org.aredis.cache

Class JavaHandler

java.lang.Object

org.aredis.cache.JavaHandler

All Implemented Interfaces:

DataHandler

public class JavaHandler
extends Object
implements DataHandler

The default Data Handler. Strings are encoded as it is except if the encoded String begins with one of the special headers ESCAPE_MARKER, GZIP_HEADER or OBJECT_STREAM_HEADER. The encoded String is gzipped if the size exceeds the compression threshold. If serializeNumbers property is set to false which is the default, Numbers like Integer and Double are also stored as Strings instead of serializing them. Other Objects are serialized using Java Serialization and gzipped if the size crosses the compression threshold. When using java Serialization since we start with a new ObjectOutputStream every time the Class Descriptors used to describe the classes of the Objects being serialized is written for every serialization. If optimizeObjectStorage is set to true the Class Descriptors are maintained as an array in a common storage and only the indexes into that array are written. The storage is updated as and when new Class Descriptors are encountered. The default storage is the same redis server under a key called JAVA_CL_DESCRIPTORS. This can be changed to use a common redis server by using RedisClassDescriptorStorageFactory instead of the default PerConnectionRedisClassDescriptorStorageFactory. Normal and optimized serialization are prefixed by different headers so that they can be Serialized by a JavaHandler with or without the optimzeObjectStorage set.

Author:

Suresh

Field Summary

Fields

Modifier and Type	Field and Description
protected ClassDescriptorStorageFactory	classDescriptorStorageFactory Factory to get an appropriate ClassDescriptorStorage when optimizeObjectStorage is enabled.
static int	ESCAPE_MARKER
static int	GZIP_HEADER
static int	OBJECT_STREAM_HEADER
protected boolean	optimizeObjectStorage Indicates if Object Serialization is optimized by storing the Class Descriptors in a common location.
protected boolean	serializeNumbers Indicates whether to serialize numbers.

Constructor Summary

Constructors

Constructor and Description
JavaHandler() Creates a JavaHandler without optimeObjectStorage set to false.
JavaHandler(ClassDescriptorStorageFactory pclassDescriptorStorageFactory, boolean poptimizeObjectStorage) Creates a JavaHandler.

Method Summary

Methods

Modifier and Type	Method and Description
Object	deserialize(Object metaData, byte[] b, int offset, int len, ServerInfo serverInfo) de-serialize value
String	getCharEncoding() Gets the character encoding used for Serializing Strings.
int	getObjectCompressionThreshold() Gets the Object Compression Threshold.
int	getStringCompressionThreshold() Gets the String Compression Threshold, -2 indicates that the AsyncRedisConnection's compressionThreshold is to be used.
boolean	isOptimizeObjectStorage() Checks if ptimizeObjectStorage (OPTI_JAVA_HANDLER) is enabled
boolean	isSerializeNumbers() Checks if Numbers are to be Serialized as Java Objects.
void	serialize(Object data, Object metaData, CompressibleByteArrayOutputStream op, ServerInfo serverInfo) Serialze value
void	setCharEncoding(String pcharEncoding) Sets the character encoding to use for Serializing Strings.
void	setObjectCompressionThreshold(int pobjectCompressionThreshold) Sets the Object Compression Threshold.
void	setSerializeNumbers(boolean pserializeNumbers) Sets Serialization option for java Numbers.
void	setStringCompressionThreshold(int pstringCompressionThreshold) Sets the String Compression Threshold.

Methods inherited from class java.lang.Object

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

Field Detail

ESCAPE_MARKER

public static final int ESCAPE_MARKER

See Also:

Constant Field Values

GZIP_HEADER

public static final int GZIP_HEADER

See Also:

Constant Field Values

OBJECT_STREAM_HEADER

public static final int OBJECT_STREAM_HEADER

See Also:

Constant Field Values

classDescriptorStorageFactory

protected ClassDescriptorStorageFactory classDescriptorStorageFactory

Factory to get an appropriate ClassDescriptorStorage when optimizeObjectStorage is enabled.

optimizeObjectStorage

protected boolean optimizeObjectStorage

Indicates if Object Serialization is optimized by storing the Class Descriptors in a common location.

serializeNumbers

protected boolean serializeNumbers

Indicates whether to serialize numbers.

