/*
 * 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 org.apache.xerces.impl;

import java.io.EOFException;
import java.io.IOException;
import java.util.Locale;

import org.apache.xerces.impl.io.UCSReader;
import org.apache.xerces.impl.msg.XMLMessageFormatter;
import org.apache.xerces.util.SymbolTable;
import org.apache.xerces.util.XMLChar;
import org.apache.xerces.util.XMLStringBuffer;
import org.apache.xerces.xni.QName;
import org.apache.xerces.xni.XMLLocator;
import org.apache.xerces.xni.XMLString;

Implements the entity scanner methods.
Author:
Andy Clark, IBM, Neil Graham, IBM
@xerces.internal
Version:
$Id: XMLEntityScanner.java 1707346 2015-10-07 17:46:10Z mrglavas $/**
 * Implements the entity scanner methods.
 *
 * @xerces.internal

 * 
 * @author Andy Clark, IBM
 * @author Neil Graham, IBM
 * @version $Id: XMLEntityScanner.java 1707346 2015-10-07 17:46:10Z mrglavas $
 */
public class XMLEntityScanner implements XMLLocator {

    // constants
    private static final boolean DEBUG_ENCODINGS = false;
    private static final boolean DEBUG_BUFFER = false;
    
    
To signal the end of the document entity, this exception will be thrown.
/**
     * To signal the end of the document entity, this exception will be thrown.
     */
    private static final EOFException END_OF_DOCUMENT_ENTITY = new EOFException() {
        private static final long serialVersionUID = 980337771224675268L;
        public Throwable fillInStackTrace() {
            return this;
        }
    };

    //
    // Data
    //

    private XMLEntityManager fEntityManager = null;
    protected XMLEntityManager.ScannedEntity fCurrentEntity = null;

    protected SymbolTable fSymbolTable = null;

    protected int fBufferSize = XMLEntityManager.DEFAULT_BUFFER_SIZE;

    
Error reporter. This property identifier is:
http://apache.org/xml/properties/internal/error-reporter
/**
     * Error reporter. This property identifier is:
     * http://apache.org/xml/properties/internal/error-reporter
     */
    protected XMLErrorReporter fErrorReporter;
    //
    // Constructors
    //

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

    //
    // XMLEntityScanner methods
    //

    
Returns the base system identifier of the currently scanned
entity, or null if none is available.
/**
     * Returns the base system identifier of the currently scanned
     * entity, or null if none is available.
     */
    public final String getBaseSystemId() {
        return (fCurrentEntity != null && fCurrentEntity.entityLocation != null) ? fCurrentEntity.entityLocation.getExpandedSystemId() : null;
    } // getBaseSystemId():String

    
Sets the encoding of the scanner. This method is used by the
scanners if the XMLDecl or TextDecl line contains an encoding
pseudo-attribute.

Note: The underlying character reader on the
current entity will be changed to accomodate the new encoding.
However, the new encoding is ignored if the current reader was
not constructed from an input stream (e.g. an external entity
that is resolved directly to the appropriate java.io.Reader
object).
Params:
encoding – The IANA encoding name of the new encoding.
Throws:
IOException – Thrown if the new encoding is not supported.
See Also:
EncodingMap/**
     * Sets the encoding of the scanner. This method is used by the
     * scanners if the XMLDecl or TextDecl line contains an encoding
     * pseudo-attribute.
     * <p>
     * <strong>Note:</strong> The underlying character reader on the
     * current entity will be changed to accomodate the new encoding.
     * However, the new encoding is ignored if the current reader was
     * not constructed from an input stream (e.g. an external entity
     * that is resolved directly to the appropriate java.io.Reader
     * object).
     *
     * @param encoding The IANA encoding name of the new encoding.
     *
     * @throws IOException Thrown if the new encoding is not supported.
     *
     * @see org.apache.xerces.util.EncodingMap
     */
    public final void setEncoding(String encoding) throws IOException {

        if (DEBUG_ENCODINGS) {
            System.out.println("$$$ setEncoding: "+encoding);
        }

        if (fCurrentEntity.stream != null) {
            // if the encoding is the same, don't change the reader and
            // re-use the original reader used by the OneCharReader
            // NOTE: Besides saving an object, this overcomes deficiencies
            //       in the UTF-16 reader supplied with the standard Java
            //       distribution (up to and including 1.3). The UTF-16
            //       decoder buffers 8K blocks even when only asked to read
            //       a single char! -Ac
            if (fCurrentEntity.encoding == null ||
                !fCurrentEntity.encoding.equals(encoding)) {
                // UTF-16 is a bit of a special case.  If the encoding is UTF-16,
                // and we know the endian-ness, we shouldn't change readers.
                // If it's ISO-10646-UCS-(2|4), then we'll have to deduce
                // the endian-ness from the encoding we presently have.
                if(fCurrentEntity.encoding != null && fCurrentEntity.encoding.startsWith("UTF-16")) {
                    String ENCODING = encoding.toUpperCase(Locale.ENGLISH);
                    if(ENCODING.equals("UTF-16")) return;
                    if(ENCODING.equals("ISO-10646-UCS-4")) {
                        if(fCurrentEntity.encoding.equals("UTF-16BE")) {
                            fCurrentEntity.reader = new UCSReader(fCurrentEntity.stream, UCSReader.UCS4BE);
                        } else {
                            fCurrentEntity.reader = new UCSReader(fCurrentEntity.stream, UCSReader.UCS4LE);
                        }
                        return;
                    }
                    if(ENCODING.equals("ISO-10646-UCS-2")) {
                        if(fCurrentEntity.encoding.equals("UTF-16BE")) {
                            fCurrentEntity.reader = new UCSReader(fCurrentEntity.stream, UCSReader.UCS2BE);
                        } else {
                            fCurrentEntity.reader = new UCSReader(fCurrentEntity.stream, UCSReader.UCS2LE);
                        }
                        return;
                    }
                }
                // wrap a new reader around the input stream, changing
                // the encoding
                if (DEBUG_ENCODINGS) {
                    System.out.println("$$$ creating new reader from stream: "+
                                    fCurrentEntity.stream);
                }
                //fCurrentEntity.stream.reset();
                fCurrentEntity.setReader(fCurrentEntity.stream, encoding, null);
                fCurrentEntity.encoding = encoding;
            } else {
                if (DEBUG_ENCODINGS)
                    System.out.println("$$$ reusing old reader on stream");
            }
        }

    } // setEncoding(String)
    
    
Sets the XML version. This method is used by the
scanners to report the value of the version pseudo-attribute
in an XML or text declaration.
Params:
xmlVersion – the XML version of the current entity/**
     * Sets the XML version. This method is used by the
     * scanners to report the value of the version pseudo-attribute
     * in an XML or text declaration.
     *
     * @param xmlVersion the XML version of the current entity
     */
    public final void setXMLVersion(String xmlVersion) {
        fCurrentEntity.xmlVersion = xmlVersion;
    } // setXMLVersion(String)

    
Returns true if the current entity being scanned is external. /** Returns true if the current entity being scanned is external. */
    public final boolean isExternal() {
        return fCurrentEntity.isExternal();
    } // isExternal():boolean

    
Returns the next character on the input.

Note: The character is not consumed.
Throws:
IOException –  Thrown if i/o error occurs.
EOFException – Thrown on end of file./**
     * Returns the next character on the input.
     * <p>
     * <strong>Note:</strong> The character is <em>not</em> consumed.
     *
     * @throws IOException  Thrown if i/o error occurs.
     * @throws EOFException Thrown on end of file.
     */
    public int peekChar() throws IOException {
        if (DEBUG_BUFFER) {
            System.out.print("(peekChar: ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println();
        }

        // load more characters, if needed
        if (fCurrentEntity.position == fCurrentEntity.count) {
            load(0, true);
        }

        // peek at character
        int c = fCurrentEntity.ch[fCurrentEntity.position];

        // return peeked character
        if (DEBUG_BUFFER) {
            System.out.print(")peekChar: ");
            XMLEntityManager.print(fCurrentEntity);
            if (fCurrentEntity.isExternal()) {
                System.out.println(" -> '"+(c!='\r'?(char)c:'\n')+"'");
            }
            else {
                System.out.println(" -> '"+(char)c+"'");
            }
        }
        if (fCurrentEntity.isExternal()) {
            return c != '\r' ? c : '\n';
        }
        else {
            return c;
        }

    } // peekChar():int

    
Returns the next character on the input.

