Package edu.wpi.first.wpilibj

Class DataLogManager

java.lang.Object

edu.wpi.first.wpilibj.DataLogManager

public final class DataLogManager
extends Object

Centralized data log that provides automatic data log file management. It automatically cleans up old files when disk space is low and renames the file based either on current date/time or (if available) competition match number. The data file will be saved to a USB flash drive in a folder named "logs" if one is attached, or to /home/lvuser/logs otherwise.

Log files are initially named "FRC_TBD_{random}.wpilog" until the DS connects. After the DS connects, the log file is renamed to "FRC_yyyyMMdd_HHmmss.wpilog" (where the date/time is UTC). If the FMS is connected and provides a match number, the log file is renamed to "FRC_yyyyMMdd_HHmmss_{event}_{match}.wpilog".

On startup, all existing FRC_TBD log files are deleted. If there is less than 50 MB of free space on the target storage, FRC_ log files are deleted (oldest to newest) until there is 50 MB free OR there are 10 files remaining.

By default, all NetworkTables value changes are stored to the data log.

Method Summary

Modifier and Type	Method	Description
static DataLog	getLog()	Get the managed data log (for custom logging).
static String	getLogDir()	Get the log directory.
static void	log(String message)	Log a message to the "messages" entry.
static void	logNetworkTables(boolean enabled)	Enable or disable logging of NetworkTables data.
static void	start()	Start data log manager with default directory location.
static void	start(String dir)	Start data log manager.
static void	start(String dir, String filename)	Start data log manager.
static void	start(String dir, String filename, double period)	Start data log manager.
static void	stop()	Stop data log manager.

Methods inherited from class java.lang.Object

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

Method Details

start

public static void start()

Start data log manager with default directory location.

start

public static void start(String dir)

Start data log manager. The parameters have no effect if the data log manager was already started (e.g. by calling another static function).

Parameters:

dir - if not empty, directory to use for data log storage

start

public static void start(String dir, String filename)

Start data log manager. The parameters have no effect if the data log manager was already started (e.g. by calling another static function).

Parameters:

dir - if not empty, directory to use for data log storage

filename - filename to use; if none provided, the filename is automatically generated

start

public static void start(String dir, String filename, double period)

Start data log manager. The parameters have no effect if the data log manager was already started (e.g. by calling another static function).

Parameters:

dir - if not empty, directory to use for data log storage

filename - filename to use; if none provided, the filename is automatically generated

period - time between automatic flushes to disk, in seconds; this is a time/storage tradeoff

stop

public static void stop()

Stop data log manager.

log

public static void log(String message)

Log a message to the "messages" entry. The message is also printed to standard output (followed by a newline).

Parameters:

message - message

getLog

public static DataLog getLog()

Get the managed data log (for custom logging). Starts the data log manager if not already started.

Returns:

data log

getLogDir

public static String getLogDir()

Get the log directory.

Returns:

log directory, or empty string if logging not yet started

logNetworkTables

public static void logNetworkTables(boolean enabled)

Enable or disable logging of NetworkTables data. Note that unlike the network interface for NetworkTables, this will capture every value change. Defaults to enabled.

Parameters:

enabled - true to enable, false to disable