XMLFileCatalog.cpp

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#include "xercesc/dom/DOM.hpp"
#include "xercesc/framework/LocalFileFormatTarget.hpp"
#include "xercesc/framework/MemBufInputSource.hpp"
#include "xercesc/parsers/XercesDOMParser.hpp"
#include "xercesc/sax/EntityResolver.hpp"
#include "xercesc/sax/InputSource.hpp"
#include "xercesc/sax/SAXParseException.hpp"
#include "xercesc/util/PlatformUtils.hpp"
#include "xercesc/util/XMLString.hpp"
#include "xercesc/util/XMLURL.hpp"
#include "xercesc/util/XMLUni.hpp"
#include "xercesc/util/XercesDefs.hpp"

#include "GaudiKernel/MsgStream.h"
#include "GaudiKernel/Service.h"
#include <Gaudi/PluginService.h>

#include "XMLFileCatalog.h"
#include "createGuidAsString.h"

#include <fstream>
#include <iostream>
#include <stdexcept>
#include <sys/stat.h>
#include <sys/types.h>

using namespace xercesc;
using namespace Gaudi;
using namespace std;

#if _XERCES_VERSION <= 30000
// API change between XercesC 2 and 3
#define setIdAttribute( a, b ) setIdAttribute( a )
#endif

DECLARE_FACTORY( XMLFileCatalog, IFileCatalog::Factory )

namespace
{

  typedef const string& CSTR;
  inline string _toString( const XMLCh* toTranscode )
  {
    char* buff = XMLString::transcode( toTranscode );
    string tmp( buff == 0 ? "" : buff );
    XMLString::release( &buff );
    return tmp;
  }
  struct __Init {
    __Init()
    {
      try {
        XMLPlatformUtils::Initialize();
      } catch ( const XMLException& e ) {
        cout << "Xerces-c error in initialization:" << _toString( e.getMessage() ) << endl;
      }
    }
    ~__Init() { XMLPlatformUtils::Terminate(); }
  };
  __Init __In__;

  struct XMLStr {
    XMLCh* m_xml;
    XMLStr( CSTR c ) { m_xml = XMLString::transcode( c.c_str() ); }
    ~XMLStr()
    {
      if ( m_xml ) XMLString::release( &m_xml );
    }
    operator const XMLCh*() const { return m_xml; }
  };
  struct XMLTag : public XMLStr {
    string m_str;
    XMLTag( CSTR s ) : XMLStr( s ), m_str( s ) {}
    ~XMLTag() {}
    operator CSTR() const { return m_str; }
  };
  // bool operator==(const XMLTag& b, CSTR c) {  return c==b.m_str; }
  bool operator==( CSTR c, const XMLTag& b ) { return c == b.m_str; }
  struct XMLCollection {
    DOMElement* m_node;
    XMLCollection( DOMNode* n, bool use_children = true ) : m_node( (DOMElement*)n )
    {
      if ( use_children ) {
        if ( m_node ) m_node = (DOMElement*)m_node->getFirstChild();
        if ( m_node && m_node->getNodeType() != DOMNode::ELEMENT_NODE ) ++( *this );
      }
    }
    operator bool() const { return m_node; }
    operator DOMNode*() const { return m_node; }
    operator DOMElement*() const { return m_node; }
    DOMElement* operator->() const { return m_node; }
    string attr( const XMLTag& tag ) const { return _toString( m_node->getAttribute( tag ) ); }
    string attr( CSTR tag ) const { return attr( XMLTag( tag ) ); }
    string tag() const { return _toString( m_node->getTagName() ); }
    void operator++()
    {
      while ( m_node ) {
        m_node = (DOMElement*)m_node->getNextSibling();
        if ( m_node && m_node->getNodeType() == DOMNode::ELEMENT_NODE ) {
          return;
        }
      }
    }
  };
  struct ErrHandler : public ErrorHandler {
    IMessageSvc* m_msg;
    ErrHandler( IMessageSvc* m ) : m_msg( m ) {}
    void resetErrors() override {}
    void warning( const SAXParseException& /* e */ ) override {}
    void error( const SAXParseException& e ) override;
    void fatalError( const SAXParseException& e ) override;
    ~ErrHandler() override {}
  };
  struct DTDRedirect : public EntityResolver {
    InputSource* resolveEntity( const XMLCh* const /* pubId */, const XMLCh* const /* sysId */ ) override
    {
      static const char* dtdID = "redirectinmem.dtd";
      static const char* dtd   = "\
        <!ELEMENT POOLFILECATALOG (META*,File*)>\
        <!ELEMENT META EMPTY>\
        <!ELEMENT File (physical,logical,metadata*)>\
        <!ATTLIST META name CDATA #REQUIRED>\
        <!ATTLIST META type CDATA #REQUIRED>\
        <!ELEMENT physical (pfn)+>\
        <!ELEMENT logical (lfn)*>\
        <!ELEMENT metadata EMPTY>\
        <!ELEMENT lfn EMPTY>\
        <!ELEMENT pfn EMPTY>\
        <!ATTLIST File ID ID  #REQUIRED>\
        <!ATTLIST pfn name ID #REQUIRED>\
        <!ATTLIST pfn filetype CDATA #IMPLIED>\
        <!ATTLIST pfn se CDATA #IMPLIED>\
        <!ATTLIST lfn name ID #REQUIRED>\
        <!ATTLIST metadata att_name  CDATA #REQUIRED>\
        <!ATTLIST metadata att_value CDATA #REQUIRED>\
        ";
      static const size_t len  = strlen( dtd );
      return new MemBufInputSource( (const XMLByte*)dtd, len, dtdID, false );
    }
    ~DTDRedirect() override = default;
  };

