ariba.util.log
Class AsyncAppender

java.lang.Object
  org.apache.log4j.AppenderSkeleton
      ariba.util.log.AsyncAppender

All Implemented Interfaces:

org.apache.log4j.Appender, org.apache.log4j.spi.OptionHandler

public class AsyncAppender
extends org.apache.log4j.AppenderSkeleton

Basically cloned from log4j's AsyncAppender in log4j 1.2.8. Unfortunately that class was not designed to be overridden from outside its package, so it had to be duplicated. Key differences to provide robustness and error accounting: 1) The Dispatcher call to appendLoopOnAppenders(event) is now in a try/catch block so if an exception occurs in the filtering or appending (processing) of the event it doesn't kill the dispatcher. 2) When the exceptions mentioned in (1) occur, they are captured by AsyncAppender and available externally (see the xxxMessage(s) methods, below).

See Also:

AsyncAppender

Field Summary

static int

DEFAULT_BUFFER_SIZE The default buffer size is set to 128 events.

Constructor Summary

AsyncAppender(boolean isConsoleWriteSuspended)

Method Summary

void	addAppender(org.apache.log4j.Appender newAppender)
void	append(org.apache.log4j.spi.LoggingEvent event)
void	close() Close this AsyncAppender by interrupting the dispatcher thread which will process all pending events before exiting.
java.util.Enumeration	getAllAppenders()
org.apache.log4j.Appender	getAppender(java.lang.String name)
int	getBufferSize() Returns the current value of the BufferSize option.
boolean	getLocationInfo() Returns the current value of the LocationInfo option.
boolean	isAttached(org.apache.log4j.Appender appender) Is the appender passed as parameter attached to this category?
void	removeAllAppenders()
void	removeAppender(org.apache.log4j.Appender appender)
void	removeAppender(java.lang.String name)
boolean	requiresLayout() The AsyncAppender does not require a layout.
void	setBufferSize(int size) The BufferSize option takes a non-negative integer value.
void	setLocationInfo(boolean flag) The LocationInfo option takes a boolean value.

Methods inherited from class org.apache.log4j.AppenderSkeleton

activateOptions, addFilter, clearFilters, doAppend, finalize, getErrorHandler, getFilter, getFirstFilter, getLayout, getName, getThreshold, isAsSevereAsThreshold, setErrorHandler, setLayout, setName, setThreshold

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_BUFFER_SIZE

public static final int DEFAULT_BUFFER_SIZE

The default buffer size is set to 128 events.

See Also:

Constant Field Values

Constructor Detail

AsyncAppender

public AsyncAppender(boolean isConsoleWriteSuspended)

Method Detail

addAppender

public void addAppender(org.apache.log4j.Appender newAppender)

append

public void append(org.apache.log4j.spi.LoggingEvent event)

Specified by:

append in class org.apache.log4j.AppenderSkeleton

close

public void close()

Close this AsyncAppender by interrupting the dispatcher thread which will process all pending events before exiting.

getAllAppenders

public java.util.Enumeration getAllAppenders()

getAppender

public org.apache.log4j.Appender getAppender(java.lang.String name)

getLocationInfo

public boolean getLocationInfo()

Returns the current value of the LocationInfo option.

isAttached

public boolean isAttached(org.apache.log4j.Appender appender)

Is the appender passed as parameter attached to this category?

requiresLayout

public boolean requiresLayout()

The AsyncAppender does not require a layout. Hence, this method always returns false.

removeAllAppenders

public void removeAllAppenders()

removeAppender

public void removeAppender(org.apache.log4j.Appender appender)

removeAppender

public void removeAppender(java.lang.String name)

setLocationInfo

public void setLocationInfo(boolean flag)

The LocationInfo option takes a boolean value. By default, it is set to false which means there will be no effort to extract the location information related to the event. As a result, the event that will be ultimately logged will likely to contain the wrong location information (if present in the log format).

Location information extraction is comparatively very slow and should be avoided unless performance is not a concern.

setBufferSize

public void setBufferSize(int size)

The BufferSize option takes a non-negative integer value. This integer value determines the maximum size of the bounded buffer. Increasing the size of the buffer is always safe. However, if an existing buffer holds unwritten elements, then decreasing the buffer size will result in event loss. Nevertheless, while script configuring the AsyncAppender, it is safe to set a buffer size smaller than the default buffer size because configurators guarantee that an appender cannot be used before being completely configured.

getBufferSize

public int getBufferSize()

Returns the current value of the BufferSize option.