io.zeebe.logstreams.log

Interface LogStream

All Superinterfaces:

AutoCloseable

All Known Implementing Classes:

LogStreamService

public interface LogStream
extends AutoCloseable

Represents a stream of events from a log storage.

Opening the log stream will start the indexing of the current existing log storage. The log storage will separated into blocks, these blocks will be indexed by an LogController. The LogBlockIndex is available and can be accessed via getLogBlockIndex().

The LogStream will append available events to the log storage with the help of an LogController. The events are read from a given Dispatcher, if available. This can be stopped with the closeAppender() method and re-/started with LogStream#openLogStreamController(AgentRunnerService) or LogStream#openLogStreamController(AgentRunnerService, int).

To access the current LogStorage the getLogStorage() can be used. The close() method will close all LogController and the log storage.

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_MAX_APPEND_BLOCK_SIZE

Method Summary

Modifier and Type	Method and Description
void	close() Closes the log stream synchronously.
ActorFuture<Void>	closeAppender() Stops the streaming to the log storage.
ActorFuture<Void>	closeAsync() Closes the log stream asynchronous.
long	getCommitPosition()
LogBlockIndex	getLogBlockIndex() Returns the LogBlockIndex object, which is used for indexing the LogStorage.
LogBlockIndexWriter	getLogBlockIndexWriter() Returns the log block index controller, which creates periodically the block index for the log storage.
String	getLogName() Returns the name of the log stream.
LogStorage	getLogStorage() Returns the log storage, which is accessed by the LogStream.
LogStorageAppender	getLogStorageAppender() Returns the log stream controller, which streams the logged events from the write buffer into the log storage.
int	getPartitionId()
int	getTerm()
Dispatcher	getWriteBuffer() Returns the writeBuffer, which is used by the LogStreamController to stream the content into the log storage.
ActorFuture<LogStorageAppender>	openAppender() This method delegates to #openLogStreamController(AgentRunnerService, int).
void	registerOnAppendCondition(ActorCondition condition)
void	registerOnCommitPositionUpdatedCondition(ActorCondition condition)
void	removeOnAppendCondition(ActorCondition condition)
void	removeOnCommitPositionUpdatedCondition(ActorCondition condition)
void	setCommitPosition(long commitPosition) Sets the log streams commit position to the given position.
void	setTerm(int term) Sets the log streams term.
void	truncate(long position) Truncates the log stream from the given position to the end of the stream.

Field Detail

DEFAULT_MAX_APPEND_BLOCK_SIZE

static final int DEFAULT_MAX_APPEND_BLOCK_SIZE

See Also:

Constant Field Values

Method Detail

getPartitionId

int getPartitionId()

Returns:

the partition id of the log stream

getLogName

String getLogName()

Returns the name of the log stream.

Returns:

the log stream name

close

void close()

Closes the log stream synchronously. This blocks until the log stream is closed.

Specified by:

close in interface AutoCloseable

closeAsync

ActorFuture<Void> closeAsync()

Closes the log stream asynchronous.

getCommitPosition

long getCommitPosition()

Returns:

the current commit position, or a negative value if no entry is committed.

setCommitPosition

void setCommitPosition(long commitPosition)

Sets the log streams commit position to the given position.

getTerm

int getTerm()

Returns:

the current term in which the log stream is active

setTerm

void setTerm(int term)

Sets the log streams term.

getLogStorage

LogStorage getLogStorage()

Returns the log storage, which is accessed by the LogStream.

Returns:

the log storage

getLogBlockIndex

LogBlockIndex getLogBlockIndex()

Returns the LogBlockIndex object, which is used for indexing the LogStorage.

Returns:

the log block index

getWriteBuffer

Dispatcher getWriteBuffer()

Returns the writeBuffer, which is used by the LogStreamController to stream the content into the log storage.

Returns:

the writebuffer, which is used by the LogStreamController

getLogStorageAppender

LogStorageAppender getLogStorageAppender()

Returns the log stream controller, which streams the logged events from the write buffer into the log storage.

Returns:

the log stream controller

getLogBlockIndexWriter

LogBlockIndexWriter getLogBlockIndexWriter()

Returns the log block index controller, which creates periodically the block index for the log storage.

Returns:

the log block index controller

closeAppender

ActorFuture<Void> closeAppender()

Stops the streaming to the log storage. New events are no longer append to the log storage.

openAppender

ActorFuture<LogStorageAppender> openAppender()

This method delegates to #openLogStreamController(AgentRunnerService, int).

The DEFAULT_MAX_APPEND_BLOCK_SIZE is used as default max append block size and the old agent runner service is reused.

Returns:

returns the future for the log stream controller opening

See Also:

#openLogStreamController(AgentRunnerService, int)}

truncate

void truncate(long position)

Truncates the log stream from the given position to the end of the stream. Each event which has a higher position as the given will be truncated. This method will truncated the log storage and block index.

Parameters:

position - the position to start the truncation

registerOnCommitPositionUpdatedCondition

void registerOnCommitPositionUpdatedCondition(ActorCondition condition)

removeOnCommitPositionUpdatedCondition

void removeOnCommitPositionUpdatedCondition(ActorCondition condition)

registerOnAppendCondition

void registerOnAppendCondition(ActorCondition condition)

removeOnAppendCondition

void removeOnAppendCondition(ActorCondition condition)