org.apache.zookeeper.server.persistence

Class FileTxnLog.FileTxnIterator

java.lang.Object

org.apache.zookeeper.server.persistence.FileTxnLog.FileTxnIterator

All Implemented Interfaces:

Closeable, AutoCloseable, TxnLog.TxnIterator

Enclosing class:

FileTxnLog

public static class FileTxnLog.FileTxnIterator
extends Object
implements TxnLog.TxnIterator

this class implements the txnlog iterator interface which is used for reading the transaction logs

Constructor Summary

Constructors

Constructor and Description
FileTxnIterator(File logDir, long zxid) create an iterator over a transaction database directory
FileTxnIterator(File logDir, long zxid, boolean fastForward) create an iterator over a transaction database directory

Method Summary

Modifier and Type	Method and Description
void	close() close the iterator and release the resources.
protected InputArchive	createInputArchive(File logFile) Invoked to indicate that the input stream has been created.
TxnDigest	getDigest()
TxnHeader	getHeader() return the current header
long	getStorageSize() Return total storage size of txnlog that will return by this iterator.
Record	getTxn() return the current transaction
protected void	inStreamCreated(InputArchive ia, InputStream is) read the header from the inputarchive
protected Checksum	makeChecksumAlgorithm() create a checksum algorithm
boolean	next() the iterator that moves to the next transaction

Methods inherited from class java.lang.Object

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

Constructor Detail

FileTxnIterator

public FileTxnIterator(File logDir,
                       long zxid,
                       boolean fastForward)
                throws IOException

create an iterator over a transaction database directory

Parameters:

logDir - the transaction database directory

zxid - the zxid to start reading from

fastForward - true if the iterator should be fast forwarded to point to the txn of a given zxid, else the iterator will point to the starting txn of a txnlog that may contain txn of a given zxid

Throws:

IOException

FileTxnIterator

public FileTxnIterator(File logDir,
                       long zxid)
                throws IOException

create an iterator over a transaction database directory

Parameters:

logDir - the transaction database directory

zxid - the zxid to start reading from

Throws:

IOException

Method Detail

getStorageSize

public long getStorageSize()

Return total storage size of txnlog that will return by this iterator.

Specified by:

getStorageSize in interface TxnLog.TxnIterator

inStreamCreated

protected void inStreamCreated(InputArchive ia,
                               InputStream is)
                        throws IOException

read the header from the inputarchive

Parameters:

ia - the inputarchive to be read from

is - the inputstream

Throws:

IOException

createInputArchive

protected InputArchive createInputArchive(File logFile)
                                   throws IOException

Invoked to indicate that the input stream has been created.

Parameters:

logFile - the file to read.

Throws:

IOException

makeChecksumAlgorithm

protected Checksum makeChecksumAlgorithm()

create a checksum algorithm

Returns:

the checksum algorithm

next

public boolean next()
             throws IOException

the iterator that moves to the next transaction

Specified by:

next in interface TxnLog.TxnIterator

Returns:

true if there is more transactions to be read false if not.

Throws:

IOException

getHeader

public TxnHeader getHeader()

return the current header

Specified by:

getHeader in interface TxnLog.TxnIterator

Returns:

the current header that is read

getTxn

public Record getTxn()

return the current transaction

Specified by:

getTxn in interface TxnLog.TxnIterator

Returns:

the current transaction that is read

getDigest

public TxnDigest getDigest()

Specified by:

getDigest in interface TxnLog.TxnIterator

Returns:

the digest associated with the transaction.

close

public void close()
           throws IOException

close the iterator and release the resources.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in interface TxnLog.TxnIterator

Throws:

IOException