mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-05 16:46:26 +00:00
103 lines
3.8 KiB
Java
103 lines
3.8 KiB
Java
/* -*- Mode: java; indent-tabs-mode: nil; c-basic-offset: 2 -*-
|
|
*
|
|
* The contents of this file are subject to the Mozilla Public
|
|
* License Version 1.1 (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.mozilla.org/MPL/
|
|
*
|
|
* Software distributed under the License is distributed on an "AS
|
|
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
|
|
* implied. See the License for the specific language governing
|
|
* rights and limitations under the License.
|
|
*
|
|
* The Original Code is the Grendel mail/news client.
|
|
*
|
|
* The Initial Developer of the Original Code is Netscape Communications
|
|
* Corporation. Portions created by Netscape are
|
|
* Copyright (C) 1997 Netscape Communications Corporation. All
|
|
* Rights Reserved.
|
|
*
|
|
* Contributor(s):
|
|
*
|
|
* Created: Jamie Zawinski <jwz@netscape.com>, 26 Sep 1997.
|
|
*/
|
|
|
|
package grendel.util;
|
|
|
|
import calypso.util.ByteBuf;
|
|
|
|
/** This class generates globally-unique message IDs.
|
|
These IDs conform to RFC 822, RFC 1036, and the
|
|
so-called son-of-1036 draft.
|
|
*/
|
|
public class MessageIDGenerator {
|
|
|
|
private MessageIDGenerator() { } // only static methods
|
|
|
|
|
|
/** Generates a new Message-ID string.
|
|
@param hostname The `domain' part of the ID to generate.
|
|
<P>
|
|
Generally, this should be the fully-qualified name of
|
|
the local host. In situations where that is impossible
|
|
to determine, or where the local host name might be
|
|
considered confidential information, the host part of
|
|
the return address of the authoring user will do.
|
|
<P>
|
|
If the provided host name is not syntactically valid,
|
|
an error is signalled.
|
|
<P>
|
|
The host name may be null; in that case, a random
|
|
sequence of characters will be used for the host name,
|
|
resulting in a syntactically valid Message-ID. Note,
|
|
however, that this is strongly discouraged by the
|
|
relevant RFCs: Message-IDs should have valid host
|
|
names in them if at all possible.
|
|
|
|
@return The new ID, a String.
|
|
*/
|
|
public static String generate(String host_name) {
|
|
if (host_name != null) {
|
|
checkHostName(host_name);
|
|
if (host_name.length() == 0)
|
|
host_name = null;
|
|
}
|
|
|
|
int radix = 36; // keep the strings short
|
|
long time = System.currentTimeMillis(); // millisec resolution
|
|
long salt = Double.doubleToLongBits(Math.random()); // 64 random bits
|
|
|
|
ByteBuf out = ByteBuf.Alloc();
|
|
out.append((byte) '<');
|
|
out.append(Long.toString(Math.abs(time), radix));
|
|
out.append((byte) '.');
|
|
out.append(Long.toString(Math.abs(salt), radix));
|
|
out.append((byte) '@');
|
|
|
|
if (host_name != null)
|
|
out.append(host_name);
|
|
else {
|
|
out.append((byte) 'h'); // domain part must begin with a letter
|
|
salt = (Double.doubleToLongBits(Math.random()) & 0xFFFFFFFFL); // 32 bits
|
|
out.append(Long.toString(Math.abs(salt), radix));
|
|
}
|
|
out.append((byte) '>');
|
|
|
|
String result = out.toString();
|
|
ByteBuf.Recycle(out);
|
|
return result;
|
|
}
|
|
|
|
private static void checkHostName(String string) {
|
|
int L = string.length();
|
|
for (int i = 0; i < L; i++) {
|
|
char c = string.charAt(i);
|
|
if (!Character.isLetterOrDigit(c) && c != '-' && c != '_' && c != '.')
|
|
throw new Error("illegal character in host name for Message-ID: " +
|
|
"`" +
|
|
new String(new char[] { c }) +
|
|
"' (" + string + ")");
|
|
}
|
|
}
|
|
}
|