From: Anthony Geay <anthony.geay@edf.fr>
Date: Mon, 10 Oct 2016 11:49:21 +0000 (+0200)
Subject: End of refacto. Now ready for MEDFilemem implementation and for selection of MED... 
X-Git-Tag: V8_2_0a1~11
X-Git-Url: http://git.salome-platform.org/gitweb/?a=commitdiff_plain;h=6ff0c473a6c62af57a92e7e23cc940ebd09a7311;p=tools%2Fmedcoupling.git

End of refacto. Now ready for MEDFilemem implementation and for selection of MED file version on write.
---

diff --git a/src/MEDLoader/CMakeLists.txt b/src/MEDLoader/CMakeLists.txt
index 76dd3dd34..d1c2583b6 100644
--- a/src/MEDLoader/CMakeLists.txt
+++ b/src/MEDLoader/CMakeLists.txt
@@ -56,6 +56,7 @@ INCLUDE_DIRECTORIES(
 SET(medloader_SOURCES
   MEDLoader.cxx
   MEDLoaderBase.cxx
+  MEDLoaderTraits.cxx
   MEDFileUtilities.cxx
   MEDFileMesh.cxx
   MEDFileMeshElt.cxx
diff --git a/src/MEDLoader/MEDFileData.cxx b/src/MEDLoader/MEDFileData.cxx
index 5adb571fa..ab7b59e69 100644
--- a/src/MEDLoader/MEDFileData.cxx
+++ b/src/MEDLoader/MEDFileData.cxx
@@ -24,7 +24,13 @@ using namespace MEDCoupling;
 
 MEDFileData *MEDFileData::New(const std::string& fileName)
 {
-  return new MEDFileData(fileName);
+  MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid);
+}
+
+MEDFileData *MEDFileData::New(med_idt fid)
+{
+  return new MEDFileData(fid);
 }
 
 MEDFileData *MEDFileData::New()
@@ -291,12 +297,12 @@ MEDFileData::MEDFileData()
 {
 }
 
-MEDFileData::MEDFileData(const std::string& fileName)
+MEDFileData::MEDFileData(med_idt fid)
 try
 {
-    _fields=MEDFileFields::New(fileName);
-    _meshes=MEDFileMeshes::New(fileName);
-    _params=MEDFileParameters::New(fileName);
+    _fields=MEDFileFields::New(fid);
+    _meshes=MEDFileMeshes::New(fid);
+    _params=MEDFileParameters::New(fid);
 }
 catch(INTERP_KERNEL::Exception& e)
 {
diff --git a/src/MEDLoader/MEDFileData.hxx b/src/MEDLoader/MEDFileData.hxx
index d483d08f0..6b31f2096 100644
--- a/src/MEDLoader/MEDFileData.hxx
+++ b/src/MEDLoader/MEDFileData.hxx
@@ -35,6 +35,7 @@ namespace MEDCoupling
   {
   public:
     MEDLOADER_EXPORT static MEDFileData *New(const std::string& fileName);
+    MEDLOADER_EXPORT static MEDFileData *New(med_idt fid);
     MEDLOADER_EXPORT static MEDFileData *New();
     MEDLOADER_EXPORT MEDFileData *deepCopy() const;
     MEDLOADER_EXPORT std::size_t getHeapMemorySizeWithoutChildren() const;
@@ -58,7 +59,7 @@ namespace MEDCoupling
     MEDLOADER_EXPORT void writeLL(med_idt fid) const;
   private:
     MEDFileData();
-    MEDFileData(const std::string& fileName);
+    MEDFileData(med_idt fid);
   private:
     MCAuto<MEDFileFields> _fields;
     MCAuto<MEDFileMeshes> _meshes;
diff --git a/src/MEDLoader/MEDFileField.cxx b/src/MEDLoader/MEDFileField.cxx
index 8949f50cc..810e06da6 100644
--- a/src/MEDLoader/MEDFileField.cxx
+++ b/src/MEDLoader/MEDFileField.cxx
@@ -6719,6 +6719,11 @@ MEDFileIntField1TS *MEDFileIntField1TS::New()
 MEDFileIntField1TS *MEDFileIntField1TS::New(const std::string& fileName, bool loadAll)
 {
   MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return MEDFileIntField1TS::New(fid,loadAll);
+}
+
+MEDFileIntField1TS *MEDFileIntField1TS::New(med_idt fid, bool loadAll)
+{
   MCAuto<MEDFileIntField1TS> ret(new MEDFileIntField1TS(fid,loadAll,0));
   ret->contentNotNull();
   return ret.retn();
@@ -6727,6 +6732,11 @@ MEDFileIntField1TS *MEDFileIntField1TS::New(const std::string& fileName, bool lo
 MEDFileIntField1TS *MEDFileIntField1TS::New(const std::string& fileName, const std::string& fieldName, bool loadAll)
 {
   MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return MEDFileIntField1TS::New(fid,fieldName,loadAll);
+}
+
+MEDFileIntField1TS *MEDFileIntField1TS::New(med_idt fid, const std::string& fieldName, bool loadAll)
+{
   MCAuto<MEDFileIntField1TS> ret(new MEDFileIntField1TS(fid,fieldName,loadAll,0));
   ret->contentNotNull();
   return ret.retn();
@@ -6735,6 +6745,11 @@ MEDFileIntField1TS *MEDFileIntField1TS::New(const std::string& fileName, const s
 MEDFileIntField1TS *MEDFileIntField1TS::New(const std::string& fileName, const std::string& fieldName, int iteration, int order, bool loadAll)
 {
   MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return MEDFileIntField1TS::New(fid,fieldName,iteration,order,loadAll);
+}
+
+MEDFileIntField1TS *MEDFileIntField1TS::New(med_idt fid, const std::string& fieldName, int iteration, int order, bool loadAll)
+{
   MCAuto<MEDFileIntField1TS> ret(new MEDFileIntField1TS(fid,fieldName,iteration,order,loadAll,0));
   ret->contentNotNull();
   return ret.retn();
@@ -8204,27 +8219,33 @@ MEDFileAnyTypeFieldMultiTSWithoutSDA *MEDFileAnyTypeFieldMultiTS::BuildContentFr
   return ret.retn();
 }
 
-MEDFileAnyTypeFieldMultiTS *MEDFileAnyTypeFieldMultiTS::BuildNewInstanceFromContent(MEDFileAnyTypeFieldMultiTSWithoutSDA *c, const std::string& fileName)
+MEDFileAnyTypeFieldMultiTS *MEDFileAnyTypeFieldMultiTS::BuildNewInstanceFromContent(MEDFileAnyTypeFieldMultiTSWithoutSDA *c)
 {
   if(!c)
     throw INTERP_KERNEL::Exception("MEDFileAnyTypeFieldMultiTS::BuildNewInstanceFromContent : empty content in input : unable to build a new instance !");
   if(dynamic_cast<const MEDFileFieldMultiTSWithoutSDA *>(c))
     {
       MCAuto<MEDFileFieldMultiTS> ret(MEDFileFieldMultiTS::New());
-      ret->setFileName(fileName);
       ret->_content=c;  c->incrRef();
       return ret.retn();
     }
   if(dynamic_cast<const MEDFileIntFieldMultiTSWithoutSDA *>(c))
     {
       MCAuto<MEDFileIntFieldMultiTS> ret(MEDFileIntFieldMultiTS::New());
-      ret->setFileName(fileName);
       ret->_content=c;  c->incrRef();
       return ret.retn();
     }
   throw INTERP_KERNEL::Exception("MEDFileAnyTypeFieldMultiTS::BuildNewInstanceFromContent : internal error ! a content of type different from FLOAT64 and INT32 has been built but not intercepted !");
 }
 