Note: The character is consumed.
Throws:
IOException –  Thrown if i/o error occurs.
EOFException – Thrown on end of file./**
     * Returns the next character on the input.
     * <p>
     * <strong>Note:</strong> The character is consumed.
     *
     * @throws IOException  Thrown if i/o error occurs.
     * @throws EOFException Thrown on end of file.
     */
    public int scanChar() throws IOException {
        if (DEBUG_BUFFER) {
            System.out.print("(scanChar: ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println();
        }

        // load more characters, if needed
        if (fCurrentEntity.position == fCurrentEntity.count) {
            load(0, true);
        }

        // scan character
        int c = fCurrentEntity.ch[fCurrentEntity.position++];
        boolean external = false;
        if (c == '\n' ||
            (c == '\r' && (external = fCurrentEntity.isExternal()))) {
            fCurrentEntity.lineNumber++;
            fCurrentEntity.columnNumber = 1;
            if (fCurrentEntity.position == fCurrentEntity.count) {
                fCurrentEntity.ch[0] = (char)c;
                load(1, false);
            }
            if (c == '\r' && external) {
                if (fCurrentEntity.ch[fCurrentEntity.position++] != '\n') {
                    fCurrentEntity.position--;
                }
                c = '\n';
            }
        }

        // return character that was scanned
        if (DEBUG_BUFFER) {
            System.out.print(")scanChar: ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println(" -> '"+(char)c+"'");
        }
        fCurrentEntity.columnNumber++;
        return c;

    } // scanChar():int

    
Returns a string matching the NMTOKEN production appearing immediately
on the input as a symbol, or null if NMTOKEN Name string is present.

Note: The NMTOKEN characters are consumed.

Note: The string returned must be a symbol. The
SymbolTable can be used for this purpose.
Throws:
IOException –  Thrown if i/o error occurs.
EOFException – Thrown on end of file.
See Also:
SymbolTable
XMLChar.isName/**
     * Returns a string matching the NMTOKEN production appearing immediately
     * on the input as a symbol, or null if NMTOKEN Name string is present.
     * <p>
     * <strong>Note:</strong> The NMTOKEN characters are consumed.
     * <p>
     * <strong>Note:</strong> The string returned must be a symbol. The
     * SymbolTable can be used for this purpose.
     *
     * @throws IOException  Thrown if i/o error occurs.
     * @throws EOFException Thrown on end of file.
     *
     * @see org.apache.xerces.util.SymbolTable
     * @see org.apache.xerces.util.XMLChar#isName
     */
    public String scanNmtoken() throws IOException {
        if (DEBUG_BUFFER) {
            System.out.print("(scanNmtoken: ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println();
        }

        // load more characters, if needed
        if (fCurrentEntity.position == fCurrentEntity.count) {
            load(0, true);
        }

        // scan nmtoken
        int offset = fCurrentEntity.position;
        while (XMLChar.isName(fCurrentEntity.ch[fCurrentEntity.position])) {
            if (++fCurrentEntity.position == fCurrentEntity.count) {
                int length = fCurrentEntity.position - offset;
                if (length == fCurrentEntity.ch.length) {
                    // bad luck we have to resize our buffer
                    resizeBuffer(offset, length);
                }
                else {
                    System.arraycopy(fCurrentEntity.ch, offset,
                                     fCurrentEntity.ch, 0, length);
                }
                offset = 0;
                if (load(length, false)) {
                    break;
                }
            }
        }
        int length = fCurrentEntity.position - offset;
        fCurrentEntity.columnNumber += length;

        // return nmtoken
        String symbol = null;
        if (length > 0) {
            symbol = fSymbolTable.addSymbol(fCurrentEntity.ch, offset, length);
        }
        if (DEBUG_BUFFER) {
            System.out.print(")scanNmtoken: ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println(" -> "+String.valueOf(symbol));
        }
        return symbol;

    } // scanNmtoken():String

    
Returns a string matching the Name production appearing immediately
on the input as a symbol, or null if no Name string is present.

Note: The Name characters are consumed.

Note: The string returned must be a symbol. The
SymbolTable can be used for this purpose.
Throws:
IOException –  Thrown if i/o error occurs.
EOFException – Thrown on end of file.
See Also:
SymbolTable
XMLChar.isName
XMLChar.isNameStart/**
     * Returns a string matching the Name production appearing immediately
     * on the input as a symbol, or null if no Name string is present.
     * <p>
     * <strong>Note:</strong> The Name characters are consumed.
     * <p>
     * <strong>Note:</strong> The string returned must be a symbol. The
     * SymbolTable can be used for this purpose.
     *
     * @throws IOException  Thrown if i/o error occurs.
     * @throws EOFException Thrown on end of file.
     *
     * @see org.apache.xerces.util.SymbolTable
     * @see org.apache.xerces.util.XMLChar#isName
     * @see org.apache.xerces.util.XMLChar#isNameStart
     */
    public String scanName() throws IOException {
        if (DEBUG_BUFFER) {
            System.out.print("(scanName: ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println();
        }

        // load more characters, if needed
        if (fCurrentEntity.position == fCurrentEntity.count) {
            load(0, true);
        }

        // scan name
        int offset = fCurrentEntity.position;
        if (XMLChar.isNameStart(fCurrentEntity.ch[offset])) {
            if (++fCurrentEntity.position == fCurrentEntity.count) {
                fCurrentEntity.ch[0] = fCurrentEntity.ch[offset];
                offset = 0;
                if (load(1, false)) {
                    fCurrentEntity.columnNumber++;
                    String symbol = fSymbolTable.addSymbol(fCurrentEntity.ch, 0, 1);
                    if (DEBUG_BUFFER) {
                        System.out.print(")scanName: ");
                        XMLEntityManager.print(fCurrentEntity);
                        System.out.println(" -> "+String.valueOf(symbol));
                    }
                    return symbol;
                }
            }
            while (XMLChar.isName(fCurrentEntity.ch[fCurrentEntity.position])) {
                if (++fCurrentEntity.position == fCurrentEntity.count) {
                    int length = fCurrentEntity.position - offset;
                    if (length == fCurrentEntity.ch.length) {
                        // bad luck we have to resize our buffer
                        resizeBuffer(offset, length);
                    }
                    else {
                        System.arraycopy(fCurrentEntity.ch, offset,
                                         fCurrentEntity.ch, 0, length);
                    }
                    offset = 0;
                    if (load(length, false)) {
                        break;
                    }
                }
            }
        }
        int length = fCurrentEntity.position - offset;
        fCurrentEntity.columnNumber += length;

        // return name
        String symbol = null;
        if (length > 0) {
            symbol = fSymbolTable.addSymbol(fCurrentEntity.ch, offset, length);
        }
        if (DEBUG_BUFFER) {
            System.out.print(")scanName: ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println(" -> "+String.valueOf(symbol));
        }
        return symbol;

    } // scanName():String

    
Returns a string matching the NCName production appearing immediately
on the input as a symbol, or null if no NCName string is present.

Note: The NCName characters are consumed.

Note: The string returned must be a symbol. The
SymbolTable can be used for this purpose.
Throws:
IOException –  Thrown if i/o error occurs.
EOFException – Thrown on end of file.
See Also:
SymbolTable
XMLChar.isNCName
XMLChar.isNCNameStart/**
     * Returns a string matching the NCName production appearing immediately
     * on the input as a symbol, or null if no NCName string is present.
     * <p>
     * <strong>Note:</strong> The NCName characters are consumed.
     * <p>
     * <strong>Note:</strong> The string returned must be a symbol. The
     * SymbolTable can be used for this purpose.
     *
     * @throws IOException  Thrown if i/o error occurs.
     * @throws EOFException Thrown on end of file.
     *
     * @see org.apache.xerces.util.SymbolTable
     * @see org.apache.xerces.util.XMLChar#isNCName
     * @see org.apache.xerces.util.XMLChar#isNCNameStart
     */
    public String scanNCName() throws IOException {
        if (DEBUG_BUFFER) {
            System.out.print("(scanNCName: ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println();
        }

        // load more characters, if needed
        if (fCurrentEntity.position == fCurrentEntity.count) {
            load(0, true);
        }

