diff options
Diffstat (limited to 'src/plugins')
| -rw-r--r-- | src/plugins/xml/XmlParser.cpp | 134 | ||||
| -rw-r--r-- | src/plugins/xml/XmlParser.hpp | 63 |
2 files changed, 197 insertions, 0 deletions
diff --git a/src/plugins/xml/XmlParser.cpp b/src/plugins/xml/XmlParser.cpp new file mode 100644 index 0000000..f9bb43e --- /dev/null +++ b/src/plugins/xml/XmlParser.cpp @@ -0,0 +1,134 @@ +/* + Ousía + Copyright (C) 2014, 2015 Benjamin Paaßen, Andreas Stöckel + + This program 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 3 of the License, or + (at your option) any later version. + + This program 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 more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include <expat.h> + +#include "XmlParser.hpp" + +namespace ousia { + +/** + * The XmlParserData struct holds all information relevant to the expat callback + * functions. + */ +struct XmlParserData { + Rooted<Node> context; + Logger &logger; + + XmlParserData(Handle<Node> context, Logger &logger) + : context(context), logger(logger) + { + } +}; + +/** + * Wrapper class around the XML_Parser pointer which safely frees it whenever + * the scope is left (e.g. because an exception was thrown). + */ +class ScopedExpatXmlParser { +private: + /** + * Internal pointer to the XML_Parser instance. + */ + XML_Parser parser; + +public: + /** + * Constructor of the ScopedExpatXmlParser class. Calls XML_ParserCreateNS + * from the expat library. Throws a parser exception if the XML parser + * cannot be initialized. + * + * @param encoding is the protocol-defined encoding passed to expat (or + * nullptr if expat should determine the encoding by itself). + * @param namespaceSeparator is the separator used to separate the namespace + * components in the node name given by expat. + */ + ScopedExpatXmlParser(const XML_Char *encoding, XML_Char namespaceSeparator) + : parser(nullptr) + { + parser = XML_ParserCreateNS("UTF-8", ':'); + if (!parser) { + throw ParserException{ + "Internal error: Could not create expat XML parser!"}; + } + } + + /** + * Destuctor of the ScopedExpatXmlParser, frees the XML parser instance. + */ + ~ScopedExpatXmlParser() + { + if (parser) { + XML_ParserFree(parser); + parser = nullptr; + } + } + + /** + * Returns the XML_Parser pointer. + */ + XML_Parser operator&() { return parser; } +}; + +std::set<std::string> XmlParser::mimetypes() +{ + return std::set<std::string>{{"text/vnd.ousia.oxm", "text/vnd.ousia.oxd"}}; +} + +Rooted<Node> XmlParser::parse(std::istream &is, Handle<Node> context, + Logger &logger) +{ + // Create the parser object + ScopedExpatXmlParser p{"UTF-8", ':'}; + + // Set the callback functions, provide a pointer to a XmlParserData instance + // as user data. + XmlParserData ctx{context, logger}; + + // Feed data into expat while there is data to process + const std::streamsize BUFFER_SIZE = 4096; // TODO: Move to own header? + while (true) { + // Fetch a buffer from expat for the input data + char *buf = static_cast<char *>(XML_GetBuffer(&p, BUFFER_SIZE)); + if (!buf) { + throw ParserException{"Internal error: XML parser out of memory!"}; + } + + // Read the input data from the stream + const std::streamsize bytesRead = is.read(buf, BUFFER_SIZE).gcount(); + + // Parse the data and handle any XML error + if (!XML_ParseBuffer(&p, bytesRead, bytesRead == 0)) { + const int line = XML_GetCurrentLineNumber(&p); + const int column = XML_GetCurrentColumnNumber(&p); + const XML_Error code = XML_GetErrorCode(&p); + const std::string msg = std::string{XML_ErrorString(code)}; + logger.error("XML: " + msg, line, column); + break; + } + + // Abort once there are no more bytes in the stream + if (bytesRead == 0) { + break; + } + } + + return nullptr; +} +} + diff --git a/src/plugins/xml/XmlParser.hpp b/src/plugins/xml/XmlParser.hpp new file mode 100644 index 0000000..f6fb060 --- /dev/null +++ b/src/plugins/xml/XmlParser.hpp @@ -0,0 +1,63 @@ +/* + Ousía + Copyright (C) 2014, 2015 Benjamin Paaßen, Andreas Stöckel + + This program 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 3 of the License, or + (at your option) any later version. + + This program 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 more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +/** + * @file XmlParser.hpp + * + * Contains the parser responsible for reading Ousía XML Documents (extension + * oxd) and Ousía XML Modules (extension oxm). + * + * @author Andreas Stöckel (astoecke@techfak.uni-bielefeld.de) + */ + +#ifndef _OUSIA_XML_PARSER_HPP_ +#define _OUSIA_XML_PARSER_HPP_ + +#include <core/Parser.hpp> + +namespace ousia { + +/** + * The XmlParser class implements parsing the various types of Ousía XML + * documents using the expat stream XML parser. + */ +class XmlParser : public Parser { +public: + /** + * Returns the mimetype supported by the XmlParser which is + * "text/vnd.ousia.oxm" and "text/vnd.ousia.oxd". + * + * @return a list containing the mimetype supported by Ousía. + */ + std::set<std::string> mimetypes() override; + + /** + * Parses the given input stream as XML file and returns the parsed + * top-level node. Throws + * + * @param is is the input stream that will be parsed. + */ + Rooted<Node> parse(std::istream &is, Handle<Node> context, + Logger &logger) override; + + using Parser::parse; +}; +} + +#endif /* _OUSIA_XML_PARSER_HPP_ */ + |