+MEDFileAnyTypeFieldMultiTS *MEDFileAnyTypeFieldMultiTS::BuildNewInstanceFromContent(MEDFileAnyTypeFieldMultiTSWithoutSDA *c, med_idt fid)
+{
+  MEDFileAnyTypeFieldMultiTS *ret(BuildNewInstanceFromContent(c));
+  std::string fileName(FileNameFromFID(fid));
+  ret->setFileName(fileName);
+  return ret;
+}
+
 MEDFileAnyTypeFieldMultiTS::MEDFileAnyTypeFieldMultiTS(med_idt fid, const std::string& fieldName, bool loadAll, const MEDFileMeshes *ms, const std::vector< std::pair<TypeOfField,INTERP_KERNEL::NormalizedCellType> > *entities)
 try:MEDFileFieldGlobsReal(fid)
 {
@@ -8330,8 +8351,13 @@ MEDFileFieldMultiTSWithoutSDA *MEDFileIntFieldMultiTSWithoutSDA::convertToDouble
 MEDFileAnyTypeFieldMultiTS *MEDFileAnyTypeFieldMultiTS::New(const std::string& fileName, bool loadAll)
 {
   MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid,loadAll);
+}
+
+MEDFileAnyTypeFieldMultiTS *MEDFileAnyTypeFieldMultiTS::New(med_idt fid, bool loadAll)
+{
   MCAuto<MEDFileAnyTypeFieldMultiTSWithoutSDA> c(BuildContentFrom(fid,loadAll,0));
-  MCAuto<MEDFileAnyTypeFieldMultiTS> ret(BuildNewInstanceFromContent(c,fileName));
+  MCAuto<MEDFileAnyTypeFieldMultiTS> ret(BuildNewInstanceFromContent(c,fid));
   ret->loadGlobals(fid);
   return ret.retn();
 }
@@ -8349,8 +8375,13 @@ MEDFileAnyTypeFieldMultiTS *MEDFileAnyTypeFieldMultiTS::New(const std::string& f
 MEDFileAnyTypeFieldMultiTS *MEDFileAnyTypeFieldMultiTS::New(const std::string& fileName, const std::string& fieldName, bool loadAll)
 {
   MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid,fieldName,loadAll);
+}
+
+MEDFileAnyTypeFieldMultiTS *MEDFileAnyTypeFieldMultiTS::New(med_idt fid, const std::string& fieldName, bool loadAll)
+{
   MCAuto<MEDFileAnyTypeFieldMultiTSWithoutSDA> c(BuildContentFrom(fid,fieldName,loadAll,0,0));
-  MCAuto<MEDFileAnyTypeFieldMultiTS> ret=BuildNewInstanceFromContent(c,fileName);
+  MCAuto<MEDFileAnyTypeFieldMultiTS> ret(BuildNewInstanceFromContent(c,fid));
   ret->loadGlobals(fid);
   return ret.retn();
 }
@@ -9127,6 +9158,11 @@ MEDFileFieldMultiTS *MEDFileFieldMultiTS::New()
 MEDFileFieldMultiTS *MEDFileFieldMultiTS::New(const std::string& fileName, bool loadAll)
 {
   MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid,loadAll);
+}
+
+MEDFileFieldMultiTS *MEDFileFieldMultiTS::New(med_idt fid, bool loadAll)
+{
   MCAuto<MEDFileFieldMultiTS> ret(new MEDFileFieldMultiTS(fid,loadAll,0));
   ret->contentNotNull();//to check that content type matches with \a this type.
   return ret.retn();
@@ -9145,6 +9181,11 @@ MEDFileFieldMultiTS *MEDFileFieldMultiTS::New(const std::string& fileName, bool
 MEDFileFieldMultiTS *MEDFileFieldMultiTS::New(const std::string& fileName, const std::string& fieldName, bool loadAll)
 {
   MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid,fieldName,loadAll);
+}
+
+MEDFileFieldMultiTS *MEDFileFieldMultiTS::New(med_idt fid, const std::string& fieldName, bool loadAll)
+{
   MCAuto<MEDFileFieldMultiTS> ret(new MEDFileFieldMultiTS(fid,fieldName,loadAll,0));
   ret->contentNotNull();//to check that content type matches with \a this type.
   return ret.retn();
@@ -9207,7 +9248,7 @@ MEDFileIntFieldMultiTS *MEDFileFieldMultiTS::convertToInt(bool isDeepCpyGlobs) c
       if(!contc)
         throw INTERP_KERNEL::Exception("MEDFileFieldMultiTS::convertToInt : the content inside this is not FLOAT64 ! This is incoherent !");
       MCAuto<MEDFileIntFieldMultiTSWithoutSDA> newc(contc->convertToInt());
-      ret=static_cast<MEDFileIntFieldMultiTS *>(MEDFileAnyTypeFieldMultiTS::BuildNewInstanceFromContent((MEDFileIntFieldMultiTSWithoutSDA *)newc,getFileName()));
+      ret=static_cast<MEDFileIntFieldMultiTS *>(MEDFileAnyTypeFieldMultiTS::BuildNewInstanceFromContent((MEDFileIntFieldMultiTSWithoutSDA *)newc));
     }
   else
     ret=MEDFileIntFieldMultiTS::New();
@@ -9609,6 +9650,11 @@ MEDFileIntFieldMultiTS *MEDFileIntFieldMultiTS::New()
 MEDFileIntFieldMultiTS *MEDFileIntFieldMultiTS::New(const std::string& fileName, bool loadAll)
 {
   MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid,loadAll);
+}
+
+MEDFileIntFieldMultiTS *MEDFileIntFieldMultiTS::New(med_idt fid, bool loadAll)
+{
   MCAuto<MEDFileIntFieldMultiTS> ret(new MEDFileIntFieldMultiTS(fid,loadAll,0));
   ret->contentNotNull();//to check that content type matches with \a this type.
   return ret.retn();
@@ -9627,6 +9673,11 @@ MEDFileIntFieldMultiTS *MEDFileIntFieldMultiTS::New(const std::string& fileName,
 MEDFileIntFieldMultiTS *MEDFileIntFieldMultiTS::New(const std::string& fileName, const std::string& fieldName, bool loadAll)
 {
   MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid,fieldName,loadAll);
+}
+
+MEDFileIntFieldMultiTS *MEDFileIntFieldMultiTS::New(med_idt fid, const std::string& fieldName, bool loadAll)
+{
   MCAuto<MEDFileIntFieldMultiTS> ret(new MEDFileIntFieldMultiTS(fid,fieldName,loadAll,0));
   ret->contentNotNull();//to check that content type matches with \a this type.
   return ret.retn();
@@ -9675,7 +9726,7 @@ MEDFileFieldMultiTS *MEDFileIntFieldMultiTS::convertToDouble(bool isDeepCpyGlobs
       if(!contc)
         throw INTERP_KERNEL::Exception("MEDFileIntFieldMultiTS::convertToInt : the content inside this is not INT32 ! This is incoherent !");
       MCAuto<MEDFileFieldMultiTSWithoutSDA> newc(contc->convertToDouble());
-      ret=static_cast<MEDFileFieldMultiTS *>(MEDFileAnyTypeFieldMultiTS::BuildNewInstanceFromContent((MEDFileFieldMultiTSWithoutSDA *)newc,getFileName()));
+      ret=static_cast<MEDFileFieldMultiTS *>(MEDFileAnyTypeFieldMultiTS::BuildNewInstanceFromContent((MEDFileFieldMultiTSWithoutSDA *)newc));
     }
   else
     ret=MEDFileFieldMultiTS::New();
@@ -10040,6 +10091,11 @@ MEDFileFields *MEDFileFields::New()
 MEDFileFields *MEDFileFields::New(const std::string& fileName, bool loadAll)
 {
   MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid,loadAll);
+}
+
+MEDFileFields *MEDFileFields::New(med_idt fid, bool loadAll)
+{
   return new MEDFileFields(fid,loadAll,0,0);
 }
 
@@ -10073,8 +10129,8 @@ std::vector<const BigMemoryObject *> MEDFileFields::getDirectChildrenWithNull()
 
 MEDFileFields *MEDFileFields::deepCopy() const
 {
-  MCAuto<MEDFileFields> ret=shallowCpy();
-  std::size_t i=0;
+  MCAuto<MEDFileFields> ret(shallowCpy());
+  std::size_t i(0);
   for(std::vector< MCAuto<MEDFileAnyTypeFieldMultiTSWithoutSDA> >::const_iterator it=_fields.begin();it!=_fields.end();it++,i++)
     {
       if((const MEDFileAnyTypeFieldMultiTSWithoutSDA*)*it)
@@ -10133,7 +10189,7 @@ int MEDFileFields::getNumberOfFields() const
 std::vector<std::string> MEDFileFields::getFieldsNames() const
 {
   std::vector<std::string> ret(_fields.size());
-  int i=0;
+  int i(0);
   for(std::vector< MCAuto<MEDFileAnyTypeFieldMultiTSWithoutSDA> >::const_iterator it=_fields.begin();it!=_fields.end();it++,i++)
     {
       const MEDFileAnyTypeFieldMultiTSWithoutSDA *f=(*it);
@@ -10172,7 +10228,7 @@ std::string MEDFileFields::simpleRepr() const
 
 void MEDFileFields::simpleRepr(int bkOffset, std::ostream& oss) const
 {
-  int nbOfFields=getNumberOfFields();
+  int nbOfFields(getNumberOfFields());
   std::string startLine(bkOffset,' ');
   oss << startLine << "There are " << nbOfFields << " fields in this :" << std::endl;
   int i=0;
@@ -10358,7 +10414,7 @@ std::vector<std::string> MEDFileFields::getLocsReallyUsed() const
   std::set<std::string> ret2;
   for(std::vector< MCAuto< MEDFileAnyTypeFieldMultiTSWithoutSDA > >::const_iterator it=_fields.begin();it!=_fields.end();it++)
     {
-      std::vector<std::string> tmp=(*it)->getLocsReallyUsed2();
+      std::vector<std::string> tmp((*it)->getLocsReallyUsed2());
       for(std::vector<std::string>::const_iterator it2=tmp.begin();it2!=tmp.end();it2++)
         if(ret2.find(*it2)==ret2.end())
           {
@@ -10374,7 +10430,7 @@ std::vector<std::string> MEDFileFields::getPflsReallyUsedMulti() const
   std::vector<std::string> ret;
   for(std::vector< MCAuto< MEDFileAnyTypeFieldMultiTSWithoutSDA > >::const_iterator it=_fields.begin();it!=_fields.end();it++)
     {
-      std::vector<std::string> tmp=(*it)->getPflsReallyUsedMulti2();
+      std::vector<std::string> tmp((*it)->getPflsReallyUsedMulti2());
       ret.insert(ret.end(),tmp.begin(),tmp.end());
     }
   return ret;
@@ -10385,7 +10441,7 @@ std::vector<std::string> MEDFileFields::getLocsReallyUsedMulti() const
   std::vector<std::string> ret;
   for(std::vector< MCAuto< MEDFileAnyTypeFieldMultiTSWithoutSDA > >::const_iterator it=_fields.begin();it!=_fields.end();it++)
     {
-      std::vector<std::string> tmp=(*it)->getLocsReallyUsed2();
+      std::vector<std::string> tmp((*it)->getLocsReallyUsed2());
       ret.insert(ret.end(),tmp.begin(),tmp.end());
     }
   return ret;
@@ -10460,7 +10516,7 @@ void MEDFileFields::destroyFieldsAtPos(const int *startIds, const int *endIds)
 void MEDFileFields::destroyFieldsAtPos2(int bg, int end, int step)
 {
   static const char msg[]="MEDFileFields::destroyFieldsAtPos2";
-  int nbOfEntriesToKill=DataArrayInt::GetNumberOfItemGivenBESRelative(bg,end,step,msg);
+  int nbOfEntriesToKill(DataArrayInt::GetNumberOfItemGivenBESRelative(bg,end,step,msg));
   std::vector<bool> b(_fields.size(),true);
   int k=bg;
   for(int i=0;i<nbOfEntriesToKill;i++,k+=step)
@@ -10473,7 +10529,7 @@ void MEDFileFields::destroyFieldsAtPos2(int bg, int end, int step)
       b[k]=false;
     }
   std::vector< MCAuto<MEDFileAnyTypeFieldMultiTSWithoutSDA> > fields(std::count(b.begin(),b.end(),true));
-  std::size_t j=0;
+  std::size_t j(0);
   for(std::size_t i=0;i<_fields.size();i++)
     if(b[i])
       fields[j++]=_fields[i];
@@ -10482,7 +10538,7 @@ void MEDFileFields::destroyFieldsAtPos2(int bg, int end, int step)
 