        // scan name
        int offset = fCurrentEntity.position;
        if (XMLChar.isNCNameStart(fCurrentEntity.ch[offset])) {
            if (++fCurrentEntity.position == fCurrentEntity.count) {
                fCurrentEntity.ch[0] = fCurrentEntity.ch[offset];
                offset = 0;
                if (load(1, false)) {
                    fCurrentEntity.columnNumber++;
                    String symbol = fSymbolTable.addSymbol(fCurrentEntity.ch, 0, 1);
                    if (DEBUG_BUFFER) {
                        System.out.print(")scanNCName: ");
                        XMLEntityManager.print(fCurrentEntity);
                        System.out.println(" -> "+String.valueOf(symbol));
                    }
                    return symbol;
                }
            }
            while (XMLChar.isNCName(fCurrentEntity.ch[fCurrentEntity.position])) {
                if (++fCurrentEntity.position == fCurrentEntity.count) {
                    int length = fCurrentEntity.position - offset;
                    if (length == fCurrentEntity.ch.length) {
                        // bad luck we have to resize our buffer
                        resizeBuffer(offset, length);
                    }
                    else {
                        System.arraycopy(fCurrentEntity.ch, offset,
                                         fCurrentEntity.ch, 0, length);
                    }
                    offset = 0;
                    if (load(length, false)) {
                        break;
                    }
                }
            }
        }
        int length = fCurrentEntity.position - offset;
        fCurrentEntity.columnNumber += length;

        // return name
        String symbol = null;
        if (length > 0) {
            symbol = fSymbolTable.addSymbol(fCurrentEntity.ch, offset, length);
        }
        if (DEBUG_BUFFER) {
            System.out.print(")scanNCName: ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println(" -> "+String.valueOf(symbol));
        }
        return symbol;

    } // scanNCName():String

    
Scans a qualified name from the input, setting the fields of the
QName structure appropriately.

Note: The qualified name characters are consumed.

Note: The strings used to set the values of the
QName structure must be symbols. The SymbolTable can be used for
this purpose.
Params:
qname – The qualified name structure to fill.
Throws:
IOException –  Thrown if i/o error occurs.
EOFException – Thrown on end of file.
See Also:
SymbolTable
XMLChar.isName
XMLChar.isNameStart
Returns:
Returns true if a qualified name appeared immediately on
        the input and was scanned, false otherwise./**
     * Scans a qualified name from the input, setting the fields of the
     * QName structure appropriately.
     * <p>
     * <strong>Note:</strong> The qualified name characters are consumed.
     * <p>
     * <strong>Note:</strong> The strings used to set the values of the
     * QName structure must be symbols. The SymbolTable can be used for
     * this purpose.
     *
     * @param qname The qualified name structure to fill.
     *
     * @return Returns true if a qualified name appeared immediately on
     *         the input and was scanned, false otherwise.
     *
     * @throws IOException  Thrown if i/o error occurs.
     * @throws EOFException Thrown on end of file.
     *
     * @see org.apache.xerces.util.SymbolTable
     * @see org.apache.xerces.util.XMLChar#isName
     * @see org.apache.xerces.util.XMLChar#isNameStart
     */
    public boolean scanQName(QName qname) throws IOException {
        if (DEBUG_BUFFER) {
            System.out.print("(scanQName, "+qname+": ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println();
        }

        // load more characters, if needed
        if (fCurrentEntity.position == fCurrentEntity.count) {
            load(0, true);
        }

        // scan qualified name
        int offset = fCurrentEntity.position;
        if (XMLChar.isNCNameStart(fCurrentEntity.ch[offset])) {
            if (++fCurrentEntity.position == fCurrentEntity.count) {
                fCurrentEntity.ch[0] = fCurrentEntity.ch[offset];
                offset = 0;
                if (load(1, false)) {
                    fCurrentEntity.columnNumber++;
                    String name =
                        fSymbolTable.addSymbol(fCurrentEntity.ch, 0, 1);
                    qname.setValues(null, name, name, null);
                    if (DEBUG_BUFFER) {
                        System.out.print(")scanQName, "+qname+": ");
                        XMLEntityManager.print(fCurrentEntity);
                        System.out.println(" -> true");
                    }
                    return true;
                }
            }
            int index = -1;
            while (XMLChar.isName(fCurrentEntity.ch[fCurrentEntity.position])) {
                char c = fCurrentEntity.ch[fCurrentEntity.position];

                if (c == ':') {
                    if (index != -1) {
                        break;
                    }
                    index = fCurrentEntity.position;
                }
                if (++fCurrentEntity.position == fCurrentEntity.count) {
                    int length = fCurrentEntity.position - offset;
                    if (length == fCurrentEntity.ch.length) {
                        // bad luck we have to resize our buffer
                        resizeBuffer(offset, length);
                    }
                    else {
                        System.arraycopy(fCurrentEntity.ch, offset,
                                         fCurrentEntity.ch, 0, length);
                    }
                    if (index != -1) {
                        index = index - offset;
                    }
                    offset = 0;
                    if (load(length, false)) {
                        break;
                    }
                }
            }
            int length = fCurrentEntity.position - offset;
            fCurrentEntity.columnNumber += length;
            if (length > 0) {
                String prefix = null;
                String localpart = null;
                String rawname = fSymbolTable.addSymbol(fCurrentEntity.ch,
                                                        offset, length);
                if (index != -1) {
                    int prefixLength = index - offset;
                    prefix = fSymbolTable.addSymbol(fCurrentEntity.ch,
                                                    offset, prefixLength);
                    int len = length - prefixLength - 1;
                    int startLocal = index +1;
                    if (!XMLChar.isNCNameStart(fCurrentEntity.ch[startLocal])){
                        fErrorReporter.reportError(XMLMessageFormatter.XML_DOMAIN,
                                                 "IllegalQName",
                                                  null,
                                                  XMLErrorReporter.SEVERITY_FATAL_ERROR);
                    }
                    localpart = fSymbolTable.addSymbol(fCurrentEntity.ch,
                                                       startLocal, len);

                }
                else {
                    localpart = rawname;
                }
                qname.setValues(prefix, localpart, rawname, null);
                if (DEBUG_BUFFER) {
                    System.out.print(")scanQName, "+qname+": ");
                    XMLEntityManager.print(fCurrentEntity);
                    System.out.println(" -> true");
                }
                return true;
            }
        }

        // no qualified name found
        if (DEBUG_BUFFER) {
            System.out.print(")scanQName, "+qname+": ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println(" -> false");
        }
        return false;

    } // scanQName(QName):boolean

    
Scans a range of parsed character data, setting the fields of the
XMLString structure, appropriately.

Note: The characters are consumed.

Note: This method does not guarantee to return
the longest run of parsed character data. This method may return
before markup due to reaching the end of the input buffer or any
other reason.

Note: The fields contained in the XMLString
structure are not guaranteed to remain valid upon subsequent calls
to the entity scanner. Therefore, the caller is responsible for
immediately using the returned character data or making a copy of
the character data.
Params:
content – The content structure to fill.
Throws:
IOException –  Thrown if i/o error occurs.
EOFException – Thrown on end of file.
Returns:
Returns the next character on the input, if known. This
        value may be -1 but this does note designate
        end of file./**
     * Scans a range of parsed character data, setting the fields of the
     * XMLString structure, appropriately.
     * <p>
     * <strong>Note:</strong> The characters are consumed.
     * <p>
     * <strong>Note:</strong> This method does not guarantee to return
     * the longest run of parsed character data. This method may return
     * before markup due to reaching the end of the input buffer or any
     * other reason.
     * <p>
     * <strong>Note:</strong> The fields contained in the XMLString
     * structure are not guaranteed to remain valid upon subsequent calls
     * to the entity scanner. Therefore, the caller is responsible for
     * immediately using the returned character data or making a copy of
     * the character data.
     *
     * @param content The content structure to fill.
     *
     * @return Returns the next character on the input, if known. This
     *         value may be -1 but this does <em>note</em> designate
     *         end of file.
     *
     * @throws IOException  Thrown if i/o error occurs.
     * @throws EOFException Thrown on end of file.
     */
    public int scanContent(XMLString content) throws IOException {
        if (DEBUG_BUFFER) {
            System.out.print("(scanContent: ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println();
        }

        // load more characters, if needed
        if (fCurrentEntity.position == fCurrentEntity.count) {
            load(0, true);
        }
        else if (fCurrentEntity.position == fCurrentEntity.count - 1) {
            fCurrentEntity.ch[0] = fCurrentEntity.ch[fCurrentEntity.count - 1];
            load(1, false);
            fCurrentEntity.position = 0;
            fCurrentEntity.startPosition = 0;
        }

