net.sf.farrago.type.runtime
Class EncodedSqlDecimal

java.lang.Object
  net.sf.farrago.type.runtime.EncodedSqlDecimal

All Implemented Interfaces:

AssignableValue, DataValue

public abstract class EncodedSqlDecimal
extends Object
implements AssignableValue

Runtime type for decimal values. The usage of decimal values is highly restricted within the Farrago runtime. The operations allowed for decimals are:

• A decimal may be casted to or from strings.
• A decimal may be assigned from another decimal
• A decimal may be reinterpreted to or from its internal representation, a long value.

The optimizer does not allow other operations to reach to the Farrago runtime. As usual, the method getNullableData returns an external data type, conforming to SQL standards.

Note: the code may be inefficient, since it relies on Java libraries for decimal support and allocates memory on a per row basis.

Since:

Dec 21, 2005

Version:

$Id: //open/dev/farrago/src/net/sf/farrago/type/runtime/EncodedSqlDecimal.java#19 $

Author:

jpham

Nested Class Summary

class

EncodedSqlDecimal.AssignableDecimal Class which assigns a value to an EncodedSqlDecimal.

Field Summary

static String	ASSIGN_TO_METHOD_NAME
static String	GET_PRECISION_METHOD_NAME
static String	GET_SCALE_METHOD_NAME
private EncodedSqlDecimal.AssignableDecimal	helper
private boolean	isNull
static String	NARROW_CAST_METHOD_NAME
private long	overflowValue
static String	REINTERPRET_METHOD_NAME
long	value
static String	VALUE_FIELD_NAME

Fields inherited from interface net.sf.farrago.type.runtime.AssignableValue

ASSIGNMENT_METHOD_NAME

Constructor Summary

EncodedSqlDecimal()
Creates a runtime object

Method Summary

void	assignFrom(long l)
void	assignFrom(Object obj) Assigns value from an Object.
void	assignTo(NullablePrimitive.NullableLong target) Assigns the internal value of this decimal to a long variable
Object	getNullableData()
protected abstract int	getPrecision()
protected abstract int	getScale()
boolean	isNull()
void	narrowCast(Object o) Narrows an external BigDecimal value (potentially larger than the database can handle) into a native value.
void	reinterpret(long value) Encodes a long value as an EncodedSqlDecimal without an overflow check.
void	reinterpret(long value, boolean overflowCheck) Encodes a long value as an EncodedSqlDecimal, with an optional overflow check.
void	reinterpret(NullablePrimitive.NullableLong primitive) Encodes a long value as an EncodedSqlDecimal without an overflow check.
void	reinterpret(NullablePrimitive.NullableLong primitive, boolean overflowCheck) Encodes a long value as an EncodedSqlDecimal, with an optional overflow check.
void	setNull(boolean b)
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

GET_PRECISION_METHOD_NAME

public static final String GET_PRECISION_METHOD_NAME

See Also:

Constant Field Values

GET_SCALE_METHOD_NAME

public static final String GET_SCALE_METHOD_NAME

See Also:

Constant Field Values

REINTERPRET_METHOD_NAME

public static final String REINTERPRET_METHOD_NAME

See Also:

Constant Field Values

ASSIGN_TO_METHOD_NAME

public static final String ASSIGN_TO_METHOD_NAME

See Also:

Constant Field Values

VALUE_FIELD_NAME

public static final String VALUE_FIELD_NAME

See Also:

Constant Field Values

NARROW_CAST_METHOD_NAME

public static final String NARROW_CAST_METHOD_NAME

See Also:

Constant Field Values

isNull

private boolean isNull

value

public long value

helper

private EncodedSqlDecimal.AssignableDecimal helper

overflowValue

private long overflowValue

Constructor Detail

EncodedSqlDecimal

public EncodedSqlDecimal()

Creates a runtime object

Method Detail

getPrecision

protected abstract int getPrecision()

Returns:

the decimal precision of this number

getScale

protected abstract int getScale()

Returns:

the decimal scale of this number

isNull

public boolean isNull()

setNull

public void setNull(boolean b)

assignFrom

public void assignFrom(Object obj)

Description copied from interface: AssignableValue

Assigns value from an Object.

Specified by:

assignFrom in interface AssignableValue

Parameters:

obj - value to assign, or null to set null

assignFrom

public void assignFrom(long l)

getNullableData

public Object getNullableData()

Specified by:

getNullableData in interface DataValue

Returns:

an Object representation of this value's data, or null if this value is null

reinterpret

public void reinterpret(long value,
                        boolean overflowCheck)

Encodes a long value as an EncodedSqlDecimal, with an optional overflow check.

Parameters:

value - value to be encoded as an EncodedSqlDecimal

overflowCheck - whether to check for overflow

reinterpret

public void reinterpret(long value)

Encodes a long value as an EncodedSqlDecimal without an overflow check.

Parameters:

value - value to be encoded as an EncodedSqlDecimal

reinterpret

public void reinterpret(NullablePrimitive.NullableLong primitive,
                        boolean overflowCheck)

Encodes a long value as an EncodedSqlDecimal, with an optional overflow check.

Parameters:

primitive - value to be encoded as an EncodedSqlDecimal

overflowCheck - whether to check for overflow

reinterpret

public void reinterpret(NullablePrimitive.NullableLong primitive)

Encodes a long value as an EncodedSqlDecimal without an overflow check.

Parameters:

primitive - value to be encoded as an EncodedSqlDecimal

assignTo

public void assignTo(NullablePrimitive.NullableLong target)

Assigns the internal value of this decimal to a long variable

Parameters:

target - the variable to be assigned

toString

public String toString()

Overrides:

toString in class Object

narrowCast

public void narrowCast(Object o)

Narrows an external BigDecimal value (potentially larger than the database can handle) into a native value. Unsupported values are replaced with null.

Parameters:

o - the BigDecimal value