  void ErrHandler::error( const SAXParseException& e )
  {
    string m( _toString( e.getMessage() ) );
    if ( m.find( "The values for attribute 'name' must be names or name tokens" ) != string::npos ||
         m.find( "The values for attribute 'ID' must be names or name tokens" ) != string::npos ||
         m.find( "for attribute 'name' must be Name or Nmtoken" ) != string::npos ||
         m.find( "for attribute 'ID' must be Name or Nmtoken" ) != string::npos ||
         m.find( "for attribute 'name' is invalid Name or NMTOKEN value" ) != string::npos ||
         m.find( "for attribute 'ID' is invalid Name or NMTOKEN value" ) != string::npos )
      return;
    string sys( _toString( e.getSystemId() ) );
    MsgStream log( m_msg, "XMLCatalog" );
    log << MSG::ERROR << "Error at file \"" << sys << "\", line " << e.getLineNumber() << ", column "
        << e.getColumnNumber() << endmsg << "Message: " << m << endmsg;
  }
  void ErrHandler::fatalError( const SAXParseException& e )
  {
    MsgStream log( m_msg, "XMLCatalog" );
    string m( _toString( e.getMessage() ) );
    string sys( _toString( e.getSystemId() ) );
    log << MSG::ERROR << "Fatal Error at file \"" << sys << "\", line " << e.getLineNumber() << ", column "
        << e.getColumnNumber() << endmsg << "Message: " << m << endmsg;
    throw runtime_error( "Standard pool exception : Fatal Error on the DOM Parser" );
  }

  const XMLTag EmptyCatalog( "<!-- Edited By POOL -->\n"
                             "<!DOCTYPE POOLFILECATALOG SYSTEM \"InMemory\">\n"
                             "<POOLFILECATALOG>\n"
                             "</POOLFILECATALOG>\n" );
  const XMLTag PFNCOLL( "physical" );
  const XMLTag LFNCOLL( "logical" );
  const XMLTag PFNNODE( "pfn" );
  const XMLTag LFNNODE( "lfn" );
  const XMLTag Attr_type( "type" );
  const XMLTag Attr_ID( "ID" );
  const XMLTag Attr_name( "name" );
  const XMLTag Attr_ftype( "filetype" );
  const XMLTag MetaNode( "metadata" );
  const XMLTag Attr_metaName( "att_name" );
  const XMLTag Attr_metaValue( "att_value" );
}

