code: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements. See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership. The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the  "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  /*
   * $Id$
   */
  package org.apache.xpath.compiler;
  
  import org.apache.xpath.Expression;
  import org.apache.xpath.functions.Function;
  import java.util.HashMap;
  import javax.xml.transform.TransformerException;
  
  /**
   * The function table for XPath.
   */
  public class FunctionTable
  {
  
    /** The 'current()' id. */
    public static final int FUNC_CURRENT = 0;
  
    /** The 'last()' id. */
    public static final int FUNC_LAST = 1;
  
    /** The 'position()' id. */
    public static final int FUNC_POSITION = 2;
  
    /** The 'count()' id. */
    public static final int FUNC_COUNT = 3;
  
    /** The 'id()' id. */
    public static final int FUNC_ID = 4;
  
    /** The 'key()' id (XSLT). */
    public static final int FUNC_KEY = 5;
  
    /** The 'local-name()' id. */
    public static final int FUNC_LOCAL_PART = 7;
  
    /** The 'namespace-uri()' id. */
    public static final int FUNC_NAMESPACE = 8;
  
    /** The 'name()' id. */
    public static final int FUNC_QNAME = 9;
  
    /** The 'generate-id()' id. */
    public static final int FUNC_GENERATE_ID = 10;
  
    /** The 'not()' id. */
    public static final int FUNC_NOT = 11;
  
    /** The 'true()' id. */
    public static final int FUNC_TRUE = 12;
  
    /** The 'false()' id. */
    public static final int FUNC_FALSE = 13;
  
    /** The 'boolean()' id. */
    public static final int FUNC_BOOLEAN = 14;
  
    /** The 'number()' id. */
    public static final int FUNC_NUMBER = 15;
  
    /** The 'floor()' id. */
    public static final int FUNC_FLOOR = 16;
  
    /** The 'ceiling()' id. */
    public static final int FUNC_CEILING = 17;
  
    /** The 'round()' id. */
    public static final int FUNC_ROUND = 18;
  
    /** The 'sum()' id. */
    public static final int FUNC_SUM = 19;
  
    /** The 'string()' id. */
    public static final int FUNC_STRING = 20;
  
    /** The 'starts-with()' id. */
    public static final int FUNC_STARTS_WITH = 21;
  
    /** The 'contains()' id. */
    public static final int FUNC_CONTAINS = 22;
  
    /** The 'substring-before()' id. */
    public static final int FUNC_SUBSTRING_BEFORE = 23;
  
    /** The 'substring-after()' id. */
    public static final int FUNC_SUBSTRING_AFTER = 24;
  
    /** The 'normalize-space()' id. */
    public static final int FUNC_NORMALIZE_SPACE = 25;
  
    /** The 'translate()' id. */
    public static final int FUNC_TRANSLATE = 26;
  
    /** The 'concat()' id. */
    public static final int FUNC_CONCAT = 27;
  
    /** The 'substring()' id. */
    public static final int FUNC_SUBSTRING = 29;
  
    /** The 'string-length()' id. */
    public static final int FUNC_STRING_LENGTH = 30;
  
    /** The 'system-property()' id. */
    public static final int FUNC_SYSTEM_PROPERTY = 31;
  
    /** The 'lang()' id. */
    public static final int FUNC_LANG = 32;
  
    /** The 'function-available()' id (XSLT). */
    public static final int FUNC_EXT_FUNCTION_AVAILABLE = 33;
  
    /** The 'element-available()' id (XSLT). */
    public static final int FUNC_EXT_ELEM_AVAILABLE = 34;
  
    /** The 'unparsed-entity-uri()' id (XSLT). */
    public static final int FUNC_UNPARSED_ENTITY_URI = 36;
  
    // Proprietary
  
    /** The 'document-location()' id (Proprietary). */
    public static final int FUNC_DOCLOCATION = 35;
  
    /**
     * The function table.
     */
    private static Class m_functions[];
  
    /** Table of function name to function ID associations. */
    private static HashMap m_functionID = new HashMap();
      
    /**
     * The function table contains customized functions
     */
    private Class m_functions_customer[] = new Class[NUM_ALLOWABLE_ADDINS];
  
    /**
     * Table of function name to function ID associations for customized functions
     */
    private HashMap m_functionID_customer = new HashMap();
    
