/*
GNU GENERAL PUBLIC LICENSE
Copyright (C) 2006 The Lobo Project
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 2 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 Public License for more details.
You should have received a copy of the GNU General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
Contact info: lobochief@users.sourceforge.net
*/
package org.lobobrowser.primary.ext;
import java.util.Arrays;
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;
import org.eclipse.jdt.annotation.NonNull;
import org.eclipse.jdt.annotation.Nullable;
import org.lobobrowser.util.ArrayUtilities;
public abstract class BaseHistory<T> implements java.io.Serializable {
private static final long serialVersionUID = 2257845020000200400L;
protected BaseHistory() {
super();
}
private final SortedSet<@NonNull String> historySortedSet = new TreeSet<>();
private final Map<String, TimedEntry> historyMap = new HashMap<>();
private final SortedSet<TimedEntry> historyTimedSet = new TreeSet<>();
private final int commonEntriesCapacity = 1000;
public boolean hasRecentEntries() {
synchronized (this) {
return this.historyTimedSet.size() > 0;
}
}
public Collection<String> getRecentItems(final int maxNumItems) {
synchronized (this) {
final Collection<String> items = new LinkedList<>();
final Iterator<TimedEntry> i = this.historyTimedSet.iterator();
int count = 0;
while (i.hasNext() && (count++ < maxNumItems)) {
final TimedEntry entry = i.next();
items.add(entry.value);
}
return items;
}
}
public Collection<T> getRecentItemInfo(final int maxNumItems) {
synchronized (this) {
final Collection<T> items = new LinkedList<>();
final Iterator<TimedEntry> i = this.historyTimedSet.iterator();
int count = 0;
while (i.hasNext() && (count++ < maxNumItems)) {
final TimedEntry entry = i.next();
items.add(entry.itemInfo);
}
return items;
}
}
public Collection<HostEntry> getRecentHostEntries(final int maxNumItems) {
synchronized (this) {
final Collection<HostEntry> items = new LinkedList<>();
final Iterator<TimedEntry> i = this.historyTimedSet.iterator();
final Set<String> hosts = new HashSet<>();
while (i.hasNext()) {
final TimedEntry entry = i.next();
final 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;
}
}
public Collection<HistoryEntry<T>> getAllEntries() {
synchronized (this) {
final Collection<HistoryEntry<T>> items = new LinkedList<>();
final Iterator<TimedEntry> i = this.historyTimedSet.iterator();
while (i.hasNext()) {
final TimedEntry entry = i.next();
items.add(new HistoryEntry<>(entry.url, entry.timestamp, entry.itemInfo));
}
return items;
}
}
public Collection<HistoryEntry<T>> getRecentEntries(final int maxNumItems) {
synchronized (this) {
final Collection<HistoryEntry<T>> items = new LinkedList<>();
final Iterator<TimedEntry> i = this.historyTimedSet.iterator();
while (i.hasNext()) {
final TimedEntry entry = i.next();
if (items.size() >= maxNumItems) {
break;
}
items.add(new HistoryEntry<>(entry.url, entry.timestamp, entry.itemInfo));
}
return items;
}
}
public Collection<String> getHeadMatchItems(final String itemPrefix, final int maxNumItems) {
synchronized (this) {
final String[] array = ArrayUtilities.copy(this.historySortedSet, String.class);
final int idx = Arrays.binarySearch(array, itemPrefix);
final int startIdx = idx >= 0 ? idx : (-idx - 1);
int count = 0;
final Collection<String> items = new LinkedList<>();
for (int i = startIdx; (i < array.length) && (count++ < maxNumItems); i++) {
final String potentialItem = array[i];
if (potentialItem.startsWith(itemPrefix)) {
items.add(potentialItem);
} else {
break;
}
}
return items;
}
}
public void addAsRecent(final java.net.URL url, final T itemInfo) {
final @NonNull 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
final TimedEntry entryToRemove = this.historyTimedSet.last();
this.historyMap.remove(entryToRemove.value);
this.historySortedSet.remove(entryToRemove.value);
this.historyTimedSet.remove(entryToRemove);
}
}
}
}
public void touch(final java.net.URL url) {
final String item = url.toExternalForm();
synchronized (this) {
final TimedEntry entry = this.historyMap.get(item);
if (entry != null) {
this.historyTimedSet.remove(entry);
entry.touch();
this.historyTimedSet.add(entry);
}
}
}
public @Nullable T getExistingInfo(final String item) {
final TimedEntry entry = this.historyMap.get(item);
return entry == null ? null : entry.itemInfo;
}
private class TimedEntry implements Comparable<TimedEntry>, java.io.Serializable {
private static final long serialVersionUID = 2257845000000000200L;
private long timestamp = System.currentTimeMillis();
private final java.net.URL url;
private final String value;
private T itemInfo;
/**
* @param url
*/
public TimedEntry(final java.net.URL url, final String textValue, final T itemInfo) {
this.itemInfo = itemInfo;
this.value = textValue;
this.url = url;
}
public void touch() {
this.timestamp = System.currentTimeMillis();
}
@Override
public boolean equals(final Object obj) {
if (obj instanceof BaseHistory.TimedEntry) {
@SuppressWarnings("unchecked")
final BaseHistory<T>.TimedEntry other = (BaseHistory<T>.TimedEntry) obj;
return other.value.equals(this.value);
} else {
return false;
}
}
/*
* (non-Javadoc)
*
* @see java.lang.Comparable#compareTo(java.lang.Object)
*/
public int compareTo(final TimedEntry arg0) {
if (this.equals(arg0)) {
return 0;
}
final TimedEntry other = arg0;
final long time1 = this.timestamp;
final 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);
}
}
}
}