com.sun.mail.imap.protocol.MessageSet Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package com.sun.mail.imap.protocol;
import java.util.List;
import java.util.ArrayList;
/**
* This class holds the 'start' and 'end' for a range of messages.
*/
public class MessageSet {
public int start;
public int end;
public MessageSet() { }
public MessageSet(int start, int end) {
this.start = start;
this.end = end;
}
/**
* Count the total number of elements in a MessageSet
*
* @return how many messages in this MessageSet
*/
public int size() {
return end - start + 1;
}
/**
* Convert an array of integers into an array of MessageSets
*
* @param msgs the messages
* @return array of MessageSet objects
*/
public static MessageSet[] createMessageSets(int[] msgs) {
List v = new ArrayList<>();
int i,j;
for (i=0; i < msgs.length; i++) {
MessageSet ms = new MessageSet();
ms.start = msgs[i];
// Look for contiguous elements
for (j=i+1; j < msgs.length; j++) {
if (msgs[j] != msgs[j-1] +1)
break;
}
ms.end = msgs[j-1];
v.add(ms);
i = j-1; // i gets incremented @ top of the loop
}
return v.toArray(new MessageSet[v.size()]);
}
/**
* Convert an array of MessageSets into an IMAP sequence range
*
* @param msgsets the MessageSets
* @return IMAP sequence string
*/
public static String toString(MessageSet[] msgsets) {
if (msgsets == null || msgsets.length == 0) // Empty msgset
return null;
int i = 0; // msgset index
StringBuilder s = new StringBuilder();
int size = msgsets.length;
int start, end;
for (;;) {
start = msgsets[i].start;
end = msgsets[i].end;
if (end > start)
s.append(start).append(':').append(end);
else // end == start means only one element
s.append(start);
i++; // Next MessageSet
if (i >= size) // No more MessageSets
break;
else
s.append(',');
}
return s.toString();
}
/*
* Count the total number of elements in an array of MessageSets
*/
public static int size(MessageSet[] msgsets) {
int count = 0;
if (msgsets == null) // Null msgset
return 0;
for (int i=0; i < msgsets.length; i++)
count += msgsets[i].size();
return count;
}
}