        // normalize newlines
        int offset = fCurrentEntity.position;
        int c = fCurrentEntity.ch[offset];
        int newlines = 0;
        boolean external = fCurrentEntity.isExternal();
        if (c == '\n' || (c == '\r' && external)) {
            if (DEBUG_BUFFER) {
                System.out.print("[newline, "+offset+", "+fCurrentEntity.position+": ");
                XMLEntityManager.print(fCurrentEntity);
                System.out.println();
            }
            do {
                c = fCurrentEntity.ch[fCurrentEntity.position++];
                if (c == '\r' && external) {
                    newlines++;
                    fCurrentEntity.lineNumber++;
                    fCurrentEntity.columnNumber = 1;
                    if (fCurrentEntity.position == fCurrentEntity.count) {
                        offset = 0;
                        fCurrentEntity.baseCharOffset += (fCurrentEntity.position - fCurrentEntity.startPosition);
                        fCurrentEntity.position = newlines;
                        fCurrentEntity.startPosition = newlines;
                        if (load(newlines, false)) {
                            break;
                        }
                    }
                    if (fCurrentEntity.ch[fCurrentEntity.position] == '\n') {
                        fCurrentEntity.position++;
                        offset++;
                    }
                    /*** NEWLINE NORMALIZATION ***/
                    else {
                        newlines++;
                    }
                }
                else if (c == '\n') {
                    newlines++;
                    fCurrentEntity.lineNumber++;
                    fCurrentEntity.columnNumber = 1;
                    if (fCurrentEntity.position == fCurrentEntity.count) {
                        offset = 0;
                        fCurrentEntity.baseCharOffset += (fCurrentEntity.position - fCurrentEntity.startPosition);
                        fCurrentEntity.position = newlines;
                        fCurrentEntity.startPosition = newlines;
                        if (load(newlines, false)) {
                            break;
                        }
                    }
                }
                else {
                    fCurrentEntity.position--;
                    break;
                }
            } while (fCurrentEntity.position < fCurrentEntity.count - 1);
            for (int i = offset; i < fCurrentEntity.position; i++) {
                fCurrentEntity.ch[i] = '\n';
            }
            int length = fCurrentEntity.position - offset;
            if (fCurrentEntity.position == fCurrentEntity.count - 1) {
                content.setValues(fCurrentEntity.ch, offset, length);
                if (DEBUG_BUFFER) {
                    System.out.print("]newline, "+offset+", "+fCurrentEntity.position+": ");
                    XMLEntityManager.print(fCurrentEntity);
                    System.out.println();
                }
                return -1;
            }
            if (DEBUG_BUFFER) {
                System.out.print("]newline, "+offset+", "+fCurrentEntity.position+": ");
                XMLEntityManager.print(fCurrentEntity);
                System.out.println();
            }
        }

        // inner loop, scanning for content
        while (fCurrentEntity.position < fCurrentEntity.count) {
            c = fCurrentEntity.ch[fCurrentEntity.position++];
            if (!XMLChar.isContent(c)) {
                fCurrentEntity.position--;
                break;
            }
        }
        int length = fCurrentEntity.position - offset;
        fCurrentEntity.columnNumber += length - newlines;
        content.setValues(fCurrentEntity.ch, offset, length);

        // return next character
        if (fCurrentEntity.position != fCurrentEntity.count) {
            c = fCurrentEntity.ch[fCurrentEntity.position];
            // REVISIT: Does this need to be updated to fix the
            //          #x0D ^#x0A newline normalization problem? -Ac
            if (c == '\r' && external) {
                c = '\n';
            }
        }
        else {
            c = -1;
        }
        if (DEBUG_BUFFER) {
            System.out.print(")scanContent: ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println(" -> '"+(char)c+"'");
        }
        return c;

    } // scanContent(XMLString):int

    
Scans a range of attribute value data, setting the fields of the
XMLString structure, appropriately.

Note: The characters are consumed.

Note: This method does not guarantee to return
the longest run of attribute value data. This method may return
before the quote character due to reaching the end of the input
buffer or any other reason.

Note: The fields contained in the XMLString
structure are not guaranteed to remain valid upon subsequent calls
to the entity scanner. Therefore, the caller is responsible for
immediately using the returned character data or making a copy of
the character data.
Params:
quote –   The quote character that signifies the end of the
               attribute value data.
content – The content structure to fill.
Throws:
IOException –  Thrown if i/o error occurs.
EOFException – Thrown on end of file.
Returns:
Returns the next character on the input, if known. This
        value may be -1 but this does note designate
        end of file./**
     * Scans a range of attribute value data, setting the fields of the
     * XMLString structure, appropriately.
     * <p>
     * <strong>Note:</strong> The characters are consumed.
     * <p>
     * <strong>Note:</strong> This method does not guarantee to return
     * the longest run of attribute value data. This method may return
     * before the quote character due to reaching the end of the input
     * buffer or any other reason.
     * <p>
     * <strong>Note:</strong> The fields contained in the XMLString
     * structure are not guaranteed to remain valid upon subsequent calls
     * to the entity scanner. Therefore, the caller is responsible for
     * immediately using the returned character data or making a copy of
     * the character data.
     *
     * @param quote   The quote character that signifies the end of the
     *                attribute value data.
     * @param content The content structure to fill.
     *
     * @return Returns the next character on the input, if known. This
     *         value may be -1 but this does <em>note</em> designate
     *         end of file.
     *
     * @throws IOException  Thrown if i/o error occurs.
     * @throws EOFException Thrown on end of file.
     */
    public int scanLiteral(int quote, XMLString content)
        throws IOException {
        if (DEBUG_BUFFER) {
            System.out.print("(scanLiteral, '"+(char)quote+"': ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println();
        }

        // load more characters, if needed
        if (fCurrentEntity.position == fCurrentEntity.count) {
            load(0, true);
        }
        else if (fCurrentEntity.position == fCurrentEntity.count - 1) {
            fCurrentEntity.ch[0] = fCurrentEntity.ch[fCurrentEntity.count - 1];
            load(1, false);
            fCurrentEntity.position = 0;
            fCurrentEntity.startPosition = 0;
        }

        // normalize newlines
        int offset = fCurrentEntity.position;
        int c = fCurrentEntity.ch[offset];
        int newlines = 0;
        boolean external = fCurrentEntity.isExternal();
        if (c == '\n' || (c == '\r' && external)) {
            if (DEBUG_BUFFER) {
                System.out.print("[newline, "+offset+", "+fCurrentEntity.position+": ");
                XMLEntityManager.print(fCurrentEntity);
                System.out.println();
            }
            do {
                c = fCurrentEntity.ch[fCurrentEntity.position++];
                if (c == '\r' && external) {
                    newlines++;
                    fCurrentEntity.lineNumber++;
                    fCurrentEntity.columnNumber = 1;
                    if (fCurrentEntity.position == fCurrentEntity.count) {
                        offset = 0;
                        fCurrentEntity.baseCharOffset += (fCurrentEntity.position - fCurrentEntity.startPosition);
                        fCurrentEntity.position = newlines;
                        fCurrentEntity.startPosition = newlines;
                        if (load(newlines, false)) {
                            break;
                        }
                    }
                    if (fCurrentEntity.ch[fCurrentEntity.position] == '\n') {
                        fCurrentEntity.position++;
                        offset++;
                    }
                    /*** NEWLINE NORMALIZATION ***/
                    else {
                        newlines++;
                    }
                    /***/
                }
                else if (c == '\n') {
                    newlines++;
                    fCurrentEntity.lineNumber++;
                    fCurrentEntity.columnNumber = 1;
                    if (fCurrentEntity.position == fCurrentEntity.count) {
                        offset = 0;
                        fCurrentEntity.baseCharOffset += (fCurrentEntity.position - fCurrentEntity.startPosition);
                        fCurrentEntity.position = newlines;
                        fCurrentEntity.startPosition = newlines;
                        if (load(newlines, false)) {
                            break;
                        }
                    }
                }
                else {
                    fCurrentEntity.position--;
                    break;
                }
            } while (fCurrentEntity.position < fCurrentEntity.count - 1);
            for (int i = offset; i < fCurrentEntity.position; i++) {
                fCurrentEntity.ch[i] = '\n';
            }
            int length = fCurrentEntity.position - offset;
            if (fCurrentEntity.position == fCurrentEntity.count - 1) {
                content.setValues(fCurrentEntity.ch, offset, length);
                if (DEBUG_BUFFER) {
                    System.out.print("]newline, "+offset+", "+fCurrentEntity.position+": ");
                    XMLEntityManager.print(fCurrentEntity);
                    System.out.println();
                }
                return -1;
            }
            if (DEBUG_BUFFER) {
                System.out.print("]newline, "+offset+", "+fCurrentEntity.position+": ");
                XMLEntityManager.print(fCurrentEntity);
                System.out.println();
            }
        }

        // scan literal value
        while (fCurrentEntity.position < fCurrentEntity.count) {
            c = fCurrentEntity.ch[fCurrentEntity.position++];
            if ((c == quote &&
                 (!fCurrentEntity.literal || external))
                || c == '%' || !XMLChar.isContent(c)) {
                fCurrentEntity.position--;
                break;
            }
        }
        int length = fCurrentEntity.position - offset;
        fCurrentEntity.columnNumber += length - newlines;
        content.setValues(fCurrentEntity.ch, offset, length);

        // return next character
        if (fCurrentEntity.position != fCurrentEntity.count) {
            c = fCurrentEntity.ch[fCurrentEntity.position];
            // NOTE: We don't want to accidentally signal the
            //       end of the literal if we're expanding an
            //       entity appearing in the literal. -Ac
            if (c == quote && fCurrentEntity.literal) {
                c = -1;
            }
        }
        else {
            c = -1;
        }
        if (DEBUG_BUFFER) {
            System.out.print(")scanLiteral, '"+(char)quote+"': ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println(" -> '"+(char)c+"'");
        }
        return c;

    } // scanLiteral(int,XMLString):int

    
Scans a range of character data up to the specified delimiter,
setting the fields of the XMLString structure, appropriately.

