[mapguide-trac] #1398: Upgrade to DbXml 2.5.16

MapGuide Open Source trac_mapguide at osgeo.org
Fri Jul 9 08:48:24 EDT 2010


#1398: Upgrade to DbXml 2.5.16
-----------------------+----------------------------------------------------
   Reporter:  rohitr   |       Owner:                     
       Type:  task     |      Status:  new                
   Priority:  low      |   Milestone:  2.3                
  Component:  General  |     Version:  2.2.0              
   Severity:  trivial  |    Keywords:  dbxml, upgrade, oem
External_id:           |  
-----------------------+----------------------------------------------------
 1.> Used DbEnv.get_DB_ENV and DbTxn.get_DB_TXN to get the underlying
 DB_ENV and DB_TXN structure and used that with the DbXml public interface.

 Changed
 {{{ environment->GetXmlManager().createTransaction(m_dbTxn))); }}} to
 {{{environment->GetXmlManager().createTransaction(m_dbTxn->get_DB_TXN())));
 }}} and {{{ m_xmlMan = XmlManager(&m_dbEnv, DBXML_ALLOW_EXTERNAL_ACCESS);
 to m_xmlMan = XmlManager(m_dbEnv.get_DB_ENV(),
 DBXML_ALLOW_EXTERNAL_ACCESS); }}} .

 2.>Added a function DbXml::getContentAsDOM(const XmlValue &value). and
 used the constructor of the XmlValue to get an XmlValue handle on xmlDoc.
 The function is modified from an example in dbxml/example folder. Its a
 hack and I plan to make a proper class pretty soon.

 Created 2 files xercesDomTranslator.h and xercesDomTranslator.cpp. These
 are trivially modified forms of the file of the same name in dbxml example
 folder. However the function is trivial and I would make a class to
 encapsulate it, after I finish compilation.
 The function defined is
 {{{ XERCES_CPP_NAMESPACE_QUALIFIER DOMDocument *getContentAsDOM(const
 DbXml::XmlValue &value); }}}It requires an Xmlvalue and this is
 constructed by the constructor of the XmlValue class from the XmlDocument
 passed to it.

 3.>Since XmlModify has been removed, we can use a simple Xquery Update to
 delete records. For example where our query was
 {{{ query = "/Role/Users/User[Name=<foobar>]"; }}} we change it to    {{{
 query = "delete nodes /Role/Users/User[Name=<foobar>]"; }}} and just
 execute the query with XmlManager::query().

 4.>The function for assigning flags to DbEnv has been changed from
 set_flags to log_set_config. The define LOG_INMEMORY is no longer defined.
 It has been replaced with LOG_IN_MEMORY, which is functionally equivalent.

 5.>Included db_cxx.h . Also removed the 'catch' for DbException. This isnt
 completely necessary but seeing that DbXml wants to encapsulate
 DbException inside XmlException and the functionality was similar, I
 removed it.
 {{{
 catch (XmlException& e)
 \
     {
 \
         MgStringCollection arguments;
 \
         STRING message;
 \
 \
         if (DB_LOCK_DEADLOCK == e.getDbErrno())
 \
         {
 \
             message = MgUtil::GetResourceMessage(
 \
                 MgResources::ResourceService, L"MgRepositoryBusy");
 \
         }
 \
         else
 \
         {
 \
             MgUtil::MultiByteToWideChar(string(e.what()), message);
 \
         }
 \
 \
         arguments.Add(message);
 \
         mgException = new MgDbXmlException(methodName, __LINE__,
 __WFILE__, NULL, L"MgFormatInnerExceptionMessage", &arguments); \
 (static_cast<MgThirdPartyException*>(mgException.p))->SetErrorCode(e.getDbErrno());
 \
     }
 }}}
 and
 {{{
 catch (DbException& e)
 \
     {
 \
         MgStringCollection arguments;
 \
         STRING message;
 \
 \
         if (DB_LOCK_DEADLOCK == e.get_errno())
 \
         {
 \
             message = MgUtil::GetResourceMessage(
 \
                 MgResources::ResourceService, L"MgRepositoryBusy");
 \
         }
 \
         else
 \
         {
 \
             MgUtil::MultiByteToWideChar(string(e.what()), message);
 \
         }
 \
 \
         arguments.Add(message);
 \
         mgException = new MgDbException(methodName, __LINE__, __WFILE__,
 NULL, L"MgFormatInnerExceptionMessage", &arguments); \
 (static_cast<MgThirdPartyException*>(mgException.p))->SetErrorCode(e.get_errno());
 \
     }
 }}}
 Since XmlException would be triggered on a DbException and would give the
 same DbErrno and what() string, it seemed redundant to include this. Note
 the initial motivation was this to go with the philosophy of dbxml of
 hiding DB as much as possible. Unfortunately due to MapGuides use of DB
 objects in multiple places, that won't be possible.

 6.>As there is no other option, but to go with LiveValues and afaik there
 appears to be no difference, I have just removed the lines.

-- 
Ticket URL: <http://trac.osgeo.org/mapguide/ticket/1398>
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