 bool MEDFileFields::changeMeshNames(const std::vector< std::pair<std::string,std::string> >& modifTab)
 {
-  bool ret=false;
+  bool ret(false);
   for(std::vector< MCAuto<MEDFileAnyTypeFieldMultiTSWithoutSDA> >::iterator it=_fields.begin();it!=_fields.end();it++)
     {
       MEDFileAnyTypeFieldMultiTSWithoutSDA *cur(*it);
@@ -10503,7 +10559,7 @@ bool MEDFileFields::changeMeshNames(const std::vector< std::pair<std::string,std
  */
 bool MEDFileFields::renumberEntitiesLyingOnMesh(const std::string& meshName, const std::vector<int>& oldCode, const std::vector<int>& newCode, const DataArrayInt *renumO2N)
 {
-  bool ret=false;
+  bool ret(false);
   for(std::vector< MCAuto<MEDFileAnyTypeFieldMultiTSWithoutSDA> >::iterator it=_fields.begin();it!=_fields.end();it++)
     {
       MEDFileAnyTypeFieldMultiTSWithoutSDA *fmts(*it);
@@ -10552,8 +10608,8 @@ MEDFileAnyTypeFieldMultiTS *MEDFileFields::getFieldAtPos(int i) const
   if(!fmts)
     return 0;
   MCAuto<MEDFileAnyTypeFieldMultiTS> ret;
-  const MEDFileFieldMultiTSWithoutSDA *fmtsC=dynamic_cast<const MEDFileFieldMultiTSWithoutSDA *>(fmts);
-  const MEDFileIntFieldMultiTSWithoutSDA *fmtsC2=dynamic_cast<const MEDFileIntFieldMultiTSWithoutSDA *>(fmts);
+  const MEDFileFieldMultiTSWithoutSDA *fmtsC(dynamic_cast<const MEDFileFieldMultiTSWithoutSDA *>(fmts));
+  const MEDFileIntFieldMultiTSWithoutSDA *fmtsC2(dynamic_cast<const MEDFileIntFieldMultiTSWithoutSDA *>(fmts));
   if(fmtsC)
     ret=MEDFileFieldMultiTS::New(*fmtsC,false);
   else if(fmtsC2)
@@ -10631,10 +10687,10 @@ bool MEDFileFields::removeFieldsWithoutAnyTimeStep()
  */
 MEDFileFields *MEDFileFields::partOfThisLyingOnSpecifiedMeshName(const std::string& meshName) const
 {
-  MCAuto<MEDFileFields> ret=MEDFileFields::New();
+  MCAuto<MEDFileFields> ret(MEDFileFields::New());
   for(std::vector< MCAuto<MEDFileAnyTypeFieldMultiTSWithoutSDA> >::const_iterator it=_fields.begin();it!=_fields.end();it++)
     {
-      const MEDFileAnyTypeFieldMultiTSWithoutSDA *cur=(*it);
+      const MEDFileAnyTypeFieldMultiTSWithoutSDA *cur(*it);
       if(!cur)
         continue;
       if(cur->getMeshName()==meshName)
@@ -10663,10 +10719,10 @@ MEDFileFields *MEDFileFields::partOfThisLyingOnSpecifiedMeshName(const std::stri
  */
 MEDFileFields *MEDFileFields::partOfThisLyingOnSpecifiedTimeSteps(const std::vector< std::pair<int,int> >& timeSteps) const
 {
-  MCAuto<MEDFileFields> ret=MEDFileFields::New();
+  MCAuto<MEDFileFields> ret(MEDFileFields::New());
   for(std::vector< MCAuto<MEDFileAnyTypeFieldMultiTSWithoutSDA> >::const_iterator it=_fields.begin();it!=_fields.end();it++)
     {
-      const MEDFileAnyTypeFieldMultiTSWithoutSDA *cur=(*it);
+      const MEDFileAnyTypeFieldMultiTSWithoutSDA *cur(*it);
       if(!cur)
         continue;
       MCAuto<MEDFileAnyTypeFieldMultiTSWithoutSDA> elt=cur->partOfThisLyingOnSpecifiedTimeSteps(timeSteps);
@@ -10684,7 +10740,7 @@ MEDFileFields *MEDFileFields::partOfThisNotLyingOnSpecifiedTimeSteps(const std::
   MCAuto<MEDFileFields> ret=MEDFileFields::New();
   for(std::vector< MCAuto<MEDFileAnyTypeFieldMultiTSWithoutSDA> >::const_iterator it=_fields.begin();it!=_fields.end();it++)
     {
-      const MEDFileAnyTypeFieldMultiTSWithoutSDA *cur=(*it);
+      const MEDFileAnyTypeFieldMultiTSWithoutSDA *cur(*it);
       if(!cur)
         continue;
       MCAuto<MEDFileAnyTypeFieldMultiTSWithoutSDA> elt=cur->partOfThisNotLyingOnSpecifiedTimeSteps(timeSteps);
@@ -10706,7 +10762,7 @@ int MEDFileFields::getPosFromFieldName(const std::string& fieldName) const
   std::vector<std::string> poss;
   for(std::size_t i=0;i<_fields.size();i++)
     {
-      const MEDFileAnyTypeFieldMultiTSWithoutSDA *f=_fields[i];
+      const MEDFileAnyTypeFieldMultiTSWithoutSDA *f(_fields[i]);
       if(f)
         {
           std::string fname(f->getName());
diff --git a/src/MEDLoader/MEDFileField.hxx b/src/MEDLoader/MEDFileField.hxx
index 51886a565..f201eed5a 100644
--- a/src/MEDLoader/MEDFileField.hxx
+++ b/src/MEDLoader/MEDFileField.hxx
@@ -786,8 +786,11 @@ namespace MEDCoupling
   public:
     MEDLOADER_EXPORT static MEDFileIntField1TS *New();
     MEDLOADER_EXPORT static MEDFileIntField1TS *New(const std::string& fileName, bool loadAll=true);
+    MEDLOADER_EXPORT static MEDFileIntField1TS *New(med_idt fid, bool loadAll=true);
     MEDLOADER_EXPORT static MEDFileIntField1TS *New(const std::string& fileName, const std::string& fieldName, bool loadAll=true);
+    MEDLOADER_EXPORT static MEDFileIntField1TS *New(med_idt fid, const std::string& fieldName, bool loadAll=true);
     MEDLOADER_EXPORT static MEDFileIntField1TS *New(const std::string& fileName, const std::string& fieldName, int iteration, int order, bool loadAll=true);
+    MEDLOADER_EXPORT static MEDFileIntField1TS *New(med_idt fid, const std::string& fieldName, int iteration, int order, bool loadAll=true);
     MEDLOADER_EXPORT static MEDFileIntField1TS *New(const MEDFileIntField1TSWithoutSDA& other, bool shallowCopyOfContent);
     MEDLOADER_EXPORT MEDFileField1TS *convertToDouble(bool isDeepCpyGlobs=true) const;
     MEDLOADER_EXPORT MEDFileAnyTypeField1TS *shallowCpy() const;
@@ -952,12 +955,15 @@ namespace MEDCoupling
     MEDFileAnyTypeFieldMultiTS(med_idt fid, bool loadAll, const MEDFileMeshes *ms);
     MEDFileAnyTypeFieldMultiTS(med_idt fid, const std::string& fieldName, bool loadAll, const MEDFileMeshes *ms, const std::vector< std::pair<TypeOfField,INTERP_KERNEL::NormalizedCellType> > *entities=0);
     MEDFileAnyTypeFieldMultiTS(const MEDFileAnyTypeFieldMultiTSWithoutSDA& other, bool shallowCopyOfContent);
-    static MEDFileAnyTypeFieldMultiTS *BuildNewInstanceFromContent(MEDFileAnyTypeFieldMultiTSWithoutSDA *c, const std::string& fileName);
+    static MEDFileAnyTypeFieldMultiTS *BuildNewInstanceFromContent(MEDFileAnyTypeFieldMultiTSWithoutSDA *c);
+    static MEDFileAnyTypeFieldMultiTS *BuildNewInstanceFromContent(MEDFileAnyTypeFieldMultiTSWithoutSDA *c, med_idt fid);
     static MEDFileAnyTypeFieldMultiTSWithoutSDA *BuildContentFrom(med_idt fid, bool loadAll, const MEDFileMeshes *ms);
     static MEDFileAnyTypeFieldMultiTSWithoutSDA *BuildContentFrom(med_idt fid, const std::string& fieldName, bool loadAll, const MEDFileMeshes *ms, const std::vector< std::pair<TypeOfField,INTERP_KERNEL::NormalizedCellType> > *entities);
   public:
     MEDLOADER_EXPORT static MEDFileAnyTypeFieldMultiTS *New(const std::string& fileName, bool loadAll=true);
+    MEDLOADER_EXPORT static MEDFileAnyTypeFieldMultiTS *New(med_idt fid, bool loadAll=true);
     MEDLOADER_EXPORT static MEDFileAnyTypeFieldMultiTS *New(const std::string& fileName, const std::string& fieldName, bool loadAll=true);
+    MEDLOADER_EXPORT static MEDFileAnyTypeFieldMultiTS *New(med_idt fid, const std::string& fieldName, bool loadAll=true);
     MEDLOADER_EXPORT void loadArrays();
     MEDLOADER_EXPORT void loadArraysIfNecessary();
     MEDLOADER_EXPORT void unloadArrays();
@@ -1041,7 +1047,9 @@ namespace MEDCoupling
   public:
     MEDLOADER_EXPORT static MEDFileFieldMultiTS *New();
     MEDLOADER_EXPORT static MEDFileFieldMultiTS *New(const std::string& fileName, bool loadAll=true);
+    MEDLOADER_EXPORT static MEDFileFieldMultiTS *New(med_idt fid, bool loadAll=true);
     MEDLOADER_EXPORT static MEDFileFieldMultiTS *New(const std::string& fileName, const std::string& fieldName, bool loadAll=true);
+    MEDLOADER_EXPORT static MEDFileFieldMultiTS *New(med_idt fid, const std::string& fieldName, bool loadAll=true);
     MEDLOADER_EXPORT static MEDFileFieldMultiTS *New(const MEDFileFieldMultiTSWithoutSDA& other, bool shallowCopyOfContent);
     MEDLOADER_EXPORT static MEDFileFieldMultiTS *LoadSpecificEntities(const std::string& fileName, const std::string& fieldName, const std::vector< std::pair<TypeOfField,INTERP_KERNEL::NormalizedCellType> >& entities, bool loadAll=true);
     MEDLOADER_EXPORT MEDFileAnyTypeFieldMultiTS *shallowCpy() const;
@@ -1086,7 +1094,9 @@ namespace MEDCoupling
   public:
     MEDLOADER_EXPORT static MEDFileIntFieldMultiTS *New();
     MEDLOADER_EXPORT static MEDFileIntFieldMultiTS *New(const std::string& fileName, bool loadAll=true);
+    MEDLOADER_EXPORT static MEDFileIntFieldMultiTS *New(med_idt fid, bool loadAll=true);
     MEDLOADER_EXPORT static MEDFileIntFieldMultiTS *New(const std::string& fileName, const std::string& fieldName, bool loadAll=true);
+    MEDLOADER_EXPORT static MEDFileIntFieldMultiTS *New(med_idt fid, const std::string& fieldName, bool loadAll=true);
     MEDLOADER_EXPORT static MEDFileIntFieldMultiTS *New(const MEDFileIntFieldMultiTSWithoutSDA& other, bool shallowCopyOfContent);
     MEDLOADER_EXPORT static MEDFileIntFieldMultiTS *LoadSpecificEntities(const std::string& fileName, const std::string& fieldName, const std::vector< std::pair<TypeOfField,INTERP_KERNEL::NormalizedCellType> >& entities, bool loadAll=true);
     MEDLOADER_EXPORT MEDFileAnyTypeFieldMultiTS *shallowCpy() const;
@@ -1141,6 +1151,7 @@ namespace MEDCoupling
   public:
     MEDLOADER_EXPORT static MEDFileFields *New();
     MEDLOADER_EXPORT static MEDFileFields *New(const std::string& fileName, bool loadAll=true);
+    MEDLOADER_EXPORT static MEDFileFields *New(med_idt fid, bool loadAll=true);
     MEDLOADER_EXPORT static MEDFileFields *LoadPartOf(const std::string& fileName, bool loadAll=true, const MEDFileMeshes *ms=0);
     MEDLOADER_EXPORT static MEDFileFields *LoadSpecificEntities(const std::string& fileName, const std::vector< std::pair<TypeOfField,INTERP_KERNEL::NormalizedCellType> >& entities, bool loadAll=true);
     MEDLOADER_EXPORT std::size_t getHeapMemorySizeWithoutChildren() const;
diff --git a/src/MEDLoader/MEDFileMesh.cxx b/src/MEDLoader/MEDFileMesh.cxx
index c88c69e3a..d001e5ce9 100644
--- a/src/MEDLoader/MEDFileMesh.cxx
+++ b/src/MEDLoader/MEDFileMesh.cxx
@@ -23,6 +23,7 @@
 #include "MEDFileFieldOverView.hxx"
 #include "MEDFileField.hxx"
 #include "MEDLoader.hxx"
+#include "MEDLoaderNS.hxx"
 #include "MEDFileSafeCaller.txx"
 #include "MEDLoaderBase.hxx"
 
