// =================================================================================================
// Copyright 2002-2008 Adobe Systems Incorporated
// All Rights Reserved.
//
// NOTICE:  Adobe permits you to use, modify, and distribute this file in accordance with the terms
// of the Adobe license agreement accompanying it.
//
// Adobe patent application tracking #P435, entitled 'Unique markers to simplify embedding data of
// one format in a file with a different format', inventors: Sean Parent, Greg Gilley.
// =================================================================================================

#include "XMP_Environment.h"	// ! This must be the first include!
#include "XMPCore_Impl.hpp"
#include "XMPMeta.hpp"

#include "XMP_Version.h"
#include "UnicodeInlines.incl_cpp"
#include "UnicodeConversions.hpp"

#if XMP_DebugBuild
    #include <iostream>
#endif

using namespace std;

namespace DngXmpSdk {

#if XMP_WinBuild
    #pragma warning ( disable : 4533 )	// initialization of '...' is skipped by 'goto ...'
    #pragma warning ( disable : 4702 )	// unreachable code
    #pragma warning ( disable : 4800 )	// forcing value to bool 'true' or 'false' (performance warning)
#endif


// *** Use the XMP_PropIsXyz (Schema, Simple, Struct, Array, ...) macros
// *** Add debug codegen checks, e.g. that typical masking operations really work
// *** Change all uses of strcmp and strncmp to XMP_LitMatch and XMP_LitNMatch


// =================================================================================================
// Local Types and Constants
// =========================

static const char * kPacketHeader  = "<?xpacket begin=\"\xEF\xBB\xBF\" id=\"W5M0MpCehiHzreSzNTczkc9d\"?>";
static const char * kPacketTrailer = "<?xpacket end=\"w\"?>";	// ! The w/r is at [size-4].

static const char * kPXMP_SchemaGroup = "XMP_SchemaGroup";

static const char * kRDF_XMPMetaStart = "<x:xmpmeta xmlns:x=\"adobe:ns:meta/\" x:xmptk=\"";
static const char * kRDF_XMPMetaEnd   = "</x:xmpmeta>";

static const char * kRDF_RDFStart     = "<rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\">";
static const char * kRDF_RDFEnd       = "</rdf:RDF>";

static const char * kRDF_SchemaStart  = "<rdf:Description rdf:about=";
static const char * kRDF_SchemaEnd    = "</rdf:Description>";

static const char * kRDF_StructStart  = "<rdf:Description>";
static const char * kRDF_StructEnd    = "</rdf:Description>";

static const char * kRDF_BagStart     = "<rdf:Bag>";
static const char * kRDF_BagEnd       = "</rdf:Bag>";

static const char * kRDF_SeqStart     = "<rdf:Seq>";
static const char * kRDF_SeqEnd       = "</rdf:Seq>";

static const char * kRDF_AltStart     = "<rdf:Alt>";
static const char * kRDF_AltEnd       = "</rdf:Alt>";

static const char * kRDF_ItemStart    = "<rdf:li>";
static const char * kRDF_ItemEnd      = "</rdf:li>";

static const char * kRDF_ValueStart   = "<rdf:value>";
static const char * kRDF_ValueEnd     = "</rdf:value>";


// =================================================================================================
// Static Variables
// ================


// =================================================================================================
// Local Utilities
// ===============


// -------------------------------------------------------------------------------------------------
// EstimateRDFSize
// ---------------

//  *** Pull the strlen(kXyz) calls into constants.

static size_t
EstimateRDFSize ( const XMP_Node * currNode, XMP_Index indent, size_t indentLen )
{
    size_t outputLen = 2 * (indent*indentLen + currNode->name.size() + 4);	// The property element tags.

    if ( ! currNode->qualifiers.empty() ) {
        // This node has qualifiers, assume it is written using rdf:value and estimate the qualifiers.

        indent += 2;	// Everything else is indented inside the rdf:Description element.
        outputLen += 2 * ((indent-1)*indentLen + strlen(kRDF_StructStart) + 2);	// The rdf:Description tags.
        outputLen += 2 * (indent*indentLen + strlen(kRDF_ValueStart) + 2);		// The rdf:value tags.

        for ( size_t qualNum = 0, qualLim = currNode->qualifiers.size(); qualNum < qualLim; ++qualNum ) {
            const XMP_Node * currQual = currNode->qualifiers[qualNum];
            outputLen += EstimateRDFSize ( currQual, indent, indentLen );
        }

    }

    if ( currNode->options & kXMP_PropValueIsStruct ) {
        indent += 1;
        outputLen += 2 * (indent*indentLen + strlen(kRDF_StructStart) + 2);	// The rdf:Description tags.
    } else if ( currNode->options & kXMP_PropValueIsArray ) {
        indent += 2;
        outputLen += 2 * ((indent-1)*indentLen + strlen(kRDF_BagStart) + 2);		// The rdf:Bag/Seq/Alt tags.
        outputLen += 2 * currNode->children.size() * (strlen(kRDF_ItemStart) + 2);	// The rdf:li tags, indent counted in children.
    } else if ( ! (currNode->options & kXMP_SchemaNode) ) {
        outputLen += currNode->value.size();	// This is a leaf value node.
    }

    for ( size_t childNum = 0, childLim = currNode->children.size(); childNum < childLim; ++childNum ) {
        const XMP_Node * currChild = currNode->children[childNum];
        outputLen += EstimateRDFSize ( currChild, indent+1, indentLen );
    }

    return outputLen;

}	// EstimateRDFSize


// -------------------------------------------------------------------------------------------------
// DeclareOneNamespace
// -------------------

static void
DeclareOneNamespace	( const XMP_VarString &	nsPrefix,
                      const XMP_VarString &	nsURI,
                      XMP_VarString	&		usedNS,		// ! A catenation of the prefixes with colons.
                      XMP_VarString &		outputStr,
                      XMP_StringPtr			newline,
                      XMP_StringPtr			indentStr,
                      XMP_Index				indent )
{
    size_t nsPos = usedNS.find ( nsPrefix );

    if ( nsPos == XMP_VarString::npos ) {

        outputStr += newline;
        for ( ; indent > 0; --indent ) outputStr += indentStr;
        outputStr += "xmlns:";
        outputStr += nsPrefix;
        outputStr[outputStr.size()-1] = '=';	// Change the colon to =.
        outputStr += '"';
        outputStr += nsURI;
        outputStr += '"';

        usedNS += nsPrefix;

