Clock (Javadocs [I2P+ 2.13.0+] - API Version 0.9.70+)

java.lang.Object
- net.i2p.util.Clock

All Implemented Interfaces:
Timestamper.UpdateListener
Direct Known Subclasses:
RouterClock
```
public class Clock
extends Object
implements Timestamper.UpdateListener
```
Alternate location for determining the time which takes into account an offset. This offset will ideally be periodically updated so as to serve as the difference between the local computer's current time and the time as known by some reference (such as an NTP synchronized clock). Protected members are used in the subclass RouterClock, which has access to a router's transports (particularly peer clock skews) to second-guess the sanity of clock adjustments.

Nested Class Summary
Nested Classes
Modifier and Type Class and Description
static interface Clock.ClockUpdateListener
Listener for clock offset changes.

Nested Classes
Modifier and Type	Class and Description
`static interface`	`Clock.ClockUpdateListener` Listener for clock offset changes.

Field Summary

Fields
Modifier and Type	Field and Description
`protected boolean`	`_alreadyChanged` whether the offset has ever been changed
`protected I2PAppContext`	`_context` the I2P application context
`protected boolean`	`_isSystemClockBad` whether the system clock was determined to be invalid at startup
`protected long`	`_offset` the current offset from system time
`protected long`	`_startedOn` the time when this clock was started
`protected boolean`	`_statCreated` whether the clock skew stat has been created
`static long`	`MAX_LIVE_OFFSET` after we've started up and shifted the clock, don't allow shifts of more than 10 minutes
`static long`	`MAX_OFFSET` if the clock is skewed by 3+ days, forget it
`static long`	`MIN_OFFSET_CHANGE` if the clock skewed changes by less than this, ignore the update (so we don't slide all over the place)

Constructor Summary
Constructors
Constructor and Description
Clock(I2PAppContext context)
Create a new Clock with the given context, detecting system clock validity.

