org.dynalang.dynalink

Interface CallSiteDescriptor

All Known Implementing Classes:

AbstractCallSiteDescriptor

public interface CallSiteDescriptor

An immutable descriptor of a call site. It is an immutable objects that contains all the information about a call site: the class performing the lookups, the name of the method being invoked, and the method signature. The library has a default CallSiteDescriptorFactory for descriptors that you can use, or you can create your own descriptor classes, especially if you need to add further information (values passed in additional parameters to the bootstrap method) to them. Call site descriptors are used in this library in place of passing a real call site to guarding linkers so they aren't tempted to directly manipulate the call sites. The constructors of built-in RelinkableCallSite implementations all need a call site descriptor. Even if you create your own call site descriptors consider using CallSiteDescriptorFactory.tokenizeName(String) in your implementation.

Author:

Attila Szegedi

Field Summary

Fields

Modifier and Type	Field and Description
static int	NAME_OPERAND The index of the name token that will usually carry a name of an operand (of a property, method, etc.)
static int	OPERATOR The index of the name token that will usually carry the operation name.
static String	OPERATOR_DELIMITER Character used to delimit operation names in a composite operation specification.
static int	SCHEME The index of the name token that will carry the operation scheme prefix (usually, "dyn").
static String	TOKEN_DELIMITER Character used to delimit tokens in an call site name.

Method Summary

Methods

Modifier and Type	Method and Description
CallSiteDescriptor	changeParameterType(int num, Class<?> newType) Creates a new call site descriptor from this descriptor, which is identical to this, except it changes the type of one of the parameters in the method type.
CallSiteDescriptor	changeReturnType(Class<?> newType) Creates a new call site descriptor from this descriptor, which is identical to this, except it changes the return type in the method type.
CallSiteDescriptor	dropParameterTypes(int from, int to) Creates a new call site descriptor from this descriptor, which is identical to this, except it drops few of the parameters from the method type.
MethodHandles.Lookup	getLookup() Returns the lookup passed to the bootstrap method.
MethodType	getMethodType() The type of the method at the call site.
String	getName() Returns the name of the method at the call site.
String	getNameToken(int i) Returns the ith token in the method name at the call site.
int	getNameTokenCount() Returns the number of tokens in the name of the method at the call site.

Field Detail

SCHEME

static final int SCHEME

The index of the name token that will carry the operation scheme prefix (usually, "dyn").

See Also:

Constant Field Values

OPERATOR

static final int OPERATOR

The index of the name token that will usually carry the operation name.

See Also:

Constant Field Values

NAME_OPERAND

static final int NAME_OPERAND

The index of the name token that will usually carry a name of an operand (of a property, method, etc.)

See Also:

Constant Field Values

TOKEN_DELIMITER

static final String TOKEN_DELIMITER

Character used to delimit tokens in an call site name.

See Also:

Constant Field Values

OPERATOR_DELIMITER

static final String OPERATOR_DELIMITER

Character used to delimit operation names in a composite operation specification.

See Also:

Constant Field Values

Method Detail

getNameTokenCount

int getNameTokenCount()

Returns the number of tokens in the name of the method at the call site. Method names are tokenized with the colon ":" character, i.e. "dyn:getProp:color" would be the name used to describe a method that retrieves the property named "color" on the object it is invoked on.

Returns:

the number of tokens in the name of the method at the call site.

getNameToken

String getNameToken(int i)

Returns the i^th token in the method name at the call site. Method names are tokenized with the colon ":" character.

Parameters:

i - the index of the token. Must be between 0 (inclusive) and getNameTokenCount() (exclusive)

Returns:

the i^th token in the method name at the call site. The returned strings are interned.

Throws:

IllegalArgumentException - if the index is outside the allowed range.

getName

String getName()

Returns the name of the method at the call site. Note that the object internally only stores the tokenized name, and has to reconstruct the full name from tokens on each invocation.

Returns:

the name of the method at the call site.

getMethodType

MethodType getMethodType()

The type of the method at the call site.

Returns:

type of the method at the call site.

getLookup

MethodHandles.Lookup getLookup()

Returns the lookup passed to the bootstrap method.

Returns:

the lookup passed to the bootstrap method.

dropParameterTypes

CallSiteDescriptor dropParameterTypes(int from,
                                    int to)

Creates a new call site descriptor from this descriptor, which is identical to this, except it drops few of the parameters from the method type.

Parameters:

from - the index of the first parameter to drop

to - the index of the first parameter after "from" not to drop

Returns:

a new call site descriptor with the parameter dropped.

changeParameterType

CallSiteDescriptor changeParameterType(int num,
                                     Class<?> newType)

Creates a new call site descriptor from this descriptor, which is identical to this, except it changes the type of one of the parameters in the method type.

Parameters:

num - the index of the parameter type to change

newType - the new type for the parameter

Returns:

a new call site descriptor, with the type of the parameter in the method type changed.

changeReturnType

CallSiteDescriptor changeReturnType(Class<?> newType)

Creates a new call site descriptor from this descriptor, which is identical to this, except it changes the return type in the method type.

Parameters:

newType - the new return type

Returns:

a new call site descriptor, with the return type in the method type changed.