Note: The characters are consumed.

Note: This assumes that the internal buffer is
at least the same size, or bigger, than the length of the delimiter
and that the delimiter contains at least one character.

Note: This method does not guarantee to return
the longest run of character data. This method may return before
the delimiter due to reaching the end of the input buffer or any
other reason.

Note: The fields contained in the XMLString
structure are not guaranteed to remain valid upon subsequent calls
to the entity scanner. Therefore, the caller is responsible for
immediately using the returned character data or making a copy of
the character data.
Params:
delimiter – The string that signifies the end of the character
                 data to be scanned.
buffer –    The XMLStringBuffer to fill.
Throws:
IOException –  Thrown if i/o error occurs.
EOFException – Thrown on end of file.
Returns:
Returns true if there is more data to scan, false otherwise./**
     * Scans a range of character data up to the specified delimiter,
     * setting the fields of the XMLString structure, appropriately.
     * <p>
     * <strong>Note:</strong> The characters are consumed.
     * <p>
     * <strong>Note:</strong> This assumes that the internal buffer is
     * at least the same size, or bigger, than the length of the delimiter
     * and that the delimiter contains at least one character.
     * <p>
     * <strong>Note:</strong> This method does not guarantee to return
     * the longest run of character data. This method may return before
     * the delimiter due to reaching the end of the input buffer or any
     * other reason.
     * <p>
     * <strong>Note:</strong> The fields contained in the XMLString
     * structure are not guaranteed to remain valid upon subsequent calls
     * to the entity scanner. Therefore, the caller is responsible for
     * immediately using the returned character data or making a copy of
     * the character data.
     *
     * @param delimiter The string that signifies the end of the character
     *                  data to be scanned.
     * @param buffer    The XMLStringBuffer to fill.
     *
     * @return Returns true if there is more data to scan, false otherwise.
     *
     * @throws IOException  Thrown if i/o error occurs.
     * @throws EOFException Thrown on end of file.
     */
    public boolean scanData(String delimiter, XMLStringBuffer buffer)
        throws IOException {

        // REVISIT: This method does not need to use a string buffer.
        //          The change would avoid the array copies and increase
        //          performance. -Ac
        //
        //          Currently, this method is called for scanning CDATA
        //          sections, comments,  and processing instruction data. 
        //          So if this code is updated to NOT buffer, the scanning
        //          code for comments and processing instructions will 
        //          need to be updated to do its own buffering. The code 
        //          for CDATA sections is safe as-is. -Ac

        boolean found = false;
        int delimLen = delimiter.length();
        char charAt0 = delimiter.charAt(0);
        boolean external = fCurrentEntity.isExternal();
        if (DEBUG_BUFFER) {
            System.out.print("(scanData: ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println();
        }

        // load more characters, if needed

        if (fCurrentEntity.position == fCurrentEntity.count) {
            load(0, true);
        }

        boolean bNextEntity = false;

        while ((fCurrentEntity.position > fCurrentEntity.count - delimLen)
            && (!bNextEntity))
        {
          System.arraycopy(fCurrentEntity.ch,
                           fCurrentEntity.position,
                           fCurrentEntity.ch,
                           0,
                           fCurrentEntity.count - fCurrentEntity.position);

          bNextEntity = load(fCurrentEntity.count - fCurrentEntity.position, false);
          fCurrentEntity.position = 0;
          fCurrentEntity.startPosition = 0;
        }

        if (fCurrentEntity.position > fCurrentEntity.count - delimLen) {
            // something must be wrong with the input:  e.g., file ends in an unterminated comment
            int length = fCurrentEntity.count - fCurrentEntity.position;
            buffer.append (fCurrentEntity.ch, fCurrentEntity.position, length); 
            fCurrentEntity.columnNumber += fCurrentEntity.count;
            fCurrentEntity.baseCharOffset += (fCurrentEntity.position - fCurrentEntity.startPosition);
            fCurrentEntity.position = fCurrentEntity.count;
            fCurrentEntity.startPosition = fCurrentEntity.count;
            load(0,true);
            return false;
        }

        // normalize newlines
        int offset = fCurrentEntity.position;
        int c = fCurrentEntity.ch[offset];
        int newlines = 0;
        if (c == '\n' || (c == '\r' && external)) {
            if (DEBUG_BUFFER) {
                System.out.print("[newline, "+offset+", "+fCurrentEntity.position+": ");
                XMLEntityManager.print(fCurrentEntity);
                System.out.println();
            }
            do {
                c = fCurrentEntity.ch[fCurrentEntity.position++];
                if (c == '\r' && external) {
                    newlines++;
                    fCurrentEntity.lineNumber++;
                    fCurrentEntity.columnNumber = 1;
                    if (fCurrentEntity.position == fCurrentEntity.count) {
                        offset = 0;
                        fCurrentEntity.baseCharOffset += (fCurrentEntity.position - fCurrentEntity.startPosition);
                        fCurrentEntity.position = newlines;
                        fCurrentEntity.startPosition = newlines;
                        if (load(newlines, false)) {
                            break;
                        }
                    }
                    if (fCurrentEntity.ch[fCurrentEntity.position] == '\n') {
                        fCurrentEntity.position++;
                        offset++;
                    }
                    /*** NEWLINE NORMALIZATION ***/
                    else {
                        newlines++;
                    }
                }
                else if (c == '\n') {
                    newlines++;
                    fCurrentEntity.lineNumber++;
                    fCurrentEntity.columnNumber = 1;
                    if (fCurrentEntity.position == fCurrentEntity.count) {
                        offset = 0;
                        fCurrentEntity.baseCharOffset += (fCurrentEntity.position - fCurrentEntity.startPosition);
                        fCurrentEntity.position = newlines;
                        fCurrentEntity.startPosition = newlines;
                        fCurrentEntity.count = newlines;
                        if (load(newlines, false)) {
                            break;
                        }
                    }
                }
                else {
                    fCurrentEntity.position--;
                    break;
                }
            } while (fCurrentEntity.position < fCurrentEntity.count - 1);
            for (int i = offset; i < fCurrentEntity.position; i++) {
                fCurrentEntity.ch[i] = '\n';
            }
            int length = fCurrentEntity.position - offset;
            if (fCurrentEntity.position == fCurrentEntity.count - 1) {
                buffer.append(fCurrentEntity.ch, offset, length);
                if (DEBUG_BUFFER) {
                    System.out.print("]newline, "+offset+", "+fCurrentEntity.position+": ");
                    XMLEntityManager.print(fCurrentEntity);
                    System.out.println();
                }
                return true;
            }
            if (DEBUG_BUFFER) {
                System.out.print("]newline, "+offset+", "+fCurrentEntity.position+": ");
                XMLEntityManager.print(fCurrentEntity);
                System.out.println();
            }
        }

        // iterate over buffer looking for delimiter
        OUTER: while (fCurrentEntity.position < fCurrentEntity.count) {
            c = fCurrentEntity.ch[fCurrentEntity.position++];
            if (c == charAt0) {
                // looks like we just hit the delimiter
                int delimOffset = fCurrentEntity.position - 1;
                for (int i = 1; i < delimLen; i++) {
                    if (fCurrentEntity.position == fCurrentEntity.count) {
                        fCurrentEntity.position -= i;
                        break OUTER;
                    }
                    c = fCurrentEntity.ch[fCurrentEntity.position++];
                    if (delimiter.charAt(i) != c) {
                        fCurrentEntity.position--;
                        break;
                    }
                }
                if (fCurrentEntity.position == delimOffset + delimLen) {
                    found = true;
                    break;
                }
            }
            else if (c == '\n' || (external && c == '\r')) {
                fCurrentEntity.position--;
                break;
            }
            else if (XMLChar.isInvalid(c)) {
                fCurrentEntity.position--;
                int length = fCurrentEntity.position - offset;
                fCurrentEntity.columnNumber += length - newlines;
                buffer.append(fCurrentEntity.ch, offset, length); 
                return true;
            }
        }
        int length = fCurrentEntity.position - offset;
        fCurrentEntity.columnNumber += length - newlines;
        if (found) {
            length -= delimLen;
        }
        buffer.append (fCurrentEntity.ch, offset, length);

        // return true if string was skipped
        if (DEBUG_BUFFER) {
            System.out.print(")scanData: ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println(" -> " + !found);
        }
        return !found;

    } // scanData(String,XMLString):boolean

    
Skips a character appearing immediately on the input.

