org.apache.solr.update

Class TransactionLog

java.lang.Object

org.apache.solr.update.TransactionLog

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

CdcrTransactionLog, HdfsTransactionLog

public class TransactionLog
extends Object
implements Closeable

Log Format: List{Operation, Version, ...} ADD, VERSION, DOC DELETE, VERSION, ID_BYTES DELETE_BY_QUERY, VERSION, String TODO: keep two files, one for [operation, version, id] and the other for the actual document data. That way we could throw away document log files more readily while retaining the smaller operation log files longer (and we can retrieve the stored fields from the latest documents from the index). This would require keeping all source fields stored of course. This would also allow to not log document data for requests with commit=true in them (since we know that if the request succeeds, all docs will be committed)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	TransactionLog.FSReverseReader
class	TransactionLog.LogCodec
class	TransactionLog.LogReader
class	TransactionLog.ReverseReader

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	deleteOnClose
static String	END_MESSAGE

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	TransactionLog()

Method Summary

Modifier and Type	Method and Description
protected void	addGlobalStrings(Collection<String> strings)
void	close()
void	closeOutput() Move to a read-only state, closing and releasing resources while keeping the log available for reads
void	decref()
protected void	endRecord(long startRecordPosition)
boolean	endsWithCommit()
void	finish(UpdateLog.SyncLevel syncLevel)
void	forceClose()
long	getLogSize()
TransactionLog.LogReader	getReader(long startingPos) Returns a reader that can be used while a log is still in use.
TransactionLog.ReverseReader	getReverseReader() Returns a single threaded reverse reader
void	incref()
Object	lookup(long pos)
int	numRecords() Returns the number of records in the log (currently includes the header and an optional commit).
long	position() returns the current position in the log file
void	rollback(long pos)
long	snapshot() takes a snapshot of the current position and number of records for later possible rollback, and returns the position
String	toString()
boolean	try_incref()
long	write(AddUpdateCommand cmd, int flags)
long	writeCommit(CommitUpdateCommand cmd, int flags)
long	writeData(Object o)
long	writeDelete(DeleteUpdateCommand cmd, int flags)
long	writeDeleteByQuery(DeleteUpdateCommand cmd, int flags)
protected void	writeLogHeader(TransactionLog.LogCodec codec)

Methods inherited from class java.lang.Object

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

Field Detail

END_MESSAGE

public static final String END_MESSAGE

See Also:

Constant Field Values

deleteOnClose

protected volatile boolean deleteOnClose

Constructor Detail

TransactionLog

protected TransactionLog()

Method Detail

numRecords

public int numRecords()

Returns the number of records in the log (currently includes the header and an optional commit). Note: currently returns 0 for reopened existing log files.

endsWithCommit

public boolean endsWithCommit()
                       throws IOException

Throws:

IOException

snapshot

public long snapshot()

takes a snapshot of the current position and number of records for later possible rollback, and returns the position

rollback

public void rollback(long pos)
              throws IOException

Throws:

IOException

writeData

public long writeData(Object o)

addGlobalStrings

protected void addGlobalStrings(Collection<String> strings)

writeLogHeader

protected void writeLogHeader(TransactionLog.LogCodec codec)
                       throws IOException

Throws:

IOException

endRecord

protected void endRecord(long startRecordPosition)
                  throws IOException

Throws:

IOException

write

public long write(AddUpdateCommand cmd,
                  int flags)

writeDelete

public long writeDelete(DeleteUpdateCommand cmd,
                        int flags)

writeDeleteByQuery

public long writeDeleteByQuery(DeleteUpdateCommand cmd,
                               int flags)

writeCommit

public long writeCommit(CommitUpdateCommand cmd,
                        int flags)

lookup

public Object lookup(long pos)

incref

public void incref()

try_incref

public boolean try_incref()

decref

public void decref()

position

public long position()

returns the current position in the log file

closeOutput

public void closeOutput()

Move to a read-only state, closing and releasing resources while keeping the log available for reads

finish

public void finish(UpdateLog.SyncLevel syncLevel)

close

public void close()

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

forceClose

public void forceClose()

toString

public String toString()

Overrides:

toString in class Object

getLogSize

public long getLogSize()

getReader

public TransactionLog.LogReader getReader(long startingPos)

Returns a reader that can be used while a log is still in use. Currently only *one* LogReader may be outstanding, and that log may only be used from a single thread.

getReverseReader

public TransactionLog.ReverseReader getReverseReader()
                                              throws IOException

Returns a single threaded reverse reader

Throws:

IOException