org.apache.hadoop.hdfs.server.namenode

Class FSDirectory

java.lang.Object

org.apache.hadoop.hdfs.server.namenode.FSDirectory

All Implemented Interfaces:

Closeable, AutoCloseable

public class FSDirectory
extends Object
implements Closeable

FSDirectory stores the filesystem directory state. It handles writing/loading values to disk, and logging changes as we go. It keeps the filename->blockset mapping always-current and logged to disk.

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Shutdown the filestore
void	concat(String target, String[] srcs) Concat all the blocks from srcs to trg and delete the srcs files
int	getReadHoldCount()
int	getWriteHoldCount()
void	replaceNode(String path, INodeFile oldnode, INodeFile newnode) Replaces the specified inode with the specified one.
protected void	setReady(boolean flag)
void	unprotectedConcat(String target, String[] srcs, long timestamp) Concat all the blocks from srcs to trg and delete the srcs files
protected <T extends INode> void	verifyFsLimits(INode[] pathComponents, int pos, T child) Verify that filesystem limit constraints are not violated

Methods inherited from class java.lang.Object

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

Method Detail

getReadHoldCount

public int getReadHoldCount()

getWriteHoldCount

public int getWriteHoldCount()

setReady

protected void setReady(boolean flag)

close

public void close()
           throws IOException

Shutdown the filestore

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException

concat

public void concat(String target,
          String[] srcs)
            throws org.apache.hadoop.fs.UnresolvedLinkException

Concat all the blocks from srcs to trg and delete the srcs files

Throws:

org.apache.hadoop.fs.UnresolvedLinkException

unprotectedConcat

public void unprotectedConcat(String target,
                     String[] srcs,
                     long timestamp)
                       throws org.apache.hadoop.fs.UnresolvedLinkException

Concat all the blocks from srcs to trg and delete the srcs files

Parameters:

target - target file to move the blocks to

srcs - list of file to move the blocks from Must be public because also called from EditLogs NOTE: - it does not update quota (not needed for concat)

Throws:

org.apache.hadoop.fs.UnresolvedLinkException

replaceNode

public void replaceNode(String path,
               INodeFile oldnode,
               INodeFile newnode)
                 throws IOException,
                        org.apache.hadoop.fs.UnresolvedLinkException

Replaces the specified inode with the specified one.

Throws:

IOException

org.apache.hadoop.fs.UnresolvedLinkException

verifyFsLimits

protected <T extends INode> void verifyFsLimits(INode[] pathComponents,
                                    int pos,
                                    T child)
                       throws org.apache.hadoop.hdfs.protocol.FSLimitException

Verify that filesystem limit constraints are not violated

Throws:

FSLimitException.PathComponentTooLongException - child's name is too long

FSLimitException.MaxDirectoryItemsExceededException - items per directory is exceeded

org.apache.hadoop.hdfs.protocol.FSLimitException