| /* |
| * Copyright (C) 2019, Google LLC and others |
| * |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Distribution License v. 1.0 which is available at |
| * https://www.eclipse.org/org/documents/edl-v10.php. |
| * |
| * SPDX-License-Identifier: BSD-3-Clause |
| */ |
| |
| package org.eclipse.jgit.internal.storage.reftable; |
| |
| import org.eclipse.jgit.lib.ReflogEntry; |
| import org.eclipse.jgit.lib.ReflogReader; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.concurrent.locks.Lock; |
| |
| /** |
| * Implement the ReflogReader interface for a reflog stored in reftable. |
| */ |
| public class ReftableReflogReader implements ReflogReader { |
| private final Lock lock; |
| |
| private final Reftable reftable; |
| |
| private final String refname; |
| |
| ReftableReflogReader(Lock lock, Reftable merged, String refname) { |
| this.lock = lock; |
| this.reftable = merged; |
| this.refname = refname; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public ReflogEntry getLastEntry() throws IOException { |
| lock.lock(); |
| try { |
| LogCursor cursor = reftable.seekLog(refname); |
| return cursor.next() ? cursor.getReflogEntry() : null; |
| } finally { |
| lock.unlock(); |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public List<ReflogEntry> getReverseEntries() throws IOException { |
| return getReverseEntries(Integer.MAX_VALUE); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public ReflogEntry getReverseEntry(int number) throws IOException { |
| lock.lock(); |
| try { |
| LogCursor cursor = reftable.seekLog(refname); |
| while (true) { |
| if (!cursor.next() || number < 0) { |
| return null; |
| } |
| if (number == 0) { |
| return cursor.getReflogEntry(); |
| } |
| number--; |
| } |
| } finally { |
| lock.unlock(); |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public List<ReflogEntry> getReverseEntries(int max) throws IOException { |
| lock.lock(); |
| try { |
| LogCursor cursor = reftable.seekLog(refname); |
| |
| List<ReflogEntry> result = new ArrayList<>(); |
| while (cursor.next() && result.size() < max) { |
| result.add(cursor.getReflogEntry()); |
| } |
| |
| return result; |
| } finally { |
| lock.unlock(); |
| } |
| } |
| } |