com.sleepycat.persist.impl

Class EnhancedAccessor

java.lang.Object

com.sleepycat.persist.impl.EnhancedAccessor

public class EnhancedAccessor
extends Object

Implements Accessor for a complex persistent class.

Author:

Mark Hayes

Field Summary

Fields

Modifier and Type	Field and Description
static boolean	EXPECT_ENHANCED
static int	MAX_FIELD_NUM A large field value to use instead of Integer.MAX_VALUE, to work around Java JIT compiler bug when doing an (X <= Integer.MAX_VALUE) as would be done in readXxxKeyFields methods.

Method Summary

Modifier and Type	Method and Description
Object	getField(Object o, int field, int superLevel, boolean isSecField) Returns the value of a given field, representing primitives as primitive wrapper objects.
boolean	isPriKeyFieldNullOrZero(Object o) Returns whether the primary key field is null (for a reference type) or zero (for a primitive integer type).
Object	newArray(int len) Creates a new one dimensional array of the given length, having the target class as its component type.
Object	newInstance() Creates a new instance of the target class using its default constructor.
void	readCompositeKeyFields(Object o, EntityInput input) Reads all composite key field values from the given EntityInput, reading in declared field number order.
void	readNonKeyFields(Object o, EntityInput input, int startField, int endField, int superLevel) Reads a range of non-key field values from the given EntityInput, reading fields in super classes first and in name order within class.
void	readPriKeyField(Object o, EntityInput input) Reads the primary key field value from the given EntityInput.
void	readSecKeyFields(Object o, EntityInput input, int startField, int endField, int superLevel) Reads a range of secondary key field values from the given EntityInput, reading fields in super classes first and in name order within class.
static void	registerClass(String className, Enhanced prototype) Registers a prototype instance, and should be called during initialization of the prototype class.
void	setField(Object o, int field, int superLevel, boolean isSecField, Object value) Changes the value of a given field, representing primitives as primitive wrapper objects.
void	setPriField(Object o, Object value) Changes the value of the primary key field, representing primitives as primitive wrapper objects.
void	writeCompositeKeyFields(Object o, EntityOutput output) Writes all composite key field values to the given EntityOutput, writing in declared field number order.
void	writeNonKeyFields(Object o, EntityOutput output) Writes all non-key field values to the given EntityOutput, writing fields in super classes first and in name order within class.
void	writePriKeyField(Object o, EntityOutput output) Writes the primary key field value to the given EntityOutput.
void	writeSecKeyFields(Object o, EntityOutput output) Writes all secondary key field values to the given EntityOutput, writing fields in super classes first and in name order within class.

Methods inherited from class java.lang.Object

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

Field Detail

EXPECT_ENHANCED

public static final boolean EXPECT_ENHANCED

MAX_FIELD_NUM

public static final int MAX_FIELD_NUM

A large field value to use instead of Integer.MAX_VALUE, to work around Java JIT compiler bug when doing an (X <= Integer.MAX_VALUE) as would be done in readXxxKeyFields methods.

See Also:

Constant Field Values

Method Detail

registerClass

public static void registerClass(String className,
                                 Enhanced prototype)

Registers a prototype instance, and should be called during initialization of the prototype class. The prototype may be null for an abstract class.

newInstance

public Object newInstance()

Creates a new instance of the target class using its default constructor.

newArray

public Object newArray(int len)

Creates a new one dimensional array of the given length, having the target class as its component type.

Using a special method for a one dimensional array, which can be implemented by bytecode generation, is a compromise. We use reflection to create multidimensional arrays. We could in the future generate code to create arrays as they are encountered, if there is a need to avoid reflection for multidimensional arrays.

isPriKeyFieldNullOrZero

public boolean isPriKeyFieldNullOrZero(Object o)

Returns whether the primary key field is null (for a reference type) or zero (for a primitive integer type). Null and zero are used as an indication that the key should be assigned from a sequence.

writePriKeyField

public void writePriKeyField(Object o,
                             EntityOutput output)
                      throws RefreshException

Writes the primary key field value to the given EntityOutput.

To write a primary key with a reference type, this method must call EntityOutput.writeKeyObject.

Parameters:

o - is the object whose primary key field is to be written.

output - the output data to write to.

Throws:

RefreshException

readPriKeyField

public void readPriKeyField(Object o,
                            EntityInput input)
                     throws RefreshException

Reads the primary key field value from the given EntityInput.

To read a primary key with a reference type, this method must call EntityInput.readKeyObject.

Parameters:

o - is the object whose primary key field is to be read.

input - the input data to read from.

