serp.bytecode.lowlevel
Class ConstantPool

java.lang.Object
  serp.bytecode.lowlevel.ConstantPool

All Implemented Interfaces:

VisitAcceptor

public class ConstantPool
extends Object
implements VisitAcceptor

A bytecode constant pool, containing entries for all strings, constants, classes, etc referenced in the class structure and method opcodes. In keeping with the low-level bytecode representation, all pool indexes are 1-based and LongEntrys and DoubleEntrys each occupy two indexes in the pool.

Author:

Abe White

Constructor Summary

ConstantPool()
Default constructor.

Method Summary

void	acceptVisit(BCVisitor visit) Accept a visit from a BCVisitor, calling the appropriate methods to notify the visitor that it has entered this entity, and to provide it with the proper callbacks for each sub-entity owned by this one.
int	addEntry(Entry entry) Add an entry to the pool.
void	clear() Clear all entries from the pool.
int	findClassEntry(String name, boolean add) Return the constant pool index of the ClassEntry for the given class name, or 0 if it does not exist.
int	findDoubleEntry(double value, boolean add) Return the constant pool index of the DoubleEntry for the given value, or 0 if it does not exist.
int	findFieldEntry(String owner, String name, String desc, boolean add) Return the constant pool index of the FieldEntry for the given name, descriptor, and owner class name.
int	findFloatEntry(float value, boolean add) Return the constant pool index of the FloatEntry for the given value, or 0 if it does not exist.
int	findIntEntry(int value, boolean add) Return the constant pool index of the IntEntry for the given value, or 0 if it does not exist.
int	findInterfaceMethodEntry(String owner, String name, String desc, boolean add) Return the constant pool index of the InterfaceMethodEntry for the given name, descriptor, and owner class name.
int	findLongEntry(long value, boolean add) Return the constant pool index of the LongEntry for the given value, or 0 if it does not exist.
int	findMethodEntry(String owner, String name, String desc, boolean add) Return the constant pool index of the MethodEntry for the given name, descriptor, and owner class name.
int	findNameAndTypeEntry(String name, String desc, boolean add) Return the constant pool index of the NameAndTypeEntry for the given name and descriptor, or 0 if it does not exist.
int	findStringEntry(String value, boolean add) Return the constant pool index of the StringEntry for the given string value, or 0 if it does not exist.
int	findUTF8Entry(String value, boolean add) Return the index of the UTF8Entry with the given value, or 0 if it does not exist.
Entry[]	getEntries() Return all the entries in the pool.
Entry	getEntry(int index) Retrieve the entry at the specified 1-based index.
int	indexOf(Entry entry) Return the index of the given entry, or 0 if it is not in the pool.
void	read(DataInput in) Fill the constant pool from the given bytecode stream.
boolean	removeEntry(Entry entry) Remove the given entry from the pool.
int	size() Return the number of places occupied in the pool, including the fact that long and double entries occupy two places.
void	write(DataOutput out) Write the constant pool to the given bytecode stream.

Methods inherited from class java.lang.Object

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

Constructor Detail

ConstantPool

public ConstantPool()

Default constructor.

Method Detail

getEntries

public Entry[] getEntries()

Return all the entries in the pool.

getEntry

public Entry getEntry(int index)

Retrieve the entry at the specified 1-based index.

Throws:

IndexOutOfBoundsException - if index is invalid, including the case that it points to the second slot of a long or double entry

indexOf

public int indexOf(Entry entry)

Return the index of the given entry, or 0 if it is not in the pool.

addEntry

public int addEntry(Entry entry)

Add an entry to the pool.

Returns:

the index at which the entry was added

removeEntry

public boolean removeEntry(Entry entry)

Remove the given entry from the pool.

Returns:

false if the entry is not in the pool, true otherwise

clear

public void clear()

Clear all entries from the pool.

size

public int size()

Return the number of places occupied in the pool, including the fact that long and double entries occupy two places.

findUTF8Entry

public int findUTF8Entry(String value,
                         boolean add)

Return the index of the UTF8Entry with the given value, or 0 if it does not exist.