Note: The character is consumed only if it matches
the specified character.
Params:
c – The character to skip.
Throws:
IOException –  Thrown if i/o error occurs.
EOFException – Thrown on end of file.
Returns:
Returns true if the character was skipped./**
     * Skips a character appearing immediately on the input.
     * <p>
     * <strong>Note:</strong> The character is consumed only if it matches
     * the specified character.
     *
     * @param c The character to skip.
     *
     * @return Returns true if the character was skipped.
     *
     * @throws IOException  Thrown if i/o error occurs.
     * @throws EOFException Thrown on end of file.
     */
    public boolean skipChar(int c) throws IOException {
        if (DEBUG_BUFFER) {
            System.out.print("(skipChar, '"+(char)c+"': ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println();
        }

        // load more characters, if needed
        if (fCurrentEntity.position == fCurrentEntity.count) {
            load(0, true);
        }

        // skip character
        int cc = fCurrentEntity.ch[fCurrentEntity.position];
        if (cc == c) {
            fCurrentEntity.position++;
            if (c == '\n') {
                fCurrentEntity.lineNumber++;
                fCurrentEntity.columnNumber = 1;
            }
            else {
                fCurrentEntity.columnNumber++;
            }
            if (DEBUG_BUFFER) {
                System.out.print(")skipChar, '"+(char)c+"': ");
                XMLEntityManager.print(fCurrentEntity);
                System.out.println(" -> true");
            }
            return true;
        }
        else if (c == '\n' && cc == '\r' && fCurrentEntity.isExternal()) {
            // handle newlines
            if (fCurrentEntity.position == fCurrentEntity.count) {
                fCurrentEntity.ch[0] = (char)cc;
                load(1, false);
            }
            fCurrentEntity.position++;
            if (fCurrentEntity.ch[fCurrentEntity.position] == '\n') {
                fCurrentEntity.position++;
            }
            fCurrentEntity.lineNumber++;
            fCurrentEntity.columnNumber = 1;
            if (DEBUG_BUFFER) {
                System.out.print(")skipChar, '"+(char)c+"': ");
                XMLEntityManager.print(fCurrentEntity);
                System.out.println(" -> true");
            }
            return true;
        }

        // character was not skipped
        if (DEBUG_BUFFER) {
            System.out.print(")skipChar, '"+(char)c+"': ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println(" -> false");
        }
        return false;

    } // skipChar(int):boolean

    
Skips space characters appearing immediately on the input.

Note: The characters are consumed only if they are
space characters.
Throws:
IOException –  Thrown if i/o error occurs.
EOFException – Thrown on end of file.
See Also:
XMLChar.isSpace
Returns:
Returns true if at least one space character was skipped./**
     * Skips space characters appearing immediately on the input.
     * <p>
     * <strong>Note:</strong> The characters are consumed only if they are
     * space characters.
     *
     * @return Returns true if at least one space character was skipped.
     *
     * @throws IOException  Thrown if i/o error occurs.
     * @throws EOFException Thrown on end of file.
     *
     * @see org.apache.xerces.util.XMLChar#isSpace
     */
    public boolean skipSpaces() throws IOException {
        if (DEBUG_BUFFER) {
            System.out.print("(skipSpaces: ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println();
        }

        // load more characters, if needed
        if (fCurrentEntity.position == fCurrentEntity.count) {
            load(0, true);
        }

        // skip spaces
        int c = fCurrentEntity.ch[fCurrentEntity.position];
        if (XMLChar.isSpace(c)) {
            boolean external = fCurrentEntity.isExternal();
            do {
                boolean entityChanged = false;
                // handle newlines
                if (c == '\n' || (external && c == '\r')) {
                    fCurrentEntity.lineNumber++;
                    fCurrentEntity.columnNumber = 1;
                    if (fCurrentEntity.position == fCurrentEntity.count - 1) {
                        fCurrentEntity.ch[0] = (char)c;
                        entityChanged = load(1, true);
                        if (!entityChanged) {
                            // the load change the position to be 1,
                            // need to restore it when entity not changed
                            fCurrentEntity.position = 0;
                            fCurrentEntity.startPosition = 0;
                        }
                    }
                    if (c == '\r' && external) {
                        // REVISIT: Does this need to be updated to fix the
                        //          #x0D ^#x0A newline normalization problem? -Ac
                        if (fCurrentEntity.ch[++fCurrentEntity.position] != '\n') {
                            fCurrentEntity.position--;
                        }
                    }
                    /*** NEWLINE NORMALIZATION ***
                    else {
                        if (fCurrentEntity.ch[fCurrentEntity.position + 1] == '\r'
                            && external) {
                            fCurrentEntity.position++;
                        }
                    }
                    /***/
                }
                else {
                    fCurrentEntity.columnNumber++;
                }
                // load more characters, if needed
                if (!entityChanged)
                    fCurrentEntity.position++;
                if (fCurrentEntity.position == fCurrentEntity.count) {
                    load(0, true);
                }
            } while (XMLChar.isSpace(c = fCurrentEntity.ch[fCurrentEntity.position]));
            if (DEBUG_BUFFER) {
                System.out.print(")skipSpaces: ");
                XMLEntityManager.print(fCurrentEntity);
                System.out.println(" -> true");
            }
            return true;
        }

        // no spaces were found
        if (DEBUG_BUFFER) {
            System.out.print(")skipSpaces: ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println(" -> false");
        }
        return false;

    } // skipSpaces():boolean

    
Skips space characters appearing immediately on the input that would
match non-terminal S (0x09, 0x0A, 0x0D, 0x20) before end of line 
normalization is performed. This is useful when scanning structures 
such as the XMLDecl and TextDecl that can only contain US-ASCII 
characters.

Note: The characters are consumed only if they would
match non-terminal S before end of line normalization is performed.
Throws:
IOException –  Thrown if i/o error occurs.
EOFException – Thrown on end of file.
See Also:
XMLChar.isSpace
Returns:
Returns true if at least one space character was skipped./**
     * Skips space characters appearing immediately on the input that would
     * match non-terminal S (0x09, 0x0A, 0x0D, 0x20) before end of line 
     * normalization is performed. This is useful when scanning structures 
     * such as the XMLDecl and TextDecl that can only contain US-ASCII 
     * characters.
     * <p>
     * <strong>Note:</strong> The characters are consumed only if they would
     * match non-terminal S before end of line normalization is performed.
     *
     * @return Returns true if at least one space character was skipped.
     *
     * @throws IOException  Thrown if i/o error occurs.
     * @throws EOFException Thrown on end of file.
     *
     * @see org.apache.xerces.util.XMLChar#isSpace
     */
    public final boolean skipDeclSpaces() throws IOException {
        if (DEBUG_BUFFER) {
            System.out.print("(skipDeclSpaces: ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println();
        }

        // load more characters, if needed
        if (fCurrentEntity.position == fCurrentEntity.count) {
            load(0, true);
        }