    /**
     * Number of built in functions.  Be sure to update this as
     * built-in functions are added.
     */
    private static final int NUM_BUILT_IN_FUNCS = 37;
  
    /**
     * Number of built-in functions that may be added.
     */
    private static final int NUM_ALLOWABLE_ADDINS = 30;
  
    /**
     * The index to the next free function index.
     */
    private int m_funcNextFreeIndex = NUM_BUILT_IN_FUNCS;
    
    static
    {
      m_functions = new Class[NUM_BUILT_IN_FUNCS];
      m_functions[FUNC_CURRENT] = org.apache.xpath.functions.FuncCurrent.class;
      m_functions[FUNC_LAST] = org.apache.xpath.functions.FuncLast.class;
      m_functions[FUNC_POSITION] = org.apache.xpath.functions.FuncPosition.class;
      m_functions[FUNC_COUNT] = org.apache.xpath.functions.FuncCount.class;
      m_functions[FUNC_ID] = org.apache.xpath.functions.FuncId.class;
      m_functions[FUNC_KEY] =
        org.apache.xalan.templates.FuncKey.class;
      m_functions[FUNC_LOCAL_PART] = 
        org.apache.xpath.functions.FuncLocalPart.class;
      m_functions[FUNC_NAMESPACE] = 
        org.apache.xpath.functions.FuncNamespace.class;
      m_functions[FUNC_QNAME] = org.apache.xpath.functions.FuncQname.class;
      m_functions[FUNC_GENERATE_ID] = 
        org.apache.xpath.functions.FuncGenerateId.class;
      m_functions[FUNC_NOT] = org.apache.xpath.functions.FuncNot.class;
      m_functions[FUNC_TRUE] = org.apache.xpath.functions.FuncTrue.class;
      m_functions[FUNC_FALSE] = org.apache.xpath.functions.FuncFalse.class;
      m_functions[FUNC_BOOLEAN] = org.apache.xpath.functions.FuncBoolean.class;
      m_functions[FUNC_LANG] = org.apache.xpath.functions.FuncLang.class;
      m_functions[FUNC_NUMBER] = org.apache.xpath.functions.FuncNumber.class;
      m_functions[FUNC_FLOOR] = org.apache.xpath.functions.FuncFloor.class;
      m_functions[FUNC_CEILING] = org.apache.xpath.functions.FuncCeiling.class;
      m_functions[FUNC_ROUND] = org.apache.xpath.functions.FuncRound.class;
      m_functions[FUNC_SUM] = org.apache.xpath.functions.FuncSum.class;
      m_functions[FUNC_STRING] = org.apache.xpath.functions.FuncString.class;
      m_functions[FUNC_STARTS_WITH] = 
        org.apache.xpath.functions.FuncStartsWith.class;
      m_functions[FUNC_CONTAINS] = org.apache.xpath.functions.FuncContains.class;
      m_functions[FUNC_SUBSTRING_BEFORE] = 
        org.apache.xpath.functions.FuncSubstringBefore.class;
      m_functions[FUNC_SUBSTRING_AFTER] = 
        org.apache.xpath.functions.FuncSubstringAfter.class;
      m_functions[FUNC_NORMALIZE_SPACE] = 
        org.apache.xpath.functions.FuncNormalizeSpace.class;
      m_functions[FUNC_TRANSLATE] = 
        org.apache.xpath.functions.FuncTranslate.class;
      m_functions[FUNC_CONCAT] = org.apache.xpath.functions.FuncConcat.class;
      m_functions[FUNC_SYSTEM_PROPERTY] = 
        org.apache.xpath.functions.FuncSystemProperty.class;
      m_functions[FUNC_EXT_FUNCTION_AVAILABLE] =
        org.apache.xpath.functions.FuncExtFunctionAvailable.class;
      m_functions[FUNC_EXT_ELEM_AVAILABLE] =
        org.apache.xpath.functions.FuncExtElementAvailable.class;
      m_functions[FUNC_SUBSTRING] = 
        org.apache.xpath.functions.FuncSubstring.class;
      m_functions[FUNC_STRING_LENGTH] = 
        org.apache.xpath.functions.FuncStringLength.class;
      m_functions[FUNC_DOCLOCATION] = 
        org.apache.xpath.functions.FuncDoclocation.class;
      m_functions[FUNC_UNPARSED_ENTITY_URI] =
        org.apache.xpath.functions.FuncUnparsedEntityURI.class;
    }
  
