diff options
Diffstat (limited to 'org/apache/commons/net/ntp/TimeInfo.java')
| -rw-r--r-- | org/apache/commons/net/ntp/TimeInfo.java | 295 |
1 files changed, 0 insertions, 295 deletions
diff --git a/org/apache/commons/net/ntp/TimeInfo.java b/org/apache/commons/net/ntp/TimeInfo.java deleted file mode 100644 index 4ef17fd..0000000 --- a/org/apache/commons/net/ntp/TimeInfo.java +++ /dev/null @@ -1,295 +0,0 @@ -package org.apache.commons.net.ntp;
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You 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.
- */
-
-
-import java.util.ArrayList;
-import java.util.List;
-
-/**
- * Wrapper class to network time packet messages (NTP, etc) that computes
- * related timing info and stats.
- *
- * @author Jason Mathews, MITRE Corp
- *
- * @version $Revision: 658518 $ $Date: 2008-05-21 02:04:30 +0100 (Wed, 21 May 2008) $
- */
-public class TimeInfo {
-
- private NtpV3Packet _message;
- private List<String> _comments;
- private Long _delay;
- private Long _offset;
-
- /**
- * time at which time message packet was received by local machine
- */
- private long _returnTime;
-
- /**
- * flag indicating that the TimeInfo details was processed and delay/offset were computed
- */
- private boolean _detailsComputed;
-
- /**
- * Create TimeInfo object with raw packet message and destination time received.
- *
- * @param message NTP message packet
- * @param returnTime destination receive time
- * @throws IllegalArgumentException if message is null
- */
- public TimeInfo(NtpV3Packet message, long returnTime) {
- this(message, returnTime, null, true);
- }
-
- /**
- * Create TimeInfo object with raw packet message and destination time received.
- *
- * @param message NTP message packet
- * @param returnTime destination receive time
- * @param comments List of errors/warnings identified during processing
- * @throws IllegalArgumentException if message is null
- */
- public TimeInfo(NtpV3Packet message, long returnTime, List<String> comments)
- {
- this(message, returnTime, comments, true);
- }
-
- /**
- * Create TimeInfo object with raw packet message and destination time received.
- * Auto-computes details if computeDetails flag set otherwise this is delayed
- * until computeDetails() is called. Delayed computation is for fast
- * intialization when sub-millisecond timing is needed.
- *
- * @param msgPacket NTP message packet
- * @param returnTime destination receive time
- * @param doComputeDetails flag to pre-compute delay/offset values
- * @throws IllegalArgumentException if message is null
- */
- public TimeInfo(NtpV3Packet msgPacket, long returnTime, boolean doComputeDetails)
- {
- this(msgPacket, returnTime, null, doComputeDetails);
- }
-
- /**
- * Create TimeInfo object with raw packet message and destination time received.
- * Auto-computes details if computeDetails flag set otherwise this is delayed
- * until computeDetails() is called. Delayed computation is for fast
- * intialization when sub-millisecond timing is needed.
- *
- * @param message NTP message packet
- * @param returnTime destination receive time
- * @param comments list of comments used to store errors/warnings with message
- * @param doComputeDetails flag to pre-compute delay/offset values
- * @throws IllegalArgumentException if message is null
- */
- public TimeInfo(NtpV3Packet message, long returnTime, List<String> comments,
- boolean doComputeDetails)
- {
- if (message == null)
- throw new IllegalArgumentException("message cannot be null");
- this._returnTime = returnTime;
- this._message = message;
- this._comments = comments;
- if (doComputeDetails)
- computeDetails();
- }
-
- /**
- * Add comment (error/warning) to list of comments associated
- * with processing of NTP parameters. If comment list not create
- * then one will be created.
- *
- * @param comment
- */
- public void addComment(String comment)
- {
- if (_comments == null) {
- _comments = new ArrayList<String>();
- }
- _comments.add(comment);
- }
-
- /**
- * Compute and validate details of the NTP message packet. Computed
- * fields include the offset and delay.
- */
- public void computeDetails()
- {
- if (_detailsComputed) {
- return; // details already computed - do nothing
- }
- _detailsComputed = true;
- if (_comments == null) {
- _comments = new ArrayList<String>();
- }
-
- TimeStamp origNtpTime = _message.getOriginateTimeStamp();
- long origTime = origNtpTime.getTime();
-
- // Receive Time is time request received by server (t2)
- TimeStamp rcvNtpTime = _message.getReceiveTimeStamp();
- long rcvTime = rcvNtpTime.getTime();
-
- // Transmit time is time reply sent by server (t3)
- TimeStamp xmitNtpTime = _message.getTransmitTimeStamp();
- long xmitTime = xmitNtpTime.getTime();
-
- /*
- * Round-trip network delay and local clock offset (or time drift) is calculated
- * according to this standard NTP equation:
- *
- * LocalClockOffset = ((ReceiveTimestamp - OriginateTimestamp) +
- * (TransmitTimestamp - DestinationTimestamp)) / 2
- *
- * equations from RFC-1305 (NTPv3)
- * roundtrip delay = (t4 - t1) - (t3 - t2)
- * local clock offset = ((t2 - t1) + (t3 - t4)) / 2
- *
- * It takes into account network delays and assumes that they are symmetrical.
