/*
GNU GENERAL LICENSE
Copyright (C) 2006 The Lobo Project. Copyright (C) 2014 - 2017 Lobo Evolution
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public
License as published by the Free Software Foundation; either
verion 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General License for more details.
You should have received a copy of the GNU General Public
along with this program. If not, see <http://www.gnu.org/licenses/>.
Contact info: lobochief@users.sourceforge.net; ivan.difrancesco@yahoo.it
*/
package org.lobobrowser.primary.ext;
import java.net.URL;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Map;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;
/**
* The Class BaseHistory.
*
* @param <T>
* the generic type
*/
public abstract class BaseHistory<T> implements java.io.Serializable {
/** The Constant serialVersionUID. */
private static final long serialVersionUID = 2257845020000200400L;
/**
* Instantiates a new base history.
*/
protected BaseHistory() {
super();
}
/** The history sorted set. */
private final SortedSet<String> historySortedSet = new TreeSet<String>();
/** The history map. */
private final Map<String, TimedEntry> historyMap = new HashMap<String, TimedEntry>();
/** The history timed set. */
private final SortedSet<TimedEntry> historyTimedSet = new TreeSet<TimedEntry>();
/** The common entries capacity. */
private final int commonEntriesCapacity = 1000;
/**
* Checks for recent entries.
*
* @return true, if successful
*/
public boolean hasRecentEntries() {
synchronized (this) {
return this.historyTimedSet.size() > 0;
}
}
/**
* Gets the recent items.
*
* @param maxNumItems
* the max num items
* @return the recent items
*/
public Collection<String> getRecentItems(int maxNumItems) {
synchronized (this) {
Collection<String> items = new LinkedList<String>();
Iterator<TimedEntry> i = this.historyTimedSet.iterator();
int count = 0;
while (i.hasNext() && (count++ < maxNumItems)) {
TimedEntry entry = i.next();
items.add(entry.value);
}
return items;
}
}
/**
* Gets the recent item info.
*
* @param maxNumItems
* the max num items
* @return the recent item info
*/
public Collection<T> getRecentItemInfo(int maxNumItems) {
synchronized (this) {
Collection<T> items = new LinkedList<T>();
Iterator<TimedEntry> i = this.historyTimedSet.iterator();
int count = 0;
while (i.hasNext() && (count++ < maxNumItems)) {
TimedEntry entry = i.next();
items.add(entry.itemInfo);
}
return items;
}
}
/**
* Gets the recent host entries.
*
* @param maxNumItems
* the max num items
* @return the recent host entries
*/
public Collection<HostEntry> getRecentHostEntries(int maxNumItems) {
synchronized (this) {
Collection<HostEntry> items = new LinkedList<HostEntry>();
Iterator<TimedEntry> i = this.historyTimedSet.iterator();
Set<String> hosts = new HashSet<String>();
while (i.hasNext()) {
TimedEntry entry = i.next();
String host = entry.url.getHost();
if ((host != null) && (host.length() != 0)) {
if (!hosts.contains(host)) {
hosts.add(host);
if (hosts.size() >= maxNumItems) {
break;
}
items.add(new HostEntry(host, entry.timestamp));
}
}
}
return items;
}
}
/**
* Gets the all entries.
*
* @return the all entries
*/
public Collection<HistoryEntry<T>> getAllEntries() {
synchronized (this) {
Collection<HistoryEntry<T>> items = new LinkedList<HistoryEntry<T>>();
Iterator<TimedEntry> i = this.historyTimedSet.iterator();
while (i.hasNext()) {
TimedEntry entry = i.next();
items.add(new HistoryEntry<T>(entry.url, entry.timestamp, entry.itemInfo));
}
return items;
}
}
/**
* Gets the recent entries.
