| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| SystemClockImpl |
|
| 2.0;2 |
| 1 | /* | |
| 2 | * Licensed to the Apache Software Foundation (ASF) under one or more | |
| 3 | * contributor license agreements. See the NOTICE file distributed with | |
| 4 | * this work for additional information regarding copyright ownership. | |
| 5 | * The ASF licenses this file to You under the Apache License, Version 2.0 | |
| 6 | * (the "License"); you may not use this file except in compliance with | |
| 7 | * the License. You may obtain a copy of the License at | |
| 8 | * | |
| 9 | * http://www.apache.org/licenses/LICENSE-2.0 | |
| 10 | * | |
| 11 | * Unless required by applicable law or agreed to in writing, software | |
| 12 | * distributed under the License is distributed on an "AS IS" BASIS, | |
| 13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
| 14 | * See the License for the specific language governing permissions and | |
| 15 | * limitations under the License. | |
| 16 | */ | |
| 17 | ||
| 18 | package org.apache.commons.id.uuid.clock; | |
| 19 | ||
| 20 | /** | |
| 21 | * <p><code>SystemClockImpl</code> provides a timing mechanism for returning the | |
| 22 | * current time in 100-nano second intervals since 00:00:00.00, 15 October 1582. | |
| 23 | * </p> | |
| 24 | * | |
| 25 | * @see org.apache.commons.id.uuid.clock.Clock | |
| 26 | * @author Commons-Id Team | |
| 27 | * @version $Revision: 480488 $ $Date: 2006-11-29 08:57:26 +0000 (Wed, 29 Nov 2006) $ | |
| 28 | */ | |
| 29 | ||
| 30 | public final class SystemClockImpl implements Clock { | |
| 31 | /** Counter for the number of calls during the current millisecond */ | |
| 32 | 19 | private long generatedThisMilli = 0; |
| 33 | ||
| 34 | /** The current time in milliseconds held in this clock thread. */ | |
| 35 | private long currentTimeMillis; | |
| 36 | ||
| 37 | /** | |
| 38 | * <p>Public constructor.</p> | |
| 39 | */ | |
| 40 | public SystemClockImpl() { | |
| 41 | 19 | super(); |
| 42 | 19 | } |
| 43 | ||
| 44 | /** @see org.apache.commons.id.uuid.clock.Clock#getUUIDTime() */ | |
| 45 | public long getUUIDTime() throws OverClockedException { | |
| 46 | 54002 | return getTimeSynchronized(); |
| 47 | } | |
| 48 | ||
| 49 | /** | |
| 50 | * <p>Object synchronized method returns the current time in 100ns | |
| 51 | * intervals since the Gregorian change offset.</p> | |
| 52 | * | |
| 53 | * @return the current time in 100ns intervals since the Gregorian change | |
| 54 | * offset. | |
| 55 | * @throws OverClockedException an exception raised if too many timestamps | |
| 56 | * have been generated for the system time interval. | |
| 57 | */ | |
| 58 | private synchronized long getTimeSynchronized() | |
| 59 | throws OverClockedException { | |
| 60 | 54002 | if (currentTimeMillis != System.currentTimeMillis()) { |
| 61 | 300 | currentTimeMillis = System.currentTimeMillis(); |
| 62 | 300 | generatedThisMilli = 0; |
| 63 | } | |
| 64 | // Set time as current time millis plus offset times 100 ns ticks | |
| 65 | 54002 | long currentTime = |
| 66 | (currentTimeMillis + GREGORIAN_CHANGE_OFFSET) | |
| 67 | * INTERVALS_PER_MILLI; | |
| 68 | ||
| 69 | // Return the same time - generator/client code must check to see if overclocked | |
| 70 | 54001 | if (generatedThisMilli + 1 >= INTERVALS_PER_MILLI) { |
| 71 | 0 | throw new OverClockedException(); |
| 72 | } | |
| 73 | // Return the uuid time plus the artifical tick incremented | |
| 74 | 54002 | return (currentTime + generatedThisMilli++); |
| 75 | } | |
| 76 | } |