Class DurableLogDiagnosticHarness

java.lang.Object

org.j7m.middleware.durablelog.internal.DurableLogDiagnosticHarness

public final class DurableLogDiagnosticHarness
extends Object

Internal deterministic crash and corruption diagnostic harness.

This type is intentionally placed in a non-exported package. It supports Phase 6.2 tests and the local crash-recovery demo, but it is not part of the durable-log public API.

Constructor Summary

Constructors

Constructor	Description
DurableLogDiagnosticHarness()	Creates a diagnostic harness.

Method Summary

Modifier and Type	Method	Description
void	corruptByte(Path directory, long offset)	Flips one byte in the active segment payload or header area.
Path	lastSegment(Path directory)	Returns latest segment path.
void	truncateTail(Path directory, int bytes)	Truncates bytes from the active segment tail.

Methods inherited from class Object

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

Constructor Details

DurableLogDiagnosticHarness

public DurableLogDiagnosticHarness()

Creates a diagnostic harness.

Method Details

truncateTail

public void truncateTail(Path directory,
 int bytes)
                  throws IOException

Truncates bytes from the active segment tail.

Parameters:

directory - log directory

bytes - number of bytes to remove

Throws:

IOException - when segment access fails

corruptByte

public void corruptByte(Path directory,
 long offset)
                 throws IOException

Flips one byte in the active segment payload or header area.

Parameters:

directory - log directory

offset - byte offset to modify

Throws:

IOException - when segment access fails

lastSegment

public Path lastSegment(Path directory)
                 throws IOException

Returns latest segment path.

Parameters:

directory - log directory

Returns:

latest segment path

Throws:

IOException - when no segment can be found or listed