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 * Licensed to the Apache Software Foundation (ASF) under one or more
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 * 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,
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 * See the License for the specific language governing permissions and
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package org.apache.xerces.impl.xs;

import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;

A class used to hold the internal schema grammar set for the current instance
Author:
Sandy Gao, IBM
@xerces.internal
Version:
$Id: XSGrammarBucket.java 779298 2009-05-27 20:26:13Z knoaman $/**
 * A class used to hold the internal schema grammar set for the current instance
 * 
 * @xerces.internal  
 * 
 * @author Sandy Gao, IBM
 * @version $Id: XSGrammarBucket.java 779298 2009-05-27 20:26:13Z knoaman $
 */
public class XSGrammarBucket {

    // Data

    
Hashtable that maps between Namespace and a Grammar
/**
     * Hashtable that maps between Namespace and a Grammar
     */
    Hashtable fGrammarRegistry = new Hashtable();
    SchemaGrammar fNoNSGrammar = null;

    
Get the schema grammar for the specified namespace
Params:
namespace – 
Returns:
SchemaGrammar associated with the namespace/**
     * Get the schema grammar for the specified namespace
     *
     * @param namespace
     * @return SchemaGrammar associated with the namespace
     */
    public SchemaGrammar getGrammar(String namespace) {
        if (namespace == null)
            return fNoNSGrammar;
        return (SchemaGrammar)fGrammarRegistry.get(namespace);
    }

    
Put a schema grammar into the registry
This method is for internal use only: it assumes that a grammar with
the same target namespace is not already in the bucket.
Params:
grammar –   the grammar to put in the registry/**
     * Put a schema grammar into the registry
     * This method is for internal use only: it assumes that a grammar with
     * the same target namespace is not already in the bucket.
     *
     * @param grammar   the grammar to put in the registry
     */
    public void putGrammar(SchemaGrammar grammar) {
        if (grammar.getTargetNamespace() == null)
            fNoNSGrammar = grammar;
        else
            fGrammarRegistry.put(grammar.getTargetNamespace(), grammar);
    }

    
put a schema grammar and any grammars imported by it (directly or
inderectly) into the registry. when a grammar with the same target
namespace is already in the bucket, and different from the one being
added, it's an error, and no grammar will be added into the bucket.
Params:
grammar –   the grammar to put in the registry
deep –      whether to add imported grammars
Returns:
         whether the process succeeded/**
     * put a schema grammar and any grammars imported by it (directly or
     * inderectly) into the registry. when a grammar with the same target
     * namespace is already in the bucket, and different from the one being
     * added, it's an error, and no grammar will be added into the bucket.
     *
     * @param grammar   the grammar to put in the registry
     * @param deep      whether to add imported grammars
     * @return          whether the process succeeded
     */
    public boolean putGrammar(SchemaGrammar grammar, boolean deep) {
        // whether there is one with the same tns
        SchemaGrammar sg = getGrammar(grammar.fTargetNamespace);
        if (sg != null) {
            // if the one we have is different from the one passed, it's an error
            return sg == grammar;
        }
        // not deep import, then just add this one grammar
        if (!deep) {
            putGrammar(grammar);
            return true;
        }

        // get all imported grammars, and make a copy of the Vector, so that
        // we can recursively process the grammars, and add distinct ones
        // to the same vector
        Vector currGrammars = (Vector)grammar.getImportedGrammars();
        if (currGrammars == null) {
            putGrammar(grammar);
            return true;
        }
        
        Vector grammars = ((Vector)currGrammars.clone());
        SchemaGrammar sg1, sg2;
        Vector gs;
        // for all (recursively) imported grammars
        for (int i = 0; i < grammars.size(); i++) {
            // get the grammar
            sg1 = (SchemaGrammar)grammars.elementAt(i);
            // check whether the bucket has one with the same tns
            sg2 = getGrammar(sg1.fTargetNamespace);
            if (sg2 == null) {
                // we need to add grammars imported by sg1 too
                gs = sg1.getImportedGrammars();
                // for all grammars imported by sg2, but not in the vector
                // we add them to the vector
                if(gs == null) continue;
                for (int j = gs.size() - 1; j >= 0; j--) {
                    sg2 = (SchemaGrammar)gs.elementAt(j);
                    if (!grammars.contains(sg2))
                        grammars.addElement(sg2);
                }
            }
            // we found one with the same target namespace
            // if the two grammars are not the same object, then it's an error
            else if (sg2 != sg1) {
                return false;
            }
        }