// ----------------------------------------------------------------------------
XMLFileCatalog::XMLFileCatalog( CSTR uri, IMessageSvc* m )
    : m_rdOnly( false ), m_update( false ), m_doc( 0 ), m_file( uri ), m_msgSvc( m )
{
}
// ----------------------------------------------------------------------------
std::string XMLFileCatalog::createFID() const { return createGuidAsString(); }
// ----------------------------------------------------------------------------
DOMDocument* XMLFileCatalog::getDoc( bool throw_if_no_exists ) const
{
  if ( !m_doc && throw_if_no_exists ) printError( "The XML catalog was not started.", true );
  return m_doc;
}
// ----------------------------------------------------------------------------
void XMLFileCatalog::printError( CSTR msg, bool rethrow ) const
{
  MsgStream log( m_msgSvc, "XMLCatalog" );
  log << MSG::FATAL << msg << endmsg;
  if ( rethrow ) {
    throw runtime_error( "XMLFileCatalog> " + msg );
  }
}
// ----------------------------------------------------------------------------
void XMLFileCatalog::init()
{
  string xmlFile = getfile( false );
  try {
    m_parser.reset( new XercesDOMParser );
    m_parser->setValidationScheme( XercesDOMParser::Val_Auto );
    m_parser->setDoNamespaces( false );
    DTDRedirect dtdinmem;
    m_parser->setEntityResolver( &dtdinmem );
    if ( !m_errHdlr ) m_errHdlr.reset( new ErrHandler( m_msgSvc ) );
    m_parser->setErrorHandler( m_errHdlr.get() );
    if ( !xmlFile.empty() ) {
      m_parser->parse( xmlFile.c_str() );
    } else {
      const std::string& s = EmptyCatalog;
      MemBufInputSource src( (const XMLByte*)s.c_str(), s.length(), "MemCatalog" );
      m_parser->parse( src );
    }
    m_doc = m_parser->getDocument();
  } catch ( const XMLException& e ) {
    printError( "XML parse error[" + xmlFile + "]: " + _toString( e.getMessage() ) );
  } catch ( const DOMException& e ) {
    printError( "XML parse error[" + xmlFile + "]: " + _toString( e.getMessage() ) );
  } catch ( ... ) {
    printError( "UNKNOWN XML parse error in file " + xmlFile );
  }
}
// ----------------------------------------------------------------------------
string XMLFileCatalog::lookupFID( const std::string& fid ) const
{
  std::string result;
  DOMNode* e = element( fid, false );
  e          = e ? e->getParentNode() : 0; // Mode up to <logical>
  e          = e ? e->getParentNode() : 0; // Mode up to <File>
  if ( e ) {
    if ( e->getAttributes() ) { // Need to check this. The node may be no DOMElement
      char* nam         = XMLString::transcode( ( (DOMElement*)e )->getAttribute( Attr_ID ) );
      if ( nam ) result = nam;
      XMLString::release( &nam );
    }
  }
  return result;
}
// ----------------------------------------------------------------------------
void XMLFileCatalog::getFID( Strings& fids ) const
{
  fids.clear();
  DOMNode* fde = getDoc( true )->getElementsByTagName( XMLStr( "*" ) )->item( 0 );
  for ( XMLCollection c( child( fde, "File" ), false ); c; ++c ) fids.push_back( c.attr( Attr_ID ) );
}
// ----------------------------------------------------------------------------
void XMLFileCatalog::getPFN( CSTR fid, Files& files ) const
{
  files.clear();
  for ( XMLCollection c( child( child( element( fid, false ), PFNCOLL ), PFNNODE ), false ); c; ++c )
    files.emplace_back( c.attr( Attr_name ), c.attr( Attr_ftype ) );
}
// ----------------------------------------------------------------------------
void XMLFileCatalog::getLFN( CSTR fid, Files& files ) const
{
  files.clear();
