org.agrona.concurrent.status

Class CountersManager

java.lang.Object

org.agrona.concurrent.status.CountersReader

org.agrona.concurrent.status.CountersManager

public class CountersManager
extends CountersReader

Manages the allocation and freeing of counters that are normally stored in a memory-mapped file. This class in not threadsafe. Counters should be centrally managed. Values Buffer

   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
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |                        Counter Value                          |
  |                                                               |
  +---------------------------------------------------------------+
  |                     120 bytes of padding                     ...
 ...                                                              |
  +---------------------------------------------------------------+
  |                   Repeats to end of buffer                   ...
  |                                                               |
 ...                                                              |
  +---------------------------------------------------------------+
 

Meta Data Buffer

   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
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |                        Record State                           |
  +---------------------------------------------------------------+
  |                          Type Id                              |
  +---------------------------------------------------------------+
  |                      120 bytes for key                       ...
 ...                                                              |
  +-+-------------------------------------------------------------+
  |R|                      Label Length                           |
  +-+-------------------------------------------------------------+
  |                  124 bytes of Label in UTF-8                 ...
 ...                                                              |
  +---------------------------------------------------------------+
  |                   Repeats to end of buffer                   ...
  |                                                               |
 ...                                                              |
  +---------------------------------------------------------------+
 

Nested Class Summary

Nested classes/interfaces inherited from class org.agrona.concurrent.status.CountersReader

CountersReader.MetaData

Field Summary

Fields

Modifier and Type	Field and Description
static java.util.function.Consumer<MutableDirectBuffer>	DEFAULT_KEY_FUNC Default function to set a key when none is supplied.
static int	DEFAULT_TYPE_ID Default type id of a counter when none is supplied.

Fields inherited from class org.agrona.concurrent.status.CountersReader

COUNTER_LENGTH, FULL_LABEL_LENGTH, KEY_OFFSET, LABEL_OFFSET, MAX_KEY_LENGTH, MAX_LABEL_LENGTH, METADATA_LENGTH, metaDataBuffer, RECORD_ALLOCATED, RECORD_RECLAIMED, RECORD_UNUSED, TYPE_ID_OFFSET, valuesBuffer

Constructor Summary

Constructors

Constructor and Description
CountersManager(AtomicBuffer metaDataBuffer, AtomicBuffer valuesBuffer) Create a new counter buffer manager over two buffers.

Method Summary

Modifier and Type	Method and Description
int	allocate(java.lang.String label) Allocate a new counter with a given label.
int	allocate(java.lang.String label, int typeId, java.util.function.Consumer<MutableDirectBuffer> keyFunc) Allocate a new counter with a given label.
void	free(int counterId) Free the counter identified by counterId.
AtomicCounter	newCounter(java.lang.String label) Allocate a counter record and wrap it with a new AtomicCounter for use.
AtomicCounter	newCounter(java.lang.String label, int typeId, java.util.function.Consumer<MutableDirectBuffer> keyFunc) Allocate a counter record and wrap it with a new AtomicCounter for use.
void	setCounterValue(int counterId, long value) Set an AtomicCounter value based on counterId.

Methods inherited from class org.agrona.concurrent.status.CountersReader

counterOffset, forEach, forEach, getCounterValue, metaDataBuffer, metaDataOffset, valuesBuffer

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_TYPE_ID

public static final int DEFAULT_TYPE_ID

Default type id of a counter when none is supplied.

See Also:

Constant Field Values

DEFAULT_KEY_FUNC

public static final java.util.function.Consumer<MutableDirectBuffer> DEFAULT_KEY_FUNC

Default function to set a key when none is supplied.

Constructor Detail

CountersManager

public CountersManager(AtomicBuffer metaDataBuffer,
                       AtomicBuffer valuesBuffer)

Create a new counter buffer manager over two buffers.

Parameters:

metaDataBuffer - containing the types, keys, and labels for the counters.

valuesBuffer - containing the values of the counters themselves.

Method Detail

allocate

public int allocate(java.lang.String label)

Allocate a new counter with a given label.

Parameters:

label - to describe the counter.

Returns:

the id allocated for the counter.

allocate

public int allocate(java.lang.String label,
                    int typeId,
                    java.util.function.Consumer<MutableDirectBuffer> keyFunc)

Allocate a new counter with a given label. The key function will be called with a buffer with the exact length of available key space in the record for the user to store what they want for the key. No offset is required.

Parameters:

label - to describe the counter.

typeId - for the type of counter.

keyFunc - for setting the key value for the counter.

Returns:

the id allocated for the counter.

newCounter

public AtomicCounter newCounter(java.lang.String label)

Allocate a counter record and wrap it with a new AtomicCounter for use.

Parameters:

label - to describe the counter.

Returns:

a newly allocated AtomicCounter

newCounter

public AtomicCounter newCounter(java.lang.String label,
                                int typeId,
                                java.util.function.Consumer<MutableDirectBuffer> keyFunc)

Allocate a counter record and wrap it with a new AtomicCounter for use.

Parameters:

label - to describe the counter.

typeId - for the type of counter.

keyFunc - for setting the key value for the counter.

Returns:

a newly allocated AtomicCounter

free

public void free(int counterId)

Free the counter identified by counterId.

Parameters:

counterId - the counter to freed

setCounterValue

public void setCounterValue(int counterId,
                            long value)

Set an AtomicCounter value based on counterId.

Parameters:

counterId - to be set.

value - to set for the counter.