    }

}	// DeclareOneNamespace


// -------------------------------------------------------------------------------------------------
// DeclareElemNamespace
// --------------------

static void
DeclareElemNamespace ( const XMP_VarString & elemName,
                       XMP_VarString &		 usedNS,
                       XMP_VarString &		 outputStr,
                       XMP_StringPtr		 newline,
                       XMP_StringPtr		 indentStr,
                       XMP_Index			 indent )
{
    size_t colonPos = elemName.find ( ':' );

    if ( colonPos != XMP_VarString::npos ) {
        XMP_VarString nsPrefix ( elemName.substr ( 0, colonPos+1 ) );
        XMP_StringMapPos prefixPos = sNamespacePrefixToURIMap->find ( nsPrefix );
        XMP_Enforce ( prefixPos != sNamespacePrefixToURIMap->end() );
        DeclareOneNamespace ( nsPrefix, prefixPos->second, usedNS, outputStr, newline, indentStr, indent );
    }

}	// DeclareElemNamespace


// -------------------------------------------------------------------------------------------------
// DeclareUsedNamespaces
// ---------------------

// ??? Should iterators be passed by reference to avoid temp copies?

static void
DeclareUsedNamespaces ( const XMP_Node * currNode,
                        XMP_VarString &  usedNS,
                        XMP_VarString &	 outputStr,
                        XMP_StringPtr	 newline,
                        XMP_StringPtr	 indentStr,
                        XMP_Index		 indent )
{

    if ( currNode->options & kXMP_SchemaNode ) {
        // The schema node name is the URI, the value is the prefix.
        DeclareOneNamespace ( currNode->value, currNode->name, usedNS, outputStr, newline, indentStr, indent );
    } else if ( currNode->options & kXMP_PropValueIsStruct ) {
        for ( size_t fieldNum = 0, fieldLim = currNode->children.size(); fieldNum < fieldLim; ++fieldNum ) {
            const XMP_Node * currField = currNode->children[fieldNum];
            DeclareElemNamespace ( currField->name, usedNS, outputStr, newline, indentStr, indent );
        }
    }

    for ( size_t childNum = 0, childLim = currNode->children.size(); childNum < childLim; ++childNum ) {
        const XMP_Node * currChild = currNode->children[childNum];
        DeclareUsedNamespaces ( currChild, usedNS, outputStr, newline, indentStr, indent );
    }

    for ( size_t qualNum = 0, qualLim = currNode->qualifiers.size(); qualNum < qualLim; ++qualNum ) {
        const XMP_Node * currQual = currNode->qualifiers[qualNum];
        DeclareElemNamespace ( currQual->name, usedNS, outputStr, newline, indentStr, indent );
        DeclareUsedNamespaces ( currQual, usedNS, outputStr, newline, indentStr, indent );
    }

}	// DeclareUsedNamespaces

// -------------------------------------------------------------------------------------------------
// EmitRDFArrayTag
// ---------------

// ??? Should iterators be passed by reference to avoid temp copies?

enum {
    kIsStartTag = true,
    kIsEndTag   = false
};

static void
EmitRDFArrayTag	( XMP_OptionBits  arrayForm,
                  XMP_VarString & outputStr,
                  XMP_StringPtr	  newline,
                  XMP_StringPtr	  indentStr,
                  XMP_Index		  indent,
                  XMP_Index		  arraySize,
                  bool			  isStartTag )
{
    if ( (! isStartTag) && (arraySize == 0) ) return;

    for ( XMP_Index level = indent; level > 0; --level ) outputStr += indentStr;
    if ( isStartTag ) {
        outputStr += "<rdf:";
    } else {
        outputStr += "</rdf:";
    }

    if ( arrayForm & kXMP_PropArrayIsAlternate ) {
        outputStr += "Alt";
    } else if ( arrayForm & kXMP_PropArrayIsOrdered ) {
        outputStr += "Seq";
    } else {
        outputStr += "Bag";
    }

    if ( isStartTag && (arraySize == 0) ) outputStr += '/';
    outputStr += '>';
    outputStr += newline;

}	// EmitRDFArrayTag


// -------------------------------------------------------------------------------------------------
// AppendNodeValue
// ---------------
//
// Append a property or qualifier value to the output with appropriate XML escaping. The escaped
// characters for elements and attributes are '&', '<', '>', and ASCII controls (tab, LF, CR). In
// addition, '"' is escaped for attributes. For efficiency, this is done in a double loop. The outer
// loop makes sure the whole value is processed. The inner loop does a contiguous unescaped run
// followed by one escaped character (if we're not at the end).
//
// We depend on parsing and SetProperty logic to make sure there are no invalid ASCII controls in
// the XMP values. The XML spec only allows tab, LF, and CR. Others are not even allowed as
// numeric escape sequences.

enum {
    kForAttribute = true,
    kForElement   = false
};

static void
AppendNodeValue ( XMP_VarString & outputStr, const XMP_VarString & value, bool forAttribute )
{

    unsigned char * runStart = (unsigned char *) value.c_str();
    unsigned char * runLimit  = runStart + value.size();
    unsigned char * runEnd;
    unsigned char   ch;

    while ( runStart < runLimit ) {

        for ( runEnd = runStart; runEnd < runLimit; ++runEnd ) {
            ch = *runEnd;
            if ( forAttribute && (ch == '"') ) break;
            if ( (ch < 0x20) || (ch == '&') || (ch == '<') || (ch == '>') ) break;
        }

        outputStr.append ( (char *) runStart, (runEnd - runStart) );

        if ( runEnd < runLimit ) {

            if ( ch < 0x20 ) {

                XMP_Assert ( (ch == kTab) || (ch == kLF) || (ch == kCR) );

                char hexBuf[16];
                memcpy ( hexBuf, "&#xn;", 5 );
                hexBuf[3] = kHexDigits[ch&0xF];
                outputStr.append ( hexBuf, 5 );

            } else {

                if ( ch == '"' ) {
                    outputStr += "&quot;";
                } else if ( ch == '<' ) {
                    outputStr += "&lt;";
                } else if ( ch == '>' ) {
                    outputStr += "&gt;";
                } else {
                    XMP_Assert ( ch == '&' );
                    outputStr += "&amp;";
                }

            }

            ++runEnd;

        }

        runStart = runEnd;

    }

}	// AppendNodeValue


// -------------------------------------------------------------------------------------------------
// CanBeRDFAttrProp
// ----------------

static bool
CanBeRDFAttrProp ( const XMP_Node * propNode )
{

    if ( propNode->name[0] == '[' ) return false;
    if ( ! propNode->qualifiers.empty() ) return false;
    if ( propNode->options & kXMP_PropValueIsURI ) return false;
    if ( propNode->options & kXMP_PropCompositeMask ) return false;

    return true;