@@ -79,15 +80,19 @@ std::vector<const BigMemoryObject *> MEDFileMesh::getDirectChildrenWithNull() co
  */
 MEDFileMesh *MEDFileMesh::New(const std::string& fileName, MEDFileMeshReadSelector *mrs)
 {
-  std::vector<std::string> ms=MEDCoupling::GetMeshNames(fileName);
+  MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid,mrs);
+}
+
+MEDFileMesh *MEDFileMesh::New(med_idt fid, MEDFileMeshReadSelector *mrs)
+{
+  std::vector<std::string> ms(MEDLoaderNS::getMeshNamesFid(fid));
   if(ms.empty())
     {
-      std::ostringstream oss; oss << "MEDFileMesh::New : no meshes in file \"" << fileName << "\" !";
+      std::ostringstream oss; oss << "MEDFileMesh::New : no meshes in file \"" << FileNameFromFID(fid) << "\" !";
       throw INTERP_KERNEL::Exception(oss.str().c_str());
     }
-  MEDFileUtilities::CheckFileForRead(fileName);
   MEDCoupling::MEDCouplingMeshType meshType;
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
   int dt,it;
   std::string dummy2;
   MEDCoupling::MEDCouplingAxisType dummy3;
@@ -139,9 +144,13 @@ MEDFileMesh *MEDFileMesh::New(const std::string& fileName, MEDFileMeshReadSelect
  */
 MEDFileMesh *MEDFileMesh::New(const std::string& fileName, const std::string& mName, int dt, int it, MEDFileMeshReadSelector *mrs, MEDFileJoints* joints)
 {
-  MEDFileUtilities::CheckFileForRead(fileName);
+  MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid,mName,dt,it,mrs,joints);
+}
+
+MEDFileMesh *MEDFileMesh::New(med_idt fid, const std::string& mName, int dt, int it, MEDFileMeshReadSelector *mrs, MEDFileJoints* joints)
+{
   MEDCoupling::MEDCouplingMeshType meshType;
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
   int dummy0,dummy1;
   std::string dummy2;
   MEDCoupling::MEDCouplingAxisType dummy3;
@@ -2224,8 +2233,12 @@ void MEDFileMesh::getFamilyRepr(std::ostream& oss) const
  */
 MEDFileUMesh *MEDFileUMesh::New(const std::string& fileName, const std::string& mName, int dt, int it, MEDFileMeshReadSelector *mrs)
 {
-  MEDFileUtilities::CheckFileForRead(fileName);
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
+  MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid,mName,dt,it,mrs);
+}
+
+MEDFileUMesh *MEDFileUMesh::New(med_idt fid, const std::string& mName, int dt, int it, MEDFileMeshReadSelector *mrs)
+{
   return new MEDFileUMesh(fid,mName,dt,it,mrs);
 }
 
@@ -2241,20 +2254,30 @@ MEDFileUMesh *MEDFileUMesh::New(const std::string& fileName, const std::string&
  */
 MEDFileUMesh *MEDFileUMesh::New(const std::string& fileName, MEDFileMeshReadSelector *mrs)
 {
-  std::vector<std::string> ms(MEDCoupling::GetMeshNames(fileName));
+  MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid,mrs);
+}
+
+template<class T>
+T *NewForTheFirstMeshInFile(med_idt fid, MEDFileMeshReadSelector *mrs)
+{
+  std::vector<std::string> ms(MEDLoaderNS::getMeshNamesFid(fid));
   if(ms.empty())
     {
-      std::ostringstream oss; oss << "MEDFileUMesh::New : no meshes in file \"" << fileName << "\" !";
+      std::ostringstream oss; oss << MLMeshTraits<T>::ClassName << "::New : no meshes in file \"" << MEDFileWritable::FileNameFromFID(fid) << "\" !";
       throw INTERP_KERNEL::Exception(oss.str().c_str());
     }
-  MEDFileUtilities::CheckFileForRead(fileName);
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
   int dt,it;
   MEDCoupling::MEDCouplingMeshType meshType;
   std::string dummy2;
   MEDCoupling::MEDCouplingAxisType dummy3;
   MEDFileMeshL2::GetMeshIdFromName(fid,ms.front(),meshType,dummy3,dt,it,dummy2);
-  return new MEDFileUMesh(fid,ms.front(),dt,it,mrs);
+  return T::New(fid,ms.front(),dt,it,mrs);
+}
+
+MEDFileUMesh *MEDFileUMesh::New(med_idt fid, MEDFileMeshReadSelector *mrs)
+{
+  return NewForTheFirstMeshInFile<MEDFileUMesh>(fid,mrs);
 }
 
 /*!
@@ -6400,20 +6423,13 @@ MEDFileCMesh *MEDFileCMesh::New()
  */
 MEDFileCMesh *MEDFileCMesh::New(const std::string& fileName, MEDFileMeshReadSelector *mrs)
 {
-  std::vector<std::string> ms(MEDCoupling::GetMeshNames(fileName));
-  if(ms.empty())
-    {
-      std::ostringstream oss; oss << "MEDFileUMesh::New : no meshes in file \"" << fileName << "\" !";
-      throw INTERP_KERNEL::Exception(oss.str().c_str());
-    }
-  MEDFileUtilities::CheckFileForRead(fileName);
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
-  int dt,it;
-  MEDCoupling::MEDCouplingMeshType meshType;
-  std::string dummy2;
-  MEDCoupling::MEDCouplingAxisType dummy3;
-  MEDFileMeshL2::GetMeshIdFromName(fid,ms.front(),meshType,dummy3,dt,it,dummy2);
-  return new MEDFileCMesh(fid,ms.front(),dt,it,mrs);
+  MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid,mrs);
+}
+
+MEDFileCMesh *MEDFileCMesh::New(med_idt fid, MEDFileMeshReadSelector *mrs)
+{
+  return NewForTheFirstMeshInFile<MEDFileCMesh>(fid,mrs);
 }
 
 /*!
@@ -6432,8 +6448,12 @@ MEDFileCMesh *MEDFileCMesh::New(const std::string& fileName, MEDFileMeshReadSele
  */
 MEDFileCMesh *MEDFileCMesh::New(const std::string& fileName, const std::string& mName, int dt, int it, MEDFileMeshReadSelector *mrs)
 {
-  MEDFileUtilities::CheckFileForRead(fileName);
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
+  MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid,mName,dt,it,mrs);
+}
+
+MEDFileCMesh *MEDFileCMesh::New(med_idt fid, const std::string& mName, int dt, int it, MEDFileMeshReadSelector *mrs)
+{
   return new MEDFileCMesh(fid,mName,dt,it,mrs);
 }
 
@@ -6696,28 +6716,25 @@ MEDFileCurveLinearMesh *MEDFileCurveLinearMesh::New()
   return new MEDFileCurveLinearMesh;
 }
 
+MEDFileCurveLinearMesh *MEDFileCurveLinearMesh::New(med_idt fid, MEDFileMeshReadSelector *mrs)
+{
+  return NewForTheFirstMeshInFile<MEDFileCurveLinearMesh>(fid,mrs);
+}
+
 MEDFileCurveLinearMesh *MEDFileCurveLinearMesh::New(const std::string& fileName, MEDFileMeshReadSelector *mrs)
 {
-  std::vector<std::string> ms(MEDCoupling::GetMeshNames(fileName));
-  if(ms.empty())
-    {
-      std::ostringstream oss; oss << "MEDFileUMesh::New : no meshes in file \"" << fileName << "\" !";
-      throw INTERP_KERNEL::Exception(oss.str().c_str());
-    }
-  MEDFileUtilities::CheckFileForRead(fileName);
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
-  int dt,it;
-  MEDCoupling::MEDCouplingMeshType meshType;
-  MEDCoupling::MEDCouplingAxisType dummy3;
-  std::string dummy2;
-  MEDFileMeshL2::GetMeshIdFromName(fid,ms.front(),meshType,dummy3,dt,it,dummy2);
-  return new MEDFileCurveLinearMesh(fid,ms.front(),dt,it,mrs);
+  MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid,mrs);
 }
 
