More serialization work

git-svn-id: http://svn.drobilla.net/lad/ingen@206 a436a847-0d15-0410-975c-d299462d15a1

1 files changed, 211 insertions, 0 deletions

diff --git a/src/libs/client/RDFWriter.cpp b/src/libs/client/RDFWriter.cpp
new file mode 100644
index 00000000..e1762ed2
--- /dev/null
+++ b/src/libs/client/RDFWriter.cpp
@@ -0,0 +1,211 @@
+/* This file is part of Ingen.  Copyright (C) 2006 Dave Robillard.
+ * 
+ * Ingen is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 2 of the License, or (at your option) any later
+ * version.
+ * 
+ * Ingen is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "RDFWriter.h"
+#include "raul/AtomRaptor.h"
+
+#define U(x) ((const unsigned char*)(x))
+
+static const char* const RDF_LANG = "rdfxml-abbrev";
+//static const char* const RDF_LANG = "turtle";
+
+
+RDFWriter::RDFWriter()
+	: _serializer(NULL)
+	, _string_output(NULL)
+{
+	//_prefixes["xsd"]       = "http://www.w3.org/2001/XMLSchema#";
+	_prefixes["rdf"]       = "http://www.w3.org/1999/02/22-rdf-syntax-ns#";
+	_prefixes["ingen"]     = "http://codeson.net/ns/ingen#";
+	_prefixes["ingenuity"] = "http://codeson.net/ns/ingenuity#";
+}
+
+
+void
+RDFWriter::setup_prefixes()
+{
+	for (map<string,string>::const_iterator i = _prefixes.begin(); i != _prefixes.end(); ++i) {
+		raptor_serialize_set_namespace(_serializer,
+			raptor_new_uri(U(i->second.c_str())), U(i->first.c_str()));
+	}
+}
+
+
+/** Expands the prefix of URI, if the prefix is registered.
+ *
+ * If uri is not a valid URI, the empty string is returned (so invalid URIs won't be serialized).
+ */
+string
+RDFWriter::expand_uri(const string& uri)
+{
+	// FIXME: slow, stupid
+	for (map<string,string>::const_iterator i = _prefixes.begin(); i != _prefixes.end(); ++i)
+		if (uri.substr(0, i->first.length()+1) == i->first + ":")
+			return i->second + uri.substr(i->first.length()+1);
+
+	// FIXME: find a correct way to validate a URI
+	if (uri.find(":") == string::npos && uri.find("/") == string::npos)
+		return "";
+	else
+		return uri;
+}
+
+
+
+/** Begin a serialization to a file.
+ *
+ * This must be called before any write methods.
+ */
+void
+RDFWriter::start_to_filename(const string& filename) throw (std::logic_error)
+{
+	if (_serializer)
+		throw std::logic_error("start_to_string called with serialization in progress");
+
+	raptor_init();
+	_serializer = raptor_new_serializer(RDF_LANG);
+	setup_prefixes();
+	raptor_serialize_start_to_filename(_serializer, filename.c_str());
+}
+
+
+/** Begin a serialization to a string.
+ *
+ * This must be called before any write methods.
+ *
+ * The results of the serialization will be returned by the finish() method after
+ * the desired objects have been serialized.
+ */
+void
+RDFWriter::start_to_string() throw (std::logic_error)
+{
+	if (_serializer)
+		throw std::logic_error("start_to_string called with serialization in progress");
+
+	raptor_init();
+	_serializer = raptor_new_serializer(RDF_LANG);
+	setup_prefixes();
+	raptor_serialize_start_to_string(_serializer,
+	                                 NULL /*base_uri*/,
+									 (void**)&_string_output,
+									 NULL /*size*/);
+}
+
+
+/** Finish a serialization.
+ *
+ * If this was a serialization to a string, the serialization output
+ * will be returned, otherwise the empty string is returned.
+ */
+string
+RDFWriter::finish() throw(std::logic_error)
+{
+	string ret = "";
+
+	if (!_serializer)
+		throw std::logic_error("finish() called with no serialization in progress");
+
+	raptor_serialize_end(_serializer);
+
+	if (_string_output) {
+		ret = string((char*)_string_output);
+		free(_string_output);
+		_string_output = NULL;
+	}
+
+	raptor_free_serializer(_serializer);
+	_serializer = NULL;
+
+	return ret;
+}
+
+
+void
+RDFWriter::write(const RdfId& subject,
+                 const RdfId& predicate,
+                 const RdfId& object)
+{
+	assert(_serializer);
+
+	raptor_statement triple;
+	
+	// FIXME: leaks?
+	
+	if (subject.type() == RdfId::RESOURCE) {
+		triple.subject = (void*)raptor_new_uri((const unsigned char*)subject.to_string().c_str());
+		triple.subject_type = RAPTOR_IDENTIFIER_TYPE_RESOURCE;
+	} else {
+		assert(subject.type() == RdfId::ANONYMOUS);
+		triple.subject = (unsigned char*)(strdup(subject.to_string().c_str()));
+		triple.subject_type = RAPTOR_IDENTIFIER_TYPE_ANONYMOUS;
+	}
+	
+	assert(predicate.type() == RdfId::RESOURCE);
+	triple.predicate = (void*)raptor_new_uri((const unsigned char*)predicate.to_string().c_str());
+	triple.predicate_type = RAPTOR_IDENTIFIER_TYPE_RESOURCE;
+
+	if (object.type() == RdfId::RESOURCE) {
+		triple.object = (void*)raptor_new_uri((const unsigned char*)object.to_string().c_str());
+		triple.object_type = RAPTOR_IDENTIFIER_TYPE_RESOURCE;
+	} else {
+		assert(object.type() == RdfId::ANONYMOUS);
+		triple.object = (unsigned char*)(strdup(object.to_string().c_str()));
+		triple.object_type = RAPTOR_IDENTIFIER_TYPE_ANONYMOUS;
+	}
+	
+	raptor_serialize_statement(_serializer, &triple);
+	
+	if (subject.type() == RdfId::RESOURCE)
+		raptor_free_uri((raptor_uri*)triple.subject);
+	
+	raptor_free_uri((raptor_uri*)triple.predicate);
+	
+	if (object.type() == RdfId::RESOURCE)
+		raptor_free_uri((raptor_uri*)triple.object);
+}
+
+
+void
+RDFWriter::write(const RdfId& subject,
+                 const RdfId& predicate,
+                 const Atom&  object)
+{
+	assert(_serializer);
+
+	raptor_statement triple;
+	
+	if (subject.type() == RdfId::RESOURCE) {
+		triple.subject = (void*)raptor_new_uri((const unsigned char*)subject.to_string().c_str());
+		triple.subject_type = RAPTOR_IDENTIFIER_TYPE_RESOURCE;
+	} else {
+		assert(subject.type() == RdfId::ANONYMOUS);
+		triple.subject = (unsigned char*)(strdup(subject.to_string().c_str()));
+		triple.subject_type = RAPTOR_IDENTIFIER_TYPE_ANONYMOUS;
+	}
+	
+	assert(predicate.type() == RdfId::RESOURCE);
+	triple.predicate = (void*)raptor_new_uri((const unsigned char*)predicate.to_string().c_str());
+	triple.predicate_type = RAPTOR_IDENTIFIER_TYPE_RESOURCE;
+
+	AtomRaptor::atom_to_triple_object(&triple, object);
+	
+	raptor_serialize_statement(_serializer, &triple);
+	
+	if (subject.type() == RdfId::RESOURCE)
+		raptor_free_uri((raptor_uri*)triple.subject);
+	
+	raptor_free_uri((raptor_uri*)triple.predicate);
+}