        // skip spaces
        int c = fCurrentEntity.ch[fCurrentEntity.position];
        if (XMLChar.isSpace(c)) {
            boolean external = fCurrentEntity.isExternal();
            do {
                boolean entityChanged = false;
                // handle newlines
                if (c == '\n' || (external && c == '\r')) {
                    fCurrentEntity.lineNumber++;
                    fCurrentEntity.columnNumber = 1;
                    if (fCurrentEntity.position == fCurrentEntity.count - 1) {
                        fCurrentEntity.ch[0] = (char)c;
                        entityChanged = load(1, true);
                        if (!entityChanged) {
                            // the load change the position to be 1,
                            // need to restore it when entity not changed
                            fCurrentEntity.position = 0;
                            fCurrentEntity.startPosition = 0;
                        }
                    }
                    if (c == '\r' && external) {
                        // REVISIT: Does this need to be updated to fix the
                        //          #x0D ^#x0A newline normalization problem? -Ac
                        if (fCurrentEntity.ch[++fCurrentEntity.position] != '\n') {
                            fCurrentEntity.position--;
                        }
                    }
                    /*** NEWLINE NORMALIZATION ***
                    else {
                        if (fCurrentEntity.ch[fCurrentEntity.position + 1] == '\r'
                            && external) {
                            fCurrentEntity.position++;
                        }
                    }
                    /***/
                }
                else {
                    fCurrentEntity.columnNumber++;
                }
                // load more characters, if needed
                if (!entityChanged)
                    fCurrentEntity.position++;
                if (fCurrentEntity.position == fCurrentEntity.count) {
                    load(0, true);
                }
            } while (XMLChar.isSpace(c = fCurrentEntity.ch[fCurrentEntity.position]));
            if (DEBUG_BUFFER) {
                System.out.print(")skipDeclSpaces: ");
                XMLEntityManager.print(fCurrentEntity);
                System.out.println(" -> true");
            }
            return true;
        }

        // no spaces were found
        if (DEBUG_BUFFER) {
            System.out.print(")skipDeclSpaces: ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println(" -> false");
        }
        return false;

    } // skipDeclSpaces():boolean

    
Skips the specified string appearing immediately on the input.

Note: The characters are consumed only if they are
space characters.
Params:
s – The string to skip.
Throws:
IOException –  Thrown if i/o error occurs.
EOFException – Thrown on end of file.
Returns:
Returns true if the string was skipped./**
     * Skips the specified string appearing immediately on the input.
     * <p>
     * <strong>Note:</strong> The characters are consumed only if they are
     * space characters.
     *
     * @param s The string to skip.
     *
     * @return Returns true if the string was skipped.
     *
     * @throws IOException  Thrown if i/o error occurs.
     * @throws EOFException Thrown on end of file.
     */
    public boolean skipString(String s) throws IOException {
        if (DEBUG_BUFFER) {
            System.out.print("(skipString, \""+s+"\": ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println();
        }

        // load more characters, if needed
        if (fCurrentEntity.position == fCurrentEntity.count) {
            load(0, true);
        }

        // skip string
        final int length = s.length();
        for (int i = 0; i < length; i++) {
            char c = fCurrentEntity.ch[fCurrentEntity.position++];
            if (c != s.charAt(i)) {
                fCurrentEntity.position -= i + 1;
                if (DEBUG_BUFFER) {
                    System.out.print(")skipString, \""+s+"\": ");
                    XMLEntityManager.print(fCurrentEntity);
                    System.out.println(" -> false");
                }
                return false;
            }
            if (i < length - 1 && fCurrentEntity.position == fCurrentEntity.count) {
                System.arraycopy(fCurrentEntity.ch, fCurrentEntity.count - i - 1, fCurrentEntity.ch, 0, i + 1);
                // REVISIT: Can a string to be skipped cross an
                //          entity boundary? -Ac
                if (load(i + 1, false)) {
                    fCurrentEntity.startPosition -= i + 1; 
                    fCurrentEntity.position -= i + 1;
                    if (DEBUG_BUFFER) {
                        System.out.print(")skipString, \""+s+"\": ");
                        XMLEntityManager.print(fCurrentEntity);
                        System.out.println(" -> false");
                    }
                    return false;
                }
            }
        }
        if (DEBUG_BUFFER) {
            System.out.print(")skipString, \""+s+"\": ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println(" -> true");
        }
        fCurrentEntity.columnNumber += length;
        return true;

    } // skipString(String):boolean

    //
    // Locator methods
    //

    
Return the public identifier for the current document event.

The return value is the public identifier of the document
entity or of the external parsed entity in which the markup
triggering the event appears.
Returns:
A string containing the public identifier, or
        null if none is available./**
     * Return the public identifier for the current document event.
     * <p>
     * The return value is the public identifier of the document
     * entity or of the external parsed entity in which the markup
     * triggering the event appears.
     *
     * @return A string containing the public identifier, or
     *         null if none is available.
     */
    public final String getPublicId() {
        return (fCurrentEntity != null && fCurrentEntity.entityLocation != null) ? fCurrentEntity.entityLocation.getPublicId() : null;
    } // getPublicId():String

    
Return the expanded system identifier for the current document event.

The return value is the expanded system identifier of the document
entity or of the external parsed entity in which the markup
triggering the event appears.

If the system identifier is a URL, the parser must resolve it
fully before passing it to the application.
Returns:
A string containing the expanded system identifier, or null
        if none is available./**
     * Return the expanded system identifier for the current document event.
     * <p>
     * The return value is the expanded system identifier of the document
     * entity or of the external parsed entity in which the markup
     * triggering the event appears.
     * <p>
     * If the system identifier is a URL, the parser must resolve it
     * fully before passing it to the application.
     *
     * @return A string containing the expanded system identifier, or null
     *         if none is available.
     */
    public final String getExpandedSystemId() {
        if (fCurrentEntity != null) {
            if (fCurrentEntity.entityLocation != null &&
                    fCurrentEntity.entityLocation.getExpandedSystemId() != null ) {
                return fCurrentEntity.entityLocation.getExpandedSystemId();
            }
            else {
                // get the current entity to return something appropriate:
                return fCurrentEntity.getExpandedSystemId();
            }
        }
        return null;
    } // getExpandedSystemId():String

    
Return the literal system identifier for the current document event.

The return value is the literal system identifier of the document
entity or of the external parsed entity in which the markup
triggering the event appears.

Returns:
A string containing the literal system identifier, or null
        if none is available./**
     * Return the literal system identifier for the current document event.
     * <p>
     * The return value is the literal system identifier of the document
     * entity or of the external parsed entity in which the markup
     * triggering the event appears.
     * <p>
     * @return A string containing the literal system identifier, or null
     *         if none is available.
     */
    public final String getLiteralSystemId() {
        if (fCurrentEntity != null) {
            if (fCurrentEntity.entityLocation != null &&
                    fCurrentEntity.entityLocation.getLiteralSystemId() != null ) {
                return fCurrentEntity.entityLocation.getLiteralSystemId();
            }
            else {
                // get the current entity to do it:
                return fCurrentEntity.getLiteralSystemId();
            }
        }
        return null;
    } // getLiteralSystemId():String

    
Returns the line number where the current document event ends.

Warning: The return value from the method
is intended only as an approximation for the sake of error
reporting; it is not intended to provide sufficient information
to edit the character content of the original XML document.

The return value is an approximation of the line number
in the document entity or external parsed entity where the
markup triggering the event appears.

If possible, the line position of the first character after the 
text associated with the document event should be provided.
The first line in the document is line 1.
Returns:
The line number, or -1 if none is available./**
     * Returns the line number where the current document event ends.
     * <p>
     * <strong>Warning:</strong> The return value from the method
     * is intended only as an approximation for the sake of error
     * reporting; it is not intended to provide sufficient information
     * to edit the character content of the original XML document.
     * <p>
     * The return value is an approximation of the line number
     * in the document entity or external parsed entity where the
     * markup triggering the event appears.
     * <p>
     * If possible, the line position of the first character after the 
     * text associated with the document event should be provided.
     * The first line in the document is line 1.
     *
     * @return The line number, or -1 if none is available.
     */
    public final int getLineNumber() {
        if (fCurrentEntity != null) {
            if (fCurrentEntity.isExternal()) {
                return fCurrentEntity.lineNumber;
            }
            else {
                // ask the current entity to return something appropriate:
                return fCurrentEntity.getLineNumber();
            }
        }

        return -1;

    } // getLineNumber():int

    
Returns the column number where the current document event ends.

Warning: The return value from the method
is intended only as an approximation for the sake of error
reporting; it is not intended to provide sufficient information
to edit the character content of the original XML document.

The return value is an approximation of the column number
in the document entity or external parsed entity where the
markup triggering the event appears.