Constructor Detail

JavaHandler

public JavaHandler()

Creates a JavaHandler without optimeObjectStorage set to false.

JavaHandler

public JavaHandler(ClassDescriptorStorageFactory pclassDescriptorStorageFactory,
           boolean poptimizeObjectStorage)

Creates a JavaHandler.

Parameters:

pclassDescriptorStorageFactory - Factory to Store ClassDescriptors. This must be non null if optimizeObjectStorage parameter is passed as true.

poptimizeObjectStorage - true for Optimizing Object Storage (OPTI_JAVA_HANDLER), false for regular java serialization

Method Detail

serialize

public void serialize(Object data,
             Object metaData,
             CompressibleByteArrayOutputStream op,
             ServerInfo serverInfo)
               throws IOException

Description copied from interface: DataHandler

Serialze value

Specified by:

serialize in interface DataHandler

Parameters:

data - Data to serialize

metaData - Additional Info to serialize if required by the handler like the Object Class for example. Pass null if the Data Handler does not require addtional info.

op - An output stream which can automatically compress the data in a session if it crosses a configured. Compression Threshold

serverInfo - Redis ServerInfo containing the Redis Server details

Throws:

IOException - If there is an error during serialization

deserialize

public Object deserialize(Object metaData,
                 byte[] b,
                 int offset,
                 int len,
                 ServerInfo serverInfo)
                   throws IOException

Description copied from interface: DataHandler

de-serialize value

Specified by:

deserialize in interface DataHandler

Parameters:

metaData - Additional Info to de-serialize if required by the handler

b - Byte Array containing the data from the Redis Server

offset - Starting offset of the data

len - Length of the data in bytes

serverInfo - Redis ServerInfo containing the Redis Server details

Returns:

De-serialized Data

Throws:

IOException - If there is an error during de-serialization

getCharEncoding

public String getCharEncoding()

Gets the character encoding used for Serializing Strings.

Returns:

Character Encoding

setCharEncoding

public void setCharEncoding(String pcharEncoding)

Sets the character encoding to use for Serializing Strings.

Parameters:

pcharEncoding - Character Encoding

getStringCompressionThreshold

public int getStringCompressionThreshold()

Gets the String Compression Threshold, -2 indicates that the AsyncRedisConnection's compressionThreshold is to be used.

Returns:

String CompressionThreshold

setStringCompressionThreshold

public void setStringCompressionThreshold(int pstringCompressionThreshold)

Sets the String Compression Threshold. -2 which is the default indicates that the AsyncRedisConnection's compressionThreshold is to be used. -1 is for disabling compression and any other positiive value sets the compression threshold to that value for Strings.

Parameters:

pstringCompressionThreshold - String CompressionThreshold

getObjectCompressionThreshold

public int getObjectCompressionThreshold()

Gets the Object Compression Threshold. Interpretation of values is similar to the String Compression Threshold.

Returns:

Object CompressionThreshold

setObjectCompressionThreshold

public void setObjectCompressionThreshold(int pobjectCompressionThreshold)

Sets the Object Compression Threshold. Interpretation of values is similar to the String Compression Threshold.

Parameters:

pobjectCompressionThreshold - Object CompressionThreshold

isOptimizeObjectStorage

public boolean isOptimizeObjectStorage()

Checks if ptimizeObjectStorage (OPTI_JAVA_HANDLER) is enabled

Returns:

true if optimizeObjectStorage is enable, false otherwise

isSerializeNumbers

public boolean isSerializeNumbers()

Checks if Numbers are to be Serialized as Java Objects. The default is false.

Returns:

true if Numbers are serialized as Objects, false if they are serialized as Strings

setSerializeNumbers

public void setSerializeNumbers(boolean pserializeNumbers)

Sets Serialization option for java Numbers.

Parameters:

pserializeNumbers - true to serialize Numbers as Obects, false to serialize them as String