 MEDFileCurveLinearMesh *MEDFileCurveLinearMesh::New(const std::string& fileName, const std::string& mName, int dt, int it, MEDFileMeshReadSelector *mrs)
 {
-  MEDFileUtilities::CheckFileForRead(fileName);
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
+  MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid,mName,dt,it,mrs);
+}
+
+MEDFileCurveLinearMesh *MEDFileCurveLinearMesh::New(med_idt fid, const std::string& mName, int dt, int it, MEDFileMeshReadSelector *mrs)
+{
   return new MEDFileCurveLinearMesh(fid,mName,dt,it,mrs);
 }
 
@@ -6940,21 +6957,33 @@ MEDFileMeshMultiTS *MEDFileMeshMultiTS::New()
   return new MEDFileMeshMultiTS;
 }
 
+MEDFileMeshMultiTS *MEDFileMeshMultiTS::New(med_idt fid)
+{
+  return new MEDFileMeshMultiTS(fid);
+}
+
 MEDFileMeshMultiTS *MEDFileMeshMultiTS::New(const std::string& fileName)
 {
-  return new MEDFileMeshMultiTS(fileName);
+  MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid);
+}
+
+MEDFileMeshMultiTS *MEDFileMeshMultiTS::New(med_idt fid, const std::string& mName)
+{
+  return new MEDFileMeshMultiTS(fid,mName);
 }
 
 MEDFileMeshMultiTS *MEDFileMeshMultiTS::New(const std::string& fileName, const std::string& mName)
 {
-  return new MEDFileMeshMultiTS(fileName,mName);
+  MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid,mName);
 }
 
 MEDFileMeshMultiTS *MEDFileMeshMultiTS::deepCopy() const
 {
-  MCAuto<MEDFileMeshMultiTS> ret=MEDFileMeshMultiTS::New();
+  MCAuto<MEDFileMeshMultiTS> ret(MEDFileMeshMultiTS::New());
   std::vector< MCAuto<MEDFileMesh> > meshOneTs(_mesh_one_ts.size());
-  std::size_t i=0;
+  std::size_t i(0);
   for(std::vector< MCAuto<MEDFileMesh> >::const_iterator it=_mesh_one_ts.begin();it!=_mesh_one_ts.end();it++,i++)
     if((const MEDFileMesh *)*it)
       meshOneTs[i]=(*it)->deepCopy();
@@ -7069,50 +7098,47 @@ void MEDFileMeshMultiTS::writeLL(med_idt fid) const
   (const_cast<MEDFileMeshMultiTS*>(this))->setJoints( joints ); // restore joints
 }
 
-void MEDFileMeshMultiTS::loadFromFile(const std::string& fileName, const std::string& mName)
+void MEDFileMeshMultiTS::loadFromFile(med_idt fid, const std::string& mName)
 {
-  MEDFileJoints* joints = 0;
+  MEDFileJoints *joints(0);
   if ( !_mesh_one_ts.empty() && getOneTimeStep() )
     {
       // joints of mName already read, pass them to MEDFileMesh::New() to prevent repeated reading
       joints = getOneTimeStep()->getJoints();
     }
-
   _mesh_one_ts.clear();  //for the moment to be improved
-  _mesh_one_ts.push_back( MEDFileMesh::New(fileName,mName,-1,-1,0, joints ));
+  _mesh_one_ts.push_back( MEDFileMesh::New(fid,mName,-1,-1,0, joints ));
 }
 
 MEDFileMeshMultiTS::MEDFileMeshMultiTS()
 {
 }
 
-MEDFileMeshMultiTS::MEDFileMeshMultiTS(const std::string& fileName)
+MEDFileMeshMultiTS::MEDFileMeshMultiTS(med_idt fid)
 try
 {
-  std::vector<std::string> ms(MEDCoupling::GetMeshNames(fileName));
+  std::vector<std::string> ms(MEDLoaderNS::getMeshNamesFid(fid));
     if(ms.empty())
       {
-        std::ostringstream oss; oss << "MEDFileUMesh::New : no meshes in file \"" << fileName << "\" !";
+        std::ostringstream oss; oss << "MEDFileMeshMultiTS : no meshes in file \"" << FileNameFromFID(fid) << "\" !";
         throw INTERP_KERNEL::Exception(oss.str().c_str());
       }
-    MEDFileUtilities::CheckFileForRead(fileName);
-    MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
     int dt,it;
     MEDCoupling::MEDCouplingMeshType meshType;
     std::string dummy2;
     MEDCoupling::MEDCouplingAxisType dummy3;
     MEDFileMeshL2::GetMeshIdFromName(fid,ms.front(),meshType,dummy3,dt,it,dummy2);
-    loadFromFile(fileName,ms.front());
+    loadFromFile(fid,ms.front());
 }
 catch(INTERP_KERNEL::Exception& e)
 {
     throw e;
 }
 
-MEDFileMeshMultiTS::MEDFileMeshMultiTS(const std::string& fileName, const std::string& mName)
+MEDFileMeshMultiTS::MEDFileMeshMultiTS(med_idt fid, const std::string& mName)
 try
 {
-    loadFromFile(fileName,mName);
+    loadFromFile(fid,mName);
 }
 catch(INTERP_KERNEL::Exception& e)
 {
@@ -7124,9 +7150,15 @@ MEDFileMeshes *MEDFileMeshes::New()
   return new MEDFileMeshes;
 }
 
+MEDFileMeshes *MEDFileMeshes::New(med_idt fid)
+{
+  return new MEDFileMeshes(fid);
+}
+
 MEDFileMeshes *MEDFileMeshes::New(const std::string& fileName)
 {
-  return new MEDFileMeshes(fileName);
+  MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid);
 }
 
 void MEDFileMeshes::writeLL(med_idt fid) const
@@ -7253,23 +7285,23 @@ void MEDFileMeshes::destroyMeshAtPos(int i)
   _meshes.erase(_meshes.begin()+i);
 }
 
-void MEDFileMeshes::loadFromFile(const std::string& fileName)
+void MEDFileMeshes::loadFromFile(med_idt fid)
 {
-  std::vector<std::string> ms(MEDCoupling::GetMeshNames(fileName));
+  std::vector<std::string> ms(MEDLoaderNS::getMeshNamesFid(fid));
   int i=0;
   _meshes.resize(ms.size());
   for(std::vector<std::string>::const_iterator it=ms.begin();it!=ms.end();it++,i++)
-    _meshes[i]=MEDFileMeshMultiTS::New(fileName,(*it));
+    _meshes[i]=MEDFileMeshMultiTS::New(fid,(*it));
 }
 