}	// CanBeRDFAttrProp


// -------------------------------------------------------------------------------------------------
// IsRDFAttrQualifier
// ------------------

static XMP_StringPtr sAttrQualifiers[] = { "xml:lang", "rdf:resource", "rdf:ID", "rdf:bagID", "rdf:nodeID", "" };

static bool
IsRDFAttrQualifier ( XMP_VarString qualName )
{

    for ( size_t i = 0; *sAttrQualifiers[i] != 0; ++i ) {
        if ( qualName == sAttrQualifiers[i] ) return true;
    }

    return false;

}	// IsRDFAttrQualifier


// -------------------------------------------------------------------------------------------------
// SerializePrettyRDFProperty
// --------------------------
//
// Recursively handles the "value" for a node. It does not matter if it is a top level property, a
// field of a struct, or an item of an array.  The indent is that for the property element. An
// xml:lang qualifier is written as an attribute of the property start tag, not by itself forcing
// the qualified property form. The patterns below mostly ignore attribute qualifiers like xml:lang.
// Except for the one struct case, attribute qualifiers don't affect the output form.
//
//	<ns:UnqualifiedSimpleProperty>value</ns:UnqualifiedSimpleProperty>
//
//	<ns:UnqualifiedStructProperty rdf:parseType="Resource">	(If no rdf:resource qualifier)
//		... Fields, same forms as top level properties
//	</ns:UnqualifiedStructProperty>
//
//	<ns:ResourceStructProperty rdf:resource="URI"
//		... Fields as attributes
//	>
//
//	<ns:UnqualifiedArrayProperty>
//		<rdf:Bag> or Seq or Alt
//			... Array items as rdf:li elements, same forms as top level properties
//		</rdf:Bag>
//	</ns:UnqualifiedArrayProperty>
//
//	<ns:QualifiedProperty rdf:parseType="Resource">
//		<rdf:value> ... Property "value" following the unqualified forms ... </rdf:value>
//		... Qualifiers looking like named struct fields
//	</ns:QualifiedProperty>

static void
SerializePrettyRDFProperty ( const XMP_Node * propNode,
                             XMP_VarString &  outputStr,
                             XMP_StringPtr	  newline,
                             XMP_StringPtr	  indentStr,
                             XMP_Index		  indent,
                             bool			  emitAsRDFValue = false )
{
    XMP_Index level;
    bool emitEndTag   = true;
    bool indentEndTag = true;

    XMP_OptionBits propForm = propNode->options & kXMP_PropCompositeMask;

    // ------------------------------------------------------------------------------------------
    // Determine the XML element name. Open the start tag with the name and attribute qualifiers.

    XMP_StringPtr elemName = propNode->name.c_str();
    if ( emitAsRDFValue ) {
        elemName= "rdf:value";
    } else if ( *elemName == '[' ) {
        elemName = "rdf:li";
    }

    for ( level = indent; level > 0; --level ) outputStr += indentStr;
    outputStr += '<';
    outputStr += elemName;

    #define isCompact	false
    bool hasGeneralQualifiers = isCompact;	// Might also become true later.
    bool hasRDFResourceQual   = false;

    for ( size_t qualNum = 0, qualLim = propNode->qualifiers.size(); qualNum < qualLim; ++qualNum ) {
        const XMP_Node * currQual = propNode->qualifiers[qualNum];
        if ( ! IsRDFAttrQualifier ( currQual->name ) ) {
            hasGeneralQualifiers = true;
        } else {
            if ( currQual->name == "rdf:resource" ) hasRDFResourceQual = true;
            if ( ! emitAsRDFValue ) {
                outputStr += ' ';
                outputStr += currQual->name;
                outputStr += "=\"";
                AppendNodeValue ( outputStr, currQual->value, kForAttribute );
                outputStr += '"';
            }
        }
    }

    // --------------------------------------------------------
    // Process the property according to the standard patterns.

    if ( hasGeneralQualifiers && (! emitAsRDFValue) ) {

        // -----------------------------------------------------------------------------------------
        // This node has general, non-attribute, qualifiers. Emit using the qualified property form.
        // ! The value is output by a recursive call ON THE SAME NODE with emitAsRDFValue set.

        if ( hasRDFResourceQual ) {
            XMP_Throw ( "Can't mix rdf:resource and general qualifiers", kXMPErr_BadRDF );
        }

        outputStr += " rdf:parseType=\"Resource\">";
        outputStr += newline;

        SerializePrettyRDFProperty ( propNode, outputStr, newline, indentStr, indent+1, true );

        for ( size_t qualNum = 0, qualLim = propNode->qualifiers.size(); qualNum < qualLim; ++qualNum ) {
            const XMP_Node * currQual = propNode->qualifiers[qualNum];
            if ( IsRDFAttrQualifier ( currQual->name ) ) continue;
            SerializePrettyRDFProperty ( currQual, outputStr, newline, indentStr, indent+1 );
        }

    } else {

        // --------------------------------------------------------------------
        // This node has no general qualifiers. Emit using an unqualified form.

        if ( propForm == 0 ) {

            // --------------------------
            // This is a simple property.

            if ( propNode->options & kXMP_PropValueIsURI ) {
                outputStr += " rdf:resource=\"";
                AppendNodeValue ( outputStr, propNode->value, kForAttribute );
                outputStr += "\"/>";
                outputStr += newline;
                emitEndTag = false;
            } else if ( propNode->value.empty() ) {
                outputStr += "/>";
                outputStr += newline;
                emitEndTag = false;
            } else {
                outputStr += '>';
                AppendNodeValue ( outputStr, propNode->value, kForElement );
                indentEndTag = false;
            }

        } else if ( propForm & kXMP_PropValueIsArray ) {

            // This is an array.
            outputStr += '>';
            outputStr += newline;
            EmitRDFArrayTag ( propForm, outputStr, newline, indentStr, indent+1, propNode->children.size(), kIsStartTag );
            if ( XMP_ArrayIsAltText(propNode->options) ) NormalizeLangArray ( (XMP_Node*)propNode );
            for ( size_t childNum = 0, childLim = propNode->children.size(); childNum < childLim; ++childNum ) {
                const XMP_Node * currChild = propNode->children[childNum];
                SerializePrettyRDFProperty ( currChild, outputStr, newline, indentStr, indent+2 );
            }
            EmitRDFArrayTag ( propForm, outputStr, newline, indentStr, indent+1, propNode->children.size(), kIsEndTag );


