RepoindexFileReader.cc

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/*---------------------------------------------------------------------\
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|                           / / \ V /|  _/  _/                         |
|                          / /__ | | | | | |                           |
|                         /_____||_| |_| |_|                           |
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\---------------------------------------------------------------------*/
#include <iostream>
#include <unordered_map>

#include "zypp/base/String.h"
#include "zypp/base/Logger.h"
#include "zypp/base/Gettext.h"
#include "zypp/base/InputStream.h"

#include "zypp/Pathname.h"

#include "zypp/parser/xml/Reader.h"
#include "zypp/parser/ParseException.h"

#include "zypp/RepoInfo.h"

#include "zypp/parser/RepoindexFileReader.h"


#undef ZYPP_BASE_LOGGER_LOGGROUP
#define ZYPP_BASE_LOGGER_LOGGROUP "parser"

using std::endl;

namespace zypp
{
  namespace parser
  {
    using xml::Reader;
    using xml::XmlString;

    namespace
    {
      class VarReplacer : private base::NonCopyable
      {
      public:
        void setVar( const std::string & key_r, const std::string & val_r )
        {
          MIL << "*** Inject " << key_r << " = " << val_r;
          _vars[key_r] = replace( val_r );
          MIL << " (" << _vars[key_r] << ")" << endl;
        }

        std::string replace( const std::string & val_r ) const
        {
          std::string::size_type vbeg = val_r.find( "%{", 0 );
          if ( vbeg == std::string::npos )
            return val_r;

          str::Str ret;
          std::string::size_type cbeg = 0;
          for( ; vbeg != std::string::npos; vbeg = val_r.find( "%{", vbeg ) )
          {
            std::string::size_type nbeg = vbeg+2;
            std::string::size_type nend = val_r.find( "}", nbeg );
            if ( nend == std::string::npos )
            {
              WAR << "Incomplete variable in '" << val_r << "'" << endl;
              break;
            }
            const auto & iter = _vars.find( val_r.substr( nbeg, nend-nbeg ) );
            if ( iter != _vars.end() )
            {
              if ( cbeg < vbeg )
                ret << val_r.substr( cbeg, vbeg-cbeg );
              ret << iter->second;
              cbeg = nend+1;
            }
            else
              WAR << "Undefined variable %{" << val_r.substr( nbeg, nend-nbeg ) << "} in '" << val_r << "'" << endl;
            vbeg = nend+1;
          }
          if ( cbeg < val_r.size() )
            ret << val_r.substr( cbeg );

          return ret;
        }
      private:
        std::unordered_map<std::string,std::string> _vars;
      };
    } // namespace

  //
  //  CLASS NAME : RepoindexFileReader::Impl
  //
  class RepoindexFileReader::Impl : private base::NonCopyable
  {
  public:
    Impl(const InputStream &is, const ProcessResource & callback);

    bool consumeNode( Reader & reader_r );

  private:
    bool getAttrValue( const std::string & key_r, Reader & reader_r, std::string & value_r )
    {
      const XmlString & s( reader_r->getAttribute( key_r ) );
      if ( s.get() )
      {
        value_r = _replacer.replace( s.asString() );
        return !value_r.empty();
      }
      value_r.clear();
      return false;
    }

  private:
    ProcessResource _callback;
    VarReplacer _replacer;
  };

  RepoindexFileReader::Impl::Impl(const InputStream &is,
                                  const ProcessResource & callback)
    : _callback(callback)
  {
    Reader reader( is );
    MIL << "Reading " << is.path() << endl;
    reader.foreachNode( bind( &RepoindexFileReader::Impl::consumeNode, this, _1 ) );
  }

  // --------------------------------------------------------------------------

  /*
   * xpath and multiplicity of processed nodes are included in the code
   * for convenience:
   *
   * // xpath: <xpath> (?|*|+)
   *
   * if multiplicity is ommited, then the node has multiplicity 'one'.
   */

  // --------------------------------------------------------------------------

  bool RepoindexFileReader::Impl::consumeNode( Reader & reader_r )
  {
    if ( reader_r->nodeType() == XML_READER_TYPE_ELEMENT )
    {
      // xpath: /repoindex
      if ( reader_r->name() == "repoindex" )
      {
        while ( reader_r.nextNodeAttribute() )
          _replacer.setVar( reader_r->localName().asString(), reader_r->value().asString() );
        return true;
      }

      // xpath: /repoindex/data (+)
      if ( reader_r->name() == "repo" )
      {
        RepoInfo info;
        // Set some defaults that are not contained in the repo information
        info.setAutorefresh( true );
        info.setEnabled(false);

        std::string attrValue;

        // required alias
        // mandatory, so we can allow it in var replacement without reset
        if ( getAttrValue( "alias", reader_r, attrValue ) )
        {
          info.setAlias( attrValue );
          _replacer.setVar( "alias", attrValue );
        }
        else
          throw ParseException(str::form(_("Required attribute '%s' is missing."), "alias"));

        // required url
        // SLES HACK: or path, but beware of the hardcoded '/repo' prefix!
        {
          std::string urlstr;
          std::string pathstr;
          getAttrValue( "url", reader_r, urlstr );
          getAttrValue( "path", reader_r, pathstr );
          if ( urlstr.empty() )
          {
            if ( pathstr.empty() )
              throw ParseException(str::form(_("One or both of '%s' or '%s' attributes is required."), "url", "path"));
            else
              info.setPath( Pathname("/repo") / pathstr );
          }
          else
          {
            if ( pathstr.empty() )
              info.setBaseUrl( Url(urlstr) );
            else
            {
              Url url( urlstr );
              url.setPathName( Pathname(url.getPathName()) / "repo" / pathstr );
              info.setBaseUrl( url );
            }
          }
        }

        // optional name
        if ( getAttrValue( "name", reader_r, attrValue ) )
          info.setName( attrValue );

        // optional targetDistro
        if ( getAttrValue( "distro_target", reader_r, attrValue ) )
          info.setTargetDistribution( attrValue );

        // optional priority
        if ( getAttrValue( "priority", reader_r, attrValue ) )
          info.setPriority( str::strtonum<unsigned>( attrValue ) );


        // optional enabled
        if ( getAttrValue( "enabled", reader_r, attrValue ) )
          info.setEnabled( str::strToBool( attrValue, info.enabled() ) );

        // optional autorefresh
        if ( getAttrValue( "autorefresh", reader_r, attrValue ) )
          info.setAutorefresh( str::strToBool( attrValue, info.autorefresh() ) );

        DBG << info << endl;

        // ignore the rest
        _callback(info);
        return true;
      }
    }

    return true;
  }


  //
  //  CLASS NAME : RepoindexFileReader
  //

  RepoindexFileReader::RepoindexFileReader(
      const Pathname & repoindex_file, const ProcessResource & callback)
    :
      _pimpl(new Impl(InputStream(repoindex_file), callback))
  {}

  RepoindexFileReader::RepoindexFileReader(
       const InputStream &is, const ProcessResource & callback )
    : _pimpl(new Impl(is, callback))
  {}

  RepoindexFileReader::~RepoindexFileReader()
  {}


  } // ns parser
} // ns zypp

// vim: set ts=2 sts=2 sw=2 et ai: