/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999-2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xerces" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact apache\@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation, and was
 * originally based on software copyright (c) 1999, International
 * Business Machines, Inc., http://www.ibm.com .  For more information
 * on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

/*
 * $Id$
 */


// ---------------------------------------------------------------------------
//  This sample program which invokes the DOMParser to build a DOM tree for
//  the specified input file. It then walks the tree, and prints out the data
//  as an XML file.
//
//   Limitations:
//      1.  The encoding="xxx" clause in the XML header should reflect
//          the system local code page, but does not.
//      2.  Cases where the XML data contains characters that can not
//          be represented in the system local code page are not handled.
//      3.  Enabled namespace processing won't affect the output, since
//          DOM doesn't do namespace yet. But it will confirm that all
//          prefixes are correctly mapped, else you'll get errors.
// ---------------------------------------------------------------------------


// ---------------------------------------------------------------------------
//  Includes
// ---------------------------------------------------------------------------
#include <util/PlatformUtils.hpp>
#include <util/XMLString.hpp>
#include <util/XMLUniDefs.hpp>
#include <framework/XMLFormatter.hpp>
#include <util/TranscodingException.hpp>


#include <dom/DOM_DOMException.hpp>

#include <parsers/DOMParser.hpp>
#include <dom/DOM.hpp>
#include "DOMTreeErrorReporter.hpp"
#include <string.h>
#include <stdlib.h>


// ---------------------------------------------------------------------------
//  Local const data
//
//  Note: This is the 'safe' way to do these strings. If you compiler supports
//        L"" style strings, and portability is not a concern, you can use
//        those types constants directly.
// ---------------------------------------------------------------------------
static const XMLCh  gEndElement[] = { chOpenAngle, chForwardSlash, chNull };
static const XMLCh  gEndPI[] = { chQuestion, chCloseAngle, chNull};
static const XMLCh  gStartPI[] = { chOpenAngle, chQuestion, chNull };
static const XMLCh  gXMLDecl1[] =
{
        chOpenAngle, chQuestion, chLatin_x, chLatin_m, chLatin_l
    ,   chSpace, chLatin_v, chLatin_e, chLatin_r, chLatin_s, chLatin_i
    ,   chLatin_o, chLatin_n, chEqual, chDoubleQuote, chNull
};
static const XMLCh  gXMLDecl2[] =
{
        chDoubleQuote, chSpace, chLatin_e, chLatin_n, chLatin_c
    ,   chLatin_o, chLatin_d, chLatin_i, chLatin_n, chLatin_g, chEqual
    ,   chDoubleQuote, chNull
};
static const XMLCh  gXMLDecl3[] =
{
        chDoubleQuote, chSpace, chLatin_s, chLatin_t, chLatin_a
    ,   chLatin_n, chLatin_d, chLatin_a, chLatin_l, chLatin_o
    ,   chLatin_n, chLatin_e, chEqual, chDoubleQuote, chNull
};
static const XMLCh  gXMLDecl4[] =
{
        chDoubleQuote, chQuestion, chCloseAngle
    ,   chLF, chNull
};

static const XMLCh  gStartCDATA[] =
{
        chOpenAngle, chBang, chOpenSquare, chLatin_C, chLatin_D,
        chLatin_A, chLatin_T, chLatin_A, chOpenSquare, chNull
};

static const XMLCh  gEndCDATA[] =
{
    chCloseSquare, chCloseSquare, chCloseAngle, chNull
};
static const XMLCh  gStartComment[] =
{
    chOpenAngle, chBang, chDash, chDash, chNull
};

static const XMLCh  gEndComment[] =
{
    chDash, chDash, chCloseAngle, chNull
};

static const XMLCh  gStartDoctype[] =
{
    chOpenAngle, chBang, chLatin_D, chLatin_O, chLatin_C, chLatin_T,
    chLatin_Y, chLatin_P, chLatin_E, chSpace, chNull
};
static const XMLCh  gPublic[] =
{
    chLatin_P, chLatin_U, chLatin_B, chLatin_L, chLatin_I,
    chLatin_C, chSpace, chDoubleQuote, chNull
};
static const XMLCh  gSystem[] =
{
    chLatin_S, chLatin_Y, chLatin_S, chLatin_T, chLatin_E,
    chLatin_M, chSpace, chDoubleQuote, chNull
};
static const XMLCh  gStartEntity[] =
{
    chOpenAngle, chBang, chLatin_E, chLatin_N, chLatin_T, chLatin_I,
    chLatin_T, chLatin_Y, chSpace, chNull
};
static const XMLCh  gNotation[] =
{
    chLatin_N, chLatin_D, chLatin_A, chLatin_T, chLatin_A,
    chSpace, chDoubleQuote, chNull
};