If possible, the line position of the first character after the 
text associated with the document event should be provided.
The first column in each line is column 1.
Returns:
The column number, or -1 if none is available./**
     * Returns the column number where the current document event ends.
     * <p>
     * <strong>Warning:</strong> The return value from the method
     * is intended only as an approximation for the sake of error
     * reporting; it is not intended to provide sufficient information
     * to edit the character content of the original XML document.
     * <p>
     * The return value is an approximation of the column number
     * in the document entity or external parsed entity where the
     * markup triggering the event appears.
     * <p>
     * If possible, the line position of the first character after the 
     * text associated with the document event should be provided.
     * The first column in each line is column 1.
     *
     * @return The column number, or -1 if none is available.
     */
    public final int getColumnNumber() {
        if (fCurrentEntity != null) {
            if (fCurrentEntity.isExternal()) {
                return fCurrentEntity.columnNumber;
            }
            else {
                // ask current entity to find appropriate column number
                return fCurrentEntity.getColumnNumber();
            }
        }

        return -1;
    } // getColumnNumber():int
    
    
Returns the character offset where the current document event ends.

Warning: The return value from the method
is intended only as an approximation for the sake of error
reporting; it is not intended to provide sufficient information
to edit the character content of the original XML document.

The return value is an approximation of the character offset
in the document entity or external parsed entity where the
markup triggering the event appears.

If possible, the character offset of the first character after the 
text associated with the document event should be provided.
Returns:
The character offset, or -1 if none is available./**
     * Returns the character offset where the current document event ends.
     * <p>
     * <strong>Warning:</strong> The return value from the method
     * is intended only as an approximation for the sake of error
     * reporting; it is not intended to provide sufficient information
     * to edit the character content of the original XML document.
     * <p>
     * The return value is an approximation of the character offset
     * in the document entity or external parsed entity where the
     * markup triggering the event appears.
     * <p>
     * If possible, the character offset of the first character after the 
     * text associated with the document event should be provided.
     *
     * @return The character offset, or -1 if none is available.
     */
    public final int getCharacterOffset() {
        if (fCurrentEntity != null) {
            if (fCurrentEntity.isExternal()) {
                return fCurrentEntity.baseCharOffset + (fCurrentEntity.position - fCurrentEntity.startPosition);
            }
            else {
                // ask current entity to find appropriate character offset
                return fCurrentEntity.getCharacterOffset();
            }
        }
        
        return -1;
    } // getCharacterOffset():int
    
    
Returns the encoding of the current entity.  
Note that, for a given entity, this value can only be
considered final once the encoding declaration has been read (or once it
has been determined that there is no such declaration) since, no encoding
having been specified on the XMLInputSource, the parser
will make an initial "guess" which could be in error. 
/** 
     * Returns the encoding of the current entity.  
     * Note that, for a given entity, this value can only be
     * considered final once the encoding declaration has been read (or once it
     * has been determined that there is no such declaration) since, no encoding
     * having been specified on the XMLInputSource, the parser
     * will make an initial "guess" which could be in error. 
     */
    public final String getEncoding() {
        if (fCurrentEntity != null) {
            if (fCurrentEntity.isExternal()) {
                return fCurrentEntity.encoding;
            }
            else {
                // ask current entity to find appropriate encoding
                return fCurrentEntity.getEncoding();
            }
        }
        return null;
    } // getEncoding():String
    
    
Returns the XML version of the current entity. This will normally be the
value from the XML or text declaration or defaulted by the parser. Note that
that this value may be different than the version of the processing rules 
applied to the current entity. For instance, an XML 1.1 document may refer to
XML 1.0 entities. In such a case the rules of XML 1.1 are applied to the entire 
document. Also note that, for a given entity, this value can only be considered
final once the XML or text declaration has been read or once it has been
determined that there is no such declaration.
/**
     * Returns the XML version of the current entity. This will normally be the
     * value from the XML or text declaration or defaulted by the parser. Note that
     * that this value may be different than the version of the processing rules 
     * applied to the current entity. For instance, an XML 1.1 document may refer to
     * XML 1.0 entities. In such a case the rules of XML 1.1 are applied to the entire 
     * document. Also note that, for a given entity, this value can only be considered
     * final once the XML or text declaration has been read or once it has been
     * determined that there is no such declaration.
     */
    public final String getXMLVersion() {
        if (fCurrentEntity != null) {
            if (fCurrentEntity.isExternal()) {
                return fCurrentEntity.xmlVersion;
            }
            else {
                // ask current entity to find the appropriate XML version
                return fCurrentEntity.getXMLVersion();
            }
        }
        return null;
    } // getXMLVersion():String
    
    // allow entity manager to tell us what the current entityis:
    public final void setCurrentEntity(XMLEntityManager.ScannedEntity ent) {
        fCurrentEntity = ent;
    }

    // set buffer size:
    public final void setBufferSize(int size) {
        // REVISIT: Buffer size passed to entity scanner 
        // was not being kept in synch with the actual size
        // of the buffers in each scanned entity. If any
        // of the buffers were actually resized, it was possible
        // that the parser would throw an ArrayIndexOutOfBoundsException
        // for documents which contained names which are longer than
        // the current buffer size. Conceivably the buffer size passed
        // to entity scanner could be used to determine a minimum size
        // for resizing, if doubling its size is smaller than this
        // minimum. -- mrglavas 
        fBufferSize = size;
    }

    // reset what little state we have...
    public final void reset(SymbolTable symbolTable, XMLEntityManager entityManager,
                        XMLErrorReporter reporter) {
        fCurrentEntity = null;
        fSymbolTable = symbolTable;
        fEntityManager = entityManager;
        fErrorReporter = reporter;
    }

    //
    // Private methods
    //

    
Loads a chunk of text.
Params:
offset –       The offset into the character buffer to
                    read the next batch of characters.
changeEntity – True if the load should change entities
                    at the end of the entity, otherwise leave
                    the current entity in place and the entity
                    boundary will be signaled by the return
                    value.
@returns
Returns true if the entity changed as a result of this
         load operation./**
     * Loads a chunk of text.
     *
     * @param offset       The offset into the character buffer to
     *                     read the next batch of characters.
     * @param changeEntity True if the load should change entities
     *                     at the end of the entity, otherwise leave
     *                     the current entity in place and the entity
     *                     boundary will be signaled by the return
     *                     value.
     *
     * @returns Returns true if the entity changed as a result of this
     *          load operation.
     */
    final boolean load(int offset, boolean changeEntity)
        throws IOException {
        if (DEBUG_BUFFER) {
            System.out.print("(load, "+offset+": ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println();
        }

        fCurrentEntity.baseCharOffset += (fCurrentEntity.position - fCurrentEntity.startPosition);
        // read characters
        int length = fCurrentEntity.ch.length - offset;
        if (!fCurrentEntity.mayReadChunks && length > XMLEntityManager.DEFAULT_XMLDECL_BUFFER_SIZE) {
            length = XMLEntityManager.DEFAULT_XMLDECL_BUFFER_SIZE;
        }
        if (DEBUG_BUFFER) System.out.println("  length to try to read: "+length);
        int count = fCurrentEntity.reader.read(fCurrentEntity.ch, offset, length);
        if (DEBUG_BUFFER) System.out.println("  length actually read:  "+count);

        // reset count and position
        boolean entityChanged = false;
        if (count != -1) {
            if (count != 0) {
                fCurrentEntity.count = count + offset;
                fCurrentEntity.position = offset;
                fCurrentEntity.startPosition = offset;
            }
        }

        // end of this entity
        else {
            fCurrentEntity.count = offset;
            fCurrentEntity.position = offset;
            fCurrentEntity.startPosition = offset;
            entityChanged = true;
            if (changeEntity) {
                fEntityManager.endEntity();
                if (fCurrentEntity == null) {
                    throw END_OF_DOCUMENT_ENTITY;
                }
                // handle the trailing edges
                if (fCurrentEntity.position == fCurrentEntity.count) {
                    load(0, true);
                }
            }
        }
        if (DEBUG_BUFFER) {
            System.out.print(")load, "+offset+": ");
            XMLEntityManager.print(fCurrentEntity);
            System.out.println();
        }

        return entityChanged;

    } // load(int, boolean):boolean
    
    
This method is invoked to increase the size of the current entity's
buffer if an XML name being scanned is too large to fit within
the buffer at its current size. 
/**
     * This method is invoked to increase the size of the current entity's
     * buffer if an XML name being scanned is too large to fit within
     * the buffer at its current size. 
     */
    final void resizeBuffer(int offset, int length) {
        char[] tmp = new char[fCurrentEntity.ch.length << 1];
        System.arraycopy(fCurrentEntity.ch, offset,
                         tmp, 0, length);
        fCurrentEntity.ch = tmp;
    } // resizeBuffer(int, int)

} // class XMLEntityScanner