Package org.apache.log4j.helpers
Class CyclicBuffer
java.lang.Object
org.apache.log4j.helpers.CyclicBuffer
CyclicBuffer is used by other appenders to hold
LoggingEvents
for immediate or differed display.
This buffer gives read access to any element in the buffer not just the first or last element.
- Since:
- 0.9.0
- Author:
- Ceki Gülcü
-
Constructor Summary
ConstructorsConstructorDescriptionCyclicBuffer
(int maxSize) Instantiate a new CyclicBuffer of at mostmaxSize
events. -
Method Summary
Modifier and TypeMethodDescriptionvoid
add
(LoggingEvent event) Add anevent
as the last event in the buffer.get()
Get the oldest (first) element in the buffer.get
(int i) Get the ith oldest event currently in the buffer.int
int
length()
Get the number of elements in the buffer.void
resize
(int newSize) Resize the cyclic buffer tonewSize
.
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Constructor Details
-
CyclicBuffer
Instantiate a new CyclicBuffer of at mostmaxSize
events. ThemaxSize
argument must a positive integer.- Parameters:
maxSize
- The maximum number of elements in the buffer.- Throws:
IllegalArgumentException
-
-
Method Details
-
add
Add anevent
as the last event in the buffer. -
get
Get the ith oldest event currently in the buffer. If i is outside the range 0 to the number of elements currently in the buffer, thennull
is returned. -
getMaxSize
public int getMaxSize() -
get
Get the oldest (first) element in the buffer. The oldest element is removed from the buffer. -
length
public int length()Get the number of elements in the buffer. This number is guaranteed to be in the range 0 tomaxSize
(inclusive). -
resize
public void resize(int newSize) Resize the cyclic buffer tonewSize
.- Throws:
IllegalArgumentException
- ifnewSize
is negative.
-