Module org.datanucleus

Package org.datanucleus.enhancer

Class EnhanceUtils

java.lang.Object

org.datanucleus.enhancer.EnhanceUtils

public final class EnhanceUtils
extends Object

Utility class for bytecode enhancement using ASM. ASM operates around two basic pieces of information about any type.

• ASM class name (ACN) : this is the normal fully qualified class name but replacing the dots with slashes. So java.lang.String will have an ASM class name of "java/lang/String".
• Class Descriptor (CD) : this is used where a type is referred to in a calling sequence etc. and for object types is typically things like "Ljava.lang.String;", but there are variants for primitives.

Field Summary

Fields

Modifier and Type	Field	Description
static String	ACN_boolean	ASM class name for boolean.
static String	ACN_Boolean	ASM class name for Boolean.
static String	ACN_byte	ASM class name for byte.
static String	ACN_Byte	ASM class name for Byte.
static String	ACN_char	ASM class name for char.
static String	ACN_Character	ASM class name for Character.
static String	ACN_double	ASM class name for double.
static String	ACN_Double	ASM class name for Double.
static String	ACN_float	ASM class name for float.
static String	ACN_Float	ASM class name for Float.
static String	ACN_int	ASM class name for int.
static String	ACN_Integer	ASM class name for Integer.
static String	ACN_long	ASM class name for long.
static String	ACN_Long	ASM class name for Long.
static String	ACN_Object	ASM class name for java.lang.Object.
static String	ACN_short	ASM class name for short.
static String	ACN_Short	ASM class name for Short.
static String	ACN_String	ASM class name for java.lang.String.
static String	CD_Object	Descriptor for java.lang.Object.
static String	CD_String	Class descriptor for String.

Method Summary

Modifier and Type	Method	Description
static void	addBIPUSHToMethod(MethodVisitor visitor, int i)	Convenience method to add a BIPUSH-type int to the visitor.
static void	addLoadForType(MethodVisitor visitor, Class type, int number)	Convenience method to add a load statement based on the type to be loaded.
static void	addReturnForType(MethodVisitor visitor, Class type)	Convenience method to add a return statement based on the type to be returned.
static String	getASMClassNameForSingleFieldIdentityConstructor(Class fieldType)	Convenience method to return the ASM class name to use as input via the SingleFieldIdentity constructor.
static int	getAsmVersionForJRE()
static String	getTypeDescriptorForEnhanceMethod(Class cls)	Convenience method to give the descriptor for use in an enhanced "field" method.
static String	getTypeDescriptorForType(String clsName)	Return the ASM type descriptor for the input class.
static String	getTypeNameForPersistableMethod(Class cls)	Convenience method to give the type name given the type.

Methods inherited from class java.lang.Object

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

Field Detail

ACN_boolean

public static final String ACN_boolean

ASM class name for boolean.

ACN_byte

public static final String ACN_byte

ASM class name for byte.

ACN_char

public static final String ACN_char

ASM class name for char.

ACN_double

public static final String ACN_double

ASM class name for double.

ACN_float

public static final String ACN_float

ASM class name for float.

ACN_int

public static final String ACN_int

ASM class name for int.

ACN_long

public static final String ACN_long

ASM class name for long.

ACN_short

public static final String ACN_short

ASM class name for short.

ACN_Boolean

public static final String ACN_Boolean

ASM class name for Boolean.

ACN_Byte

public static final String ACN_Byte

ASM class name for Byte.

ACN_Character

public static final String ACN_Character

ASM class name for Character.

ACN_Double

public static final String ACN_Double

ASM class name for Double.

ACN_Float

public static final String ACN_Float

ASM class name for Float.

ACN_Integer

public static final String ACN_Integer

ASM class name for Integer.

ACN_Long

public static final String ACN_Long

ASM class name for Long.

ACN_Short

public static final String ACN_Short

ASM class name for Short.

ACN_String

public static final String ACN_String

ASM class name for java.lang.String.

ACN_Object

public static final String ACN_Object

ASM class name for java.lang.Object.

CD_String

public static final String CD_String

Class descriptor for String.

CD_Object

public static final String CD_Object

Descriptor for java.lang.Object.

Method Detail

addBIPUSHToMethod

public static void addBIPUSHToMethod(MethodVisitor visitor,
                                     int i)

Convenience method to add a BIPUSH-type int to the visitor.

Parameters:

visitor - The MethodVisitor

i - number

addReturnForType

public static void addReturnForType(MethodVisitor visitor,
                                    Class type)

Convenience method to add a return statement based on the type to be returned.

Parameters:

visitor - The MethodVisitor

type - The type to return

addLoadForType

public static void addLoadForType(MethodVisitor visitor,
                                  Class type,
                                  int number)

Convenience method to add a load statement based on the type to be loaded.

Parameters:

visitor - The MethodVisitor

type - The type to load

number - Number to load

getTypeNameForPersistableMethod

public static String getTypeNameForPersistableMethod(Class cls)

Convenience method to give the type name given the type. This is for the assorted methods on the StateManager called things like "replacingStringField", "replacingObjectField", "providedIntField", etc. Just returns the "type" part of the name.

• Boolean, bool : returns "Boolean"
• Byte, byte : returns "Byte"
• Character, char : returns "Char"
• Double, double : returns "Double"
• Float, float : returns "Float"
• Integer, int : returns "Int"
• Long, long : returns "Long"
• Short, short : returns "Short"
• String : returns "String"
• all others : returns "Object"

Parameters:

cls - The type of the field

Returns:

Name for the method

getTypeDescriptorForType

public static String getTypeDescriptorForType(String clsName)

Return the ASM type descriptor for the input class.

Parameters:

clsName - The input class name

Returns:

The ASM type descriptor name

getTypeDescriptorForEnhanceMethod

public static String getTypeDescriptorForEnhanceMethod(Class cls)

Convenience method to give the descriptor for use in an enhanced "field" method. This is for the assorted methods on the StateManager called things like "replacingStringField", "replacingObjectField", "providedIntField", etc. Returns the ASM descriptor equivalent for the method used

• Boolean, bool : returns "Boolean"
• Byte, byte : returns "Byte"
• Character, char : returns "Char"
• Double, double : returns "Double"
• Float, float : returns "Float"
• Integer, int : returns "Int"
• Long, long : returns "Long"
• Short, short : returns "Short"
• String : returns "String"
• all others : returns "Object"

TODO Cache these descriptors/classes etc

Parameters:

cls - The type of the field

Returns:

Name for the method

getASMClassNameForSingleFieldIdentityConstructor

public static String getASMClassNameForSingleFieldIdentityConstructor(Class fieldType)

Convenience method to return the ASM class name to use as input via the SingleFieldIdentity constructor. Means that if the fieldType is primitive we return the ASM class name of the object wrapper.

Parameters:

fieldType - Type of the field

Returns:

ASM class name to use as input in the constructor

getAsmVersionForJRE

public static int getAsmVersionForJRE()