CMSSW_4_4_3_patch1/src/PhysicsTools/MVATrainer/src/XMLDocument.cc

Go to the documentation of this file.

#include <assert.h>
#include <iostream>
#include <iomanip>
#include <sstream>
#include <memory>
#include <string>
#include <cstdio>
#include <stdio.h>
#include <ext/stdio_filebuf.h>

#include <xercesc/util/PlatformUtils.hpp>
#include <xercesc/util/XMLString.hpp>
#include <xercesc/util/XMLUni.hpp>
#include <xercesc/util/BinInputStream.hpp>
#include <xercesc/dom/DOM.hpp>
#include <xercesc/dom/DOMImplementationLS.hpp>
#include <xercesc/dom/DOMWriter.hpp>
#include <xercesc/framework/LocalFileFormatTarget.hpp>
#include <xercesc/parsers/XercesDOMParser.hpp>
#include <xercesc/sax/InputSource.hpp>
#include <xercesc/sax/HandlerBase.hpp>


#include "FWCore/Utilities/interface/Exception.h"

#include "PhysicsTools/MVATrainer/interface/XMLSimpleStr.h"
#include "PhysicsTools/MVATrainer/interface/XMLUniStr.h"
#include "PhysicsTools/MVATrainer/interface/XMLDocument.h"

XERCES_CPP_NAMESPACE_USE

unsigned int XMLDocument::XercesPlatform::instances = 0;

namespace { // anonymous
        struct DocReleaser {
                inline DocReleaser(DOMDocument *doc) : doc(doc) {}
                inline ~DocReleaser() { doc->release(); }

                DOMDocument *doc;
        };

        template<typename T>
        class XMLInputSourceWrapper :
                public XERCES_CPP_NAMESPACE_QUALIFIER InputSource {
            public:
                typedef typename T::Stream_t Stream_t;

                XMLInputSourceWrapper(std::auto_ptr<Stream_t> &obj) : obj(obj) {}
                virtual ~XMLInputSourceWrapper() {}

                virtual XERCES_CPP_NAMESPACE_QUALIFIER BinInputStream*
                                                        makeStream() const
                { return new T(*obj); }

            private:
                std::auto_ptr<Stream_t> obj;
        };

        class STLInputStream :
                        public XERCES_CPP_NAMESPACE_QUALIFIER BinInputStream {
            public:
                typedef std::istream Stream_t;

                STLInputStream(std::istream &in) : in(in) {}
                virtual ~STLInputStream() {}

                virtual unsigned int curPos() const { return pos; }

                virtual unsigned int readBytes(XMLByte *const buf,
                                               const unsigned int size);

            private:
                std::istream    &in;
                unsigned int    pos;
        };

        template<int (*close)(FILE*)>
        class stdio_istream : public std::istream {
            public:
                typedef __gnu_cxx::stdio_filebuf<char>  __filebuf_type;
                typedef stdio_istream<close>            __istream_type;

                stdio_istream(FILE *file) :
                        file_(file), filebuf_(file, std::ios_base::in)
                { this->init(&filebuf_); }

                ~stdio_istream()
                { close(file_); }

                __filebuf_type *rdbuf() const
                { return const_cast<__filebuf_type*>(&filebuf_); }

            private:
                FILE            *file_;
                __filebuf_type  filebuf_;
        };

        typedef XMLInputSourceWrapper<STLInputStream> STLInputSource;
} // anonymous namespace

unsigned int STLInputStream::readBytes(XMLByte* const buf,
                                       const unsigned int size)
{
        char *rawBuf = reinterpret_cast<char*>(buf);
        unsigned int bytes = size * sizeof(XMLByte);
        in.read(rawBuf, bytes);
        unsigned int readBytes = in.gcount();

        if (in.bad())
                throw cms::Exception("XMLDocument")
                        << "I/O stream bad in STLInputStream::readBytes()"
                        << std::endl;