// ---------------------------------------------------------------------------
//  Local classes
// ---------------------------------------------------------------------------

class DOMPrintFormatTarget : public XMLFormatTarget
{
public:
    DOMPrintFormatTarget()  {};
    ~DOMPrintFormatTarget() {};

    // -----------------------------------------------------------------------
    //  Implementations of the format target interface
    // -----------------------------------------------------------------------

    void writeChars(const   XMLByte* const  toWrite,
                    const   unsigned int    count,
                            XMLFormatter * const formatter)
    {
        // Surprisingly, Solaris was the only platform on which
        // required the char* cast to print out the string correctly.
        // Without the cast, it was printing the pointer value in hex.
        // Quite annoying, considering every other platform printed
        // the string with the explicit cast to char* below.
        cout.write((char *) toWrite, (int) count);
    };

private:
    // -----------------------------------------------------------------------
    //  Unimplemented methods.
    // -----------------------------------------------------------------------
    DOMPrintFormatTarget(const DOMPrintFormatTarget& other);
    void operator=(const DOMPrintFormatTarget& rhs);
};


// ---------------------------------------------------------------------------
//  Local data
//
//  gXmlFile
//      The path to the file to parser. Set via command line.
//
//  gDoNamespaces
//      Indicates whether namespace processing should be done.
//
//  gDoSchema
//      Indicates whether schema processing should be done.
//
//  gDoCreate
//      Indicates whether entity reference nodes needs to be created or not
//      Defaults to false
//
//  gEncodingName
//      The encoding we are to output in. If not set on the command line,
//      then it is defaults to the encoding of the input XML file.
//
//  gValScheme
//      Indicates what validation scheme to use. It defaults to 'auto', but
//      can be set via the -v= command.
//
// ---------------------------------------------------------------------------
static char*                    gXmlFile               = 0;
static bool                     gDoNamespaces          = false;
static bool                     gDoSchema              = false;
static bool                     gDoCreate              = false;
static XMLCh*                   gEncodingName          = 0;
static XMLFormatter::UnRepFlags gUnRepFlags            = XMLFormatter::UnRep_CharRef;
static DOMParser::ValSchemes    gValScheme             = DOMParser::Val_Auto;
static XMLFormatter*            gFormatter             = 0;


// ---------------------------------------------------------------------------
//  Forward references
// ---------------------------------------------------------------------------
void     usage();
ostream& operator<<(ostream& target, const DOMString& toWrite);
ostream& operator<<(ostream& target, DOM_Node& toWrite);
XMLFormatter& operator<< (XMLFormatter& strm, const DOMString& s);


// ---------------------------------------------------------------------------
//
//  Usage()
//
// ---------------------------------------------------------------------------
void usage()
{
    cout << "\nUsage: DOMPrint [options] file\n\n"
            "This program invokes the Xerces-C DOM parser and builds the DOM\n"
            "tree. It then traverses the DOM tree and prints the contents\n"
            "of the tree. Options are NOT case sensitive.\n\n"
            "Options:\n"
            "    -e          create entity reference nodes. Default is no expansion.\n"
            "    -u=xxx      Handle unrepresentable chars [fail | rep | ref*]\n"
            "    -v=xxx      Validation scheme [always | never | auto*]\n"
            "    -n          Enable namespace processing. Default is off.\n"
            "    -s          Enable schema processing. Default is off.\n"
            "    -x=XXX      Use a particular encoding for output. Default is\n"
            "                the same encoding as the input XML file. UTF-8 if\n"
            "                input XML file has not XML declaration.\n"
            "    -?          Show this help (must be the only parameter)\n\n"
            "  * = Default if not provided explicitly\n\n"
            "The parser has intrinsic support for the following encodings:\n"
            "    UTF-8, USASCII, ISO8859-1, UTF-16[BL]E, UCS-4[BL]E,\n"
            "    WINDOWS-1252, IBM1140, IBM037\n"
          <<  endl;
}


// ---------------------------------------------------------------------------
//
//  main
//
// ---------------------------------------------------------------------------
int main(int argC, char* argV[])
{
    int retval = 0;

    // Initialize the XML4C2 system
    try
    {
        XMLPlatformUtils::Initialize();
    }

    catch(const XMLException& toCatch)
    {
        cerr << "Error during Xerces-c Initialization.\n"
             << "  Exception message:"
             << DOMString(toCatch.getMessage()) << endl;
        return 1;
    }

