org.apache.arrow.memory.util

Class HistoricalLog

java.lang.Object

org.apache.arrow.memory.util.HistoricalLog

public class HistoricalLog
extends Object

Utility class that can be used to log activity within a class for later logging and debugging. Supports recording events and recording the stack at the time they occur.

Constructor Summary

Constructors

Constructor and Description
HistoricalLog(int limit, String idStringFormat, Object... args) Constructor.
HistoricalLog(String idStringFormat, Object... args) Constructor.

Method Summary

Modifier and Type	Method and Description
void	buildHistory(StringBuilder sb, boolean includeStackTrace) Write the history of this object to the given StringBuilder.
void	buildHistory(StringBuilder sb, int indent, boolean includeStackTrace) Build the history and write it to sb.
void	logHistory(org.slf4j.Logger logger) Write the history of this object to the given Logger.
void	recordEvent(String noteFormat, Object... args) Record an event.

Methods inherited from class java.lang.Object

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

Constructor Detail

HistoricalLog

public HistoricalLog(String idStringFormat,
                     Object... args)

Constructor. The format string will be formatted and have its arguments substituted at the time this is called.

Parameters:

idStringFormat - String.format(java.lang.String, java.lang.Object...) format string that can be used to identify this object in a log. Including some kind of unique identifier that can be associated with the object instance is best.

args - for the format string, or nothing if none are required

HistoricalLog

public HistoricalLog(int limit,
                     String idStringFormat,
                     Object... args)

Constructor. The format string will be formatted and have its arguments substituted at the time this is called.

This form supports the specification of a limit that will limit the number of historical entries kept (which keeps down the amount of memory used). With the limit, the first entry made is always kept (under the assumption that this is the creation site of the object, which is usually interesting), and then up to the limit number of entries are kept after that. Each time a new entry is made, the oldest that is not the first is dropped.

Parameters:

limit - the maximum number of historical entries that will be kept, not including the first entry made

idStringFormat - String.format(java.lang.String, java.lang.Object...) format string that can be used to identify this object in a log. Including some kind of unique identifier that can be associated with the object instance is best.

args - for the format string, or nothing if none are required

Method Detail

recordEvent

public void recordEvent(String noteFormat,
                        Object... args)

Record an event. Automatically captures the stack trace at the time this is called. The format string will be formatted and have its arguments substituted at the time this is called.

Parameters:

noteFormat - String.format(java.lang.String, java.lang.Object...) format string that describes the event

args - for the format string, or nothing if none are required

buildHistory

public void buildHistory(StringBuilder sb,
                         boolean includeStackTrace)

Write the history of this object to the given StringBuilder. The history includes the identifying string provided at construction time, and all the recorded events with their stack traces.

Parameters:

sb - StringBuilder to write to

includeStackTrace - whether to include the stacktrace of each event in the history

buildHistory

public void buildHistory(StringBuilder sb,
                         int indent,
                         boolean includeStackTrace)

Build the history and write it to sb.

Parameters:

sb - output

indent - starting indent (usually "")

includeStackTrace - whether to include the stacktrace of each event.

logHistory

public void logHistory(org.slf4j.Logger logger)

Write the history of this object to the given Logger. The history includes the identifying string provided at construction time, and all the recorded events with their stack traces.

Parameters:

logger - Logger to write to