Enclosing class:

Log

public static class Log.Reader
extends java.lang.Object

• Constructor Summary

  Constructors

  Constructor and Description
  Reader (Log log) Returns an instance of a reader that will access the given instance of the Log.

• Method Summary

  All Methods

  Modifier and Type	Method and Description
  Log.Position	beginning () Returns the beginning position of the log (might be out of date with respect to another replica).
  Log.Position	catchup (long timeout, java.util.concurrent.TimeUnit unit) Attempts to catch-up positions from the log for reading.
  Log.Position	ending () Returns the ending position of the log (might be out of date with respect to another replica).
  protected void	finalize ()
  protected void	initialize (Log log)
  java.util.List<Log.Entry>	read (Log.Position from, Log.Position to, long timeout, java.util.concurrent.TimeUnit unit) Attempts to read from the log between the specified positions (inclusive).

  • Methods inherited from class java.lang.Object

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

• Constructor Detail

  • Reader

    public Reader(Log log)

    Returns an instance of a reader that will access the given instance of the Log.

    Parameters:

    log - The log that this reader will access.

• Method Detail

  • read

    public java.util.List<Log.Entry> read(Log.Position from,
     Log.Position to,
     long timeout,
     java.util.concurrent.TimeUnit unit)
     throws java.util.concurrent.TimeoutException,
     Log.OperationFailedException 

    Attempts to read from the log between the specified positions (inclusive). If either of the positions are invalid, an Log.OperationFailedException will get thrown. Unfortunately, this will also get thrown in other circumstances (e.g., disk failure) and therefore it is currently impossible to tell these two cases apart.

    Parameters:

    from - Where to start reading.

    to - Where to finish reading.

    timeout - Max number of time units to wait before a TimeoutException.

    unit - Type of units used for the timeout, e.g. seconds, minutes, etc.

    Returns:

    The list of entries fetched from the Log.

    Throws:

    java.util.concurrent.TimeoutException - If the read doesn't happen before the timeout.

    Log.OperationFailedException - If the read fails due that the read no longer has the ability to perform its operations.

    See Also:

    Log.Position, TimeUnit

  • beginning

    public Log.Position beginning()

    Returns the beginning position of the log (might be out of date with respect to another replica).

    Returns:

    The beginning position of the log.

  • ending

    public Log.Position ending()

    Returns the ending position of the log (might be out of date with respect to another replica).

    Returns:

    The ending position of the log

  • catchup

    public Log.Position catchup(long timeout,
     java.util.concurrent.TimeUnit unit)
     throws java.util.concurrent.TimeoutException,
     Log.OperationFailedException 

    Attempts to catch-up positions from the log for reading.

    Parameters:

    timeout - Max number of time units to wait before a TimeoutException.

    unit - Type of time units used for the timeout, e.g. seconds, minutes, etc.

    Returns:

    The ending position of the caught-up range.

    Throws:

    java.util.concurrent.TimeoutException - If the catch-up doesn't happen before the timeout.

    Log.OperationFailedException - If the catch-up fails.

  • initialize

    protected void initialize(Log log)

  • finalize

    protected void finalize()

    Overrides:

    finalize in class java.lang.Object