io.zeebe.logstreams.log

Class BufferedLogStreamReader

java.lang.Object

io.zeebe.logstreams.log.BufferedLogStreamReader

All Implemented Interfaces:

LogStreamReader, CloseableSilently, AutoCloseable, Iterator<LoggedEvent>

public class BufferedLogStreamReader
extends Object
implements LogStreamReader

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_INITIAL_BUFFER_CAPACITY
static int	MAX_BUFFER_CAPACITY

Constructor Summary

Constructors

Constructor and Description
BufferedLogStreamReader()
BufferedLogStreamReader(boolean readUncommittedEntries)
BufferedLogStreamReader(LogStream logStream)
BufferedLogStreamReader(LogStream logStream, boolean readUncommittedEntries)

Method Summary

Modifier and Type	Method and Description
void	close()
long	getPosition() Returns the current log position of the reader.
boolean	hasNext()
boolean	isClosed() Returns true if the log stream reader was closed.
LoggedEvent	next()
boolean	seek(long position) Seek to the given log position if exists.
void	seekToFirstEvent() Seek to the log position of the first event.
void	seekToLastEvent() Seek to the log position of the last event.
void	wrap(LogStorage logStorage, LogBlockIndex logBlockIndex)
void	wrap(LogStorage logStorage, LogBlockIndex logBlockIndex, long position)
void	wrap(LogStream log) Initialize the reader and seek to the first event.
void	wrap(LogStream log, long position) Initialize the reader and seek to the given log position.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining, remove

Field Detail

DEFAULT_INITIAL_BUFFER_CAPACITY

public static final int DEFAULT_INITIAL_BUFFER_CAPACITY

See Also:

Constant Field Values

MAX_BUFFER_CAPACITY

public static final int MAX_BUFFER_CAPACITY

See Also:

Constant Field Values

Constructor Detail

BufferedLogStreamReader

public BufferedLogStreamReader()

BufferedLogStreamReader

public BufferedLogStreamReader(LogStream logStream)

BufferedLogStreamReader

public BufferedLogStreamReader(boolean readUncommittedEntries)

BufferedLogStreamReader

public BufferedLogStreamReader(LogStream logStream,
                               boolean readUncommittedEntries)

Method Detail

wrap

public void wrap(LogStream log)

Description copied from interface: LogStreamReader

Initialize the reader and seek to the first event.

Specified by:

wrap in interface LogStreamReader

Parameters:

log - the stream which provides the log

wrap

public void wrap(LogStream log,
                 long position)

Description copied from interface: LogStreamReader

Initialize the reader and seek to the given log position.

Specified by:

wrap in interface LogStreamReader

Parameters:

log - the stream which provides the log

position - the position in the log to seek to

wrap

public void wrap(LogStorage logStorage,
                 LogBlockIndex logBlockIndex)

wrap

public void wrap(LogStorage logStorage,
                 LogBlockIndex logBlockIndex,
                 long position)

seek

public boolean seek(long position)

Description copied from interface: LogStreamReader

Seek to the given log position if exists. Otherwise, it seek to the next position after this.

Specified by:

seek in interface LogStreamReader

Parameters:

position - the position in the log to seek to

Returns:

true, if the given position exists.

seekToFirstEvent

public void seekToFirstEvent()

Description copied from interface: LogStreamReader

Seek to the log position of the first event.

Specified by:

seekToFirstEvent in interface LogStreamReader

seekToLastEvent

public void seekToLastEvent()

Description copied from interface: LogStreamReader

Seek to the log position of the last event.

Specified by:

seekToLastEvent in interface LogStreamReader

getPosition

public long getPosition()

Description copied from interface: LogStreamReader

Returns the current log position of the reader.

Specified by:

getPosition in interface LogStreamReader

Returns:

the current log position, or negative value if the log is empty or not initialized

isClosed

public boolean isClosed()

Description copied from interface: LogStreamReader

Returns true if the log stream reader was closed.

Specified by:

isClosed in interface LogStreamReader

Returns:

true if closed, false otherwise

close

public void close()

Specified by:

close in interface CloseableSilently

Specified by:

close in interface AutoCloseable

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Iterator<LoggedEvent>

next

public LoggedEvent next()

Specified by:

next in interface Iterator<LoggedEvent>