  for ( XMLCollection c( child( child( element( fid, false ), LFNCOLL ), LFNNODE ), false ); c; ++c )
    files.emplace_back( c.attr( Attr_name ), fid );
}
// ----------------------------------------------------------------------------
void XMLFileCatalog::getMetaData( CSTR fid, Attributes& attr ) const
{
  attr.clear();
  for ( XMLCollection c( child( element( fid ), MetaNode ), false ); c; ++c )
    attr.emplace_back( c.attr( Attr_metaName ), c.attr( Attr_metaValue ) );
  if ( attr.size() > 0 ) attr.emplace_back( "guid", fid );
}
// ----------------------------------------------------------------------------
DOMNode* XMLFileCatalog::child( DOMNode* par, CSTR tag, CSTR attr, CSTR val ) const
{
  for ( XMLCollection c( par ); c; ++c ) {
    if ( c.tag() == tag ) {
      if ( !attr.empty() && c.attr( attr ) != val ) continue;
      return c;
    }
  }
  return 0;
}
// ----------------------------------------------------------------------------
void XMLFileCatalog::setMetaData( CSTR fid, CSTR attr, CSTR val ) const
{
  if ( !readOnly() ) {
    DOMNode* node    = element( fid );
    DOMElement* mnod = (DOMElement*)child( node, MetaNode, Attr_metaName, attr );
    if ( !mnod ) {
      mnod = getDoc( true )->createElement( MetaNode );
      node->appendChild( mnod );
      mnod->setAttribute( Attr_metaName, XMLStr( attr ) );
    }
    mnod->setAttribute( Attr_metaValue, XMLStr( val ) );
    m_update = true;
    return;
  }
  printError( "Cannot update readonly catalog!" );
}
// ----------------------------------------------------------------------------
string XMLFileCatalog::getMetaDataItem( CSTR fid, CSTR attr ) const
{
  XMLCollection c( child( getDoc( true )->getElementById( XMLStr( fid ) ), MetaNode, Attr_metaName, attr ) );
  return c ? c.attr( attr ) : string( "" );
}
// ----------------------------------------------------------------------------
void XMLFileCatalog::dropMetaData( CSTR fid, CSTR attr ) const
{
  vector<DOMNode*> gbc;
  DOMNode* fn = getDoc( true )->getElementById( XMLStr( fid ) );
  for ( XMLCollection c{child( fn, MetaNode )}; c; ++c )
    if ( attr[0] == '*' || !c.attr( attr ).empty() ) gbc.push_back( c );
  for ( const auto& i : gbc ) fn->removeChild( i );
}
// ----------------------------------------------------------------------------
DOMNode* XMLFileCatalog::element( CSTR element_name, bool print_err ) const
{
  DOMNode* node = getDoc( true )->getElementById( XMLStr( element_name ) );
  if ( !node && print_err ) printError( "Cannot find element:" + element_name );
  return node;
}
// ----------------------------------------------------------------------------
void XMLFileCatalog::deleteFID( CSTR fid ) const
{
  DOMNode *pn = nullptr, *fn = element( fid );
  if ( fn ) pn = fn->getParentNode();
  if ( pn ) pn->removeChild( fn );
}
// ----------------------------------------------------------------------------
void XMLFileCatalog::registerFID( CSTR fid ) const
{
  if ( !fid.empty() ) {
    std::pair<DOMElement*, DOMElement*> res = i_registerFID( fid );
    if ( res.first == 0 || res.second == 0 ) {
      printError( "Failed to register FID:" + fid );
    }
    return;
  }
  throw runtime_error( "XMLFileCatalog> Cannot register LFN for invalid FID:" + fid );
}
// ----------------------------------------------------------------------------
std::pair<DOMElement*, DOMElement*> XMLFileCatalog::i_registerFID( CSTR fid ) const
{
  if ( readOnly() ) {
    printError( "Cannot update readonly catalog!" );
    return {nullptr, nullptr};
  }