        unsigned int read = (unsigned int)(readBytes / sizeof(XMLByte));
        unsigned int rest = (unsigned int)(readBytes % sizeof(XMLByte));
        for(unsigned int i = 1; i <= rest; i++)
                in.putback(rawBuf[readBytes - i]);

        pos += read;
        return read;
}

XMLDocument::XercesPlatform::XercesPlatform()
{
        if (!instances++) {
                try {
                        XMLPlatformUtils::Initialize();
                } catch(const XMLException &e) {
                        throw cms::Exception("XMLDocument")
                                << "XMLPlatformUtils::Initialize failed "
                                   "because of: "
                                << XMLSimpleStr(e.getMessage()) << std::endl;
                }
        }
}

XMLDocument::XercesPlatform::~XercesPlatform()
{
        if (!--instances)
                XMLPlatformUtils::Terminate();
}

XMLDocument::XMLDocument(const std::string &fileName, bool write) :
        platform(new XercesPlatform()), fileName(fileName),
        write(write), impl(0), doc(0), rootNode(0)
{
        if (write)
                openForWrite(fileName);
        else {
                std::auto_ptr<std::istream> inputStream(
                                        new std::ifstream(fileName.c_str()));
                if (!inputStream->good())
                        throw cms::Exception("XMLDocument")
                                << "XML input file \"" << fileName << "\" "
                                   "could not be opened for reading."
                                << std::endl;
                openForRead(inputStream);
        }
}

XMLDocument::XMLDocument(const std::string &fileName,
                         const std::string &command) :
        platform(new XercesPlatform()), fileName(fileName),
        write(false), impl(0), doc(0), rootNode(0)
{
        FILE *file = popen(command.c_str(), "r");
        if (!file)
                throw cms::Exception("XMLDocument")
                        << "Could not execute XML preprocessing "
                           " command \"" << command << "\"."
                        << std::endl;

        std::auto_ptr<std::istream> inputStream(
                                        new stdio_istream<pclose>(file));
        if (!inputStream->good())
                throw cms::Exception("XMLDocument")
                        << "XML preprocessing command \"" << fileName
                        << "\" stream could not be opened for reading."
                        << std::endl;

        openForRead(inputStream);
}

XMLDocument::~XMLDocument()
{
        if (!write)
                return;

        std::auto_ptr<DocReleaser> docReleaser(new DocReleaser(doc));

        std::auto_ptr<DOMWriter> writer(static_cast<DOMImplementationLS*>(
                                                impl)->createDOMWriter());
        assert(writer.get());

        writer->setEncoding(XMLUniStr("UTF-8"));
        if (writer->canSetFeature(XMLUni::fgDOMWRTDiscardDefaultContent, true))
                writer->setFeature(XMLUni::fgDOMWRTDiscardDefaultContent, true);
        if (writer->canSetFeature(XMLUni::fgDOMWRTFormatPrettyPrint, true))
                writer->setFeature(XMLUni::fgDOMWRTFormatPrettyPrint, true);

        try {
                std::auto_ptr<XMLFormatTarget> target(
                                new LocalFileFormatTarget(fileName.c_str()));

                writer->writeNode(target.get(), *doc);
        } catch(...) {
                std::remove(fileName.c_str());
                throw;
        }
}

void XMLDocument::openForRead(std::auto_ptr<std::istream> &stream)
{
        parser.reset(new XercesDOMParser());
        parser->setValidationScheme(XercesDOMParser::Val_Auto);
        parser->setDoNamespaces(false);
        parser->setDoSchema(false);
        parser->setValidationSchemaFullChecking(false);

        errHandler.reset(new HandlerBase());
        parser->setErrorHandler(errHandler.get());
        parser->setCreateEntityReferenceNodes(false);

        inputSource.reset(new STLInputSource(stream));

        try {
                parser->parse(*inputSource);
                if (parser->getErrorCount())
                        throw cms::Exception("XMLDocument")
                                << "XML parser reported errors."
                                << std::endl;
        } catch(const XMLException &e) {
                throw cms::Exception("XMLDocument")
                        << "XML parser reported DOM error no. "
                        << (unsigned long)e.getCode()
                        << ": " << XMLSimpleStr(e.getMessage()) << "."
                        << std::endl;
        } catch(const SAXException &e) {
                throw cms::Exception("XMLDocument")
                        << "XML parser reported: "
                        << XMLSimpleStr(e.getMessage()) << "."
                        << std::endl;
        }

        doc = parser->getDocument();