Throws:

RefreshException

writeSecKeyFields

public void writeSecKeyFields(Object o,
                              EntityOutput output)
                       throws RefreshException

Writes all secondary key field values to the given EntityOutput, writing fields in super classes first and in name order within class.

Parameters:

o - is the object whose secondary key fields are to be written.

If the primary key has a reference type, this method must call EntityOutput.registerPriKeyObject before writing any other fields.

output - the output data to write to.

Throws:

RefreshException

readSecKeyFields

public void readSecKeyFields(Object o,
                             EntityInput input,
                             int startField,
                             int endField,
                             int superLevel)
                      throws RefreshException

Reads a range of secondary key field values from the given EntityInput, reading fields in super classes first and in name order within class.

If the primary key has a reference type, this method must call EntityInput.registerPriKeyObject before reading any other fields.

To read all fields, pass -1 for superLevel, zero for startField and MAX_FIELD_NUM for endField. Fields from super classes are read first.

To read a specific range of fields, pass a non-negative number for superLevel and the specific indices of the field range to be read in the class at that level.

Parameters:

o - is the object whose secondary key fields are to be read.

input - the input data to read from.

startField - the starting field index in the range of fields to read. To read all fields, the startField should be zero.

endField - the ending field index in the range of fields to read. To read all fields, the endField should be MAX_FIELD_NUM.

superLevel - is a non-negative number to read the fields of the class that is the Nth super instance; or a negative number to read fields in all classes.

Throws:

RefreshException

writeNonKeyFields

public void writeNonKeyFields(Object o,
                              EntityOutput output)
                       throws RefreshException

Writes all non-key field values to the given EntityOutput, writing fields in super classes first and in name order within class.

Parameters:

o - is the object whose non-key fields are to be written.

output - the output data to write to.

Throws:

RefreshException

readNonKeyFields

public void readNonKeyFields(Object o,
                             EntityInput input,
                             int startField,
                             int endField,
                             int superLevel)
                      throws RefreshException

Reads a range of non-key field values from the given EntityInput, reading fields in super classes first and in name order within class.

To read all fields, pass -1 for superLevel, zero for startField and MAX_FIELD_NUM for endField. Fields from super classes are read first.

To read a specific range of fields, pass a non-negative number for superLevel and the specific indices of the field range to be read in the class at that level.

Parameters:

o - is the object whose non-key fields are to be read.

input - the input data to read from.

startField - the starting field index in the range of fields to read. To read all fields, the startField should be zero.

endField - the ending field index in the range of fields to read. To read all fields, the endField should be MAX_FIELD_NUM.

superLevel - is a non-negative number to read the fields of the class that is the Nth super instance; or a negative number to read fields in all classes.

Throws:

RefreshException

writeCompositeKeyFields

public void writeCompositeKeyFields(Object o,
                                    EntityOutput output)
                             throws RefreshException

Writes all composite key field values to the given EntityOutput, writing in declared field number order.

Parameters:

o - the composite key object whose fields are to be written.

output - the output data to write to.

Throws:

RefreshException

readCompositeKeyFields

public void readCompositeKeyFields(Object o,
                                   EntityInput input)
                            throws RefreshException

Reads all composite key field values from the given EntityInput, reading in declared field number order.

Parameters:

o - the composite key object whose fields are to be read.

input - the input data to read from.

Throws:

RefreshException

getField

public Object getField(Object o,
                       int field,
                       int superLevel,
                       boolean isSecField)

Returns the value of a given field, representing primitives as primitive wrapper objects.

Parameters:

o - is the object containing the key field.

field - is the field index.

superLevel - is a positive number to identify the field of the class that is the Nth super instance; or zero to identify the field in this class.

isSecField - is true for a secondary key field or false for a non-key field.

Returns:

the current field value, or null for a reference type field that is null.

setField

public void setField(Object o,
                     int field,
                     int superLevel,
                     boolean isSecField,
                     Object value)

Changes the value of a given field, representing primitives as primitive wrapper objects.

Parameters:

o - is the object containing the key field.

field - is the field index.

superLevel - is a positive number to identify the field of the class that is the Nth super instance; or zero to identify the field in this class.

isSecField - is true for a secondary key field or false for a non-key field.

value - is the new value of the field, or null to set a reference type field to null.

setPriField

public void setPriField(Object o,
                        Object value)

Changes the value of the primary key field, representing primitives as primitive wrapper objects.

Parameters:

o - is the object containing the primary key field.

value - is the new value of the field, or null to set a reference type field to null.