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// Copyright (C) 2009 The Android Open Source Project
//
// 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.
package com.google.gerrit.server;
import com.google.gerrit.client.reviewdb.Change;
import com.google.gerrit.client.reviewdb.ReviewDb;
import com.google.gwtorm.client.OrmException;
import org.eclipse.jgit.util.Base64;
import org.eclipse.jgit.util.NB;
public class ChangeUtil {
private static int uuidPrefix;
private static int uuidSeq;
/**
* Generate a new unique identifier for change message entities.
*
* @param db the database connection, used to increment the change message
* allocation sequence.
* @return the new unique identifier.
* @throws OrmException the database couldn't be incremented.
*/
public static String messageUUID(final ReviewDb db) throws OrmException {
final byte[] raw = new byte[8];
fill(raw, db);
return Base64.encodeBytes(raw);
}
private static synchronized void fill(byte[] raw, ReviewDb db)
throws OrmException {
if (uuidSeq == 0) {
uuidPrefix = db.nextChangeMessageId();
uuidSeq = Integer.MAX_VALUE;
}
NB.encodeInt32(raw, 0, uuidPrefix);
NB.encodeInt32(raw, 4, uuidSeq--);
}
public static void updated(final Change c) {
c.resetLastUpdatedOn();
computeSortKey(c);
}
public static void computeSortKey(final Change c) {
// The encoding uses minutes since Wed Oct 1 00:00:00 2008 UTC.
// We overrun approximately 4,085 years later, so ~6093.
//
final long lastUpdatedOn =
(c.getLastUpdatedOn().getTime() / 1000L) - 1222819200L;
final StringBuilder r = new StringBuilder(16);
r.setLength(16);
formatHexInt(r, 0, (int) (lastUpdatedOn / 60));
formatHexInt(r, 8, c.getId().get());
c.setSortKey(r.toString());
}
private static final char[] hexchar =
{'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', //
'a', 'b', 'c', 'd', 'e', 'f'};
private static void formatHexInt(final StringBuilder dst, final int p, int w) {
int o = p + 7;
while (o >= p && w != 0) {
dst.setCharAt(o--, hexchar[w & 0xf]);
w >>>= 4;
}
while (o >= p) {
dst.setCharAt(o--, '0');
}
}
}
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