        } else if ( ! hasRDFResourceQual ) {

            // This is a "normal" struct, use the rdf:parseType="Resource" form.
            XMP_Assert ( propForm & kXMP_PropValueIsStruct );
            if ( propNode->children.size() == 0 ) {
                outputStr += " rdf:parseType=\"Resource\"/>";
                outputStr += newline;
                emitEndTag = false;
            } else {
                outputStr += " rdf:parseType=\"Resource\">";
                outputStr += newline;
                for ( size_t childNum = 0, childLim = propNode->children.size(); childNum < childLim; ++childNum ) {
                    const XMP_Node * currChild = propNode->children[childNum];
                    SerializePrettyRDFProperty ( currChild, outputStr, newline, indentStr, indent+1 );
                }
            }

        } else {

            // This is a struct with an rdf:resource attribute, use the "empty property element" form.
            XMP_Assert ( propForm & kXMP_PropValueIsStruct );
            for ( size_t childNum = 0, childLim = propNode->children.size(); childNum < childLim; ++childNum ) {
                const XMP_Node * currChild = propNode->children[childNum];
                if ( ! CanBeRDFAttrProp ( currChild ) ) {
                    XMP_Throw ( "Can't mix rdf:resource and complex fields", kXMPErr_BadRDF );
                }
                outputStr += newline;
                for ( level = indent+1; level > 0; --level ) outputStr += indentStr;
                outputStr += ' ';
                outputStr += currChild->name;
                outputStr += "=\"";
                outputStr += currChild->value;
                outputStr += '"';
            }
            outputStr += "/>";
            outputStr += newline;
            emitEndTag = false;

        }

    }

    // ----------------------------------
    // Emit the property element end tag.

    if ( emitEndTag ) {
        if ( indentEndTag ) for ( level = indent; level > 0; --level ) outputStr += indentStr;
        outputStr += "</";
        outputStr += elemName;
        outputStr += '>';
        outputStr += newline;
    }

}	// SerializePrettyRDFProperty


// -------------------------------------------------------------------------------------------------
// SerializePrettyRDFSchema
// ------------------------
//
// Each schema's properties are written in a separate rdf:Description element. All of the necessary
// namespaces are declared in the rdf:Description element. The baseIndent is the base level for the
// entire serialization, that of the x:xmpmeta element. An xml:lang qualifier is written as an
// attribute of the property start tag, not by itself forcing the qualified property form.
//
//	<rdf:Description rdf:about="TreeName"
//			xmlns:ns="URI" ... >
//
//		... The actual properties of the schema, see SerializePrettyRDFProperty
//
//		<!-- ns1:Alias is aliased to ns2:Actual -->  ... If alias comments are wanted
//
//	</rdf:Description>

static void
SerializePrettyRDFSchema ( const XMP_VarString & treeName,
                           const XMP_Node *		 schemaNode,
                           XMP_VarString &		 outputStr,
                           XMP_OptionBits		 options,
                           XMP_StringPtr		 newline,
                           XMP_StringPtr		 indentStr,
                           XMP_Index			 baseIndent )
{
    XMP_Assert ( schemaNode->options & kXMP_SchemaNode );
    XMP_Assert ( schemaNode->qualifiers.empty() );

    // Write the rdf:Description start tag with the namespace declarations.

    XMP_Index level;
    for ( level = baseIndent+2; level > 0; --level ) outputStr += indentStr;
    outputStr += kRDF_SchemaStart;
    outputStr += '"';
    outputStr += treeName;
    outputStr += '"';

    size_t totalLen = 8;	// Start at 8 for "xml:rdf:".
    XMP_cStringMapPos currPos = sNamespacePrefixToURIMap->begin();
    XMP_cStringMapPos endPos  = sNamespacePrefixToURIMap->end();
    for ( ; currPos != endPos; ++currPos ) totalLen += currPos->first.size();

    XMP_VarString usedNS;
    usedNS.reserve ( totalLen );
    usedNS = "xml:rdf:";
    DeclareUsedNamespaces ( schemaNode, usedNS, outputStr, newline, indentStr, baseIndent+4 );

    outputStr += ">";
    outputStr += newline;

    // Write alias comments, if wanted.

    if ( options & kXMP_WriteAliasComments ) {	// *** Hoist into a routine, used for Plain XMP also.

        #if 0	// *** Buggy, disable for now.

        XMP_cAliasMapPos aliasPos = sRegisteredAliasMap->begin();
        XMP_cAliasMapPos aliasEnd = sRegisteredAliasMap->end();

        for ( ; aliasPos != aliasEnd; ++aliasPos ) {

            size_t nsPos = aliasPos->first.find ( schemaNode->value );
            if ( nsPos == XMP_VarString::npos ) continue;
            XMP_Assert ( nsPos == 0 );

            for ( level = baseIndent+3; level > 0; --level ) outputStr += indentStr;

            outputStr += "<!-- ";
            outputStr += aliasPos->first;
            outputStr += " is aliased to ";
            for ( size_t step = 1, stepLim = aliasPos->second.size(); step != stepLim; ++step ) {
                outputStr += aliasPos->second[step].step;
            }
            outputStr += " -->";
            outputStr += newline;

        }

        #endif

    }

    // Write each of the schema's actual properties.
    for ( size_t propNum = 0, propLim = schemaNode->children.size(); propNum < propLim; ++propNum ) {
        const XMP_Node * currProp = schemaNode->children[propNum];
        SerializePrettyRDFProperty ( currProp, outputStr, newline, indentStr, baseIndent+3 );
    }

    // Write the rdf:Description end tag.
    for ( level = baseIndent+2; level > 0; --level ) outputStr += indentStr;
    outputStr += kRDF_SchemaEnd;
    outputStr += newline;

}	// SerializePrettyRDFSchema


// -------------------------------------------------------------------------------------------------
// SerializeCompactRDFAttrProps
// ----------------------------
//
// Write each of the parent's simple unqualified properties as an attribute. Returns true if all
// of the properties are written as attributes.

static bool
SerializeCompactRDFAttrProps ( const XMP_Node *	parentNode,
                               XMP_VarString &	outputStr,
                               XMP_StringPtr	newline,
                               XMP_StringPtr	indentStr,
                               XMP_Index		indent )
{
    size_t prop, propLim;
    bool allAreAttrs = true;

    for ( prop = 0, propLim = parentNode->children.size(); prop != propLim; ++prop ) {

        const XMP_Node * currProp = parentNode->children[prop];
        if ( ! CanBeRDFAttrProp ( currProp ) ) {
            allAreAttrs = false;
            continue;
        }

        outputStr += newline;
        for ( XMP_Index level = indent; level > 0; --level ) outputStr += indentStr;
        outputStr += currProp->name;
        outputStr += "=\"";
        AppendNodeValue ( outputStr, currProp->value, kForAttribute );
        outputStr += '"';

