org.apache.arrow.plasma

Class PlasmaClient

java.lang.Object

org.apache.arrow.plasma.PlasmaClient

All Implemented Interfaces:

ObjectStoreLink

public class PlasmaClient
extends Object
implements ObjectStoreLink

The PlasmaClient is used to interface with a plasma store and manager.

The PlasmaClient can ask the PlasmaStore to allocate a new buffer, seal a buffer, and get a buffer. Buffers are referred to by object IDs.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.arrow.plasma.ObjectStoreLink

ObjectStoreLink.ObjectStoreData

Constructor Summary

Constructors

Constructor and Description
PlasmaClient(String storeSocketName, String managerSocketName, int releaseDelay)

Method Summary

Modifier and Type	Method and Description
boolean	contains(byte[] objectId) Check if the object is present and has been sealed in the PlasmaStore.
ByteBuffer	create(byte[] objectId, int size, byte[] metadata) Create an object in Plasma Store with particular size.
void	delete(byte[] objectId) Removes object with given objectId from plasma store.
long	evict(long numBytes) Evict some objects to recover given count of bytes.
protected void	finalize()
List<ObjectStoreLink.ObjectStoreData>	get(byte[][] objectIds, int timeoutMs) Get buffer pairs (data & metadata) from the PlasmaStore based on objectIds.
List<byte[]>	get(byte[][] objectIds, int timeoutMs, boolean isMetadata) Get buffers from the PlasmaStore based on objectIds.
ByteBuffer	getObjAsByteBuffer(byte[] objectId, int timeoutMs, boolean isMetadata) Get an object in Plasma Store with objectId.
byte[]	hash(byte[] objectId) Compute the hash of an object in the object store.
List<byte[]>	list() List all objects in the PlasmaStore.
void	put(byte[] objectId, byte[] value, byte[] metadata) Put value in the local plasma store with object ID objectId.
void	release(byte[] objectId) Notify Plasma that the object is no longer needed.
void	seal(byte[] objectId) Seal the buffer in the PlasmaStore for a particular object ID.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.arrow.plasma.ObjectStoreLink

get

Constructor Detail

PlasmaClient

public PlasmaClient(String storeSocketName,
                    String managerSocketName,
                    int releaseDelay)

Method Detail

finalize

protected void finalize()

Overrides:

finalize in class Object

put

public void put(byte[] objectId,
                byte[] value,
                byte[] metadata)
         throws DuplicateObjectException,
                PlasmaOutOfMemoryException

Description copied from interface: ObjectStoreLink

Put value in the local plasma store with object ID objectId.

Specified by:

put in interface ObjectStoreLink

Parameters:

objectId - The object ID of the value to be put.

value - The value to put in the object store.

metadata - encodes whatever metadata the user wishes to encode.

Throws:

DuplicateObjectException

PlasmaOutOfMemoryException

get

public List<byte[]> get(byte[][] objectIds,
                        int timeoutMs,
                        boolean isMetadata)

Description copied from interface: ObjectStoreLink

Get buffers from the PlasmaStore based on objectIds.

Specified by:

get in interface ObjectStoreLink

Parameters:

objectIds - List of object IDs used to identify some objects.

timeoutMs - The number of milliseconds that the get call should block before timing out and returning. Pass -1 if the call should block and 0 if the call should return immediately.

isMetadata - false if get data, otherwise get metadata.

Returns:

List of PlasmaBuffers wrapping objects.

hash

public byte[] hash(byte[] objectId)

Description copied from interface: ObjectStoreLink

Compute the hash of an object in the object store.

Specified by:

hash in interface ObjectStoreLink

Parameters:

objectId - The object ID used to identify the object.

Returns:

A digest byte array contains object's SHA256 hash. null means that the object isn't in the object store.

get

public List<ObjectStoreLink.ObjectStoreData> get(byte[][] objectIds,
                                                 int timeoutMs)

Description copied from interface: ObjectStoreLink

Get buffer pairs (data & metadata) from the PlasmaStore based on objectIds.

Specified by:

get in interface ObjectStoreLink

Parameters:

objectIds - List of object IDs used to identify some objects.

timeoutMs - The number of milliseconds that the get call should block before timing out and returning. Pass -1 if the call should block and 0 if the call should return immediately.

Returns:

List of Pairs of PlasmaBuffer wrapping objects and its metadata.

getObjAsByteBuffer

public ByteBuffer getObjAsByteBuffer(byte[] objectId,
                                     int timeoutMs,
                                     boolean isMetadata)

Get an object in Plasma Store with objectId. Will return an off-heap ByteBuffer.

Parameters:

objectId - used to identify an object.

timeoutMs - time in milliseconfs to wait before this request time out.

isMetadata - get this object's metadata or data.

list

public List<byte[]> list()

Description copied from interface: ObjectStoreLink

List all objects in the PlasmaStore.

Specified by:

list in interface ObjectStoreLink

evict

public long evict(long numBytes)

Description copied from interface: ObjectStoreLink

Evict some objects to recover given count of bytes.

Specified by:

evict in interface ObjectStoreLink

Parameters:

numBytes - The number of bytes to attempt to recover.

Returns:

The number of bytes that have been evicted.

create

public ByteBuffer create(byte[] objectId,
                         int size,
                         byte[] metadata)
                  throws DuplicateObjectException,
                         PlasmaOutOfMemoryException

Create an object in Plasma Store with particular size. Will return an off-heap ByteBuffer.

Parameters:

objectId - used to identify an object.

size - size in bytes to be allocated for this object.

metadata - this object's metadata. It should be null if there is no metadata.

Throws:

DuplicateObjectException

PlasmaOutOfMemoryException

seal

public void seal(byte[] objectId)

Seal the buffer in the PlasmaStore for a particular object ID. Once a buffer has been sealed, the buffer is immutable and can only be accessed through get.

Parameters:

objectId - used to identify an object.

release

public void release(byte[] objectId)

Notify Plasma that the object is no longer needed.

Specified by:

release in interface ObjectStoreLink

Parameters:

objectId - used to identify an object.

delete

public void delete(byte[] objectId)

Removes object with given objectId from plasma store.

Specified by:

delete in interface ObjectStoreLink

Parameters:

objectId - used to identify an object.

contains

public boolean contains(byte[] objectId)

Check if the object is present and has been sealed in the PlasmaStore.

Specified by:

contains in interface ObjectStoreLink

Parameters:

objectId - used to identify an object.