    // Check command line and extract arguments.
    if (argC < 2)
    {
        usage();
        XMLPlatformUtils::Terminate();
        return 1;
    }

    // Watch for special case help request
    if (!strcmp(argV[1], "-?"))
    {
        usage();
        XMLPlatformUtils::Terminate();
        return 2;
    }

    // See if non validating dom parser configuration is requested.
    int parmInd;
    for (parmInd = 1; parmInd < argC; parmInd++)
    {
        // Break out on first parm not starting with a dash
        if (argV[parmInd][0] != '-')
            break;

        if (!strncmp(argV[parmInd], "-v=", 3)
        ||  !strncmp(argV[parmInd], "-V=", 3))
        {
            const char* const parm = &argV[parmInd][3];

            if (!strcmp(parm, "never"))
                gValScheme = DOMParser::Val_Never;
            else if (!strcmp(parm, "auto"))
                gValScheme = DOMParser::Val_Auto;
            else if (!strcmp(parm, "always"))
                gValScheme = DOMParser::Val_Always;
            else
            {
                cerr << "Unknown -v= value: " << parm << endl;
                return 2;
            }
        }
         else if (!strcmp(argV[parmInd], "-n")
              ||  !strcmp(argV[parmInd], "-N"))
        {
            gDoNamespaces = true;
        }
         else if (!strcmp(argV[parmInd], "-s")
              ||  !strcmp(argV[parmInd], "-S"))
        {
            gDoSchema = true;
        }
         else if (!strcmp(argV[parmInd], "-e")
              ||  !strcmp(argV[parmInd], "-E"))
        {
            gDoCreate = true;
        }
         else if (!strncmp(argV[parmInd], "-x=", 3)
              ||  !strncmp(argV[parmInd], "-X=", 3))
        {
             // Get out the encoding name
             gEncodingName = XMLString::transcode( &(argV[parmInd][3]) );
        }
         else if (!strncmp(argV[parmInd], "-u=", 3)
              ||  !strncmp(argV[parmInd], "-U=", 3))
        {
            const char* const parm = &argV[parmInd][3];

            if (!strcmp(parm, "fail"))
                gUnRepFlags = XMLFormatter::UnRep_Fail;
            else if (!strcmp(parm, "rep"))
                gUnRepFlags = XMLFormatter::UnRep_Replace;
            else if (!strcmp(parm, "ref"))
                gUnRepFlags = XMLFormatter::UnRep_CharRef;
            else
            {
                cerr << "Unknown -u= value: " << parm << endl;
                return 2;
            }
        }
        //  else if (!strcmp(argV[parmInd], "-NoEscape"))
        // {
        //     gDoEscapes = false;
        // }
         else
        {
            cerr << "Unknown option '" << argV[parmInd]
                 << "', ignoring it.\n" << endl;
        }
    }

    //
    //  And now we have to have only one parameter left and it must be
    //  the file name.
    //
    if (parmInd + 1 != argC)
    {
        usage();
        XMLPlatformUtils::Terminate();
        return 1;
    }
    gXmlFile = argV[parmInd];

    //
    //  Create our parser, then attach an error handler to the parser.
    //  The parser will call back to methods of the ErrorHandler if it
    //  discovers errors during the course of parsing the XML document.
    //
    DOMParser *parser = new DOMParser;
    parser->setValidationScheme(gValScheme);
    parser->setDoNamespaces(gDoNamespaces);
    parser->setDoSchema(gDoSchema);
    DOMTreeErrorReporter *errReporter = new DOMTreeErrorReporter();
    parser->setErrorHandler(errReporter);
    parser->setCreateEntityReferenceNodes(gDoCreate);
    parser->setToCreateXMLDeclTypeNode(true);

    //
    //  Parse the XML file, catching any XML exceptions that might propogate
    //  out of it.
    //
    bool errorsOccured = false;
    try
    {
        parser->parse(gXmlFile);
        int errorCount = parser->getErrorCount();
        if (errorCount > 0)
            errorsOccured = true;
    }

    catch (const XMLException& e)
    {
        cerr << "An error occured during parsing\n   Message: "
             << DOMString(e.getMessage()) << endl;
        errorsOccured = true;
    }


    catch (const DOM_DOMException& e)
    {
       cerr << "A DOM error occured during parsing\n   DOMException code: "
             << e.code << endl;
        errorsOccured = true;
    }

    catch (...)
    {
        cerr << "An error occured during parsing\n " << endl;
        errorsOccured = true;
    }


    // If the parse was successful, output the document data from the DOM tree
    if (!errorsOccured && !errReporter->getSawErrors())
    {
        DOM_Node doc = parser->getDocument();
        DOMPrintFormatTarget* formatTarget = new DOMPrintFormatTarget();

        if (gEncodingName == 0)
        {
            DOMString encNameStr("UTF-8");
            DOM_Node aNode = doc.getFirstChild();
            if (aNode.getNodeType() == DOM_Node::XML_DECL_NODE)
            {
                DOMString aStr = ((DOM_XMLDecl &)aNode).getEncoding();
                if (aStr != "")
                {
                    encNameStr = aStr;
                }
            }
            unsigned int lent = encNameStr.length();
            gEncodingName = new XMLCh[lent + 1];
            XMLString::copyNString(gEncodingName, encNameStr.rawBuffer(), lent);
            gEncodingName[lent] = 0;
        }


        try
        {
            gFormatter = new XMLFormatter(gEncodingName, formatTarget,
                                          XMLFormatter::NoEscapes, gUnRepFlags);
            cout << doc << endl;
        }
        catch (XMLException& e)
        {
            cerr << "An error occurred during creation of output transcoder. Msg is:"
                 << endl
                 << DOMString(e.getMessage()) << endl;
            retval = 3;
        }

    delete formatTarget;
    delete gFormatter;
    }

    delete gEncodingName;
    //
    //  Clean up the error handler. The parser does not adopt handlers
    //  since they could be many objects or one object installed for multiple
    //  handlers.
    //
    delete errReporter;

    //
    //  Delete the parser itself.  Must be done prior to calling Terminate, below.
    //
    delete parser;

    // And call the termination method
    XMLPlatformUtils::Terminate();
    // DomMemDebug().print();

    //
    //  The DOM document and its contents are reference counted, and need
    //  no explicit deletion.
    //
    return retval;
}


// ---------------------------------------------------------------------------
//  ostream << DOM_Node
//
//  Stream out a DOM node, and, recursively, all of its children. This
//  function is the heart of writing a DOM tree out as XML source. Give it
//  a document node and it will do the whole thing.
// ---------------------------------------------------------------------------
ostream& operator<<(ostream& target, DOM_Node& toWrite)
{
    // Get the name and value out for convenience
    DOMString   nodeName = toWrite.getNodeName();
    DOMString   nodeValue = toWrite.getNodeValue();
    unsigned long lent = nodeValue.length();

    switch (toWrite.getNodeType())
    {
        case DOM_Node::TEXT_NODE:
        {
            gFormatter->formatBuf(nodeValue.rawBuffer(),
                                  lent, XMLFormatter::CharEscapes);
            break;
        }


        case DOM_Node::PROCESSING_INSTRUCTION_NODE :
        {
            *gFormatter << XMLFormatter::NoEscapes << gStartPI  << nodeName;
            if (lent > 0)
            {
                *gFormatter << chSpace << nodeValue;
            }
            *gFormatter << XMLFormatter::NoEscapes << gEndPI;
            break;
        }


        case DOM_Node::DOCUMENT_NODE :
        {

            DOM_Node child = toWrite.getFirstChild();
            while( child != 0)
            {
                target << child << endl;
                child = child.getNextSibling();
            }
            break;
        }


        case DOM_Node::ELEMENT_NODE :
        {
            // The name has to be representable without any escapes
            *gFormatter  << XMLFormatter::NoEscapes
                         << chOpenAngle << nodeName;

            // Output the element start tag.

            // Output any attributes on this element
            DOM_NamedNodeMap attributes = toWrite.getAttributes();
            int attrCount = attributes.getLength();
            for (int i = 0; i < attrCount; i++)
            {
                DOM_Node  attribute = attributes.item(i);

                //
                //  Again the name has to be completely representable. But the
                //  attribute can have refs and requires the attribute style
                //  escaping.
                //
                *gFormatter  << XMLFormatter::NoEscapes
                             << chSpace << attribute.getNodeName()
                             << chEqual << chDoubleQuote
                             << XMLFormatter::AttrEscapes
                             << attribute.getNodeValue()
                             << XMLFormatter::NoEscapes
                             << chDoubleQuote;
            }

            //
            //  Test for the presence of children, which includes both
            //  text content and nested elements.
            //
            DOM_Node child = toWrite.getFirstChild();
            if (child != 0)
            {
                // There are children. Close start-tag, and output children.
                // No escapes are legal here
                *gFormatter << XMLFormatter::NoEscapes << chCloseAngle;

                while( child != 0)
                {
                    target << child;
                    child = child.getNextSibling();
                }

