org.apache.hadoop.hdfs.tools.offlineEditsViewer

Interface OfflineEditsVisitor

All Known Implementing Classes:

BinaryEditsVisitor, StatisticsEditsVisitor, XmlEditsVisitor

@InterfaceAudience.Private
@InterfaceStability.Unstable
public interface OfflineEditsVisitor

An implementation of OfflineEditsVisitor can traverse the structure of an Hadoop edits log and respond to each of the structures within the file.

Method Summary

Methods

Modifier and Type	Method and Description
void	close(Throwable error) Finish visiting the edits log structure.
void	start(int version) Begin visiting the edits log structure.
void	visitOp(FSEditLogOp op) Begin visiting an element that encloses another element, such as the beginning of the list of blocks that comprise a file.

Method Detail

start

void start(int version)
           throws IOException

Begin visiting the edits log structure. Opportunity to perform any initialization necessary for the implementing visitor.

Parameters:

version - Edit log version

Throws:

IOException

close

void close(Throwable error)
           throws IOException

Finish visiting the edits log structure. Opportunity to perform any clean up necessary for the implementing visitor.

Parameters:

error - If the visitor was closed because of an unrecoverable error in the input stream, this is the exception.

Throws:

IOException

visitOp

void visitOp(FSEditLogOp op)
             throws IOException

Begin visiting an element that encloses another element, such as the beginning of the list of blocks that comprise a file.

Parameters:

value - Token being visited

Throws:

IOException