ENH: improved handling of zone allocation in surfMesh

- relocate zone IO from Detail::MeshedSurfaceIOAllocator into surfMesh
  directly to allow re-purposing of MeshedSurfaceIOAllocator

- provide meshedSurf::emptySurface zero-sized placeholder implementation

- add concrete implementation of meshedSurf::zoneIds() to simplify
  overloading

src/surfMesh/MeshedSurface/MeshedSurface.H

@@ -124,7 +124,7 @@ private:
         surfZoneList zones_;
 
 
-    // Private Member functions
+    // Private Member Functions
 
         //- Read/construct from Istream
         Istream& read(Istream& is);

src/surfMesh/MeshedSurfaceAllocator/MeshedSurfaceIOAllocator.C

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2016-2018 OpenCFD Ltd.
+    \\  /    A nd           | Copyright (C) 2016-2019 OpenCFD Ltd.
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
                             | Copyright (C) 2011-2016 OpenFOAM Foundation
@@ -32,39 +32,33 @@ License
 Foam::Detail::MeshedSurfaceIOAllocator::MeshedSurfaceIOAllocator
 (
     const IOobject& ioPoints,
-    const IOobject& ioFaces,
-    const IOobject& ioZones
+    const IOobject& ioFaces
 )
 :
     points_(ioPoints),
-    faces_(ioFaces),
-    zones_(ioZones)
+    faces_(ioFaces)
 {}
 
 
 Foam::Detail::MeshedSurfaceIOAllocator::MeshedSurfaceIOAllocator
 (
     const IOobject& ioPoints, const pointField& points,
-    const IOobject& ioFaces,  const faceList& faces,
-    const IOobject& ioZones,  const surfZoneList& zones
+    const IOobject& ioFaces,  const faceList& faces
 )
 :
     points_(ioPoints, points),
-    faces_(ioFaces, faces),
-    zones_(ioZones, zones)
+    faces_(ioFaces, faces)
 {}
 
 
 Foam::Detail::MeshedSurfaceIOAllocator::MeshedSurfaceIOAllocator
 (
     const IOobject& ioPoints, pointField&& points,
-    const IOobject& ioFaces,  faceList&& faces,
-    const IOobject& ioZones,  surfZoneList&& zones
+    const IOobject& ioFaces,  faceList&& faces
 )
 :
     points_(ioPoints, std::move(points)),
-    faces_(ioFaces, std::move(faces)),
-    zones_(ioZones, std::move(zones))
+    faces_(ioFaces, std::move(faces))
 {}
 
 
@@ -85,7 +79,6 @@ void Foam::Detail::MeshedSurfaceIOAllocator::setInstance
 {
     points_.instance() = inst;
     faces_.instance()  = inst;
-    zones_.instance()  = inst;
 }
 
 
@@ -96,7 +89,6 @@ void Foam::Detail::MeshedSurfaceIOAllocator::setWriteOption
 {
     points_.writeOpt() = wOpt;
     faces_.writeOpt()  = wOpt;
-    zones_.writeOpt()  = wOpt;
 }
 
 
@@ -104,7 +96,6 @@ void Foam::Detail::MeshedSurfaceIOAllocator::clear()
 {
     points_.clear();
     faces_.clear();
-    zones_.clear();
 }
 
 
@@ -120,7 +111,6 @@ bool Foam::Detail::MeshedSurfaceIOAllocator::writeObject
     (
         points_.writeObject(fmt, ver, cmp, valid)
      && faces_.writeObject(fmt, ver, cmp, valid)
-     && zones_.writeObject(fmt, ver, cmp, valid)
     );
 }
 

src/surfMesh/MeshedSurfaceAllocator/MeshedSurfaceIOAllocator.H

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2016-2018 OpenCFD Ltd.
+    \\  /    A nd           | Copyright (C) 2016-2019 OpenCFD Ltd.
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
                             | Copyright (C) 2011-2016 OpenFOAM Foundation
@@ -27,7 +27,7 @@ Class
     Foam::Detail::MeshedSurfaceIOAllocator
 
 Description
-    A helper class for storing points, faces and zones with IO capabilities.
+    A helper class for storing points and faces with IO capabilities.
 
 SourceFiles
     MeshedSurfaceIOAllocator.C
@@ -39,7 +39,6 @@ SourceFiles
 
 #include "pointIOField.H"
 #include "faceIOList.H"
-#include "surfZoneIOList.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -62,9 +61,6 @@ class MeshedSurfaceIOAllocator
         //- Faces
         faceCompactIOList faces_;
 
-        //- Surface zones
-        surfZoneIOList zones_;
-
 
     // Private Member Functions
 
@@ -83,24 +79,21 @@ public:
         MeshedSurfaceIOAllocator
         (
             const IOobject& ioPoints,
-            const IOobject& ioFaces,
-            const IOobject& ioZones
+            const IOobject& ioFaces
         );
 
         //- Construct from IOobjects, copying components
         MeshedSurfaceIOAllocator
         (
             const IOobject& ioPoints, const pointField& points,
-            const IOobject& ioFaces,  const faceList& faces,
-            const IOobject& ioZones,  const surfZoneList& zones
+            const IOobject& ioFaces,  const faceList& faces
         );
 
