io.zeebe.logstreams.log

Interface LogStreamReader

All Superinterfaces:

AutoCloseable, CloseableSilently, Iterator<LoggedEvent>

All Known Implementing Classes:

BufferedLogStreamReader

public interface LogStreamReader
extends Iterator<LoggedEvent>, CloseableSilently

Reads the log stream in an iterator-like pattern. Common usage:

 
 reader.wrap(log);

 // optionally seek to a position
 reader.seek(position);

 while(reader.hasNext())
 {
     final LoggedEvent event = reader.next();
     // process the event..
 }
 
 

Method Summary

Modifier and Type	Method and Description
long	getPosition() Returns the current log position of the reader.
boolean	isClosed() Returns true if the log stream reader was closed.
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(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 interface java.util.Iterator

forEachRemaining, hasNext, next, remove

Methods inherited from interface io.zeebe.util.CloseableSilently

close

Method Detail

wrap

void wrap(LogStream log)

Initialize the reader and seek to the first event.

Parameters:

log - the stream which provides the log

wrap

void wrap(LogStream log,
          long position)

Initialize the reader and seek to the given log position.

Parameters:

log - the stream which provides the log

position - the position in the log to seek to

seek

boolean seek(long position)

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

Parameters:

position - the position in the log to seek to

Returns:

true, if the given position exists.

seekToFirstEvent

void seekToFirstEvent()

Seek to the log position of the first event.

seekToLastEvent

void seekToLastEvent()

Seek to the log position of the last event.

getPosition

long getPosition()

Returns the current log position of the reader.

Returns:

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

isClosed

boolean isClosed()

Returns true if the log stream reader was closed.

Returns:

true if closed, false otherwise