Module ch.qos.logback.core

Package ch.qos.logback.core.util

Class SimpleTimeBasedGuard

java.lang.Object

ch.qos.logback.core.util.SimpleTimeBasedGuard

public class SimpleTimeBasedGuard
extends Object

A simple time-based guard that limits the number of allowed operations within a sliding time window. This class is useful for rate limiting or preventing excessive actions over time periods. It supports time injection for testing purposes.

Since:

1.5.22

Author:

Ceki Gülcü

Field Summary

Fields

Modifier and Type	Field	Description
static int	DEFAULT_MAX_ALLOWS	Default maximum number of allows per window: 2.
static long	DEFAULT_WINDOW_MS	Default window duration in milliseconds: 30 minutes.

Constructor Summary

Constructors

Constructor	Description
SimpleTimeBasedGuard()	Convenience: uses defaults — 2 allows every 30 minutes
SimpleTimeBasedGuard(long windowDurationMs, int maxAllows)	Creates a guard with custom limits.

Method Summary

Modifier and Type	Method	Description
boolean	allow()	Checks if an operation is allowed based on the current time window.
void	clearCurrentTime()	Clears the artificial time, reverting to using System.currentTimeMillis().
int	getAllowsRemaining()	Returns the number of allows remaining in the current window.
int	getAllowsUsed()	Returns the number of allows used in the current window.
int	getMaxAllows()	Returns the maximum number of allows per window.
long	getMillisUntilNextWindow()	Returns the number of milliseconds until the next window starts.
long	getWindowDuration()	Returns the window duration in milliseconds.
void	setCurrentTimeMillis(long timestamp)	Sets the artificial current time for testing purposes.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_WINDOW_MS

public static final long DEFAULT_WINDOW_MS

Default window duration in milliseconds: 30 minutes.

See Also:

Constant Field Values

DEFAULT_MAX_ALLOWS

public static final int DEFAULT_MAX_ALLOWS

Default maximum number of allows per window: 2.

See Also:

Constant Field Values

Constructor Detail

SimpleTimeBasedGuard

public SimpleTimeBasedGuard(long windowDurationMs,
                            int maxAllows)

Creates a guard with custom limits.

Parameters:

windowDurationMs - how many millis per window (e.g. 30_000 for 30 minutes)

maxAllows - how many allows per window (e.g. 2)

SimpleTimeBasedGuard

public SimpleTimeBasedGuard()

Convenience: uses defaults — 2 allows every 30 minutes

Method Detail

allow

public boolean allow()

Checks if an operation is allowed based on the current time window. If allowed, increments the usage count for the current window. If the window has expired, resets the window and allows the operation.

Returns:

true if the operation is allowed, false otherwise

setCurrentTimeMillis

public void setCurrentTimeMillis(long timestamp)

Sets the artificial current time for testing purposes. When set, currentTimeMillis() will return this value instead of System.currentTimeMillis().

Parameters:

timestamp - the artificial timestamp in milliseconds

clearCurrentTime

public void clearCurrentTime()

Clears the artificial time, reverting to using System.currentTimeMillis().

getAllowsUsed

public int getAllowsUsed()

Returns the number of allows used in the current window.

Returns:

the number of allows used

getAllowsRemaining

public int getAllowsRemaining()

Returns the number of allows remaining in the current window.

Returns:

the number of allows remaining

getWindowDuration

public long getWindowDuration()

Returns the window duration in milliseconds.

Returns:

the window duration in milliseconds

getMaxAllows

public int getMaxAllows()

Returns the maximum number of allows per window.

Returns:

the maximum number of allows

getMillisUntilNextWindow

public long getMillisUntilNextWindow()

Returns the number of milliseconds until the next window starts. If no window has started yet, returns the full window duration.

Returns:

milliseconds until next window