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/*
 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
 */
/*
 * 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.
 */

package com.sun.org.apache.xerces.internal.util;

import com.sun.org.apache.xerces.internal.xni.NamespaceContext;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;


Namespace support for XML document handlers. This class doesn't
perform any error checking and assumes that all strings passed
as arguments to methods are unique symbols. The SymbolTable class
can be used for this purpose.

Author:Andy Clark, IBM
@LastModified: Oct 2017
/**
 * Namespace support for XML document handlers. This class doesn't
 * perform any error checking and assumes that all strings passed
 * as arguments to methods are unique symbols. The SymbolTable class
 * can be used for this purpose.
 *
 * @author Andy Clark, IBM
 *
 * @LastModified: Oct 2017
 */
public class NamespaceSupport implements NamespaceContext {

    //
    // Data
    //

    
Namespace binding information. This array is composed of a
series of tuples containing the namespace binding information:
<prefix, uri>. The default size can be set to anything
as long as it is a power of 2 greater than 1.

See Also:
/**
     * Namespace binding information. This array is composed of a
     * series of tuples containing the namespace binding information:
     * &lt;prefix, uri&gt;. The default size can be set to anything
     * as long as it is a power of 2 greater than 1.
     *
     * @see #fNamespaceSize
     * @see #fContext
     */
    protected String[] fNamespace = new String[16 * 2];

    
The top of the namespace information array. 
/** The top of the namespace information array. */
    protected int fNamespaceSize;

    // NOTE: The constructor depends on the initial context size
    //       being at least 1. -Ac

    
Context indexes. This array contains indexes into the namespace
information array. The index at the current context is the start
index of declared namespace bindings and runs to the size of the
namespace information array.

See Also:
  • fNamespaceSize
/**
     * Context indexes. This array contains indexes into the namespace
     * information array. The index at the current context is the start
     * index of declared namespace bindings and runs to the size of the
     * namespace information array.
     *
     * @see #fNamespaceSize
     */
    protected int[] fContext = new int[8];

    
The current context. 
/** The current context. */
    protected int fCurrentContext;

    protected String[] fPrefixes = new String[16];

    //
    // Constructors
    //

    
Default constructor. 
/** Default constructor. */
    public NamespaceSupport() {
    } // <init>()

    
Constructs a namespace context object and initializes it with
the prefixes declared in the specified context.

/**
     * Constructs a namespace context object and initializes it with
     * the prefixes declared in the specified context.
     */
    public NamespaceSupport(NamespaceContext context) {
        pushContext();
        // copy declaration in the context
        Enumeration<String> prefixes = context.getAllPrefixes();
        while (prefixes.hasMoreElements()){
            String prefix = prefixes.nextElement();
            String uri = context.getURI(prefix);
            declarePrefix(prefix, uri);
        }
    } // <init>(NamespaceContext)


    //
    // Public methods
    //

    
See Also:
  • reset.reset()
/**
     * @see com.sun.org.apache.xerces.internal.xni.NamespaceContext#reset()
     */
    public void reset() {

        // reset namespace and context info
        fNamespaceSize = 0;
        fCurrentContext = 0;


        // bind "xml" prefix to the XML uri
        fNamespace[fNamespaceSize++] = XMLSymbols.PREFIX_XML;
        fNamespace[fNamespaceSize++] = NamespaceContext.XML_URI;
        // bind "xmlns" prefix to the XMLNS uri
        fNamespace[fNamespaceSize++] = XMLSymbols.PREFIX_XMLNS;
        fNamespace[fNamespaceSize++] = NamespaceContext.XMLNS_URI;

        fContext[fCurrentContext] = fNamespaceSize;
        //++fCurrentContext;

    } // reset(SymbolTable)


    
See Also:
  • pushContext.pushContext()
/**
     * @see com.sun.org.apache.xerces.internal.xni.NamespaceContext#pushContext()
     */
    public void pushContext() {

        // extend the array, if necessary
        if (fCurrentContext + 1 == fContext.length) {
            int[] contextarray = new int[fContext.length * 2];
            System.arraycopy(fContext, 0, contextarray, 0, fContext.length);
            fContext = contextarray;
        }

        // push context
        fContext[++fCurrentContext] = fNamespaceSize;
        //System.out.println("calling push context, current context = " + fCurrentContext);
    } // pushContext()


    
See Also:
  • popContext.popContext()
/**
     * @see com.sun.org.apache.xerces.internal.xni.NamespaceContext#popContext()
     */
    public void popContext() {
        fNamespaceSize = fContext[fCurrentContext--];
        //System.out.println("Calling popContext, fCurrentContext = " + fCurrentContext);
    } // popContext()

