Function SerializeAsRDF

xmpsdk/src/XMPMeta-Serialize.cpp:1050–1151

// *** 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. 
 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.