*
* @param maxNumItems
* the max num items
* @return the recent entries
*/
public Collection<HistoryEntry<T>> getRecentEntries(int maxNumItems) {
synchronized (this) {
Collection<HistoryEntry<T>> items = new LinkedList<HistoryEntry<T>>();
Iterator<TimedEntry> i = this.historyTimedSet.iterator();
while (i.hasNext()) {
TimedEntry entry = i.next();
if (items.size() >= maxNumItems) {
break;
}
items.add(new HistoryEntry<T>(entry.url, entry.timestamp, entry.itemInfo));
}
return items;
}
}
/**
* Gets the head match items.
*
* @param itemPrefix
* the item prefix
* @param maxNumItems
* the max num items
* @return the head match items
*/
public Collection<String> getHeadMatchItems(String itemPrefix) {
synchronized (this) {
Object[] array = this.historySortedSet.toArray();
Collection<String> items = new ArrayList<String>();
for (int i = 0; i < array.length; i++) {
String potentialItem = (String) array[i];
if (potentialItem.contains(itemPrefix)) {
items.add(potentialItem);
}
}
return items;
}
}
/**
* Adds the as recent.
*
* @param url
* the url
* @param itemInfo
* the item info
*/
public void addAsRecent(URL url, T itemInfo) {
String item = url.toExternalForm();
synchronized (this) {
TimedEntry entry = this.historyMap.get(item);
if (entry != null) {
this.historyTimedSet.remove(entry);
entry.touch();
entry.itemInfo = itemInfo;
this.historyTimedSet.add(entry);
} else {
entry = new TimedEntry(url, item, itemInfo);
this.historyTimedSet.add(entry);
this.historyMap.put(item, entry);
this.historySortedSet.add(item);
while (this.historyTimedSet.size() > this.commonEntriesCapacity) {
// Most outdated goes last
TimedEntry entryToRemove = this.historyTimedSet.last();
this.historyMap.remove(entryToRemove.value);
this.historySortedSet.remove(entryToRemove.value);
this.historyTimedSet.remove(entryToRemove);
}
}
}
}
/**
* Touch.
*
* @param url
* the url
*/
public void touch(URL url) {
String item = url.toExternalForm();
synchronized (this) {
TimedEntry entry = this.historyMap.get(item);
if (entry != null) {
this.historyTimedSet.remove(entry);
entry.touch();
this.historyTimedSet.add(entry);
}
}
}
/**
* Gets the existing info.
*
* @param item
* the item
* @return the existing info
*/
public T getExistingInfo(String item) {
TimedEntry entry = this.historyMap.get(item);
return entry == null ? null : entry.itemInfo;
}
/**
* The Class TimedEntry.
*/
private class TimedEntry implements Comparable<Object>, java.io.Serializable {
/** The Constant serialVersionUID. */
private static final long serialVersionUID = 2257845000000000200L;
/** The timestamp. */
private long timestamp = System.currentTimeMillis();
/** The url. */
private final URL url;
/** The value. */
private final String value;
/** The item info. */
private T itemInfo;
/**
* Instantiates a new timed entry.
*
* @param url
* the url
* @param textValue
* the text value
* @param itemInfo
* the item info
*/
public TimedEntry(URL url, String textValue, T itemInfo) {
this.itemInfo = itemInfo;
this.value = textValue;
this.url = url;
}
/**
* Touch.
*/
public void touch() {
this.timestamp = System.currentTimeMillis();
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(Object obj) {
@SuppressWarnings("unchecked")
TimedEntry other = (TimedEntry) obj;
return other.value.equals(this.value);
}
/*
* (non-Javadoc)
*
* @see java.lang.Comparable#compareTo(Object)
*/
@Override
public int compareTo(Object arg0) {
if (this.equals(arg0)) {
return 0;
}
@SuppressWarnings("unchecked")
TimedEntry other = (TimedEntry) arg0;
long time1 = this.timestamp;
long time2 = other.timestamp;
if (time1 > time2) {
// More recent goes first
return -1;
} else if (time2 > time1) {
return +1;
} else {
return this.value.compareTo(other.value);
}
}
}
}