    static{
            m_functionID.put(Keywords.FUNC_CURRENT_STRING,
                            new Integer(FunctionTable.FUNC_CURRENT));
            m_functionID.put(Keywords.FUNC_LAST_STRING,
                            new Integer(FunctionTable.FUNC_LAST));
            m_functionID.put(Keywords.FUNC_POSITION_STRING,
                            new Integer(FunctionTable.FUNC_POSITION));
            m_functionID.put(Keywords.FUNC_COUNT_STRING,
                            new Integer(FunctionTable.FUNC_COUNT));
            m_functionID.put(Keywords.FUNC_ID_STRING,
                            new Integer(FunctionTable.FUNC_ID));
            m_functionID.put(Keywords.FUNC_KEY_STRING,
                            new Integer(FunctionTable.FUNC_KEY));
            m_functionID.put(Keywords.FUNC_LOCAL_PART_STRING,
                            new Integer(FunctionTable.FUNC_LOCAL_PART));
            m_functionID.put(Keywords.FUNC_NAMESPACE_STRING,
                            new Integer(FunctionTable.FUNC_NAMESPACE));
            m_functionID.put(Keywords.FUNC_NAME_STRING,
                            new Integer(FunctionTable.FUNC_QNAME));
            m_functionID.put(Keywords.FUNC_GENERATE_ID_STRING,
                            new Integer(FunctionTable.FUNC_GENERATE_ID));
            m_functionID.put(Keywords.FUNC_NOT_STRING,
                            new Integer(FunctionTable.FUNC_NOT));
            m_functionID.put(Keywords.FUNC_TRUE_STRING,
                            new Integer(FunctionTable.FUNC_TRUE));
            m_functionID.put(Keywords.FUNC_FALSE_STRING,
                            new Integer(FunctionTable.FUNC_FALSE));
            m_functionID.put(Keywords.FUNC_BOOLEAN_STRING,
                            new Integer(FunctionTable.FUNC_BOOLEAN));
            m_functionID.put(Keywords.FUNC_LANG_STRING,
                            new Integer(FunctionTable.FUNC_LANG));
            m_functionID.put(Keywords.FUNC_NUMBER_STRING,
                            new Integer(FunctionTable.FUNC_NUMBER));
            m_functionID.put(Keywords.FUNC_FLOOR_STRING,
                            new Integer(FunctionTable.FUNC_FLOOR));
            m_functionID.put(Keywords.FUNC_CEILING_STRING,
                            new Integer(FunctionTable.FUNC_CEILING));
            m_functionID.put(Keywords.FUNC_ROUND_STRING,
                            new Integer(FunctionTable.FUNC_ROUND));
            m_functionID.put(Keywords.FUNC_SUM_STRING,
                            new Integer(FunctionTable.FUNC_SUM));
            m_functionID.put(Keywords.FUNC_STRING_STRING,
                            new Integer(FunctionTable.FUNC_STRING));
            m_functionID.put(Keywords.FUNC_STARTS_WITH_STRING,
                            new Integer(FunctionTable.FUNC_STARTS_WITH));
            m_functionID.put(Keywords.FUNC_CONTAINS_STRING,
                            new Integer(FunctionTable.FUNC_CONTAINS));
            m_functionID.put(Keywords.FUNC_SUBSTRING_BEFORE_STRING,
                            new Integer(FunctionTable.FUNC_SUBSTRING_BEFORE));
            m_functionID.put(Keywords.FUNC_SUBSTRING_AFTER_STRING,
                            new Integer(FunctionTable.FUNC_SUBSTRING_AFTER));
            m_functionID.put(Keywords.FUNC_NORMALIZE_SPACE_STRING,
                            new Integer(FunctionTable.FUNC_NORMALIZE_SPACE));
            m_functionID.put(Keywords.FUNC_TRANSLATE_STRING,
                            new Integer(FunctionTable.FUNC_TRANSLATE));
            m_functionID.put(Keywords.FUNC_CONCAT_STRING,
                            new Integer(FunctionTable.FUNC_CONCAT));
            m_functionID.put(Keywords.FUNC_SYSTEM_PROPERTY_STRING,
                            new Integer(FunctionTable.FUNC_SYSTEM_PROPERTY));
            m_functionID.put(Keywords.FUNC_EXT_FUNCTION_AVAILABLE_STRING,
                          new Integer(FunctionTable.FUNC_EXT_FUNCTION_AVAILABLE));
            m_functionID.put(Keywords.FUNC_EXT_ELEM_AVAILABLE_STRING,
                            new Integer(FunctionTable.FUNC_EXT_ELEM_AVAILABLE));
            m_functionID.put(Keywords.FUNC_SUBSTRING_STRING,
                            new Integer(FunctionTable.FUNC_SUBSTRING));
            m_functionID.put(Keywords.FUNC_STRING_LENGTH_STRING,
                            new Integer(FunctionTable.FUNC_STRING_LENGTH));
            m_functionID.put(Keywords.FUNC_UNPARSED_ENTITY_URI_STRING,
                            new Integer(FunctionTable.FUNC_UNPARSED_ENTITY_URI));
            m_functionID.put(Keywords.FUNC_DOCLOCATION_STRING,
                            new Integer(FunctionTable.FUNC_DOCLOCATION));          
    }
    
