org.apache.jasper.xmlparser
Class SymbolTable

java.lang.Object
  extended byorg.apache.jasper.xmlparser.SymbolTable

public class SymbolTable
extends java.lang.Object

This class is a symbol table implementation that guarantees that strings used as identifiers are unique references. Multiple calls to addSymbol will always return the same string reference.

The symbol table performs the same task as String.intern() with the following differences:

Version:
$Id: SymbolTable.java 466606 2006-10-21 23:07:12Z markt $
Author:
Andy Clark

Nested Class Summary
protected static class SymbolTable.Entry
          This class is a symbol table entry.
 
Field Summary
protected  SymbolTable.Entry[] fBuckets
          Buckets.
protected  int fTableSize
           
protected static int TABLE_SIZE
          Default table size.
 
Constructor Summary
SymbolTable()
          Constructs a symbol table with a default number of buckets.
SymbolTable(int tableSize)
          Constructs a symbol table with a specified number of buckets.
 
Method Summary
 java.lang.String addSymbol(char[] buffer, int offset, int length)
          Adds the specified symbol to the symbol table and returns a reference to the unique symbol.
 java.lang.String addSymbol(java.lang.String symbol)
          Adds the specified symbol to the symbol table and returns a reference to the unique symbol.
 boolean containsSymbol(char[] buffer, int offset, int length)
          Returns true if the symbol table already contains the specified symbol.
 boolean containsSymbol(java.lang.String symbol)
          Returns true if the symbol table already contains the specified symbol.
 int hash(char[] buffer, int offset, int length)
          Returns a hashcode value for the specified symbol information.
 int hash(java.lang.String symbol)
          Returns a hashcode value for the specified symbol.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

TABLE_SIZE

protected static final int TABLE_SIZE
Default table size.

See Also:
Constant Field Values

fBuckets

protected SymbolTable.Entry[] fBuckets
Buckets.


fTableSize

protected int fTableSize
Constructor Detail

SymbolTable

public SymbolTable()
Constructs a symbol table with a default number of buckets.


SymbolTable

public SymbolTable(int tableSize)
Constructs a symbol table with a specified number of buckets.

Method Detail

addSymbol

public java.lang.String addSymbol(java.lang.String symbol)
Adds the specified symbol to the symbol table and returns a reference to the unique symbol. If the symbol already exists, the previous symbol reference is returned instead, in order guarantee that symbol references remain unique.

Parameters:
symbol - The new symbol.

addSymbol

public java.lang.String addSymbol(char[] buffer,
                                  int offset,
                                  int length)
Adds the specified symbol to the symbol table and returns a reference to the unique symbol. If the symbol already exists, the previous symbol reference is returned instead, in order guarantee that symbol references remain unique.

Parameters:
buffer - The buffer containing the new symbol.
offset - The offset into the buffer of the new symbol.
length - The length of the new symbol in the buffer.

hash

public int hash(java.lang.String symbol)
Returns a hashcode value for the specified symbol. The value returned by this method must be identical to the value returned by the hash(char[],int,int) method when called with the character array that comprises the symbol string.

Parameters:
symbol - The symbol to hash.

hash

public int hash(char[] buffer,
                int offset,
                int length)
Returns a hashcode value for the specified symbol information. The value returned by this method must be identical to the value returned by the hash(String) method when called with the string object created from the symbol information.

Parameters:
buffer - The character buffer containing the symbol.
offset - The offset into the character buffer of the start of the symbol.
length - The length of the symbol.

containsSymbol

public boolean containsSymbol(java.lang.String symbol)
Returns true if the symbol table already contains the specified symbol.

Parameters:
symbol - The symbol to look for.

containsSymbol

public boolean containsSymbol(char[] buffer,
                              int offset,
                              int length)
Returns true if the symbol table already contains the specified symbol.

Parameters:
buffer - The buffer containing the symbol to look for.
offset - The offset into the buffer.
length - The length of the symbol in the buffer.


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