Parameters:

add - if true, the entry will be added if it does not already exist, and the new entry's index returned

findDoubleEntry

public int findDoubleEntry(double value,
                           boolean add)

Return the constant pool index of the DoubleEntry for the given value, or 0 if it does not exist.

Parameters:

value - the value to find

add - if true, the entry will be added if it does not already exist, and the new entry's index returned

findFloatEntry

public int findFloatEntry(float value,
                          boolean add)

Return the constant pool index of the FloatEntry for the given value, or 0 if it does not exist.

Parameters:

value - the value to find

add - if true, the entry will be added if it does not already exist, and the new entry's index returned

findIntEntry

public int findIntEntry(int value,
                        boolean add)

Return the constant pool index of the IntEntry for the given value, or 0 if it does not exist.

Parameters:

value - the value to find

add - if true, the entry will be added if it does not already exist, and the new entry's index returned

findLongEntry

public int findLongEntry(long value,
                         boolean add)

Return the constant pool index of the LongEntry for the given value, or 0 if it does not exist.

Parameters:

value - the value to find

add - if true, the entry will be added if it does not already exist, and the new entry's index returned

findStringEntry

public int findStringEntry(String value,
                           boolean add)

Return the constant pool index of the StringEntry for the given string value, or 0 if it does not exist.

Parameters:

value - the value to find

add - if true, the entry will be added if it does not already exist, and the new entry's index returned

findClassEntry

public int findClassEntry(String name,
                          boolean add)

Return the constant pool index of the ClassEntry for the given class name, or 0 if it does not exist.

Parameters:

name - the class name in internal form

add - if true, the entry will be added if it does not already exist, and the new entry's index returned

findNameAndTypeEntry

public int findNameAndTypeEntry(String name,
                                String desc,
                                boolean add)

Return the constant pool index of the NameAndTypeEntry for the given name and descriptor, or 0 if it does not exist.

Parameters:

name - the name of the entity

desc - the descriptor of the entity in internal form

add - if true, the entry will be added if it does not already exist, and the new entry's index returned

findFieldEntry

public int findFieldEntry(String owner,
                          String name,
                          String desc,
                          boolean add)

Return the constant pool index of the FieldEntry for the given name, descriptor, and owner class name.

Parameters:

owner - the name of the field's owning class in internal form

name - the name of the field

desc - the descriptor of the field in internal form

add - if true, the entry will be added if it does not already exist, and the new entry's index returned

findMethodEntry

public int findMethodEntry(String owner,
                           String name,
                           String desc,
                           boolean add)

Return the constant pool index of the MethodEntry for the given name, descriptor, and owner class name.

Parameters:

owner - the name of the method's owning class in internal form

name - the name of the method

desc - the descriptor of the method in internal form

add - if true, the entry will be added if it does not already exist, and the new entry's index returned

findInterfaceMethodEntry

public int findInterfaceMethodEntry(String owner,
                                    String name,
                                    String desc,
                                    boolean add)

Return the constant pool index of the InterfaceMethodEntry for the given name, descriptor, and owner class name.

Parameters:

owner - the name of the method's owning class in internal form

name - the name of the method

desc - the descriptor of the method in internal form

add - if true, the entry will be added if it does not already exist, and the new entry's index returned

acceptVisit

public void acceptVisit(BCVisitor visit)

Description copied from interface: VisitAcceptor

Accept a visit from a BCVisitor, calling the appropriate methods to notify the visitor that it has entered this entity, and to provide it with the proper callbacks for each sub-entity owned by this one.

Specified by:

acceptVisit in interface VisitAcceptor

read

public void read(DataInput in)
          throws IOException

Fill the constant pool from the given bytecode stream.

Throws:

IOException

write

public void write(DataOutput out)
           throws IOException

Write the constant pool to the given bytecode stream.

Throws:

IOException