    }

    return allAreAttrs;

}	// SerializeCompactRDFAttrProps


// -------------------------------------------------------------------------------------------------
// SerializeCompactRDFElemProps
// ----------------------------
//
// Recursively handles the "value" for a node that must be written as an RDF property element. It
// does not matter if it is a top level property, a field of a struct, or an item of an array.  The
// indent is that for the property element. The patterns bwlow ignore attribute qualifiers such as
// xml:lang, they don't affect the output form.
//
//	<ns:UnqualifiedStructProperty-1
//		... The fields as attributes, if all are simple and unqualified
//	/>
//
//	<ns:UnqualifiedStructProperty-2 rdf:parseType="Resource">
//		... The fields as elements, if none are simple and unqualified
//	</ns:UnqualifiedStructProperty-2>
//
//	<ns:UnqualifiedStructProperty-3>
//		<rdf:Description
//			... The simple and unqualified fields as attributes
//		>
//			... The compound or qualified fields as elements
//		</rdf:Description>
//	</ns:UnqualifiedStructProperty-3>
//
//	<ns:UnqualifiedArrayProperty>
//		<rdf:Bag> or Seq or Alt
//			... Array items as rdf:li elements, same forms as top level properties
//		</rdf:Bag>
//	</ns:UnqualifiedArrayProperty>
//
//	<ns:QualifiedProperty rdf:parseType="Resource">
//		<rdf:value> ... Property "value" following the unqualified forms ... </rdf:value>
//		... Qualifiers looking like named struct fields
//	</ns:QualifiedProperty>

// *** Consider numbered array items, but has compatibility problems.
// *** Consider qualified form with rdf:Description and attributes.

static void
SerializeCompactRDFElemProps ( const XMP_Node *	parentNode,
                               XMP_VarString &	outputStr,
                               XMP_StringPtr	newline,
                               XMP_StringPtr	indentStr,
                               XMP_Index		indent )
{
    XMP_Index level;

    for ( size_t prop = 0, propLim = parentNode->children.size(); prop != propLim; ++prop ) {

        const XMP_Node * propNode = parentNode->children[prop];
        if ( CanBeRDFAttrProp ( propNode ) ) continue;

        bool emitEndTag = true;
        bool indentEndTag = true;

        XMP_OptionBits propForm = propNode->options & kXMP_PropCompositeMask;

        // -----------------------------------------------------------------------------------
        // Determine the XML element name, write the name part of the start tag. Look over the
        // qualifiers to decide on "normal" versus "rdf:value" form. Emit the attribute
        // qualifiers at the same time.

        XMP_StringPtr elemName = propNode->name.c_str();
        if ( *elemName == '[' ) elemName = "rdf:li";

        for ( level = indent; level > 0; --level ) outputStr += indentStr;
        outputStr += '<';
        outputStr += elemName;

        #define isCompact	false
        bool hasGeneralQualifiers = isCompact;	// Might also become true later.
        bool hasRDFResourceQual   = false;

        for ( size_t qualNum = 0, qualLim = propNode->qualifiers.size(); qualNum < qualLim; ++qualNum ) {
            const XMP_Node * currQual = propNode->qualifiers[qualNum];
            if ( ! IsRDFAttrQualifier ( currQual->name ) ) {
                hasGeneralQualifiers = true;
            } else {
                if ( currQual->name == "rdf:resource" ) hasRDFResourceQual = true;
                outputStr += ' ';
                outputStr += currQual->name;
                outputStr += "=\"";
                AppendNodeValue ( outputStr, currQual->value, kForAttribute );
                outputStr += '"';
            }
        }

        // --------------------------------------------------------
        // Process the property according to the standard patterns.

        if ( hasGeneralQualifiers ) {

            // -------------------------------------------------------------------------------------
            // The node has general qualifiers, ones that can't be attributes on a property element.
            // Emit using the qualified property pseudo-struct form. The value is output by a call
            // to SerializePrettyRDFProperty with emitAsRDFValue set.

            // *** We're losing compactness in the calls to SerializePrettyRDFProperty.
            // *** Should refactor to have SerializeCompactRDFProperty that does one node.

            outputStr += " rdf:parseType=\"Resource\">";
            outputStr += newline;

            SerializePrettyRDFProperty ( propNode, outputStr, newline, indentStr, indent+1, true );

            size_t qualNum = 0;
            size_t qualLim = propNode->qualifiers.size();
            if ( propNode->options & kXMP_PropHasLang ) ++qualNum;

            for ( ; qualNum < qualLim; ++qualNum ) {
                const XMP_Node * currQual = propNode->qualifiers[qualNum];
                SerializePrettyRDFProperty ( currQual, outputStr, newline, indentStr, indent+1 );
            }

        } else {

            // --------------------------------------------------------------------
            // This node has only attribute qualifiers. Emit as a property element.

            if ( propForm == 0 ) {

                // --------------------------
                // This is a simple property.

                if ( propNode->options & kXMP_PropValueIsURI ) {
                    outputStr += " rdf:resource=\"";
                    AppendNodeValue ( outputStr, propNode->value, kForAttribute );
                    outputStr += "\"/>";
                    outputStr += newline;
                    emitEndTag = false;
                } else if ( propNode->value.empty() ) {
                    outputStr += "/>";
                    outputStr += newline;
                    emitEndTag = false;
                } else {
                    outputStr += '>';
                    AppendNodeValue ( outputStr, propNode->value, kForElement );
                    indentEndTag = false;
                }

            } else if ( propForm & kXMP_PropValueIsArray ) {

                // -----------------
                // This is an array.

                outputStr += '>';
                outputStr += newline;
                EmitRDFArrayTag ( propForm, outputStr, newline, indentStr, indent+1, propNode->children.size(), kIsStartTag );

                if ( XMP_ArrayIsAltText(propNode->options) ) NormalizeLangArray ( (XMP_Node*)propNode );
                SerializeCompactRDFElemProps ( propNode, outputStr, newline, indentStr, indent+2 );

                EmitRDFArrayTag ( propForm, outputStr, newline, indentStr, indent+1, propNode->children.size(), kIsEndTag );

            } else {

                // ----------------------
                // This must be a struct.

