com.sleepycat.persist.impl
Class EnhancedAccessor

java.lang.Object
  extended by com.sleepycat.persist.impl.EnhancedAccessor

public class EnhancedAccessor
extends java.lang.Object

Implements Accessor for a complex persistent class.


Field Summary
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
 java.lang.Object getField(java.lang.Object o, int field, int superLevel, boolean isSecField)
          Returns the value of a given field, representing primitives as primitive wrapper objects.
 boolean isPriKeyFieldNullOrZero(java.lang.Object o)
          Returns whether the primary key field is null (for a reference type) or zero (for a primitive integer type).
 java.lang.Object newArray(int len)
          Creates a new one dimensional array of the given length, having the target class as its component type.
 java.lang.Object newInstance()
          Creates a new instance of the target class using its default constructor.
 void readNonKeyFields(java.lang.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(java.lang.Object o, EntityInput input)
          Reads the primary key field value from the given EntityInput.
 void readSecKeyFields(java.lang.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(java.lang.String className, Enhanced prototype)
          Registers a prototype instance, and should be called during initialization of the prototype class.
 void setField(java.lang.Object o, int field, int superLevel, boolean isSecField, java.lang.Object value)
          Changes the value of a given field, representing primitives as primitive wrapper objects.
 void writeNonKeyFields(java.lang.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(java.lang.Object o, EntityOutput output)
          Writes the primary key field value to the given EntityOutput.
 void writeSecKeyFields(java.lang.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(java.lang.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 java.lang.Object newInstance()
Creates a new instance of the target class using its default constructor.


newArray

public java.lang.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(java.lang.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(java.lang.Object o,
                             EntityOutput output)
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.

readPriKeyField

public void readPriKeyField(java.lang.Object o,
                            EntityInput input)
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.

writeSecKeyFields

public void writeSecKeyFields(java.lang.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.

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.

readSecKeyFields

public void readSecKeyFields(java.lang.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.

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.

writeNonKeyFields

public void writeNonKeyFields(java.lang.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.

Parameters:
o - is the object whose non-key fields are to be written.
output - the output data to write to.

readNonKeyFields

public void readNonKeyFields(java.lang.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.

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.

getField

public java.lang.Object getField(java.lang.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(java.lang.Object o,
                     int field,
                     int superLevel,
                     boolean isSecField,
                     java.lang.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.