    public FunctionTable(){
    }
    
    /**
     * Return the name of the a function in the static table. Needed to avoid
     * making the table publicly available.
     */
    String getFunctionName(int funcID) {
        if (funcID < NUM_BUILT_IN_FUNCS) return m_functions[funcID].getName();
        else return m_functions_customer[funcID - NUM_BUILT_IN_FUNCS].getName();
    }
  
    /**
     * Obtain a new Function object from a function ID.
     *
     * @param which  The function ID, which may correspond to one of the FUNC_XXX 
     *    values found in {@link org.apache.xpath.compiler.FunctionTable}, but may 
     *    be a value installed by an external module. 
     *
     * @return a a new Function instance.
     *
     * @throws javax.xml.transform.TransformerException if ClassNotFoundException, 
     *    IllegalAccessException, or InstantiationException is thrown.
     */
    Function getFunction(int which)
            throws javax.xml.transform.TransformerException
    {
            try{
                if (which < NUM_BUILT_IN_FUNCS) 
                    return (Function) m_functions[which].newInstance();
                else 
                    return (Function) m_functions_customer[
                        which-NUM_BUILT_IN_FUNCS].newInstance();                  
            }catch (IllegalAccessException ex){
                    throw new TransformerException(ex.getMessage());
            }catch (InstantiationException ex){
                    throw new TransformerException(ex.getMessage());
            }
    }
    
    /**
     * Obtain a function ID from a given function name
     * @param key the function name in a java.lang.String format.
     * @return a function ID, which may correspond to one of the FUNC_XXX values
     * found in {@link org.apache.xpath.compiler.FunctionTable}, but may be a 
     * value installed by an external module.
     */
    Object getFunctionID(String key){
            Object id = m_functionID_customer.get(key);
            if (null == id) id = m_functionID.get(key);
            return id;
    }
    
    /**
     * Install a built-in function.
     * @param name The unqualified name of the function, must not be null
     * @param func A Implementation of an XPath Function object.
     * @return the position of the function in the internal index.
     */
    public int installFunction(String name, Class func)
    {
  
      int funcIndex;
      Object funcIndexObj = getFunctionID(name);
  
      if (null != funcIndexObj)
      {
        funcIndex = ((Integer) funcIndexObj).intValue();
        
        if (funcIndex < NUM_BUILT_IN_FUNCS){
                funcIndex = m_funcNextFreeIndex++;
                m_functionID_customer.put(name, new Integer(funcIndex)); 
        }
        m_functions_customer[funcIndex - NUM_BUILT_IN_FUNCS] = func;          
      }
      else
      {
              funcIndex = m_funcNextFreeIndex++;
                            
              m_functions_customer[funcIndex-NUM_BUILT_IN_FUNCS] = func;
                      
              m_functionID_customer.put(name, 
                  new Integer(funcIndex));   
      }
      return funcIndex;
    }
  
    /**
     * Tell if a built-in, non-namespaced function is available.
     *
     * @param methName The local name of the function.
     *
     * @return True if the function can be executed.
     */
    public boolean functionAvailable(String methName)
    {
        Object tblEntry = m_functionID.get(methName);
        if (null != tblEntry) return true;
        else{
                tblEntry = m_functionID_customer.get(methName);
                return (null != tblEntry)? true : false;
        }
    }
  }
  