                //
                // Done with children.  Output the end tag.
                //
                *gFormatter << XMLFormatter::NoEscapes << gEndElement
                            << nodeName << chCloseAngle;
            }
            else
            {
                //
                //  There were no children. Output the short form close of
                //  the element start tag, making it an empty-element tag.
                //
                *gFormatter << XMLFormatter::NoEscapes << chForwardSlash << chCloseAngle;
            }
            break;
        }


        case DOM_Node::ENTITY_REFERENCE_NODE:
            {
                DOM_Node child;
#if 0
                for (child = toWrite.getFirstChild();
                child != 0;
                child = child.getNextSibling())
                {
                    target << child;
                }
#else
                //
                // Instead of printing the refernece tree
                // we'd output the actual text as it appeared in the xml file.
                // This would be the case when -e option was chosen
                //
                    *gFormatter << XMLFormatter::NoEscapes << chAmpersand
                        << nodeName << chSemiColon;
#endif
                break;
            }


        case DOM_Node::CDATA_SECTION_NODE:
            {
            *gFormatter << XMLFormatter::NoEscapes << gStartCDATA
                        << nodeValue << gEndCDATA;
            break;
        }


        case DOM_Node::COMMENT_NODE:
        {
            *gFormatter << XMLFormatter::NoEscapes << gStartComment
                        << nodeValue << gEndComment;
            break;
        }


        case DOM_Node::DOCUMENT_TYPE_NODE:
        {
            DOM_DocumentType doctype = (DOM_DocumentType &)toWrite;;

            *gFormatter << XMLFormatter::NoEscapes  << gStartDoctype
                        << nodeName;

            DOMString id = doctype.getPublicId();
            if (id != 0)
            {
                *gFormatter << XMLFormatter::NoEscapes << chSpace << gPublic
                    << id << chDoubleQuote;
                id = doctype.getSystemId();
                if (id != 0)
                {
                    *gFormatter << XMLFormatter::NoEscapes << chSpace
                       << chDoubleQuote << id << chDoubleQuote;
                }
            }
            else
            {
                id = doctype.getSystemId();
                if (id != 0)
                {
                    *gFormatter << XMLFormatter::NoEscapes << chSpace << gSystem
                        << id << chDoubleQuote;
                }
            }

            id = doctype.getInternalSubset();
            if (id !=0)
                *gFormatter << XMLFormatter::NoEscapes << chOpenSquare
                            << id << chCloseSquare;

            *gFormatter << XMLFormatter::NoEscapes << chCloseAngle;
            break;
        }


        case DOM_Node::ENTITY_NODE:
        {
            *gFormatter << XMLFormatter::NoEscapes << gStartEntity
                        << nodeName;

            DOMString id = ((DOM_Entity &)toWrite).getPublicId();
            if (id != 0)
                *gFormatter << XMLFormatter::NoEscapes << gPublic
                            << id << chDoubleQuote;

            id = ((DOM_Entity &)toWrite).getSystemId();
            if (id != 0)
                *gFormatter << XMLFormatter::NoEscapes << gSystem
                            << id << chDoubleQuote;

            id = ((DOM_Entity &)toWrite).getNotationName();
            if (id != 0)
                *gFormatter << XMLFormatter::NoEscapes << gNotation
                            << id << chDoubleQuote;

            *gFormatter << XMLFormatter::NoEscapes << chCloseAngle << chLF;

            break;
        }


        case DOM_Node::XML_DECL_NODE:
        {
            DOMString  str;

            *gFormatter << gXMLDecl1 << ((DOM_XMLDecl &)toWrite).getVersion();

            *gFormatter << gXMLDecl2 << gEncodingName;

            str = ((DOM_XMLDecl &)toWrite).getStandalone();
            if (str != 0)
                *gFormatter << gXMLDecl3 << str;

            *gFormatter << gXMLDecl4;

            break;
        }


        default:
            cerr << "Unrecognized node type = "
                 << (long)toWrite.getNodeType() << endl;
    }
    return target;
}


// ---------------------------------------------------------------------------
//  ostream << DOMString
//
//  Stream out a DOM string. Doing this requires that we first transcode
//  to char * form in the default code page for the system
// ---------------------------------------------------------------------------
ostream& operator<< (ostream& target, const DOMString& s)
{
    char *p = s.transcode();
    target << p;
    delete [] p;
    return target;
}


XMLFormatter& operator<< (XMLFormatter& strm, const DOMString& s)
{
    unsigned int lent = s.length();

	if (lent <= 0)
		return strm;

    XMLCh*  buf = new XMLCh[lent + 1];
    XMLString::copyNString(buf, s.rawBuffer(), lent);
    buf[lent] = 0;
    strm << buf;
    delete [] buf;
    return strm;
}