Package org.apache.jackrabbit.oak.segment.file.tar

Class TarConstants

java.lang.Object

org.apache.jackrabbit.oak.segment.file.tar.TarConstants

public class TarConstants
extends Object

Field Summary

Fields

Modifier and Type	Field	Description
static final int	BLOCK_SIZE	The tar file block size.
static final int	GRAPH_MAGIC	Magic byte sequence at the end of the graph block.

Method Summary

Methods inherited from class java.lang.Object

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

Field Details

GRAPH_MAGIC

public static final int GRAPH_MAGIC

Magic byte sequence at the end of the graph block.

The file is read from the end (the tar file is read from the end: the last entry is the index, then the graph). File format:

• 0 padding to make the footer end at a 512 byte boundary
• The list of UUIDs (segments included the graph; this includes segments in this tar file, and referenced segments in tar files with a lower sequence number). 16 bytes each.
• The graph data. The index of the source segment UUID (in the above list, 4 bytes), then the list of referenced segments (the indexes of those; 4 bytes each). Then the list is terminated by -1.
• The last part is the footer, which contains metadata of the graph (size, checksum, the number of UUIDs).

See Also:

• Constant Field Values

BLOCK_SIZE

public static final int BLOCK_SIZE

The tar file block size.

See Also:

• Constant Field Values