    
See Also:
  • declarePrefix.declarePrefix(String, String)
/**
     * @see com.sun.org.apache.xerces.internal.xni.NamespaceContext#declarePrefix(String, String)
     */
    public boolean declarePrefix(String prefix, String uri) {
        // ignore "xml" and "xmlns" prefixes
        if (prefix == XMLSymbols.PREFIX_XML || prefix == XMLSymbols.PREFIX_XMLNS) {
            return false;
        }

        // see if prefix already exists in current context
        for (int i = fNamespaceSize; i > fContext[fCurrentContext]; i -= 2) {
            if (fNamespace[i - 2] == prefix) {
                // REVISIT: [Q] Should the new binding override the
                //          previously declared binding or should it
                //          it be ignored? -Ac
                // NOTE:    The SAX2 "NamespaceSupport" helper allows
                //          re-bindings with the new binding overwriting
                //          the previous binding. -Ac
                fNamespace[i - 1] = uri;
                return true;
            }
        }

        // resize array, if needed
        if (fNamespaceSize == fNamespace.length) {
            String[] namespacearray = new String[fNamespaceSize * 2];
            System.arraycopy(fNamespace, 0, namespacearray, 0, fNamespaceSize);
            fNamespace = namespacearray;
        }

        // bind prefix to uri in current context
        fNamespace[fNamespaceSize++] = prefix;
        fNamespace[fNamespaceSize++] = uri;

        return true;

    } // declarePrefix(String,String):boolean

    
See Also:
  • getURI.getURI(String)
/**
     * @see com.sun.org.apache.xerces.internal.xni.NamespaceContext#getURI(String)
     */
    public String getURI(String prefix) {

        // find prefix in current context
        for (int i = fNamespaceSize; i > 0; i -= 2) {
            if (fNamespace[i - 2] == prefix) {
                return fNamespace[i - 1];
            }
        }

        // prefix not found
        return null;

    } // getURI(String):String


    
See Also:
  • getPrefix.getPrefix(String)
/**
     * @see com.sun.org.apache.xerces.internal.xni.NamespaceContext#getPrefix(String)
     */
    public String getPrefix(String uri) {

        // find uri in current context
        for (int i = fNamespaceSize; i > 0; i -= 2) {
            if (fNamespace[i - 1] == uri) {
                if (getURI(fNamespace[i - 2]) == uri)
                    return fNamespace[i - 2];
            }
        }

        // uri not found
        return null;

    } // getPrefix(String):String

    
See Also:
  • getDeclaredPrefixCount.getDeclaredPrefixCount()
/**
     * @see com.sun.org.apache.xerces.internal.xni.NamespaceContext#getDeclaredPrefixCount()
     */
    public int getDeclaredPrefixCount() {
        return (fNamespaceSize - fContext[fCurrentContext]) / 2;
    } // getDeclaredPrefixCount():int

    
See Also:
  • getDeclaredPrefixAt.getDeclaredPrefixAt(int)
/**
     * @see com.sun.org.apache.xerces.internal.xni.NamespaceContext#getDeclaredPrefixAt(int)
     */
    public String getDeclaredPrefixAt(int index) {
        return fNamespace[fContext[fCurrentContext] + index * 2];
    } // getDeclaredPrefixAt(int):String

    public Iterator<String> getPrefixes(){
        int count = 0;
        if (fPrefixes.length < (fNamespace.length/2)) {
            // resize prefix array
            String[] prefixes = new String[fNamespaceSize];
            fPrefixes = prefixes;
        }
        String prefix = null;
        boolean unique = true;
        for (int i = 2; i < (fNamespaceSize-2); i += 2) {
            prefix = fNamespace[i + 2];
            for (int k=0;k<count;k++){
                if (fPrefixes[k]==prefix){
                    unique = false;
                    break;
                }
            }
            if (unique){
                fPrefixes[count++] = prefix;
            }
            unique = true;
        }
        return new IteratorPrefixes(fPrefixes, count);
    }//getPrefixes
    