 MEDFileMeshes::MEDFileMeshes()
 {
 }
 
-MEDFileMeshes::MEDFileMeshes(const std::string& fileName)
+MEDFileMeshes::MEDFileMeshes(med_idt fid)
 try
 {
-    loadFromFile(fileName);
+    loadFromFile(fid);
 }
 catch(INTERP_KERNEL::Exception& /*e*/)
 {
@@ -7282,7 +7314,7 @@ MEDFileMeshes *MEDFileMeshes::deepCopy() const
   for(std::vector< MCAuto<MEDFileMeshMultiTS> >::const_iterator it=_meshes.begin();it!=_meshes.end();it++,i++)
     if((const MEDFileMeshMultiTS *)*it)
       meshes[i]=(*it)->deepCopy();
-  MCAuto<MEDFileMeshes> ret=MEDFileMeshes::New();
+  MCAuto<MEDFileMeshes> ret(MEDFileMeshes::New());
   ret->_meshes=meshes;
   return ret.retn();
 }
diff --git a/src/MEDLoader/MEDFileMesh.hxx b/src/MEDLoader/MEDFileMesh.hxx
index b9dc110c0..4bd228285 100644
--- a/src/MEDLoader/MEDFileMesh.hxx
+++ b/src/MEDLoader/MEDFileMesh.hxx
@@ -41,7 +41,9 @@ namespace MEDCoupling
   {
   public:
     MEDLOADER_EXPORT static MEDFileMesh *New(const std::string& fileName, MEDFileMeshReadSelector *mrs=0);
+    MEDLOADER_EXPORT static MEDFileMesh *New(med_idt fid, MEDFileMeshReadSelector *mrs=0);
     MEDLOADER_EXPORT static MEDFileMesh *New(const std::string& fileName, const std::string& mName, int dt=-1, int it=-1, MEDFileMeshReadSelector *mrs=0, MEDFileJoints* joints=0);
+    MEDLOADER_EXPORT static MEDFileMesh *New(med_idt fid, const std::string& mName, int dt=-1, int it=-1, MEDFileMeshReadSelector *mrs=0, MEDFileJoints* joints=0);
     MEDLOADER_EXPORT void writeLL(med_idt fid) const;
     MEDLOADER_EXPORT std::size_t getHeapMemorySizeWithoutChildren() const;
     MEDLOADER_EXPORT std::vector<const BigMemoryObject *> getDirectChildrenWithNull() const;
@@ -247,7 +249,9 @@ namespace MEDCoupling
     friend class MEDFileMesh;
   public:
     MEDLOADER_EXPORT static MEDFileUMesh *New(const std::string& fileName, const std::string& mName, int dt=-1, int it=-1, MEDFileMeshReadSelector *mrs=0);
+    MEDLOADER_EXPORT static MEDFileUMesh *New(med_idt fid, const std::string& mName, int dt=-1, int it=-1, MEDFileMeshReadSelector *mrs=0);
     MEDLOADER_EXPORT static MEDFileUMesh *New(const std::string& fileName, MEDFileMeshReadSelector *mrs=0);
+    MEDLOADER_EXPORT static MEDFileUMesh *New(med_idt fid, MEDFileMeshReadSelector *mrs=0);
     MEDLOADER_EXPORT static MEDFileUMesh *New(const MEDCouplingMappedExtrudedMesh *mem);
     MEDLOADER_EXPORT static MEDFileUMesh *New();
     MEDLOADER_EXPORT static MEDFileUMesh *LoadPartOf(const std::string& fileName, const std::string& mName, const std::vector<INTERP_KERNEL::NormalizedCellType>& types, const std::vector<int>& slicPerTyp, int dt=-1, int it=-1, MEDFileMeshReadSelector *mrs=0);
@@ -454,7 +458,9 @@ namespace MEDCoupling
   public:
     MEDLOADER_EXPORT static MEDFileCMesh *New();
     MEDLOADER_EXPORT static MEDFileCMesh *New(const std::string& fileName, MEDFileMeshReadSelector *mrs=0);
+    MEDLOADER_EXPORT static MEDFileCMesh *New(med_idt fid, MEDFileMeshReadSelector *mrs=0);
     MEDLOADER_EXPORT static MEDFileCMesh *New(const std::string& fileName, const std::string& mName, int dt=-1, int it=-1, MEDFileMeshReadSelector *mrs=0);
+    MEDLOADER_EXPORT static MEDFileCMesh *New(med_idt fid, const std::string& mName, int dt=-1, int it=-1, MEDFileMeshReadSelector *mrs=0);
     MEDLOADER_EXPORT std::size_t getHeapMemorySizeWithoutChildren() const;
     MEDLOADER_EXPORT std::vector<const BigMemoryObject *> getDirectChildrenWithNull() const;
     MEDLOADER_EXPORT MEDFileMesh *createNewEmpty() const;
@@ -487,7 +493,9 @@ namespace MEDCoupling
   public:
     MEDLOADER_EXPORT static MEDFileCurveLinearMesh *New();
     MEDLOADER_EXPORT static MEDFileCurveLinearMesh *New(const std::string& fileName, MEDFileMeshReadSelector *mrs=0);
+    MEDLOADER_EXPORT static MEDFileCurveLinearMesh *New(med_idt fid, MEDFileMeshReadSelector *mrs=0);
     MEDLOADER_EXPORT static MEDFileCurveLinearMesh *New(const std::string& fileName, const std::string& mName, int dt=-1, int it=-1, MEDFileMeshReadSelector *mrs=0);
+    MEDLOADER_EXPORT static MEDFileCurveLinearMesh *New(med_idt fid, const std::string& mName, int dt=-1, int it=-1, MEDFileMeshReadSelector *mrs=0);
     MEDLOADER_EXPORT std::size_t getHeapMemorySizeWithoutChildren() const;
     MEDLOADER_EXPORT std::vector<const BigMemoryObject *> getDirectChildrenWithNull() const;
     MEDLOADER_EXPORT MEDFileMesh *createNewEmpty() const;
@@ -517,7 +525,9 @@ namespace MEDCoupling
   {
   public:
     MEDLOADER_EXPORT static MEDFileMeshMultiTS *New();
+    MEDLOADER_EXPORT static MEDFileMeshMultiTS *New(med_idt fid);
     MEDLOADER_EXPORT static MEDFileMeshMultiTS *New(const std::string& fileName);
+    MEDLOADER_EXPORT static MEDFileMeshMultiTS *New(med_idt fid, const std::string& mName);
     MEDLOADER_EXPORT static MEDFileMeshMultiTS *New(const std::string& fileName, const std::string& mName);
     MEDLOADER_EXPORT MEDFileMeshMultiTS *deepCopy() const;
     MEDLOADER_EXPORT std::size_t getHeapMemorySizeWithoutChildren() const;
@@ -533,10 +543,10 @@ namespace MEDCoupling
     MEDLOADER_EXPORT void setJoints(MEDFileJoints* joints);
   private:
     ~MEDFileMeshMultiTS() { }
-    void loadFromFile(const std::string& fileName, const std::string& mName);
+    void loadFromFile(med_idt fid, const std::string& mName);
     MEDFileMeshMultiTS();
-    MEDFileMeshMultiTS(const std::string& fileName);
-    MEDFileMeshMultiTS(const std::string& fileName, const std::string& mName);
+    MEDFileMeshMultiTS(med_idt fid);
+    MEDFileMeshMultiTS(med_idt fid, const std::string& mName);
   private:
     std::vector< MCAuto<MEDFileMesh> > _mesh_one_ts;
   };
@@ -547,6 +557,7 @@ namespace MEDCoupling
   {
   public:
     MEDLOADER_EXPORT static MEDFileMeshes *New();
+    MEDLOADER_EXPORT static MEDFileMeshes *New(med_idt fid);
     MEDLOADER_EXPORT static MEDFileMeshes *New(const std::string& fileName);
     MEDLOADER_EXPORT MEDFileMeshes *deepCopy() const;
     MEDLOADER_EXPORT std::size_t getHeapMemorySizeWithoutChildren() const;
@@ -569,9 +580,9 @@ namespace MEDCoupling
   private:
     ~MEDFileMeshes() { }
     void checkConsistencyLight() const;
-    void loadFromFile(const std::string& fileName);
+    void loadFromFile(med_idt fid);
     MEDFileMeshes();
-    MEDFileMeshes(const std::string& fileName);
+    MEDFileMeshes(med_idt fid);
   private:
     std::vector< MCAuto<MEDFileMeshMultiTS> > _meshes;
   };
diff --git a/src/MEDLoader/MEDFileParameter.cxx b/src/MEDLoader/MEDFileParameter.cxx
index 4186eea5b..335c158d0 100644
--- a/src/MEDLoader/MEDFileParameter.cxx
+++ b/src/MEDLoader/MEDFileParameter.cxx
@@ -371,12 +371,24 @@ MEDFileParameterMultiTS *MEDFileParameterMultiTS::New()
 
 MEDFileParameterMultiTS *MEDFileParameterMultiTS::New(const std::string& fileName)
 {
-  return new MEDFileParameterMultiTS(fileName);
+  MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid);
+}
+
+MEDFileParameterMultiTS *MEDFileParameterMultiTS::New(med_idt fid)
+{
+  return new MEDFileParameterMultiTS(fid);
 }
 
 MEDFileParameterMultiTS *MEDFileParameterMultiTS::New(const std::string& fileName, const std::string& paramName)
 {
-  return new MEDFileParameterMultiTS(fileName,paramName);
+  MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid,paramName);
+}
+
+MEDFileParameterMultiTS *MEDFileParameterMultiTS::New(med_idt fid, const std::string& paramName)
+{
+  return new MEDFileParameterMultiTS(fid,paramName);
 }
 
 MEDFileParameterMultiTS::MEDFileParameterMultiTS()
@@ -394,44 +406,40 @@ MEDFileParameterMultiTS::MEDFileParameterMultiTS(const MEDFileParameterMultiTS&
       }
 }
 
-MEDFileParameterMultiTS::MEDFileParameterMultiTS(const std::string& fileName)
+MEDFileParameterMultiTS::MEDFileParameterMultiTS(med_idt fid)
 {
-  MEDFileUtilities::CheckFileForRead(fileName);
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
-  int nbPar=MEDnParameter(fid);
+  int nbPar(MEDnParameter(fid));
   if(nbPar<1)
     {
-      std::ostringstream oss; oss << "MEDFileParameterMultiTS : no parameter in file \"" << fileName << "\" !" ;
+      std::ostringstream oss; oss << "MEDFileParameterMultiTS : no parameter in file \"" << FileNameFromFID(fid) << "\" !" ;
       throw INTERP_KERNEL::Exception(oss.str().c_str());
     }
-  INTERP_KERNEL::AutoPtr<char> pName=MEDLoaderBase::buildEmptyString(MED_NAME_SIZE);
-  INTERP_KERNEL::AutoPtr<char> descName=MEDLoaderBase::buildEmptyString(MED_COMMENT_SIZE);
-  INTERP_KERNEL::AutoPtr<char> unitName=MEDLoaderBase::buildEmptyString(MED_SNAME_SIZE);
+  INTERP_KERNEL::AutoPtr<char> pName(MEDLoaderBase::buildEmptyString(MED_NAME_SIZE));
+  INTERP_KERNEL::AutoPtr<char> descName(MEDLoaderBase::buildEmptyString(MED_COMMENT_SIZE));
+  INTERP_KERNEL::AutoPtr<char> unitName(MEDLoaderBase::buildEmptyString(MED_SNAME_SIZE));
   med_parameter_type paramType;
   int nbOfSteps;
   MEDFILESAFECALLERRD0(MEDparameterInfo,(fid,1,pName,&paramType,descName,unitName,&nbOfSteps));
-  std::string paramNameCpp=MEDLoaderBase::buildStringFromFortran(pName,MED_NAME_SIZE);
+  std::string paramNameCpp(MEDLoaderBase::buildStringFromFortran(pName,MED_NAME_SIZE));
   _dt_unit=MEDLoaderBase::buildStringFromFortran(unitName,MED_SNAME_SIZE);
   _name=paramNameCpp;
   _desc_name=MEDLoaderBase::buildStringFromFortran(descName,MED_COMMENT_SIZE);
   finishLoading(fid,paramType,nbOfSteps);
 }
 
-MEDFileParameterMultiTS::MEDFileParameterMultiTS(const std::string& fileName, const std::string& paramName)
+MEDFileParameterMultiTS::MEDFileParameterMultiTS(med_idt fid, const std::string& paramName)
 {
-  MEDFileUtilities::CheckFileForRead(fileName);
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
-  int nbPar=MEDnParameter(fid);
+  int nbPar(MEDnParameter(fid));
   std::ostringstream oss; oss << "MEDFileParameterDouble1TS : no double param name \"" << paramName << "\" ! Double Parameters available are : ";
-  INTERP_KERNEL::AutoPtr<char> pName=MEDLoaderBase::buildEmptyString(MED_NAME_SIZE);
-  INTERP_KERNEL::AutoPtr<char> descName=MEDLoaderBase::buildEmptyString(MED_COMMENT_SIZE);
-  INTERP_KERNEL::AutoPtr<char> unitName=MEDLoaderBase::buildEmptyString(MED_SNAME_SIZE);
+  INTERP_KERNEL::AutoPtr<char> pName(MEDLoaderBase::buildEmptyString(MED_NAME_SIZE));
+  INTERP_KERNEL::AutoPtr<char> descName(MEDLoaderBase::buildEmptyString(MED_COMMENT_SIZE));
+  INTERP_KERNEL::AutoPtr<char> unitName(MEDLoaderBase::buildEmptyString(MED_SNAME_SIZE));
   med_parameter_type paramType;
   for(int i=0;i<nbPar;i++)
     {
       int nbOfSteps;
       MEDFILESAFECALLERRD0(MEDparameterInfo,(fid,i+1,pName,&paramType,descName,unitName,&nbOfSteps));
-      std::string paramNameCpp=MEDLoaderBase::buildStringFromFortran(pName,MED_NAME_SIZE);
+      std::string paramNameCpp(MEDLoaderBase::buildStringFromFortran(pName,MED_NAME_SIZE));
       if(paramNameCpp==paramName)
         {
           if(nbOfSteps>0)
@@ -539,7 +547,7 @@ void MEDFileParameterMultiTS::writeAdvanced(med_idt fid, const MEDFileWritable&
     throw INTERP_KERNEL::Exception("MEDFileParameterMultiTS::writeAdvanced : impossible to mix type of data in parameters in MED file ! Only float64 or only int32 ...");
   if(diffType.empty())
     return;
-  med_parameter_type typ=*diffType.begin();
+  med_parameter_type typ(*diffType.begin());
   MEDFileParameterTinyInfo::writeLLHeader(fid,typ);
   for(std::vector< MCAuto<MEDFileParameter1TS> >::const_iterator it=_param_per_ts.begin();it!=_param_per_ts.end();it++)
     {
@@ -706,25 +714,29 @@ MEDFileParameters *MEDFileParameters::New()
 