                XMP_Assert ( propForm & kXMP_PropValueIsStruct );

                bool hasAttrFields = false;
                bool hasElemFields = false;

                size_t field, fieldLim;
                for ( field = 0, fieldLim = propNode->children.size(); field != fieldLim; ++field ) {
                    XMP_Node * currField = propNode->children[field];
                    if ( CanBeRDFAttrProp ( currField ) ) {
                        hasAttrFields = true;
                        if ( hasElemFields ) break;	// No sense looking further.
                    } else {
                        hasElemFields = true;
                        if ( hasAttrFields ) break;	// No sense looking further.
                    }
                }

                if ( hasRDFResourceQual && hasElemFields ) {
                    XMP_Throw ( "Can't mix rdf:resource qualifier and element fields", kXMPErr_BadRDF );
                }

                if ( propNode->children.size() == 0 ) {

                    // Catch an empty struct as a special case. The case below would emit an empty
                    // XML element, which gets reparsed as a simple property with an empty value.
                    outputStr += " rdf:parseType=\"Resource\"/>";
                    outputStr += newline;
                    emitEndTag = false;

                } else if ( ! hasElemFields ) {

                    // All fields can be attributes, use the emptyPropertyElt form.
                    SerializeCompactRDFAttrProps ( propNode, outputStr, newline, indentStr, indent+1 );
                    outputStr += "/>";
                    outputStr += newline;
                    emitEndTag = false;

                } else if ( ! hasAttrFields ) {

                    // All fields must be elements, use the parseTypeResourcePropertyElt form.
                    outputStr += " rdf:parseType=\"Resource\">";
                    outputStr += newline;
                    SerializeCompactRDFElemProps ( propNode, outputStr, newline, indentStr, indent+1 );

                } else {

                    // Have a mix of attributes and elements, use an inner rdf:Description.
                    outputStr += '>';
                    outputStr += newline;
                    for ( level = indent+1; level > 0; --level ) outputStr += indentStr;
                    outputStr += "<rdf:Description";
                    SerializeCompactRDFAttrProps ( propNode, outputStr, newline, indentStr, indent+2 );
                    outputStr += ">";
                    outputStr += newline;
                    SerializeCompactRDFElemProps ( propNode, outputStr, newline, indentStr, indent+1 );
                    for ( level = indent+1; level > 0; --level ) outputStr += indentStr;
                    outputStr += kRDF_StructEnd;
                    outputStr += newline;

                }

            }

        }

        // ----------------------------------
        // Emit the property element end tag.

        if ( emitEndTag ) {
            if ( indentEndTag ) for ( level = indent; level > 0; --level ) outputStr += indentStr;
            outputStr += "</";
            outputStr += elemName;
            outputStr += '>';
            outputStr += newline;
        }

    }

}	// SerializeCompactRDFElemProps


// -------------------------------------------------------------------------------------------------
// SerializeCompactRDFSchemas
// --------------------------
//
// All properties from all schema are written in a single rdf:Description element, as are all of the
// necessary namespace declarations. The baseIndent is the base level for the entire serialization,
// that of the x:xmpmeta element. The x:xmpmeta and rdf:RDF elements have already been written.
//
// Top level simple unqualified properties are written as attributes of the (only) rdf:Description
// element. Structs, arrays, and qualified properties are written by SerializeCompactRDFElemProp. An
// xml:lang qualifier on a simple property prevents the attribute form.
//
//	<rdf:Description rdf:about="TreeName"
//			xmlns:ns="URI" ...
//		ns:UnqualifiedSimpleProperty="value" ... >
//		... The remaining properties of the schema, see SerializeCompactRDFElemProps
//	</rdf:Description>

static void
SerializeCompactRDFSchemas ( const XMP_Node & xmpTree,
                             XMP_VarString &  outputStr,
                             XMP_StringPtr	  newline,
                             XMP_StringPtr	  indentStr,
                             XMP_Index		  baseIndent )
{
    XMP_Index level;
    size_t schema, schemaLim;

    // Begin the rdf:Description start tag.
    for ( level = baseIndent+2; level > 0; --level ) outputStr += indentStr;
    outputStr += kRDF_SchemaStart;
    outputStr += '"';
    outputStr += xmpTree.name;
    outputStr += '"';

    // Write all necessary xmlns attributes.

    size_t totalLen = 8;	// Start at 8 for "xml:rdf:".
    XMP_cStringMapPos currPos = sNamespacePrefixToURIMap->begin();
    XMP_cStringMapPos endPos  = sNamespacePrefixToURIMap->end();
    for ( ; currPos != endPos; ++currPos ) totalLen += currPos->first.size();

    XMP_VarString usedNS;
    usedNS.reserve ( totalLen );
    usedNS = "xml:rdf:";

    for ( schema = 0, schemaLim = xmpTree.children.size(); schema != schemaLim; ++schema ) {
        const XMP_Node * currSchema = xmpTree.children[schema];
        DeclareUsedNamespaces ( currSchema, usedNS, outputStr, newline, indentStr, baseIndent+4 );
    }

    // Write the top level "attrProps" and close the rdf:Description start tag.
    bool allAreAttrs = true;
    for ( schema = 0, schemaLim = xmpTree.children.size(); schema != schemaLim; ++schema ) {
        const XMP_Node * currSchema = xmpTree.children[schema];
        allAreAttrs &= SerializeCompactRDFAttrProps ( currSchema, outputStr, newline, indentStr, baseIndent+3 );
    }
    if ( ! allAreAttrs ) {
        outputStr += ">";
        outputStr += newline;
    } else {
        outputStr += "/>";
        outputStr += newline;
        return;	// ! Done if all properties in all schema are written as attributes.
    }

    // Write the remaining properties for each schema.
    for ( schema = 0, schemaLim = xmpTree.children.size(); schema != schemaLim; ++schema ) {
        const XMP_Node * currSchema = xmpTree.children[schema];
        SerializeCompactRDFElemProps ( currSchema, outputStr, newline, indentStr, baseIndent+3 );
    }

    // Write the rdf:Description end tag.
    // *** Elide the end tag if everything (all props in all schema) is an attr.
    for ( level = baseIndent+2; level > 0; --level ) outputStr += indentStr;
    outputStr += kRDF_SchemaEnd;
    outputStr += newline;

}	// SerializeCompactRDFSchemas


// -------------------------------------------------------------------------------------------------
// SerializeAsRDF
// --------------
//
//	<?xpacket begin... ?>
//	<x:xmpmeta xmlns:x=... >
//		<rdf:RDF xmlns:rdf=... >
//
//			... The properties, see SerializePrettyRDFSchema or SerializeCompactRDFSchemas
//
//		</rdf:RDF>
//	</x:xmpmeta>
//	<?xpacket end... ?>

// *** Need to strip empty arrays?
// *** Option to strip/keep empty structs?
// *** Need to verify handling of rdf:type qualifiers in pretty and compact.
// *** Need to verify round tripping of rdf:ID and similar qualifiers, see RDF 7.2.21.
// *** Check cases of rdf:resource plus explicit attr qualifiers (like xml:lang).

static void
SerializeAsRDF ( const XMPMeta & xmpObj,
                 XMP_VarString & headStr,	// Everything up to the padding.
                 XMP_VarString & tailStr,	// Everything after the padding.
                 XMP_OptionBits	 options,
                 XMP_StringPtr	 newline,
                 XMP_StringPtr	 indentStr,
                 XMP_Index		 baseIndent )
{
    const size_t treeNameLen = xmpObj.tree.name.size();
    const size_t indentLen   = strlen ( indentStr );

    // First estimate the worst case space and reserve room in the output string. This optimization
    // avoids reallocating and copying the output as it grows. The initial count does not look at
    // the values of properties, so it does not account for character entities, e.g. &#xA; for newline.
    // Since there can be a lot of these in things like the base 64 encoding of a large thumbnail,
    // inflate the count by 1/4 (easy to do) to accommodate.