  DOMElement *file = (DOMElement *)element( fid, false ), *phyelem = 0, *logelem = 0;
  DOMDocument* doc = getDoc( true );
  if ( !file ) {
    DOMNode* fde = doc->getElementsByTagName( XMLStr( "*" ) )->item( 0 );
    file         = m_doc->createElement( XMLStr( "File" ) );
    file->setAttribute( Attr_ID, XMLStr( fid ) );
    file->setIdAttribute( Attr_ID, true );
    fde->appendChild( file );
    m_update = true;
  }
  for ( XMLCollection c1( file ); c1; ++c1 ) {
    char* nam                     = XMLString::transcode( c1->getNodeName() );
    if ( nam == PFNCOLL ) phyelem = c1;
    if ( nam == LFNCOLL ) logelem = c1;
    XMLString::release( &nam );
  }
  if ( !phyelem ) {
    phyelem = doc->createElement( PFNCOLL );
    file->appendChild( phyelem );
    m_update = true;
  }
  if ( !logelem ) {
    logelem = doc->createElement( LFNCOLL );
    file->appendChild( logelem );
    m_update = true;
  }
  return {logelem, phyelem};
}
// ----------------------------------------------------------------------------
void XMLFileCatalog::registerPFN( CSTR fid, CSTR pfn, CSTR ftype ) const
{
  if ( !fid.empty() ) {
    std::pair<DOMElement*, DOMElement*> res = i_registerFID( fid );
    DOMElement *phyelem = res.second, *fnelem = 0;
    for ( XMLCollection c( phyelem ); c; ++c ) {
      char* nam = XMLString::transcode( c->getNodeName() );
      if ( nam == PFNNODE ) {
        XMLString::release( &nam );
        nam = XMLString::transcode( c->getAttribute( Attr_name ) );
        if ( nam == pfn ) {
          XMLString::release( &nam );
          fnelem = c;
          break;
        }
      }
      XMLString::release( &nam );
    }
    if ( !fnelem ) {
      fnelem = getDoc( true )->createElement( PFNNODE );
      phyelem->appendChild( fnelem );
      fnelem->setAttribute( Attr_ftype, XMLStr( ftype ) );
      fnelem->setAttribute( Attr_name, XMLStr( pfn ) );
      fnelem->setIdAttribute( Attr_name, true );
      m_update = true;
    }
    return;
  }
  throw runtime_error( "XMLFileCatalog> Cannot register PFN for invalid FID:" + fid );
}
// ----------------------------------------------------------------------------
void XMLFileCatalog::registerLFN( CSTR fid, CSTR lfn ) const
{
  if ( !fid.empty() ) {
    std::pair<DOMElement*, DOMElement*> res = i_registerFID( fid );
    DOMElement *logelem = res.first, *fnelem = 0;
    for ( XMLCollection c( logelem ); c; ++c ) {
      char* nam = XMLString::transcode( c->getNodeName() );
      if ( nam == LFNNODE ) {
        XMLString::release( &nam );
        nam = XMLString::transcode( c->getAttribute( Attr_name ) );
        if ( nam == lfn ) {
          XMLString::release( &nam );
          fnelem = c;
          break;
        }
      }
    }
    if ( !fnelem ) {
      fnelem = getDoc( true )->createElement( LFNNODE );
      logelem->appendChild( fnelem );
      fnelem->setAttribute( Attr_name, XMLStr( lfn ) );
      fnelem->setIdAttribute( Attr_name, true );
      m_update = true;
    }
    return;
  }
  throw runtime_error( "XMLFileCatalog> Cannot register LFN for invalid FID:" + fid );
}
// ----------------------------------------------------------------------------
void XMLFileCatalog::commit()
{
  try {
    if ( dirty() && !readOnly() ) {
      string xmlfile = getfile( true );
      XMLStr ii( "LS" );
      DOMImplementation* imp = DOMImplementationRegistry::getDOMImplementation( ii );
      std::unique_ptr<XMLFormatTarget> tar{new LocalFileFormatTarget( xmlfile.c_str() )};
#if _XERCES_VERSION <= 30000
      DOMWriter* wr = imp->createDOMWriter();
      wr->setFeature( XMLUni::fgDOMWRTFormatPrettyPrint, true );
      wr->writeNode( tar.get(), *m_doc );
      wr->release();
#else
      DOMLSOutput* output = imp->createLSOutput();
      output->setByteStream( tar.get() );
      DOMLSSerializer* wr = imp->createLSSerializer();
      wr->getDomConfig()->setParameter( XMLStr( "format-pretty-print" ), true );
      wr->write( m_doc, output );
      output->release();
      wr->release();
#endif
    }
  } catch ( exception& e ) {
    printError( string( "Cannot open output file:" ) + e.what() );
  } catch ( ... ) {
    printError( "Unknown IO rrror." );
  }
}
// ----------------------------------------------------------------------------
string XMLFileCatalog::getfile( bool create )
{
  string protocol, path;
  XMLURL xerurl;
  try {
    xerurl   = (const XMLCh*)XMLStr( m_file );
    protocol = _toString( xerurl.getProtocolName() );
    path     = _toString( xerurl.getPath() );
  } catch ( const XMLException& e ) {
    printError( _toString( e.getMessage() ) );
  }
  if ( protocol.empty() ) {
    printError( "Missing protocol." );
  } else if ( protocol == "http" || protocol == "ftp" ) {
    m_rdOnly = true;
  } else if ( protocol == "file" ) {
    m_rdOnly = false;
    struct stat buff;
    int exist = ::stat( path.c_str(), &buff ) != -1;
    if ( create && !exist ) {
      MsgStream log( m_msgSvc, "XMLCatalog" );
      log << MSG::INFO << "File '" << path << "' does not exist. New file created." << endmsg;
      ofstream out{path};
      if ( !m_rdOnly && out.is_open() ) {
        out << (CSTR)EmptyCatalog << endl;
      } else {
        printError( "Problem creating file " + path );
      }
      out.close();
    } else if ( exist ) {
      return path;
    } else if ( !create ) {
      return "";
    }
  } else {
    printError( protocol + ": protocol not supported." );
  }
  return path;
}