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 deta file will be saved to a USB flash drive if one is attached, or to /home/lvuser 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 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

    • 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