Package org.apache.bookkeeper.bookie.storage.directentrylogger

Class Header

java.lang.Object

org.apache.bookkeeper.bookie.storage.directentrylogger.Header

class Header
extends Object

The 1K block at the head of the entry logger file that contains the fingerprint and meta-data.

 Header is composed of:
 Fingerprint: 4 bytes "BKLO"
 Log file HeaderVersion enum: 4 bytes
 Ledger map offset: 8 bytes
 Ledgers Count: 4 bytes
 

Field Summary

Fields

Modifier and Type	Field	Description
(package private) static final byte[]	EMPTY_HEADER
(package private) static final int	HEADER_CURRENT_VERSION
(package private) static final int	HEADER_V0
(package private) static final int	HEADER_V1
(package private) static final int	HEADER_VERSION_OFFSET
(package private) static final int	LEDGER_COUNT_OFFSET
(package private) static final int	LEDGERS_MAP_OFFSET
(package private) static final int	LOGFILE_DIRECT_HEADER_SIZE
(package private) static final int	LOGFILE_LEGACY_HEADER_SIZE

Constructor Summary

Constructors

Constructor	Description
Header()

Method Summary

Modifier and Type	Method	Description
(package private) static void	assertFingerPrint(io.netty.buffer.ByteBuf header)
(package private) static int	extractLedgerCount(io.netty.buffer.ByteBuf header)
(package private) static long	extractLedgerMapOffset(io.netty.buffer.ByteBuf header)
(package private) static int	extractVersion(io.netty.buffer.ByteBuf header)
(package private) static void	writeEmptyHeader(io.netty.buffer.ByteBuf header)
(package private) static void	writeHeader(io.netty.buffer.ByteBuf header, long ledgerMapOffset, int ledgerCount)

Methods inherited from class java.lang.Object

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

Field Details

LOGFILE_LEGACY_HEADER_SIZE

static final int LOGFILE_LEGACY_HEADER_SIZE

See Also:

• Constant Field Values

LOGFILE_DIRECT_HEADER_SIZE

static final int LOGFILE_DIRECT_HEADER_SIZE

See Also:

• Constant Field Values

HEADER_VERSION_OFFSET

static final int HEADER_VERSION_OFFSET

See Also:

• Constant Field Values

LEDGERS_MAP_OFFSET

static final int LEDGERS_MAP_OFFSET

See Also:

• Constant Field Values

LEDGER_COUNT_OFFSET

static final int LEDGER_COUNT_OFFSET

See Also:

• Constant Field Values

HEADER_V0

static final int HEADER_V0

See Also:

• Constant Field Values

HEADER_V1

static final int HEADER_V1

See Also:

• Constant Field Values

HEADER_CURRENT_VERSION

static final int HEADER_CURRENT_VERSION

See Also:

• Constant Field Values

EMPTY_HEADER

static final byte[] EMPTY_HEADER

Constructor Details

Header

Header()

Method Details

extractVersion

static int extractVersion(io.netty.buffer.ByteBuf header)
                   throws IOException

Throws:

IOException

extractLedgerMapOffset

static long extractLedgerMapOffset(io.netty.buffer.ByteBuf header)
                            throws IOException

Throws:

IOException

extractLedgerCount

static int extractLedgerCount(io.netty.buffer.ByteBuf header)
                       throws IOException

Throws:

IOException

assertFingerPrint

static void assertFingerPrint(io.netty.buffer.ByteBuf header)
                       throws IOException

Throws:

IOException

writeEmptyHeader

static void writeEmptyHeader(io.netty.buffer.ByteBuf header)
                      throws IOException

Throws:

IOException

writeHeader

static void writeHeader(io.netty.buffer.ByteBuf header,
 long ledgerMapOffset,
 int ledgerCount)
                 throws IOException

Throws:

IOException