io.zeebe.dispatcher.impl.log

Class LogBufferDescriptor

java.lang.Object

io.zeebe.dispatcher.impl.log.LogBufferDescriptor

public class LogBufferDescriptor
extends Object

Describes data layout in the log buffer

  +----------------------------+
  |        Partition 0         |
  +----------------------------+
  |        Partition 1         |
  +----------------------------+
  |        Partition 2         |
  +----------------------------+
  |   Partition Meta Data 0    |
  +----------------------------+
  |   Partition Meta Data 1    |
  +----------------------------+
  |   Partition Meta Data 2    |
  +----------------------------+
  |        Log Meta Data       |
  +----------------------------+
 

Field Summary

Fields

Modifier and Type	Field and Description
static int	LOG_ACTIVE_PARTITION_ID_OFFSET Offset within the log meta data where the active Partition id is stored.
static int	LOG_INITIAL_PARTITION_ID_OFFSET Offset within the log meta data where the active Partition id is stored.
static int	LOG_MAX_FRAME_LENGTH_OFFSET Offset within the log meta data which the MTU length is stored;
static int	LOG_META_DATA_LENGTH Total length of the log meta data buffer in bytes.
static int	LOG_PUBLISHER_LIMIT_OFFSET Offset within the log meta data where the current publisher limit is stored.
static int	PARTITION_CLEAN A Partition which is clean or in use.
static int	PARTITION_COUNT The number of Partitions the log is divided into
static int	PARTITION_META_DATA_LENGTH Total length of the Partition meta data buffer in bytes.
static int	PARTITION_MIN_LENGTH Minimum buffer length for a Partition
static int	PARTITION_NEEDS_CLEANING A Partition is dirty and requires cleaning.
static int	PARTITION_STATUS_OFFSET Offset within the Partition meta data where current status is stored
static int	PARTITION_TAIL_COUNTER_OFFSET Offset within the Partition meta data where the tail value is stored.

Constructor Summary

Constructors

Constructor and Description
LogBufferDescriptor()

Method Summary

Modifier and Type	Method and Description
static int	logMetadataOffset(int partitionSize)
static int	partitionDataSectionOffset(int partitionSize, int partitionNumber)
static int	partitionMetadataSectionOffset(int partitionSize, int partitionNumber)
static int	requiredCapacity(int partitionSize) Calculates the required capacity for a log buffer which can hold up to the provided bytes of data.

Methods inherited from class java.lang.Object

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

Field Detail

PARTITION_COUNT

public static final int PARTITION_COUNT

The number of Partitions the log is divided into

See Also:

Constant Field Values

PARTITION_MIN_LENGTH

public static final int PARTITION_MIN_LENGTH

Minimum buffer length for a Partition

See Also:

Constant Field Values

PARTITION_CLEAN

public static final int PARTITION_CLEAN

A Partition which is clean or in use.

See Also:

Constant Field Values

PARTITION_NEEDS_CLEANING

public static final int PARTITION_NEEDS_CLEANING

A Partition is dirty and requires cleaning.

See Also:

Constant Field Values

PARTITION_TAIL_COUNTER_OFFSET

public static final int PARTITION_TAIL_COUNTER_OFFSET

Offset within the Partition meta data where the tail value is stored.

PARTITION_STATUS_OFFSET

public static final int PARTITION_STATUS_OFFSET

Offset within the Partition meta data where current status is stored

PARTITION_META_DATA_LENGTH

public static final int PARTITION_META_DATA_LENGTH

Total length of the Partition meta data buffer in bytes.

LOG_PUBLISHER_LIMIT_OFFSET

public static final int LOG_PUBLISHER_LIMIT_OFFSET

Offset within the log meta data where the current publisher limit is stored.

LOG_ACTIVE_PARTITION_ID_OFFSET

public static final int LOG_ACTIVE_PARTITION_ID_OFFSET

Offset within the log meta data where the active Partition id is stored.

LOG_INITIAL_PARTITION_ID_OFFSET

public static final int LOG_INITIAL_PARTITION_ID_OFFSET

Offset within the log meta data where the active Partition id is stored.

LOG_MAX_FRAME_LENGTH_OFFSET

public static final int LOG_MAX_FRAME_LENGTH_OFFSET

Offset within the log meta data which the MTU length is stored;

LOG_META_DATA_LENGTH

public static final int LOG_META_DATA_LENGTH

Total length of the log meta data buffer in bytes.

   0                   1                   2                   3
   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |                       Publisher limit                         |
  |                                                               |
  +---------------------------------------------------------------+
  |                     Cache Line Padding                      ...
 ...                                                              |
  +---------------------------------------------------------------+
  |                     Active Partition Id                       |
  +---------------------------------------------------------------+
  |                     Cache Line Padding                      ...
 ...                                                              |
  +---------------------------------------------------------------+
  |                     Initial Partition Id                      |
  +---------------------------------------------------------------+
  |                       Max Frame Length                        |
  +---------------------------------------------------------------+
 

Constructor Detail

LogBufferDescriptor

public LogBufferDescriptor()

Method Detail

requiredCapacity

public static int requiredCapacity(int partitionSize)

Calculates the required capacity for a log buffer which can hold up to the provided bytes of data.

partitionMetadataSectionOffset

public static int partitionMetadataSectionOffset(int partitionSize,
                                                 int partitionNumber)

partitionDataSectionOffset

public static int partitionDataSectionOffset(int partitionSize,
                                             int partitionNumber)

logMetadataOffset

public static int logMetadataOffset(int partitionSize)