com.ados.hestia.utils.io
Class DBStore

java.lang.Object
  com.ados.hestia.utils.io.DBStore

All Implemented Interfaces:

IStore, Serializable

public class DBStore
extends Object
implements IStore

This realize IStore interface using database to store data.

Version:

$Revision: 1371 $ $Date: 2005-11-22 02:44:08 +0900 $

See Also:

com.ados.hestia.db.Processor, Serialized Form

Field Summary

protected DBStoreKey	m_key
protected static HashMap<String,Processor>	m_processors Store correlation beetween id and processor.
protected String	m_repositoryID
static int	MEM_SWITCH_LIMIT

Constructor Summary

	DBStore(String repositoryID) Construct empty DBStore (data size is 0).
protected	DBStore(String repositoryID, String storeID) Read Store description from DB.
	DBStore(String repositoryID, String storeID, InputStream stream) Construct DBStore.

Method Summary

OutputStream	createStream() Create output stream to write data.
protected byte[]	getContent() Read content of Store to memory.
String	getID() Returns id of store.
Processor	getProcessor() Returns processor that is responsible for database access. Used repository identification to lookup at static map
long	getSize() Returns size of data at store.
protected void	initProxy(InputStream stream) Init stream that does not support mark.
InputStream	openSharedStream() Open shared stream to read data.
InputStream	openStream() Open ordinary stream to read data.
static void	registerProcessor(String repositoryID, Processor processor) Staticly register processor to work.

Methods inherited from class java.lang.Object

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

Field Detail

MEM_SWITCH_LIMIT

public static final int MEM_SWITCH_LIMIT

See Also:

Constant Field Values

m_key

protected DBStoreKey m_key

m_repositoryID

protected String m_repositoryID

m_processors

protected static HashMap<String,Processor> m_processors

Store correlation beetween id and processor.

Constructor Detail

DBStore

public DBStore(String repositoryID)
        throws IOException

Construct empty DBStore (data size is 0).

Parameters:

repositoryID - identification of repository that owns this DBStore.

Throws:

IOException - if store cannot be allocated at database.

DBStore

public DBStore(String repositoryID,
               String storeID,
               InputStream stream)
        throws IOException

Construct DBStore. Used provided stream to fill data.

Parameters:

repositoryID - identification of repository that owns this DBStore.

storeID - store identification across repository.

stream - stream to fill initial content of DBStore.

Throws:

IOException - if stream cannot be read or store cannot be allocated.

DBStore

protected DBStore(String repositoryID,
                  String storeID)
           throws IOException

Read Store description from DB. Entry must be already present.

Parameters:

repositoryID - identification of repository that owns this DBStore.

storeID - store identification across repository. Must be present at database.

Throws:

IOException - if entry does not exist or cannot be read.

Method Detail

registerProcessor

public static void registerProcessor(String repositoryID,
                                     Processor processor)

Staticly register processor to work.

Parameters:

id - repository identification.

processor - processor corresponded Processor for repository.

getProcessor

public Processor getProcessor()
                       throws IOException

Returns processor that is responsible for database access.
Used repository identification to lookup at static map

Returns:

processor processor that is responsible for database access.

Throws:

IOException - if processor is not available for provided repository.

initProxy

protected void initProxy(InputStream stream)
                  throws IOException

Init stream that does not support mark. Need create temp store. SQL Standard requires (some db may ignore it but some required) set exact stream size for blob objects. In this way, readion to proxy storage is requied to get exact stream size.

Parameters:

stream - stream to fill content.

Throws:

IOException - if error with stream occured.

getID

public String getID()

Returns id of store.

Specified by:

getID in interface IStore

Returns:

id of store.

openStream

public InputStream openStream()
                       throws IOException

Open ordinary stream to read data.

Specified by:

openStream in interface IStore

Returns:

opened stream

Throws:

IOException - if stream can not be opened

getContent

protected byte[] getContent()
                     throws IOException,
                            ProcessorException

Read content of Store to memory. Note! use this method carefully because size of store data may be huge and will bring to memory error.

Returns:

content of Store as byte array/

Throws:

IOException - if data cannot be readed.

ProcessorException - if processor is not available or database access failed.

openSharedStream

public InputStream openSharedStream()
                             throws IOException

Open shared stream to read data.

Specified by:

openSharedStream in interface IStore

Returns:

opened shared stream

Throws:

IOException - if stream can not be opened

createStream

public OutputStream createStream()
                          throws IOException

Create output stream to write data.

Specified by:

createStream in interface IStore

Returns:

create opened stream

Throws:

IOException - if stream can not be opened

getSize

public long getSize()

Returns size of data at store.

Specified by:

getSize in interface IStore

Returns:

size of data at store