    // *** Need to include estimate for alias comments.

    size_t outputLen = 2 * (strlen(kPacketHeader) + strlen(kRDF_XMPMetaStart) + strlen(kRDF_RDFStart) + 3*baseIndent*indentLen);

    for ( size_t schemaNum = 0, schemaLim = xmpObj.tree.children.size(); schemaNum < schemaLim; ++schemaNum ) {
        const XMP_Node * currSchema = xmpObj.tree.children[schemaNum];
        outputLen += 2*(baseIndent+2)*indentLen + strlen(kRDF_SchemaStart) + treeNameLen + strlen(kRDF_SchemaEnd) + 2;
        outputLen += EstimateRDFSize ( currSchema, baseIndent+2, indentLen );
    }

    outputLen += (outputLen >> 2);	// Inflate by 1/4, an empirical fudge factor.

    // Now generate the RDF into the head string as UTF-8.

    XMP_Index level;

    headStr.erase();
    headStr.reserve ( outputLen );

    // Write the packet header PI.
    if ( ! (options & kXMP_OmitPacketWrapper) ) {
        for ( level = baseIndent; level > 0; --level ) headStr += indentStr;
        headStr += kPacketHeader;
        headStr += newline;
    }

    // Write the xmpmeta element's start tag.
    if ( ! (options & kXMP_OmitXMPMetaElement) ) {
        for ( level = baseIndent; level > 0; --level ) headStr += indentStr;
        headStr += kRDF_XMPMetaStart;
        headStr += kXMPCore_VersionMessage "\">";
        headStr += newline;
    }

    // Write the rdf:RDF start tag.
    for ( level = baseIndent+1; level > 0; --level ) headStr += indentStr;
    headStr += kRDF_RDFStart;
    headStr += newline;

    // Write all of the properties.
    if ( options & kXMP_UseCompactFormat ) {
        SerializeCompactRDFSchemas ( xmpObj.tree, headStr, newline, indentStr, baseIndent );
    } else {
        if ( xmpObj.tree.children.size() > 0 ) {
            for ( size_t schemaNum = 0, schemaLim = xmpObj.tree.children.size(); schemaNum < schemaLim; ++schemaNum ) {
                const XMP_Node * currSchema = xmpObj.tree.children[schemaNum];
                SerializePrettyRDFSchema ( xmpObj.tree.name, currSchema, headStr, options, newline, indentStr, baseIndent );
            }
        } else {
            for ( XMP_Index level = baseIndent+2; level > 0; --level ) headStr += indentStr;
            headStr += kRDF_SchemaStart;	// Special case an empty XMP object.
            headStr += '"';
            headStr += xmpObj.tree.name;
            headStr += "\"/>";
            headStr += newline;
        }
    }

    // Write the rdf:RDF end tag.
    for ( level = baseIndent+1; level > 0; --level ) headStr += indentStr;
    headStr += kRDF_RDFEnd;
    headStr += newline;

    // Write the xmpmeta end tag.
    if ( ! (options & kXMP_OmitXMPMetaElement) ) {
        for ( level = baseIndent; level > 0; --level ) headStr += indentStr;
        headStr += kRDF_XMPMetaEnd;
        headStr += newline;
    }

    // Write the packet trailer PI into the tail string as UTF-8.
    tailStr.erase();
    if ( ! (options & kXMP_OmitPacketWrapper) ) {
        tailStr.reserve ( strlen(kPacketTrailer) + (strlen(indentStr) * baseIndent) );
        for ( level = baseIndent; level > 0; --level ) tailStr += indentStr;
        tailStr += kPacketTrailer;
        if ( options & kXMP_ReadOnlyPacket ) tailStr[tailStr.size()-4] = 'r';
    }

    // ! This assert is just a performance check, to see if the reserve was enough.
    // *** XMP_Assert ( headStr.size() <= outputLen );
    // *** Don't use an assert. Think of some way to track this without risk of aborting the client.

}	// SerializeAsRDF

// -------------------------------------------------------------------------------------------------
// SerializeToBuffer
// -----------------

void
XMPMeta::SerializeToBuffer ( XMP_StringPtr * rdfString,
                             XMP_StringLen * rdfSize,
                             XMP_OptionBits	 options,
                             XMP_StringLen	 padding,
                             XMP_StringPtr	 newline,
                             XMP_StringPtr	 indentStr,
                             XMP_Index		 baseIndent ) const
{
    XMP_Assert ( (rdfString != 0) && (rdfSize != 0) && (newline != 0) && (indentStr != 0) );

    // Fix up some default parameters.

    enum { kDefaultPad = 2048 };
    size_t unicodeUnitSize = 1;
    XMP_OptionBits charEncoding = options & kXMP_EncodingMask;

    if ( charEncoding != kXMP_EncodeUTF8 ) {
        if ( options & _XMP_UTF16_Bit ) {
            if ( options & _XMP_UTF32_Bit ) XMP_Throw ( "Can't use both _XMP_UTF16_Bit and _XMP_UTF32_Bit", kXMPErr_BadOptions );
            unicodeUnitSize = 2;
        } else if ( options & _XMP_UTF32_Bit ) {
            unicodeUnitSize = 4;
        } else {
            XMP_Throw ( "Can't use _XMP_LittleEndian_Bit by itself", kXMPErr_BadOptions );
        }
    }

    if ( options & kXMP_OmitAllFormatting ) {
        newline = " ";	// ! Yes, a space for "newline". This ensures token separation.
        indentStr = "";
    } else {
        if ( *newline == 0 ) newline = "\xA";	// Linefeed
        if ( *indentStr == 0 ) {
            indentStr = " ";
            if ( ! (options & kXMP_UseCompactFormat) ) indentStr  = "   ";
        }
    }

