org.lsst.ccs.utilities.taitime

Class CCSTimeStamp

java.lang.Object

org.lsst.ccs.utilities.taitime.CCSTimeStamp

All Implemented Interfaces:

Serializable, Comparable<CCSTimeStamp>

public class CCSTimeStamp
extends Object
implements Serializable, Comparable<CCSTimeStamp>

This class represents a CCS timestamp, which encapsulates both a TAI and UTC timestamp. If we are running in strict mode, both the TAI and UTC time are obtained by appropriate kernel routine calls, and if the kernel interface library cannot be loaded, or if the the kernel is not correctly configured, then the class will throw an exception. In non-strict mode, if the kernel libraries cannot be loaded the class will fall back to using the built-in Java time, plus a list of leap seconds read from an external URL.

The following system properties control how the class works:

Property	Default	Description
org.lsst.ccs.utilities.taitime.useStrict	false	Controls whether strict mode is set or not
org.lsst.ccs.utilities.taitime.libName	timeaccess	The name of the JNI library to load
org.lsst.ccs.utilities.taitime.minLeapSeconds	30	The minimum number of leap seconds for the kernel to be considered configured correctly

Author:

Farrukh Azfar

See Also:

leaps-seconds.list, Serialized Form

Method Summary

Modifier and Type	Method and Description
int	compareTo(CCSTimeStamp o)
static CCSTimeStamp	currentTime() Attempts to get the current timestamp.
static CCSTimeStamp	currentTimeFromMillis(long milliseconds) Deprecated.
boolean	equals(Object obj)
static CCSTimeStamp	fromTAI(Instant taiTime, int dtai) Create an instance of CCSTimeStamp based on the current TAI time, and the delta between TAI and UTC in effect at the time.
double	getTAIDouble()
Instant	getTAIInstant()
double	getUTCDouble()
Instant	getUTCInstant()
int	hashCode()
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

currentTime

public static CCSTimeStamp currentTime()

Attempts to get the current timestamp. If we are in strict mode, and the kernel library cannot be loaded, or the leap seconds offset does not seem reasonable, an exception will be thrown.

Returns:

A CCSTimeStamp for the current time

Throws:

RuntimeException - If the TAI time offset is not available.

fromTAI

public static CCSTimeStamp fromTAI(Instant taiTime,
                                   int dtai)

Create an instance of CCSTimeStamp based on the current TAI time, and the delta between TAI and UTC in effect at the time.

Parameters:

taiTime - The TAI time, as an Instant

dtai - The difference between TAI and UTC in seconds, at the tai instant given. See the definition of dtai in leap-seconds.list.

Returns:

The corresponding CCSTimeStamp

currentTimeFromMillis

@Deprecated
public static CCSTimeStamp currentTimeFromMillis(long milliseconds)

Deprecated.

Attempts to create a CCSTimeStamp from a utc milliseconds value. This is a temporary method to allow migrating from old java time based milliseconds values to CCSTimeStamp.

Parameters:

milliseconds - A standard Java milliseconds values (as returned by System.currentTimeMills())

Returns:

A CCSTimeStamp corresponding to the given timestamp.

getTAIInstant

public Instant getTAIInstant()

getUTCInstant

public Instant getUTCInstant()

getTAIDouble

public double getTAIDouble()

getUTCDouble

public double getUTCDouble()

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

compareTo

public int compareTo(CCSTimeStamp o)

Specified by:

compareTo in interface Comparable<CCSTimeStamp>