- *
- * Note the typo in SNTP RFCs 1769/2030 which state that the delay
- * is (T4 - T1) - (T2 - T3) with the "T2" and "T3" switched.
- */
- if (origNtpTime.ntpValue() == 0)
- {
- // without originate time cannot determine when packet went out
- // might be via a broadcast NTP packet...
- if (xmitNtpTime.ntpValue() != 0)
- {
- _offset = Long.valueOf(xmitTime - _returnTime);
- _comments.add("Error: zero orig time -- cannot compute delay");
- } else
- _comments.add("Error: zero orig time -- cannot compute delay/offset");
- } else if (rcvNtpTime.ntpValue() == 0 || xmitNtpTime.ntpValue() == 0)
- {
- _comments.add("Warning: zero rcvNtpTime or xmitNtpTime");
- // assert destTime >= origTime since network delay cannot be negative
- if (origTime > _returnTime)
- _comments.add("Error: OrigTime > DestRcvTime");
- else
- {
- // without receive or xmit time cannot figure out processing time
- // so delay is simply the network travel time
- _delay = Long.valueOf(_returnTime - origTime);
- }
- // TODO: is offset still valid if rcvNtpTime=0 || xmitNtpTime=0 ???
- // Could always hash origNtpTime (sendTime) but if host doesn't set it
- // then it's an malformed ntp host anyway and we don't care?
- // If server is in broadcast mode then we never send out a query in first place...
- if (rcvNtpTime.ntpValue() != 0)
- {
- // xmitTime is 0 just use rcv time
- _offset = Long.valueOf(rcvTime - origTime);
- } else if (xmitNtpTime.ntpValue() != 0)
- {
- // rcvTime is 0 just use xmitTime time
- _offset = Long.valueOf(xmitTime - _returnTime);
- }
- } else
- {
- long delayValue = _returnTime - origTime;
- // assert xmitTime >= rcvTime: difference typically < 1ms
- if (xmitTime < rcvTime)
- {
- // server cannot send out a packet before receiving it...
- _comments.add("Error: xmitTime < rcvTime"); // time-travel not allowed
- } else
- {
- // subtract processing time from round-trip network delay
- long delta = xmitTime - rcvTime;
- // in normal cases the processing delta is less than
- // the total roundtrip network travel time.
- if (delta <= delayValue)
- {
- delayValue -= delta; // delay = (t4 - t1) - (t3 - t2)
- } else
- {
- // if delta - delayValue == 1 ms then it's a round-off error
- // e.g. delay=3ms, processing=4ms
- if (delta - delayValue == 1)
- {
- // delayValue == 0 -> local clock saw no tick change but destination clock did
- if (delayValue != 0)
- {
- _comments.add("Info: processing time > total network time by 1 ms -> assume zero delay");
- delayValue = 0;
- }
- } else
- _comments.add("Warning: processing time > total network time");
- }
- }
- _delay = Long.valueOf(delayValue);
- if (origTime > _returnTime) // assert destTime >= origTime
- _comments.add("Error: OrigTime > DestRcvTime");
-
- _offset = Long.valueOf(((rcvTime - origTime) + (xmitTime - _returnTime)) / 2);
- }
- }
-
- /**
- * Return list of comments (if any) during processing of NTP packet.
- *
- * @return List or null if not yet computed
- */
- public List<String> getComments()
- {
- return _comments;
- }
-
- /**
- * Get round-trip network delay. If null then could not compute the delay.
- *
- * @return Long or null if delay not available.
- */
- public Long getDelay()
- {
- return _delay;
- }
-
- /**
- * Get clock offset needed to adjust local clock to match remote clock. If null then could not
- * compute the offset.
- *
- * @return Long or null if offset not available.
- */
- public Long getOffset()
- {
- return _offset;
- }
-
- /**
- * Returns NTP message packet.
- *
- * @return NTP message packet.
- */
- public NtpV3Packet getMessage()
- {
- return _message;
- }
-
- /**
- * Returns time at which time message packet was received by local machine.
- *
- * @return packet return time.
- */
- public long getReturnTime()
- {
- return _returnTime;
- }
-
-}
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