    if ( options & kXMP_ExactPacketLength ) {
        if ( options & (kXMP_OmitPacketWrapper | kXMP_IncludeThumbnailPad) ) {
            XMP_Throw ( "Inconsistent options for exact size serialize", kXMPErr_BadOptions );
        }
        if ( (padding & (unicodeUnitSize-1)) != 0 ) {
            XMP_Throw ( "Exact size must be a multiple of the Unicode element", kXMPErr_BadOptions );
        }
    } else if ( options & kXMP_ReadOnlyPacket ) {
        if ( options & (kXMP_OmitPacketWrapper | kXMP_IncludeThumbnailPad) ) {
            XMP_Throw ( "Inconsistent options for read-only packet", kXMPErr_BadOptions );
        }
        padding = 0;
    } else if ( options & kXMP_OmitPacketWrapper ) {
        if ( options & kXMP_IncludeThumbnailPad ) {
            XMP_Throw ( "Inconsistent options for non-packet serialize", kXMPErr_BadOptions );
        }
        padding = 0;
    } else {
        if ( padding == 0 ) padding = kDefaultPad * unicodeUnitSize;
        if ( options & kXMP_IncludeThumbnailPad ) {
            if ( ! this->DoesPropertyExist ( kXMP_NS_XMP, "Thumbnails" ) ) padding += (10000 * unicodeUnitSize);	// *** Need a better estimate.
        }
    }

    // Serialize as UTF-8, then convert to UTF-16 or UTF-32 if necessary, and assemble with the padding and tail.

    std::string tailStr;

    SerializeAsRDF ( *this, *sOutputStr, tailStr, options, newline, indentStr, baseIndent );
    if ( charEncoding == kXMP_EncodeUTF8 ) {

        if ( options & kXMP_ExactPacketLength ) {
            size_t minSize = sOutputStr->size() + tailStr.size();
            if ( minSize > padding ) XMP_Throw ( "Can't fit into specified packet size", kXMPErr_BadSerialize );
            padding -= minSize;	// Now the actual amount of padding to add.
        }

        size_t newlineLen = strlen ( newline );

        if ( padding < newlineLen ) {
            sOutputStr->append ( padding, ' ' );
        } else {
            padding -= newlineLen;	// Write this newline last.
            while ( padding >= (100 + newlineLen) ) {
                sOutputStr->append ( 100, ' ' );
                *sOutputStr += newline;
                padding -= (100 + newlineLen);
            }
            sOutputStr->append ( padding, ' ' );
            *sOutputStr += newline;
        }

        *sOutputStr += tailStr;

    } else {

        // Need to convert the encoding. Swap the UTF-8 into a local string and convert back. Assemble everything.

        XMP_VarString utf8Str, newlineStr;
        bool bigEndian = ((charEncoding & _XMP_LittleEndian_Bit) == 0);

        if ( charEncoding & _XMP_UTF16_Bit ) {

            std::string padStr ( "  " );  padStr[0] = 0;	// Assume big endian.

            utf8Str.swap ( *sOutputStr );
            ToUTF16 ( (UTF8Unit*)utf8Str.c_str(), utf8Str.size(), sOutputStr, bigEndian );
            utf8Str.swap ( tailStr );
            ToUTF16 ( (UTF8Unit*)utf8Str.c_str(), utf8Str.size(), &tailStr, bigEndian );

            if ( options & kXMP_ExactPacketLength ) {
                size_t minSize = sOutputStr->size() + tailStr.size();
                if ( minSize > padding ) XMP_Throw ( "Can't fit into specified packet size", kXMPErr_BadSerialize );
                padding -= minSize;	// Now the actual amount of padding to add (in bytes).
            }

            utf8Str.assign ( newline );
            ToUTF16 ( (UTF8Unit*)utf8Str.c_str(), utf8Str.size(), &newlineStr, bigEndian );
            size_t newlineLen = newlineStr.size();

            if ( padding < newlineLen ) {
                for ( int i = padding/2; i > 0; --i ) *sOutputStr += padStr;
            } else {
                padding -= newlineLen;	// Write this newline last.
                while ( padding >= (200 + newlineLen) ) {
                    for ( int i = 100; i > 0; --i ) *sOutputStr += padStr;
                    *sOutputStr += newlineStr;
                    padding -= (200 + newlineLen);
                }
                for ( int i = padding/2; i > 0; --i ) *sOutputStr += padStr;
                *sOutputStr += newlineStr;
            }

            *sOutputStr += tailStr;

        } else {

            std::string padStr ( "    " );  padStr[0] = padStr[1] = padStr[2] = 0;	// Assume big endian.
            UTF8_to_UTF32_Proc Converter = UTF8_to_UTF32BE;

            if ( charEncoding & _XMP_LittleEndian_Bit ) {
                padStr[0] = ' '; padStr[1] = padStr[2] = padStr[3] = 0;
                Converter = UTF8_to_UTF32LE;
            }

            utf8Str.swap ( *sOutputStr );
            ToUTF32 ( (UTF8Unit*)utf8Str.c_str(), utf8Str.size(), sOutputStr, bigEndian );
            utf8Str.swap ( tailStr );
            ToUTF32 ( (UTF8Unit*)utf8Str.c_str(), utf8Str.size(), &tailStr, bigEndian );

            if ( options & kXMP_ExactPacketLength ) {
                size_t minSize = sOutputStr->size() + tailStr.size();
                if ( minSize > padding ) XMP_Throw ( "Can't fit into specified packet size", kXMPErr_BadSerialize );
                padding -= minSize;	// Now the actual amount of padding to add (in bytes).
            }

            utf8Str.assign ( newline );
            ToUTF32 ( (UTF8Unit*)utf8Str.c_str(), utf8Str.size(), &newlineStr, bigEndian );
            size_t newlineLen = newlineStr.size();

            if ( padding < newlineLen ) {
                for ( int i = padding/4; i > 0; --i ) *sOutputStr += padStr;
            } else {
                padding -= newlineLen;	// Write this newline last.
                while ( padding >= (400 + newlineLen) ) {
                    for ( int i = 100; i > 0; --i ) *sOutputStr += padStr;
                    *sOutputStr += newlineStr;
                    padding -= (400 + newlineLen);
                }
                for ( int i = padding/4; i > 0; --i ) *sOutputStr += padStr;
                *sOutputStr += newlineStr;
            }

            *sOutputStr += tailStr;

        }

    }

    // Return the finished string.

    *rdfString = sOutputStr->c_str();
    *rdfSize   = sOutputStr->size();

}	// SerializeToBuffer

} // namespace DngXmpSdk
// =================================================================================================
