com.scaleoutsoftware.soss.hserver.interop

Class BucketStore

java.lang.Object

com.scaleoutsoftware.soss.hserver.interop.BucketStore

public abstract class BucketStore
extends Object

This interface represents a view of ScaleOut StateServer as bucket storage. The objects are organized into buckets, which are guaranteed to be stored on a single StateServer host. The bucket is uniquely identified by a BucketId. There is one-to-one relationship between recorded splits and buckets. The KV-pairs corresponding to a split are put in one bucket. Each bucket store is created for the specific Image by the BucketStoreFactory.

Constructor Summary

Constructors

Constructor and Description
BucketStore()

Method Summary

Modifier and Type	Method and Description
static List<BucketId>	bucketizeNamedCache(int appId) Returns a full set of buckets for the NamedCache.
abstract void	clearBucket(BucketId bucketId) Clears the specified bucket.
abstract LinkedList<com.scaleoutsoftware.soss.client.da.StateServerKey>	getBucketContents(BucketId bucketId) Gets a list of all object keys in the specified bucket.
static InetAddress	getBucketLocation(BucketId bucketId) Gets the name of the host where this bucket is local.
abstract Image	getImage(boolean lock) Return the Image object corresponding to this bucket store.
static List<com.scaleoutsoftware.soss.client.da.StateServerKey>	getNamedCacheBucketContents(BucketId id) Returns the contents of the NamedCache bucket.
abstract BucketId	getNextLocalBucketId() Creates a new bucket on the local host.
static ObjectReader	getObjectReader(int initialSize) Gets an object reader which can retrieve objects based on key.
abstract void	putObject(BucketId bucketId, long objectIndex, byte[] object, int length) Writes an object to ScaleOut StateServer and assigns it to the specified bucket.
abstract void	removeImage() Removes the Image object from the StateServer.
abstract void	unlockImage() Unlocks the Image object.
abstract void	writeImage(Image image, boolean unlock) Writes the Image object to ScaleOut StateServer.

Methods inherited from class java.lang.Object

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

Constructor Detail

BucketStore

public BucketStore()

Method Detail

getBucketLocation

public static InetAddress getBucketLocation(BucketId bucketId)
                                     throws com.scaleoutsoftware.soss.client.da.StateServerException

Gets the name of the host where this bucket is local.

Parameters:

bucketId - bucket ID

Returns:

the address of the host containing the bucket

Throws:

com.scaleoutsoftware.soss.client.da.StateServerException - If there was a communication error between the JVM and ScaleOut StateServer (or if ScaleOut StateServer experienced an internal error)

getNextLocalBucketId

public abstract BucketId getNextLocalBucketId()
                                       throws com.scaleoutsoftware.soss.client.da.StateServerException

Creates a new bucket on the local host.

Returns:

the bucket ID of the created bucket

Throws:

com.scaleoutsoftware.soss.client.da.StateServerException - If there was a communication error between the JVM and ScaleOut StateServer (or if ScaleOut StateServer experienced an internal error)

putObject

public abstract void putObject(BucketId bucketId,
                               long objectIndex,
                               byte[] object,
                               int length)
                        throws com.scaleoutsoftware.soss.client.da.StateServerException

Writes an object to ScaleOut StateServer and assigns it to the specified bucket.

Parameters:

bucketId - bucket ID

objectIndex - object index in the bucket (to preserve ordering)

object - buffer, containing byte representation of the object to write

length - length of the object

Throws:

com.scaleoutsoftware.soss.client.da.StateServerException - If there was a communication error between the JVM and ScaleOut StateServer (or if ScaleOut StateServer experienced an internal error)

getBucketContents

public abstract LinkedList<com.scaleoutsoftware.soss.client.da.StateServerKey> getBucketContents(BucketId bucketId)
                                                                                          throws com.scaleoutsoftware.soss.client.da.StateServerException

Gets a list of all object keys in the specified bucket.

Parameters:

bucketId - bucket ID

Returns:

list of object chunkKeys

Throws:

com.scaleoutsoftware.soss.client.da.StateServerException - If there was a communication error between the JVM and ScaleOut StateServer (or if ScaleOut StateServer experienced an internal error)

clearBucket

public abstract void clearBucket(BucketId bucketId)
                          throws com.scaleoutsoftware.soss.client.da.StateServerException

Clears the specified bucket.

Parameters:

bucketId - bucket ID

Throws:

com.scaleoutsoftware.soss.client.da.StateServerException - If there was a communication error between the JVM and ScaleOut StateServer (or if ScaleOut StateServer experienced an internal error)

getImage

public abstract Image getImage(boolean lock)
                        throws com.scaleoutsoftware.soss.client.da.StateServerException,
                               IOException,
                               ClassNotFoundException

Return the Image object corresponding to this bucket store.

Parameters:

lock - if true, the object in the ScaleOut StateServer store is locked, so no other process can overwrite it until it is unlocked. Unlocking is performed by the writeImage(com.scaleoutsoftware.soss.hserver.interop.Image, boolean) or unlockImage() methods.

Returns:

image object

Throws:

com.scaleoutsoftware.soss.client.da.StateServerException - If there was a communication error between the JVM and ScaleOut StateServer (or if ScaleOut StateServer experienced an internal error)

IOException - If there was an error while communicating with ScaleOut StateServer

ClassNotFoundException - If there was a class path issue

writeImage

public abstract void writeImage(Image image,
                                boolean unlock)
                         throws com.scaleoutsoftware.soss.client.da.StateServerException

Writes the Image object to ScaleOut StateServer.

Parameters:

image - image object

unlock - if true, the object in the ScaleOut StateServer store is unlocked after writing.

Throws:

com.scaleoutsoftware.soss.client.da.StateServerException - If there was a communication error between the JVM and ScaleOut StateServer (or if ScaleOut StateServer experienced an internal error)

unlockImage

public abstract void unlockImage()
                          throws com.scaleoutsoftware.soss.client.da.StateServerException

Unlocks the Image object.

Throws:

com.scaleoutsoftware.soss.client.da.StateServerException - If there was a communication error between the JVM and ScaleOut StateServer (or if ScaleOut StateServer experienced an internal error)

removeImage

public abstract void removeImage()
                          throws com.scaleoutsoftware.soss.client.da.StateServerException

Removes the Image object from the StateServer.

Throws:

com.scaleoutsoftware.soss.client.da.StateServerException - If there was a communication error between the JVM and ScaleOut StateServer (or if ScaleOut StateServer experienced an internal error)

bucketizeNamedCache

public static List<BucketId> bucketizeNamedCache(int appId)

Returns a full set of buckets for the NamedCache. This method can be used to split a NamedCache for parallel execution.

Parameters:

appId - id for the cache

Returns:

list of buckets

getNamedCacheBucketContents

public static List<com.scaleoutsoftware.soss.client.da.StateServerKey> getNamedCacheBucketContents(BucketId id)
                                                                                            throws com.scaleoutsoftware.soss.client.da.StateServerException

Returns the contents of the NamedCache bucket. The bucket id should be one of the IDs create by bucketizeNamedCache(int).

Parameters:

id - bucket id;

Returns:

list of keys

Throws:

com.scaleoutsoftware.soss.client.da.StateServerException - If there was a communication error between the JVM and ScaleOut StateServer (or if ScaleOut StateServer experienced an internal error)

getObjectReader

public static ObjectReader getObjectReader(int initialSize)

Gets an object reader which can retrieve objects based on key. This object reader has an inner reusable buffer for object retrieval.

Parameters:

initialSize - initial size of the reusable buffer in bytes

Returns:

ObjectReader instance