 MEDFileParameters *MEDFileParameters::New(const std::string& fileName)
 {
-  return new MEDFileParameters(fileName);
+  MEDFileUtilities::AutoFid fid(OpenMEDFileForRead(fileName));
+  return New(fid);
 }
 
-MEDFileParameters::MEDFileParameters(const std::string& fileName)
+MEDFileParameters *MEDFileParameters::New(med_idt fid)
+{
+  return new MEDFileParameters(fid);
+}
+
+MEDFileParameters::MEDFileParameters(med_idt fid)
 {
-  MEDFileUtilities::CheckFileForRead(fileName);
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
   int nbPar=MEDnParameter(fid);
   _params.resize(nbPar);
-  INTERP_KERNEL::AutoPtr<char> pName=MEDLoaderBase::buildEmptyString(MED_NAME_SIZE);
-  INTERP_KERNEL::AutoPtr<char> descName=MEDLoaderBase::buildEmptyString(MED_COMMENT_SIZE);
-  INTERP_KERNEL::AutoPtr<char> unitName=MEDLoaderBase::buildEmptyString(MED_SNAME_SIZE);
+  INTERP_KERNEL::AutoPtr<char> pName(MEDLoaderBase::buildEmptyString(MED_NAME_SIZE));
+  INTERP_KERNEL::AutoPtr<char> descName(MEDLoaderBase::buildEmptyString(MED_COMMENT_SIZE));
+  INTERP_KERNEL::AutoPtr<char> unitName(MEDLoaderBase::buildEmptyString(MED_SNAME_SIZE));
   med_parameter_type paramType;
   for(int i=0;i<nbPar;i++)
     {
       int nbOfSteps;
       MEDFILESAFECALLERRD0(MEDparameterInfo,(fid,i+1,pName,&paramType,descName,unitName,&nbOfSteps));
-      std::string paramNameCpp=MEDLoaderBase::buildStringFromFortran(pName,MED_NAME_SIZE);
-      _params[i]=MEDFileParameterMultiTS::New(fileName,paramNameCpp);
+      std::string paramNameCpp(MEDLoaderBase::buildStringFromFortran(pName,MED_NAME_SIZE));
+      _params[i]=MEDFileParameterMultiTS::New(fid,paramNameCpp);
     }
 }
 
diff --git a/src/MEDLoader/MEDFileParameter.hxx b/src/MEDLoader/MEDFileParameter.hxx
index 9ea9fbd09..f827b23b2 100644
--- a/src/MEDLoader/MEDFileParameter.hxx
+++ b/src/MEDLoader/MEDFileParameter.hxx
@@ -122,7 +122,9 @@ namespace MEDCoupling
   public:
     MEDLOADER_EXPORT static MEDFileParameterMultiTS *New();
     MEDLOADER_EXPORT static MEDFileParameterMultiTS *New(const std::string& fileName);
+    MEDLOADER_EXPORT static MEDFileParameterMultiTS *New(med_idt fid);
     MEDLOADER_EXPORT static MEDFileParameterMultiTS *New(const std::string& fileName, const std::string& paramName);
+    MEDLOADER_EXPORT static MEDFileParameterMultiTS *New(med_idt fid, const std::string& paramName);
     MEDLOADER_EXPORT std::string getName() const { return _name; }
     MEDLOADER_EXPORT void setName(const std::string& name) { _name=name; }
     MEDLOADER_EXPORT std::size_t getHeapMemorySizeWithoutChildren() const;
@@ -145,8 +147,8 @@ namespace MEDCoupling
   protected:
     MEDFileParameterMultiTS();
     MEDFileParameterMultiTS(const MEDFileParameterMultiTS& other, bool deepCopy);
-    MEDFileParameterMultiTS(const std::string& fileName);
-    MEDFileParameterMultiTS(const std::string& fileName, const std::string& paramName);
+    MEDFileParameterMultiTS(med_idt fid);
+    MEDFileParameterMultiTS(med_idt fid, const std::string& paramName);
     void finishLoading(med_idt fid, med_parameter_type typ, int nbOfSteps);
   protected:
     std::vector< MCAuto<MEDFileParameter1TS> > _param_per_ts;
@@ -156,6 +158,7 @@ namespace MEDCoupling
   {
   public:
     MEDLOADER_EXPORT static MEDFileParameters *New();
+    MEDLOADER_EXPORT static MEDFileParameters *New(med_idt fid);
     MEDLOADER_EXPORT static MEDFileParameters *New(const std::string& fileName);
     MEDLOADER_EXPORT std::size_t getHeapMemorySizeWithoutChildren() const;
     MEDLOADER_EXPORT std::vector<const BigMemoryObject *> getDirectChildrenWithNull() const;
@@ -175,7 +178,7 @@ namespace MEDCoupling
     MEDLOADER_EXPORT int getNumberOfParams() const;
   protected:
     void simpleRepr2(int bkOffset, std::ostream& oss) const;
-    MEDFileParameters(const std::string& fileName);
+    MEDFileParameters(med_idt fid);
     MEDFileParameters(const MEDFileParameters& other, bool deepCopy);
     MEDFileParameters();
   protected:
diff --git a/src/MEDLoader/MEDLoader.cxx b/src/MEDLoader/MEDLoader.cxx
index c6ad9872e..50009ad4a 100644
--- a/src/MEDLoader/MEDLoader.cxx
+++ b/src/MEDLoader/MEDLoader.cxx
@@ -21,6 +21,7 @@
 #include "MEDLoader.hxx"
 #include "MEDLoaderBase.hxx"
 #include "MEDFileUtilities.hxx"
+#include "MEDLoaderNS.hxx"
 #include "MEDFileSafeCaller.txx"
 #include "MEDFileMesh.hxx"
 #include "MEDFileField.hxx"
@@ -139,20 +140,6 @@ int _TOO_LONG_STR=0;
 
 using namespace MEDCoupling;
 
-/// @cond INTERNAL
-
-namespace MEDLoaderNS
-{
-  int readUMeshDimFromFile(const std::string& fileName, const std::string& meshName, std::vector<int>& possibilities);
-  void dispatchElems(int nbOfElemCell, int nbOfElemFace, int& nbOfElem, med_entity_type& whichEntity);
-  void writeFieldWithoutReadingAndMappingOfMeshInFile(const std::string& fileName, const MEDCoupling::MEDCouplingFieldDouble *f, bool writeFromScratch);
-  med_int getIdFromMeshName(med_idt fid, const std::string& meshName, std::string& trueMeshName);
-  std::vector<std::string> getMeshNamesFid(med_idt fid);
-}
-
-/// @endcond
-
-
 /// @cond INTERNAL
 
 /*!
@@ -163,7 +150,7 @@ namespace MEDLoaderNS
 int MEDLoaderNS::readUMeshDimFromFile(const std::string& fileName, const std::string& meshName, std::vector<int>& possibilities)
 {
   possibilities.clear();
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
+  MEDFileUtilities::AutoFid fid(MEDCoupling::OpenMEDFileForRead(fileName));
   int ret;
   std::set<int> poss;
   char nommaa[MED_NAME_SIZE+1];
@@ -347,8 +334,7 @@ void MEDCoupling::SetTooLongStrPolicy(int val)
  */
 std::vector< std::vector< std::pair<INTERP_KERNEL::NormalizedCellType,int> > > MEDCoupling::GetUMeshGlobalInfo(const std::string& fileName, const std::string& meshName, int &meshDim, int& spaceDim, int& numberOfNodes)
 {
-  CheckFileForRead(fileName);
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
+  MEDFileUtilities::AutoFid fid(MEDCoupling::OpenMEDFileForRead(fileName));
   std::set<int> poss;
   char nommaa[MED_NAME_SIZE+1];
   char maillage_description[MED_COMMENT_SIZE+1];
@@ -410,16 +396,13 @@ void MEDCoupling::CheckFileForRead(const std::string& fileName)
 
 std::vector<std::string> MEDCoupling::GetMeshNames(const std::string& fileName)
 {
-  MEDCoupling::CheckFileForRead(fileName);
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
-  std::vector<std::string> ret=MEDLoaderNS::getMeshNamesFid(fid);
-  return ret;
+  MEDFileUtilities::AutoFid fid(MEDCoupling::OpenMEDFileForRead(fileName));
+  return MEDLoaderNS::getMeshNamesFid(fid);
 }
 
 std::vector< std::pair<std::string,std::string> > MEDCoupling::GetComponentsNamesOfField(const std::string& fileName, const std::string& fieldName)
 {
-  MEDCoupling::CheckFileForRead(fileName);
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
+  MEDFileUtilities::AutoFid fid(MEDCoupling::OpenMEDFileForRead(fileName));
   med_int nbFields(MEDnField(fid));
   std::vector<std::string> fields(nbFields);
   med_field_type typcha;
@@ -454,10 +437,9 @@ std::vector< std::pair<std::string,std::string> > MEDCoupling::GetComponentsName
 
 std::vector<std::string> MEDCoupling::GetMeshNamesOnField(const std::string& fileName, const std::string& fieldName)
 {
-  MEDCoupling::CheckFileForRead(fileName);
   std::vector<std::string> ret;
   //
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
+  MEDFileUtilities::AutoFid fid(MEDCoupling::OpenMEDFileForRead(fileName));
   med_int nbFields=MEDnField(fid);
   //
   med_field_type typcha;
@@ -483,8 +465,7 @@ std::vector<std::string> MEDCoupling::GetMeshNamesOnField(const std::string& fil
 
 std::vector<std::string> MEDCoupling::GetMeshFamiliesNames(const std::string& fileName, const std::string& meshName)
 {
-  MEDCoupling::CheckFileForRead(fileName);
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
+  MEDFileUtilities::AutoFid fid(MEDCoupling::OpenMEDFileForRead(fileName));
   med_int nfam=MEDnFamily(fid,meshName.c_str());
   std::vector<std::string> ret(nfam);
   char nomfam[MED_NAME_SIZE+1];
@@ -507,8 +488,7 @@ std::vector<std::string> MEDCoupling::GetMeshFamiliesNames(const std::string& fi
 
