| /* |
| * Copyright (C) 2016, Google Inc. 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.util.time; |
| |
| import static java.util.concurrent.TimeUnit.MICROSECONDS; |
| import static java.util.concurrent.TimeUnit.MILLISECONDS; |
| |
| import java.sql.Timestamp; |
| import java.time.Duration; |
| import java.time.Instant; |
| import java.util.Date; |
| import java.util.Iterator; |
| import java.util.concurrent.TimeUnit; |
| import java.util.concurrent.TimeoutException; |
| |
| /** |
| * A timestamp generated by |
| * {@link org.eclipse.jgit.util.time.MonotonicClock#propose()}. |
| * <p> |
| * ProposedTimestamp implements AutoCloseable so that implementations can |
| * release resources associated with obtaining certainty about time elapsing. |
| * For example the constructing MonotonicClock may start network IO with peers |
| * when creating the ProposedTimestamp, and {@link #close()} can ensure those |
| * network resources are released in a timely fashion. |
| * |
| * @since 4.6 |
| */ |
| public abstract class ProposedTimestamp implements AutoCloseable { |
| /** |
| * Wait for several timestamps. |
| * |
| * @param times |
| * timestamps to wait on. |
| * @param maxWait |
| * how long to wait for the timestamps. |
| * @throws java.lang.InterruptedException |
| * current thread was interrupted before the waiting process |
| * completed normally. |
| * @throws java.util.concurrent.TimeoutException |
| * the timeout was reached without the proposed timestamp become |
| * certainly in the past. |
| */ |
| public static void blockUntil(Iterable<ProposedTimestamp> times, |
| Duration maxWait) throws TimeoutException, InterruptedException { |
| Iterator<ProposedTimestamp> itr = times.iterator(); |
| if (!itr.hasNext()) { |
| return; |
| } |
| |
| long now = System.currentTimeMillis(); |
| long deadline = now + maxWait.toMillis(); |
| for (;;) { |
| long w = deadline - now; |
| if (w < 0) { |
| throw new TimeoutException(); |
| } |
| itr.next().blockUntil(Duration.ofMillis(w)); |
| if (itr.hasNext()) { |
| now = System.currentTimeMillis(); |
| } else { |
| break; |
| } |
| } |
| } |
| |
| /** |
| * Read the timestamp as {@code unit} since the epoch. |
| * <p> |
| * The timestamp value for a specific {@code ProposedTimestamp} object never |
| * changes, and can be read before {@link #blockUntil(Duration)}. |
| * |
| * @param unit |
| * what unit to return the timestamp in. The timestamp will be |
| * rounded if the unit is bigger than the clock's granularity. |
| * @return {@code unit} since the epoch. |
| */ |
| public abstract long read(TimeUnit unit); |
| |
| /** |
| * Wait for this proposed timestamp to be certainly in the recent past. |
| * <p> |
| * This method forces the caller to wait up to {@code timeout} for |
| * {@code this} to pass sufficiently into the past such that the creating |
| * {@link org.eclipse.jgit.util.time.MonotonicClock} instance will not |
| * create an earlier timestamp. |
| * |
| * @param maxWait |
| * how long the implementation may block the caller. |
| * @throws java.lang.InterruptedException |
| * current thread was interrupted before the waiting process |
| * completed normally. |
| * @throws java.util.concurrent.TimeoutException |
| * the timeout was reached without the proposed timestamp |
| * becoming certainly in the past. |
| */ |
| public abstract void blockUntil(Duration maxWait) |
| throws InterruptedException, TimeoutException; |
| |
| /** |
| * Get milliseconds since epoch; {@code read(MILLISECONDS}). |
| * |
| * @return milliseconds since epoch; {@code read(MILLISECONDS}). |
| */ |
| public long millis() { |
| return read(MILLISECONDS); |
| } |
| |
| /** |
| * Get microseconds since epoch; {@code read(MICROSECONDS}). |
| * |
| * @return microseconds since epoch; {@code read(MICROSECONDS}). |
| */ |
| public long micros() { |
| return read(MICROSECONDS); |
| } |
| |
| /** |
| * Get time since epoch, with up to microsecond resolution. |
| * |
| * @return time since epoch, with up to microsecond resolution. |
| */ |
| public Instant instant() { |
| long usec = micros(); |
| long secs = usec / 1000000L; |
| long nanos = (usec % 1000000L) * 1000L; |
| return Instant.ofEpochSecond(secs, nanos); |
| } |
| |
| /** |
| * Get time since epoch, with up to microsecond resolution. |
| * |
| * @return time since epoch, with up to microsecond resolution. |
| */ |
| public Timestamp timestamp() { |
| return Timestamp.from(instant()); |
| } |
| |
| /** |
| * Get time since epoch, with up to millisecond resolution. |
| * |
| * @return time since epoch, with up to millisecond resolution. |
| */ |
| public Date date() { |
| return new Date(millis()); |
| } |
| |
| /** |
| * {@inheritDoc} |
| * <p> |
| * Release resources allocated by this timestamp. |
| */ |
| @Override |
| public void close() { |
| // Do nothing by default. |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public String toString() { |
| return instant().toString(); |
| } |
| } |