See Also:
  • getAllPrefixes.getAllPrefixes()
/**
     * @see com.sun.org.apache.xerces.internal.xni.NamespaceContext#getAllPrefixes()
     */
    public Enumeration<String> getAllPrefixes() {
        int count = 0;
        if (fPrefixes.length < (fNamespace.length/2)) {
            // resize prefix array
            String[] prefixes = new String[fNamespaceSize];
            fPrefixes = prefixes;
        }
        String prefix = null;
        boolean unique = true;
        for (int i = 2; i < (fNamespaceSize-2); i += 2) {
            prefix = fNamespace[i + 2];
            for (int k=0;k<count;k++){
                if (fPrefixes[k]==prefix){
                    unique = false;
                    break;
                }
            }
            if (unique){
                fPrefixes[count++] = prefix;
            }
            unique = true;
        }
        return new Prefixes(fPrefixes, count);
    }

    public List<String> getPrefixes(String uri){
        int count = 0;
        String prefix = null;
        boolean unique = true;
        List<String> prefixList = new ArrayList<>();
        for (int i = fNamespaceSize; i >0 ; i -= 2) {
            if(fNamespace[i-1] == uri){
                if(!prefixList.contains(fNamespace[i-2]))
                    prefixList.add(fNamespace[i-2]);
            }
        }
        return prefixList;
    }

    /*
     * non-NamespaceContext methods
     */

    
Checks whether a binding or unbinding for
the given prefix exists in the context.

Params:
  • prefix – The prefix to look up.
Returns:true if the given prefix exists in the context
/**
     * Checks whether a binding or unbinding for
     * the given prefix exists in the context.
     *
     * @param prefix The prefix to look up.
     *
     * @return true if the given prefix exists in the context
     */
    public boolean containsPrefix(String prefix) {

        // find prefix in context
        for (int i = fNamespaceSize; i > 0; i -= 2) {
            if (fNamespace[i - 2] == prefix) {
                return true;
            }
        }

        // prefix not found
        return false;
    }

    
Checks whether a binding or unbinding for
the given prefix exists in the current context.

Params:
  • prefix – The prefix to look up.
Returns:true if the given prefix exists in the current context
/**
     * Checks whether a binding or unbinding for
     * the given prefix exists in the current context.
     *
     * @param prefix The prefix to look up.
     *
     * @return true if the given prefix exists in the current context
     */
    public boolean containsPrefixInCurrentContext(String prefix) {

        // find prefix in current context
        for (int i = fContext[fCurrentContext]; i < fNamespaceSize; i += 2) {
            if (fNamespace[i] == prefix) {
                return true;
            }
        }

        // prefix not found
        return false;
    }

    protected final class IteratorPrefixes implements Iterator<String>  {
        private String[] prefixes;
        private int counter = 0;
        private int size = 0;

        
Constructor for Prefixes.

/**
         * Constructor for Prefixes.
         */
        public IteratorPrefixes(String [] prefixes, int size) {
            this.prefixes = prefixes;
            this.size = size;
        }

        
See Also:
  • hasMoreElements.hasMoreElements()
/**
         * @see java.util.Enumeration#hasMoreElements()
         */
        public boolean hasNext() {
            return (counter < size);
        }

        
See Also:
  • nextElement.nextElement()
/**
         * @see java.util.Enumeration#nextElement()
         */
        public String next() {
            if (counter< size){
                return fPrefixes[counter++];
            }
            throw new NoSuchElementException("Illegal access to Namespace prefixes enumeration.");
        }

        public String toString(){
            StringBuilder buf = new StringBuilder();
            for (int i=0;i<size;i++){
                buf.append(prefixes[i]);
                buf.append(" ");
            }

            return buf.toString();
        }

        public void remove(){
            throw new UnsupportedOperationException();
        }
    }


    protected final class Prefixes implements Enumeration<String> {
        private String[] prefixes;
        private int counter = 0;
        private int size = 0;

        
Constructor for Prefixes.

/**
         * Constructor for Prefixes.
         */
        public Prefixes(String [] prefixes, int size) {
            this.prefixes = prefixes;
            this.size = size;
        }

        
See Also:
  • hasMoreElements.hasMoreElements()
/**
         * @see java.util.Enumeration#hasMoreElements()
         */
        public boolean hasMoreElements() {
            return (counter< size);
        }

        
See Also:
  • nextElement.nextElement()
/**
         * @see java.util.Enumeration#nextElement()
         */
        public String nextElement() {
            if (counter< size){
                return fPrefixes[counter++];
            }
            throw new NoSuchElementException("Illegal access to Namespace prefixes enumeration.");
        }

        public String toString(){
            StringBuilder buf = new StringBuilder();
            for (int i=0;i<size;i++){
                buf.append(prefixes[i]);
                buf.append(" ");
            }

            return buf.toString();
        }


    }

} // class NamespaceSupport