Constructors
Constructor and Description
`Clock(I2PAppContext context)` Create a new Clock with the given context, detecting system clock validity.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addUpdateListener(Clock.ClockUpdateListener lsnr)` Register a listener for clock offset changes.
`protected void`	`fireOffsetChanged(long delta)` Notify registered listeners of a clock offset change.
`static Clock`	`getInstance()` Get the global clock instance.
`protected Log`	`getLog()` Fetch the log on demand to avoid circular dependencies (logging uses the clock).
`long`	`getOffset()` Get the current offset from system time.
`Timestamper`	`getTimestamper()` This is a dummy, see RouterClock and RouterTimestamper for the real thing
`boolean`	`getUpdatedSuccessfully()` Check whether the offset has been updated at least once.
`long`	`now()` Retrieve the current time synchronized with whatever reference clock is in use.
`void`	`removeUpdateListener(Clock.ClockUpdateListener lsnr)` Unregister a listener for clock offset changes.
`void`	`setNow(long realTime)` Set the clock to the given real time, computing the offset.
`void`	`setNow(long realTime, int stratum)` Warning - overridden in RouterClock
`void`	`setOffset(long offsetMs)` Specify how far away from the "correct" time the computer is - a positive value means that the system time is slow, while a negative value means the system time is fast.
`void`	`setOffset(long offsetMs, boolean force)` Specify how far away from the "correct" time the computer is - a positive value means that the system time is slow, while a negative value means the system time is fast.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - _alreadyChanged
```
protected boolean _alreadyChanged
```
    whether the offset has ever been changed
  - _context
```
protected final I2PAppContext _context
```
    the I2P application context
  - _isSystemClockBad
```
protected final boolean _isSystemClockBad
```
    whether the system clock was determined to be invalid at startup
  - _offset
```
protected volatile long _offset
```
    the current offset from system time
  - _startedOn
```
protected long _startedOn
```
    the time when this clock was started
  - _statCreated
```
protected boolean _statCreated
```
    whether the clock skew stat has been created
  - MAX_LIVE_OFFSET
```
public static final long MAX_LIVE_OFFSET
```
    after we've started up and shifted the clock, don't allow shifts of more than 10 minutes
    See Also:
    Constant Field Values
  - MAX_OFFSET
```
public static final long MAX_OFFSET
```
    if the clock is skewed by 3+ days, forget it
    See Also:
    Constant Field Values
  - MIN_OFFSET_CHANGE
```
public static final long MIN_OFFSET_CHANGE
```
    if the clock skewed changes by less than this, ignore the update (so we don't slide all over the place)
    See Also:
    Constant Field Values
- Constructor Detail
  - Clock
```
public Clock(I2PAppContext context)
```
    Create a new Clock with the given context, detecting system clock validity.
    Parameters:
    context - the I2P app context
- Method Detail
  - addUpdateListener
```
public void addUpdateListener(Clock.ClockUpdateListener lsnr)
```
    Register a listener for clock offset changes.
    Parameters:
    lsnr - the listener to add
  - fireOffsetChanged
```
protected void fireOffsetChanged(long delta)
```
    Notify registered listeners of a clock offset change.
    Parameters:
    delta - the offset change in milliseconds
  - getInstance
```
public static Clock getInstance()
```
    Get the global clock instance.
    Returns:
    the global clock instance
  - getLog
```
protected Log getLog()
```
    Fetch the log on demand to avoid circular dependencies (logging uses the clock).
    Returns:
    the log
  - getOffset
```
public long getOffset()
```
    Get the current offset from system time.
    Returns:
    the current delta from System.currentTimeMillis() in milliseconds
  - getTimestamper
```
public Timestamper getTimestamper()
```
    This is a dummy, see RouterClock and RouterTimestamper for the real thing
    Returns:
    the timestamper
  - getUpdatedSuccessfully
```
public boolean getUpdatedSuccessfully()
```
    Check whether the offset has been updated at least once.
    Returns:
    whether the offset has been updated at least once
  - now
```
public long now()
```
    Retrieve the current time synchronized with whatever reference clock is in use.
    Returns:
    the current synchronized time in milliseconds
  - removeUpdateListener
```
public void removeUpdateListener(Clock.ClockUpdateListener lsnr)
```
    Unregister a listener for clock offset changes.
    Parameters:
    lsnr - the listener to remove
  - setNow
```
public void setNow(long realTime)
```
    Set the clock to the given real time, computing the offset.
    Parameters:
    realTime - the real time in milliseconds
  - setNow
```
public void setNow(long realTime,
                   int stratum)
```
    Warning - overridden in RouterClock
    Specified by:
    setNow in interface Timestamper.UpdateListener
    Parameters:
    stratum - ignored
    realTime - the current time
  - setOffset
```
public void setOffset(long offsetMs)
```
    Specify how far away from the "correct" time the computer is - a positive value means that the system time is slow, while a negative value means the system time is fast.
    Parameters:
    offsetMs - the delta from System.currentTimeMillis() (NOT the delta from now())
  - setOffset
```
public void setOffset(long offsetMs,
                      boolean force)
```
    Specify how far away from the "correct" time the computer is - a positive value means that the system time is slow, while a negative value means the system time is fast. Warning - overridden in RouterClock
    Parameters:
    offsetMs - the delta from System.currentTimeMillis() (NOT the delta from now())
    force - if true, bypass all sanity checks

Class Clock

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

_alreadyChanged

_context

_isSystemClockBad

_offset

_startedOn

_statCreated

MAX_LIVE_OFFSET

MAX_OFFSET

MIN_OFFSET_CHANGE

Constructor Detail

Clock

Method Detail

addUpdateListener

fireOffsetChanged

getInstance

getLog

getOffset

getTimestamper

getUpdatedSuccessfully

now

removeUpdateListener

setNow

setNow

setOffset

setOffset