org.apache.hadoop.hdfs.server.namenode
Class FSEditLogOp.Reader

java.lang.Object
  org.apache.hadoop.hdfs.server.namenode.FSEditLogOp.Reader

Enclosing class:

org.apache.hadoop.hdfs.server.namenode.FSEditLogOp

public static class FSEditLogOp.Reader
extends Object

Class for reading editlog ops from a stream

Constructor Summary

FSEditLogOp.Reader(DataInputStream in, org.apache.hadoop.hdfs.server.namenode.StreamLimiter limiter, int logVersion)
Construct the reader

Method Summary

org.apache.hadoop.hdfs.server.namenode.FSEditLogOp	readOp(boolean skipBrokenEdits) Read an operation from the input stream.
long	scanOp() Similar with decodeOp(), but instead of doing the real decoding, we skip the content of the op if the length of the editlog is supported.
void	setMaxOpSize(int maxOpSize)

Methods inherited from class java.lang.Object

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

Constructor Detail

FSEditLogOp.Reader

public FSEditLogOp.Reader(DataInputStream in,
                          org.apache.hadoop.hdfs.server.namenode.StreamLimiter limiter,
                          int logVersion)

Construct the reader

Parameters:

in - The stream to read from.

logVersion - The version of the data coming from the stream.

Method Detail

setMaxOpSize

public void setMaxOpSize(int maxOpSize)

readOp

public org.apache.hadoop.hdfs.server.namenode.FSEditLogOp readOp(boolean skipBrokenEdits)
                                                          throws IOException

Read an operation from the input stream. Note that the objects returned from this method may be re-used by future calls to the same method.

Parameters:

skipBrokenEdits - If true, attempt to skip over damaged parts of the input stream, rather than throwing an IOException

Returns:

the operation read from the stream, or null at the end of the file

Throws:

IOException - on error. This function should only throw an exception when skipBrokenEdits is false.

scanOp

public long scanOp()
            throws IOException

Similar with decodeOp(), but instead of doing the real decoding, we skip the content of the op if the length of the editlog is supported.

Returns:

the last txid of the segment, or INVALID_TXID on exception

Throws:

IOException