Package org.apache.jackrabbit.oak.segment.spi.persistence

Interface JournalFileWriter

All Superinterfaces:

AutoCloseable, Closeable

public interface JournalFileWriter
extends Closeable

The JournalFile writer. It allows to append a record to the journal file (or create a new one, if it doesn't exist).

The implementation doesn't need to be thread-safe (eg. the caller has to take care of synchronizing the writeLine(String) method calls), but the method should be:

• atomic with regards to the JournalFileReader,
• flushed to the storage.

Method Summary

Modifier and Type	Method	Description
void	batchWriteLines(List<String> lines)	Write new lines to the journal file as a batch.
void	truncate()	Truncates the journal file.
void	writeLine(String line)	Write a new line to the journal file.

Methods inherited from interface java.io.Closeable

close

Method Detail

truncate

void truncate()
       throws IOException

Truncates the journal file. This is a maintenance operation, which may break existing JournalFileReader and shouldn't be used in the concurrent environment.

Throws:

IOException

writeLine

void writeLine(String line)
        throws IOException

Write a new line to the journal file. This operation should be atomic, eg. it's should be possible to open a new reader using JournalFile.openJournalReader() in the way that it'll have access to an incomplete record line.

If this method returns successfully it means that the line was persisted on the non-volatile storage. For instance, on the local disk the flush() should be called by the implementation.

Parameters:

line - the journal record to be written

Throws:

IOException

batchWriteLines

void batchWriteLines(List<String> lines)
              throws IOException

Write new lines to the journal file as a batch. Methods allows for optimized batch implementations. This operation should be atomic, eg. it's should be possible to open a new reader using JournalFile.openJournalReader() in the way that it'll have access to an incomplete record line.

If this method returns successfully it means that the line was persisted on the non-volatile storage. For instance, on the local disk the flush() should be called by the implementation.

Parameters:

lines - List of journal records to be written

Throws:

IOException