Package org.apache.bookkeeper.bookie.storage

Interface EntryLogger

All Superinterfaces:

AutoCloseable

All Known Implementing Classes:

DefaultEntryLogger, DirectEntryLogger, ReadOnlyDefaultEntryLogger

public interface EntryLogger
extends AutoCloseable

Entry logger. Sequentially writes entries for a large number of ledgers to a small number of log files, to avoid many random writes. When an entry is added, a location is returned, which consists of the ID of the log into which the entry was added, and the offset of that entry within the log. The location is a long, with 32 bits each for the log ID and the offset. This naturally limits the offset and thus the size of the log to Integer.MAX_VALUE.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	LOG_FILE_SUFFIX
static final long	UNASSIGNED_LEDGERID

Method Summary

Modifier and Type	Method	Description
long	addEntry(long ledgerId, io.netty.buffer.ByteBuf buf)	Add an entry for ledger ```ledgerId``` to the entrylog.
void	close()
void	flush()	Flush any outstanding writes to disk.
default EntryLogMetadata	getEntryLogMetadata(long entryLogId)	Retrieve metadata for the given entrylog ID.
EntryLogMetadata	getEntryLogMetadata(long entryLogId, AbstractLogCompactor.Throttler throttler)	Retrieve metadata for the given entrylog ID.
Collection<Long>	getFlushedLogIds()	Get the log ids for the set of logs which have been completely flushed to disk.
Collection<CompactionEntryLog>	incompleteCompactionLogs()	Return a collection of all the compaction entry logs which have been compacted, but have not been cleaned up.
boolean	logExists(long logId)	Check whether an entrylog with the given ID exists.
CompactionEntryLog	newCompactionLog(long logToCompact)	Create a new entrylog into which compacted entries can be added.
io.netty.buffer.ByteBuf	readEntry(long entryLocation)	Read an entry from an entrylog location.
io.netty.buffer.ByteBuf	readEntry(long ledgerId, long entryId, long entryLocation)	Read an entry from an entrylog location, and verify that is matches the expected ledger and entry ID.
boolean	removeEntryLog(long entryLogId)	Delete the entrylog with the given ID.
void	scanEntryLog(long entryLogId, EntryLogScanner scanner)	Scan the given entrylog, returning all entries contained therein.

Field Details

UNASSIGNED_LEDGERID

static final long UNASSIGNED_LEDGERID

See Also:

• Constant Field Values

LOG_FILE_SUFFIX

static final String LOG_FILE_SUFFIX

See Also:

• Constant Field Values

Method Details

addEntry

long addEntry(long ledgerId,
 io.netty.buffer.ByteBuf buf)
       throws IOException

Add an entry for ledger ```ledgerId``` to the entrylog.

Parameters:

ledgerId - the ledger for which the entry is being added

buf - the contents of the entry (this method does not take ownership of the refcount)

Returns:

the location in the entry log of the added entry

Throws:

IOException

readEntry

io.netty.buffer.ByteBuf readEntry(long entryLocation)
                           throws IOException,
Bookie.NoEntryException

Read an entry from an entrylog location.

Parameters:

entryLocation - the location from which to read the entry

Returns:

the entry

Throws:

IOException

Bookie.NoEntryException

readEntry

io.netty.buffer.ByteBuf readEntry(long ledgerId,
 long entryId,
 long entryLocation)
                           throws IOException,
Bookie.NoEntryException

Read an entry from an entrylog location, and verify that is matches the expected ledger and entry ID.

Parameters:

ledgerId - the ledgerID to match

entryId - the entryID to match

entryLocation - the location from which to read the entry

Returns:

the entry

Throws:

IOException

Bookie.NoEntryException

flush

void flush()
    throws IOException

Flush any outstanding writes to disk.

Throws:

IOException

close

void close()
    throws IOException

Specified by:

close in interface AutoCloseable

Throws:

IOException

newCompactionLog

CompactionEntryLog newCompactionLog(long logToCompact)
                             throws IOException

Create a new entrylog into which compacted entries can be added. There is a 1-1 mapping between logs that are being compacted and the log the compacted entries are written to.

Throws:

IOException

incompleteCompactionLogs

Collection<CompactionEntryLog> incompleteCompactionLogs()

Return a collection of all the compaction entry logs which have been compacted, but have not been cleaned up.

getFlushedLogIds

Collection<Long> getFlushedLogIds()

Get the log ids for the set of logs which have been completely flushed to disk. Only log ids in this set are considered for either compaction or garbage collection.

scanEntryLog

void scanEntryLog(long entryLogId,
 EntryLogScanner scanner)
           throws IOException

Scan the given entrylog, returning all entries contained therein.

Throws:

IOException

getEntryLogMetadata

default EntryLogMetadata getEntryLogMetadata(long entryLogId)
                                      throws IOException

Retrieve metadata for the given entrylog ID. The metadata contains the size of the log, the size of the data in the log which is still active, and a list of all the ledgers contained in the log and the size of the data stored for each ledger.

Throws:

IOException

getEntryLogMetadata

EntryLogMetadata getEntryLogMetadata(long entryLogId,
 AbstractLogCompactor.Throttler throttler)
                              throws IOException

Retrieve metadata for the given entrylog ID. The metadata contains the size of the log, the size of the data in the log which is still active, and a list of all the ledgers contained in the log and the size of the data stored for each ledger.

Throws:

IOException

logExists

boolean logExists(long logId)

Check whether an entrylog with the given ID exists.

removeEntryLog

boolean removeEntryLog(long entryLogId)

Delete the entrylog with the given ID.

Returns:

false if the entrylog doesn't exist.