 std::vector<std::string> MEDCoupling::GetMeshFamiliesNamesOnGroup(const std::string& fileName, const std::string& meshName, const std::string& grpName)
 {
-  MEDCoupling::CheckFileForRead(fileName);
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
+  MEDFileUtilities::AutoFid fid(MEDCoupling::OpenMEDFileForRead(fileName));
   med_int nfam=MEDnFamily(fid,meshName.c_str());
   std::vector<std::string> ret;
   char nomfam[MED_NAME_SIZE+1];
@@ -535,9 +515,8 @@ std::vector<std::string> MEDCoupling::GetMeshFamiliesNamesOnGroup(const std::str
 
 std::vector<std::string> MEDCoupling::GetMeshGroupsNamesOnFamily(const std::string& fileName, const std::string& meshName, const std::string& famName)
 {
-  MEDCoupling::CheckFileForRead(fileName);
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
-  med_int nfam=MEDnFamily(fid,meshName.c_str());
+  MEDFileUtilities::AutoFid fid(MEDCoupling::OpenMEDFileForRead(fileName));
+  med_int nfam(MEDnFamily(fid,meshName.c_str()));
   std::vector<std::string> ret;
   char nomfam[MED_NAME_SIZE+1];
   med_int numfam;
@@ -572,8 +551,7 @@ std::vector<std::string> MEDCoupling::GetMeshGroupsNamesOnFamily(const std::stri
 
 std::vector<std::string> MEDCoupling::GetMeshGroupsNames(const std::string& fileName, const std::string& meshName)
 {
-  MEDCoupling::CheckFileForRead(fileName);
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
+  MEDFileUtilities::AutoFid fid(MEDCoupling::OpenMEDFileForRead(fileName));
   med_int nfam=MEDnFamily(fid,meshName.c_str());
   std::vector<std::string> ret;
   char nomfam[MED_NAME_SIZE+1];
@@ -632,9 +610,8 @@ std::vector<MEDCoupling::TypeOfField> MEDCoupling::GetTypesOfField(const std::st
 
 std::vector<std::string> MEDCoupling::GetAllFieldNames(const std::string& fileName)
 {
-  MEDCoupling::CheckFileForRead(fileName);
   std::vector<std::string> ret;
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
+  MEDFileUtilities::AutoFid fid(MEDCoupling::OpenMEDFileForRead(fileName));
   med_int nbFields=MEDnField(fid);
   med_field_type typcha;
   for(int i=0;i<nbFields;i++)
@@ -655,9 +632,8 @@ std::vector<std::string> MEDCoupling::GetAllFieldNames(const std::string& fileNa
 
 std::vector<std::string> MEDCoupling::GetAllFieldNamesOnMesh(const std::string& fileName, const std::string& meshName)
 {
-  MEDCoupling::CheckFileForRead(fileName);
   std::vector<std::string> ret;
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
+  MEDFileUtilities::AutoFid fid(MEDCoupling::OpenMEDFileForRead(fileName));
   med_int nbFields=MEDnField(fid);
   //
   med_field_type typcha;
@@ -700,9 +676,8 @@ std::vector<std::string> MEDCoupling::GetFieldNamesOnMesh(MEDCoupling::TypeOfFie
 
 std::vector<std::string> MEDCoupling::GetCellFieldNamesOnMesh(const std::string& fileName, const std::string& meshName)
 {
-  MEDCoupling::CheckFileForRead(fileName);
   std::vector<std::string> ret;
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
+  MEDFileUtilities::AutoFid fid(MEDCoupling::OpenMEDFileForRead(fileName));
   med_int nbFields=MEDnField(fid);
   //
   med_field_type typcha;
@@ -750,9 +725,8 @@ std::vector<std::string> MEDCoupling::GetCellFieldNamesOnMesh(const std::string&
 
 std::vector<std::string> MEDCoupling::GetNodeFieldNamesOnMesh(const std::string& fileName, const std::string& meshName)
 {
-  MEDCoupling::CheckFileForRead(fileName);
   std::vector<std::string> ret;
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
+  MEDFileUtilities::AutoFid fid(MEDCoupling::OpenMEDFileForRead(fileName));
   med_int nbFields=MEDnField(fid);
   char pflname[MED_NAME_SIZE+1]="";
   char locname[MED_NAME_SIZE+1]="";
@@ -791,9 +765,8 @@ std::vector<std::string> MEDCoupling::GetNodeFieldNamesOnMesh(const std::string&
 
 std::vector< std::pair< std::pair<int,int>, double> > MEDCoupling::GetAllFieldIterations(const std::string& fileName, const std::string& fieldName)
 {
-  MEDCoupling::CheckFileForRead(fileName);
   std::vector< std::pair< std::pair<int,int>, double > > ret;
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
+  MEDFileUtilities::AutoFid fid(MEDCoupling::OpenMEDFileForRead(fileName));
   med_int nbFields=MEDnField(fid);
   //
   med_field_type typcha;
@@ -834,8 +807,7 @@ std::vector< std::pair< std::pair<int,int>, double> > MEDCoupling::GetAllFieldIt
 
 double MEDCoupling::GetTimeAttachedOnFieldIteration(const std::string& fileName, const std::string& fieldName, int iteration, int order)
 {
-  MEDCoupling::CheckFileForRead(fileName);
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
+  MEDFileUtilities::AutoFid fid(MEDCoupling::OpenMEDFileForRead(fileName));
   med_int nbFields=MEDnField(fid);
   //
   med_field_type typcha;
@@ -896,10 +868,9 @@ std::vector< std::pair<int,int> > MEDCoupling::GetFieldIterations(MEDCoupling::T
 
 std::vector< std::pair<int,int> > MEDCoupling::GetCellFieldIterations(const std::string& fileName, const std::string& meshName, const std::string& fieldName)
 {
-  MEDCoupling::CheckFileForRead(fileName);
   std::string meshNameCpp(meshName);
   std::vector< std::pair<int,int> > ret;
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
+  MEDFileUtilities::AutoFid fid(MEDCoupling::OpenMEDFileForRead(fileName));
   med_int nbFields=MEDnField(fid);
   //
   med_field_type typcha;
@@ -968,10 +939,9 @@ std::vector< std::pair<int,int> > MEDCoupling::GetCellFieldIterations(const std:
 
 std::vector< std::pair<int,int> > MEDCoupling::GetNodeFieldIterations(const std::string& fileName, const std::string& meshName, const std::string& fieldName)
 {
-  MEDCoupling::CheckFileForRead(fileName);
   std::string meshNameCpp(meshName);
   std::vector< std::pair<int,int> > ret;
-  MEDFileUtilities::AutoFid fid=MEDfileOpen(fileName.c_str(),MED_ACC_RDONLY);
+  MEDFileUtilities::AutoFid fid(MEDCoupling::OpenMEDFileForRead(fileName));
   med_int nbFields=MEDnField(fid);
   //
   med_field_type typcha;
diff --git a/src/MEDLoader/MEDLoaderNS.hxx b/src/MEDLoader/MEDLoaderNS.hxx
new file mode 100644
index 000000000..3db880f54
--- /dev/null
+++ b/src/MEDLoader/MEDLoaderNS.hxx
@@ -0,0 +1,43 @@
+// Copyright (C) 2016  CEA/DEN, EDF R&D
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library 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
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+//
+// See http://www.salome-platform.org/ or email : webmaster.salome@opencascade.com
+//
+// Author : Anthony Geay (EDF R&D)
+
+#ifndef __MEDLOADERNS_HXX__
+#define __MEDLOADERNS_HXX__
+
+#include <vector>
+#include <string>
+
+namespace MEDCoupling
+{
+  class MEDCouplingFieldDouble;
+}
+
+#include "med.h"
+
+namespace MEDLoaderNS
+{
+  int readUMeshDimFromFile(const std::string& fileName, const std::string& meshName, std::vector<int>& possibilities);
+  void dispatchElems(int nbOfElemCell, int nbOfElemFace, int& nbOfElem, med_entity_type& whichEntity);
+  void writeFieldWithoutReadingAndMappingOfMeshInFile(const std::string& fileName, const MEDCoupling::MEDCouplingFieldDouble *f, bool writeFromScratch);
+  med_int getIdFromMeshName(med_idt fid, const std::string& meshName, std::string& trueMeshName);
+  std::vector<std::string> getMeshNamesFid(med_idt fid);
+}
+
+#endif
diff --git a/src/MEDLoader/MEDLoaderTraits.cxx b/src/MEDLoader/MEDLoaderTraits.cxx
new file mode 100644
index 000000000..4b1150ad7
--- /dev/null
+++ b/src/MEDLoader/MEDLoaderTraits.cxx
@@ -0,0 +1,25 @@
+// Copyright (C) 2016  CEA/DEN, EDF R&D
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library 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
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+//
+// See http://www.salome-platform.org/ or email : webmaster.salome@opencascade.com
+//
+// Author : Anthony Geay (EDF R&D)
+
+#include "MEDLoaderTraits.hxx"
+
+const char MEDCoupling::MLMeshTraits<MEDCoupling::MEDFileUMesh>::ClassName[]="MEDFileUMesh";
+const char MEDCoupling::MLMeshTraits<MEDCoupling::MEDFileCMesh>::ClassName[]="MEDFileCMesh";
+const char MEDCoupling::MLMeshTraits<MEDCoupling::MEDFileCurveLinearMesh>::ClassName[]="MEDFileCurveLinearMesh";
diff --git a/src/MEDLoader/MEDLoaderTraits.hxx b/src/MEDLoader/MEDLoaderTraits.hxx
index 25cdfb3ee..03f246ac5 100644
--- a/src/MEDLoader/MEDLoaderTraits.hxx
+++ b/src/MEDLoader/MEDLoaderTraits.hxx
@@ -53,6 +53,33 @@ namespace MEDCoupling
     typedef MEDFileIntField1TS F1TSType;
     typedef MEDFileIntField1TSWithoutSDA F1TSWSDAType;
   };
+
+  template<class T>
+  struct MEDLOADER_EXPORT MLMeshTraits
+  {
+  };
+  
+  class MEDFileUMesh;
+  class MEDFileCMesh;
+  class MEDFileCurveLinearMesh;
+  
+  template<>
+  struct MEDLOADER_EXPORT MLMeshTraits<MEDFileUMesh>
+  {
+    static const char ClassName[];
+  };
+  
+  template<>
+  struct MEDLOADER_EXPORT MLMeshTraits<MEDFileCMesh>
+  {
+    static const char ClassName[];
+  };
+
+  template<>
+  struct MEDLOADER_EXPORT MLMeshTraits<MEDFileCurveLinearMesh>
+  {
+    static const char ClassName[];
+  };
 }
 
 #endif