Package lcm.logging

Class Log

java.lang.Object

lcm.logging.Log

public class Log
extends Object

A class for reading and writing LCM log files.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Log.Event	Represents a single received LCM message.

Constructor Summary

Constructors

Constructor	Description
Log(String path, String mode)	Opens a log file for reading or writing.

Method Summary

Modifier and Type	Method	Description
void	close()	Closes the log file and releases and system resources used by it.
void	flush()	Flush any unwritten data to the underlying file descriptor.
String	getPath()	Retrieves the path to the log file.
double	getPositionFraction()
Log.Event	readNext()	Reads the next event in the log file
void	seekPositionFraction(double frac)	Seek to a position in the log file, specified by a fraction.
void	write(long utime, String channel, LCMEncodable msg)	A convenience method for write.
void	write(Log.Event e)	Writes an event to the log file.

Methods inherited from class java.lang.Object

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

Constructor Details

Log

public Log(String path,
 String mode)
    throws IOException

Opens a log file for reading or writing.

Parameters:

path - the filename to open

mode - Specifies the access mode, must be one of "r", "rw", "rws", or "rwd". See RandomAccessFile for more detail.

Throws:

IOException

Method Details

getPath

public String getPath()

Retrieves the path to the log file.

Returns:

the path to the log file

flush

public void flush()
           throws IOException

Flush any unwritten data to the underlying file descriptor.

Throws:

IOException

readNext

public Log.Event readNext()
                   throws IOException

Reads the next event in the log file

Throws:

EOFException - if the end of the file has been reached.

IOException

getPositionFraction

public double getPositionFraction()
                           throws IOException

Throws:

IOException

seekPositionFraction

public void seekPositionFraction(double frac)
                          throws IOException

Seek to a position in the log file, specified by a fraction.

Parameters:

frac - a number in the range [0, 1)

Throws:

IOException

write

public void write(Log.Event e)
           throws IOException

Writes an event to the log file. The user is responsible for filling in the eventNumber field, which should be sequentially increasing integers starting with 0.

Throws:

IOException

write

public void write(long utime,
 String channel,
 LCMEncodable msg)
           throws IOException

A convenience method for write. It internally manages the eventNumber field, and so calls to this method should not be mixed with calls to the other write methods.

Throws:

IOException

close

public void close()
           throws IOException

Closes the log file and releases and system resources used by it.

Throws:

IOException