab.length;
for (StringKeyLinkedEntry<V> e = tab[index]; e != null; e = e.next) {
if (CompareUtil.equals(e.getKey(), key)) {
V old = e.value;
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 old;
}
}
V value = create(key);
if (value == null)
return null;
if (max > 0) {
switch (m) {
case FORCE_FIRST:
case FIRST:
while (count >= max) {
//removeLast();
String k = header.link_prev.key;
V v = remove(k);
overflowed(k, v);
}
break;
case FORCE_LAST:
case LAST:
while (count >= max) {
//removeFirst();
String k = header.link_next.key;
V v = remove(k);
overflowed(k, v);
}
break;
}
}
if (count >= threshold) {
rehash();
tab = table;
index = hash(key) % tab.length;
}
StringKeyLinkedEntry<V> e = new StringKeyLinkedEntry<V>(key, value, 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 value;
}
protected void overflowed(String key, V value) {
}
protected V create(String key) {
throw new RuntimeException("not implemented create()");
}
public synchronized V remove(String key) {
if (key == null)
return null;
StringKeyLinkedEntry<V> tab[] = table;
int index = hash(key) % tab.length;
for (StringKeyLinkedEntry<V> 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--;
V oldValue = e.value;
e.value = null;
//
unchain(e);
return oldValue;
}
}
return null;
}
public synchronized V removeFirst() {
if (isEmpty())
return null;
return remove(header.link_next.key);
}
public synchronized V removeLast() {
if (isEmpty())
return null;
return remove(header.link_prev.key);
}
public boolean isEmpty() {
return size() == 0;
}
public synchronized void clear() {
StringKeyLinkedEntry 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();
Enumeration it = entries();
buf.append("{");
for (int i = 0; it.hasMoreElements(); i++) {
StringKeyLinkedEntry e = (StringKeyLinkedEntry) (it.nextElement());
if (i > 0)
buf.append(", ");
buf.append(e.getKey() + "=" + e.getValue());
}
buf.append("}");
return buf.toString();
}
public String toFormatString() {
StringBuffer buf = new StringBuffer();
Enumeration it = entries();
buf.append("{\n");
while (it.hasMoreElements()) {
StringKeyLinkedEntry e = (StringKeyLinkedEntry) it.nextElement();
buf.append("\t").append(e.getKey() + "=" + e.getValue()).append("\n");
}
buf.append("}");
return buf.toString();
}
public static class StringKeyLinkedEntry<V> {
String key;
V value;
StringKeyLinkedEntry<V> next;
StringKeyLinkedEntry<V> link_next, link_prev;
protected StringKeyLinkedEntry(String key, V value, StringKeyLinkedEntry<V> next) {
this.key = key;
this.value = value;
this.next = next;
}
protected Object clone() {
return new StringKeyLinkedEntry(key, value, (next == null ? null : (StringKeyLinkedEntry) next.clone()));
}
public String getKey() {
return key;
}
public V getValue() {
return value;
}
public V setValue(V value) {
V oldValue = this.value;
this.value = value;
return oldValue;
}
public boolean equals(Object o) {
if (!(o instanceof StringKeyLinkedEntry))
return false;
StringKeyLinkedEntry<V> e = (StringKeyLinkedEntry) o;
return CompareUtil.equals(e.key, key) && CompareUtil.equals(e.value, value);
}
public int hashCode() {
return key.hashCode() ^ (value == null ? 0 : value.hashCode());
}
public String toString() {
return key + "=" + value;
}
}
private enum TYPE {
KEYS, VALUES, ENTRIES
}
private class Enumer<V> implements Enumeration<V>, StringEnumer {
TYPE type;
StringKeyLinkedEntry entry = StringKeyLinkedMap.this.header.link_next;
Enumer(TYPE type) {
this.type = type;
}
public boolean hasMoreElements() {
return header != entry && entry != null;
}
public V nextElement() {
if (hasMoreElements()) {
StringKeyLinkedEntry e = entry;
entry = e.link_next;
switch (type) {
case KEYS:
return (V) e.key;
case VALUES:
return (V) e.value;
default:
return (V) e;
}
}
throw new NoSuchElementException("no more next");
}
public String nextString() {
if (hasMoreElements()) {
StringKeyLinkedEntry e = entry;
entry = e.link_next;
return e.key;
}
throw new NoSuchElementException("no more next");
}
}
private void chain(StringKeyLinkedEntry link_prev, StringKeyLinkedEntry link_next, StringKeyLinkedEntry e) {
e.link_prev = link_prev;
e.link_next = link_next;
link_prev.link_next = e;
link_next.link_prev = e;
}
private void unchain(StringKeyLinkedEntry 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 static void main(String[] args) {
}
private static void print(Object e) {
System.out.println(e);
}
}