        DOMNode *node = doc->getFirstChild();
        while(node && node->getNodeType() != DOMNode::ELEMENT_NODE)
                node = node->getNextSibling();

        if (!node)
                throw cms::Exception("XMLDocument")
                        << "XML document didn't contain a valid "
                        << "root node." << std::endl;

        rootNode = static_cast<DOMElement*>(node);
}

void XMLDocument::openForWrite(const std::string &fileName)
{
        impl = DOMImplementationRegistry::getDOMImplementation(
                                                        XMLUniStr("LS"));
        assert(impl);
}

DOMDocument *XMLDocument::createDocument(const std::string &root)
{
        if (doc)
                throw cms::Exception("XMLDocument")
                        << "Document already exists in createDocument."
                        << std::endl;

        doc = impl->createDocument(0, XMLUniStr(root.c_str()), 0);
        rootNode = doc->getDocumentElement();

        return doc;
}

// specialization of read/write method templates for bool

static bool isBool(std::string value)
{
        for(unsigned int i = 0; i < value.size(); i++)
                if (value[i] >= 'A' && value[i] <= 'Z')
                        value[i] += 'a' - 'A';

        if (value == "1" || value == "y" || value == "yes" ||
            value == "true" || value == "ok")
                return true;

        if (value == "0" || value == "n" || value == "no" || value == "false")
                return false;

        throw cms::Exception("XMLDocument")
                << "Invalid boolean value in XML document" << std::endl;
}

static const char *makeBool(bool value)
{
        return value ? "true" : "false";
}

bool XMLDocument::hasAttribute(XERCES_CPP_NAMESPACE_QUALIFIER DOMElement *elem,
                               const char *name)
{
        XMLUniStr uniName(name);
        return elem->hasAttribute(uniName);
}

template<>
bool XMLDocument::readAttribute(
                        XERCES_CPP_NAMESPACE_QUALIFIER DOMElement *elem,
                        const char *name)
{
        XMLUniStr uniName(name);
        if (!elem->hasAttribute(uniName))
                throw cms::Exception("MVAComputer")
                        << "Missing attribute " << name << " in tag "
                        << XMLSimpleStr(elem->getNodeName())
                        << "." << std::endl;
        const XMLCh *attribute = elem->getAttribute(uniName);
        return isBool(XMLSimpleStr(attribute));
}

template<>
bool XMLDocument::readAttribute(
                        XERCES_CPP_NAMESPACE_QUALIFIER DOMElement *elem,
                        const char *name, const bool &defValue)
{
        XMLUniStr uniName(name);
        if (!elem->hasAttribute(uniName))
                return defValue;
        const XMLCh *attribute = elem->getAttribute(uniName);
        return isBool(XMLSimpleStr(attribute));
}

template<>
void XMLDocument::writeAttribute(
                        XERCES_CPP_NAMESPACE_QUALIFIER DOMElement *elem,
                        const char *name, const bool &value)
{
        elem->setAttribute(XMLUniStr(name), XMLUniStr(makeBool(value)));
}

template<>
bool XMLDocument::readContent(
                        XERCES_CPP_NAMESPACE_QUALIFIER DOMNode *node)
{
        const XMLCh *content = node->getTextContent();
        return isBool(XMLSimpleStr(content));
}

template<>
void XMLDocument::writeContent(
                        XERCES_CPP_NAMESPACE_QUALIFIER DOMNode *node,
                        XERCES_CPP_NAMESPACE_QUALIFIER DOMDocument *doc,
                        const bool &value)
{
        node->appendChild(doc->createTextNode(XMLUniStr(makeBool(value))));
}