| /* |
| * Copyright (C) 2019, Thomas Wolf <thomas.wolf@paranor.ch> |
| * and other copyright owners as documented in the project's IP log. |
| * |
| * This program and the accompanying materials are made available |
| * under the terms of the Eclipse Distribution License v1.0 which |
| * accompanies this distribution, is reproduced below, and is |
| * available at http://www.eclipse.org/org/documents/edl-v10.php |
| * |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or |
| * without modification, are permitted provided that the following |
| * conditions are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * - Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer in the documentation and/or other materials provided |
| * with the distribution. |
| * |
| * - Neither the name of the Eclipse Foundation, Inc. nor the |
| * names of its contributors may be used to endorse or promote |
| * products derived from this software without specific prior |
| * written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND |
| * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, |
| * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| package org.eclipse.jgit.treewalk; |
| |
| import java.time.Instant; |
| import java.util.Comparator; |
| |
| /** |
| * Specialized comparator for {@link Instant}s. If either timestamp has a zero |
| * fraction, compares only seconds. If either timestamp has no time fraction |
| * smaller than a millisecond, compares only milliseconds. If either timestamp |
| * has no fraction smaller than a microsecond, compares only microseconds. |
| */ |
| class InstantComparator implements Comparator<Instant> { |
| |
| @Override |
| public int compare(Instant a, Instant b) { |
| return compare(a, b, false); |
| } |
| |
| /** |
| * Compares two {@link Instant}s to the lower resolution of the two |
| * instants. See {@link InstantComparator}. |
| * |
| * @param a |
| * first {@link Instant} to compare |
| * @param b |
| * second {@link Instant} to compare |
| * @param forceSecondsOnly |
| * whether to omit all fraction comparison |
| * @return a value < 0 if a < b, a value > 0 if a > b, and 0 if |
| * a == b |
| */ |
| public int compare(Instant a, Instant b, boolean forceSecondsOnly) { |
| long aSeconds = a.getEpochSecond(); |
| long bSeconds = b.getEpochSecond(); |
| int result = Long.compare(aSeconds, bSeconds); |
| if (result != 0) { |
| return result; |
| } |
| int aSubSecond = a.getNano(); |
| int bSubSecond = b.getNano(); |
| if (forceSecondsOnly || (aSubSecond == 0) |
| || (bSubSecond == 0)) { |
| // Don't check the subseconds part. |
| return 0; |
| } else if (aSubSecond != bSubSecond) { |
| // If either has nothing smaller than a millisecond, compare only |
| // milliseconds. |
| int aSubMillis = aSubSecond % 1_000_000; |
| int bSubMillis = bSubSecond % 1_000_000; |
| if (aSubMillis == 0) { |
| bSubSecond -= bSubMillis; |
| } else if (bSubMillis == 0) { |
| aSubSecond -= aSubMillis; |
| } else { |
| // Same again, but for microsecond resolution. NTFS has 100ns |
| // resolution, but WindowsFileAttributes may provide only |
| // microseconds (1000ns). Similar for some Unix file systems. |
| int aSubMicros = aSubSecond % 1000; |
| int bSubMicros = bSubSecond % 1000; |
| if (aSubMicros == 0) { |
| bSubSecond -= bSubMicros; |
| } else if (bSubMicros == 0) { |
| aSubSecond -= aSubMicros; |
| } |
| } |
| } |
| return Integer.compare(aSubSecond, bSubSecond); |
| } |
| |
| } |