        // now we have all imported grammars stored in the vector. add them
        putGrammar(grammar);
        for (int i = grammars.size() - 1; i >= 0; i--)
            putGrammar((SchemaGrammar)grammars.elementAt(i));

        return true;
    }

    
put a schema grammar and any grammars imported by it (directly or
inderectly) into the registry. when a grammar with the same target
namespace is already in the bucket, and different from the one being
added, no grammar will be added into the bucket.
Params:
grammar –        the grammar to put in the registry
deep –           whether to add imported grammars
ignoreConflict – whether to ignore grammars that already exist in the grammar
                      bucket or not - including 'grammar' parameter.
Returns:
              whether the process succeeded/**
     * put a schema grammar and any grammars imported by it (directly or
     * inderectly) into the registry. when a grammar with the same target
     * namespace is already in the bucket, and different from the one being
     * added, no grammar will be added into the bucket.
     *
     * @param grammar        the grammar to put in the registry
     * @param deep           whether to add imported grammars
     * @param ignoreConflict whether to ignore grammars that already exist in the grammar
     *                       bucket or not - including 'grammar' parameter. 
     * @return               whether the process succeeded
     */
    public boolean putGrammar(SchemaGrammar grammar, boolean deep, boolean ignoreConflict) {
        if (!ignoreConflict) {
            return putGrammar(grammar, deep);
        }

        // if grammar already exist in the bucket, we ignore the request
        SchemaGrammar sg = getGrammar(grammar.fTargetNamespace);
        if (sg == null) {
            putGrammar(grammar);
        }
        
        // not adding the imported grammars
        if (!deep) {
            return true;
        }

        // get all imported grammars, and make a copy of the Vector, so that
        // we can recursively process the grammars, and add distinct ones
        // to the same vector
        Vector currGrammars = (Vector)grammar.getImportedGrammars();
        if (currGrammars == null) {
            return true;
        }
        
        Vector grammars = ((Vector)currGrammars.clone());
        SchemaGrammar sg1, sg2;
        Vector gs;
        // for all (recursively) imported grammars
        for (int i = 0; i < grammars.size(); i++) {
            // get the grammar
            sg1 = (SchemaGrammar)grammars.elementAt(i);
            // check whether the bucket has one with the same tns
            sg2 = getGrammar(sg1.fTargetNamespace);
            if (sg2 == null) {
                // we need to add grammars imported by sg1 too
                gs = sg1.getImportedGrammars();
                // for all grammars imported by sg2, but not in the vector
                // we add them to the vector
                if(gs == null) continue;
                for (int j = gs.size() - 1; j >= 0; j--) {
                    sg2 = (SchemaGrammar)gs.elementAt(j);
                    if (!grammars.contains(sg2))
                        grammars.addElement(sg2);
                }
            }
            // we found one with the same target namespace, ignore it
            else  {
                grammars.remove(sg1);
            }
        }

        // now we have all imported grammars stored in the vector. add them
        for (int i = grammars.size() - 1; i >= 0; i--) {
            putGrammar((SchemaGrammar)grammars.elementAt(i));
        }

        return true;
    }

    
get all grammars in the registry
Returns:
an array of SchemaGrammars./**
     * get all grammars in the registry
     *
     * @return an array of SchemaGrammars.
     */
    public SchemaGrammar[] getGrammars() {
        // get the number of grammars
        int count = fGrammarRegistry.size() + (fNoNSGrammar==null ? 0 : 1);
        SchemaGrammar[] grammars = new SchemaGrammar[count];
        // get grammars with target namespace
        Enumeration schemas = fGrammarRegistry.elements();
        int i = 0;
        while (schemas.hasMoreElements())
            grammars[i++] = (SchemaGrammar)schemas.nextElement();
        // add the grammar without target namespace, if any
        if (fNoNSGrammar != null)
            grammars[count-1] = fNoNSGrammar;
        return grammars;
    }

    
Clear the registry.
REVISIT: update to use another XSGrammarBucket
/**
     * Clear the registry.
     * REVISIT: update to use another XSGrammarBucket
     */
    public void reset() {
        fNoNSGrammar = null;
        fGrammarRegistry.clear();
    }

} // class XSGrammarBucket