         //- Construct from IOobjects, moving components
         MeshedSurfaceIOAllocator
         (
             const IOobject& ioPoints, pointField&& points,
-            const IOobject& ioFaces,  faceList&& faces,
-            const IOobject& ioZones,  surfZoneList&& zones
+            const IOobject& ioFaces,  faceList&& faces
         );
 
 
@@ -133,12 +126,6 @@ public:
             return faces_;
         }
 
-        //- Non-const access to the zones
-        surfZoneIOList& storedIOZones()
-        {
-            return zones_;
-        }
-
         //- Const access to the points
         const pointIOField& storedIOPoints() const
         {
@@ -151,16 +138,10 @@ public:
             return faces_;
         }
 
-        //- Const access to the zones
-        const surfZoneIOList& storedIOZones() const
-        {
-            return zones_;
-        }
-
 
     //  Storage Management
 
-        //- Clear primitive data (points, faces and zones)
+        //- Clear primitive data (points, faces)
         void clear();
 
 

src/surfMesh/MeshedSurfaceProxy/MeshedSurfaceProxy.H

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2016-2018 OpenCFD Ltd.
+    \\  /    A nd           | Copyright (C) 2016-2019 OpenCFD Ltd.
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
                             | Copyright (C) 2011-2016 OpenFOAM Foundation
@@ -104,7 +104,7 @@ public:
             const pointField& pointLst,
             const UList<Face>& faceLst,
             const UList<surfZone>& zoneLst = List<surfZone>(),
-            const labelUList& faceMap = Foam::emptyLabelList
+            const labelUList& faceMap = labelUList::null()
         );
 
 

src/surfMesh/mergedSurf/mergedSurf.H

@@ -123,7 +123,7 @@ public:
             return faces_;
         }
 
-        //- Const access to per-face zone/region information
+        //- Per-face zone/region information
         virtual const labelList& zoneIds() const
         {
             return zones_;

src/surfMesh/meshedSurf/meshedSurf.H

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2016 OpenCFD Ltd.
+    \\  /    A nd           | Copyright (C) 2016-2019 OpenCFD Ltd.
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -49,6 +49,10 @@ class meshedSurf
 {
 public:
 
+    // Forward declarations
+    class emptySurface;
+
+
     // Constructors
 
         //- Construct null
@@ -59,19 +63,60 @@ public:
     virtual ~meshedSurf() = default;
 
 
-    // Access Member Functions
+    // Member Functions
 
-        //- Const access to (global) points used for the surface
+        //- The points used for the surface
         virtual const pointField& points() const = 0;
 
-        //- Const access to the surface faces
+        //- The faces used for the surface
         virtual const faceList& faces() const = 0;
 
-        //- Const access to per-face zone/region information
-        virtual const labelList& zoneIds() const = 0;
+        //- Per-face zone/region information.
+        //  Default is zero-sizes (ie, no zone information)
+        virtual const labelList& zoneIds() const
+        {
+            return labelList::null();
+        }
+};
+
 
+/*---------------------------------------------------------------------------*\
+                  Class meshedSurf::emptySurface Declaration
+\*---------------------------------------------------------------------------*/
+
+//- A meshedSurf class with no faces, points or zoneId
+class meshedSurf::emptySurface
+:
+    public meshedSurf
+{
+public:
+
+    // Constructors
+
+        //- Construct null
+        emptySurface() = default;
+
+
+    //- Destructor
+    virtual ~emptySurface() = default;
+
+
+    // Member Functions
+
+        //- Zero-sized point field
+        virtual const pointField& points() const
+        {
+            return pointField::null();
+        }
+
+        //- Zero-sized face list
+        virtual const faceList& faces() const
+        {
+            return faceList::null();
+        }
 };
 
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 } // End namespace Foam

src/surfMesh/meshedSurf/meshedSurfRef.H

@@ -62,7 +62,7 @@ public:
         (
             const pointField& pts,
             const faceList& faces,
-            const labelList& ids = emptyLabelList
+            const labelList& ids = labelList::null()
         )
         :
             points_(std::cref<pointField>(pts)),
@@ -77,19 +77,19 @@ public:
 
     // Member Functions
 
-        //- Const access to (global) points used for the surface
+        //- The points used for the surface
         virtual const pointField& points() const
         {
             return points_.get();
         }
 
-        //- Const access to the surface faces
+        //- The faces used for the surface
         virtual const faceList& faces() const
         {
             return faces_.get();
         }
 
-        //- Const access to per-face zone/region information
+        //- Per-face zone/region information.
         virtual const labelList& zoneIds() const
         {
             return zoneIds_.get();

src/surfMesh/surfMesh/surfMesh.C

@@ -48,10 +48,9 @@ Foam::word Foam::surfMesh::meshSubDir = "surfMesh";
 // {
 //     word zoneName;
 //
-//     surfZoneList& zones = Allocator::storedIOZones();
-//     if (zones.size())
+//     if (surfZones_.size())
 //     {
-//         zoneName = zones[0].name();
+//         zoneName = surfZones_[0].name();
 //     }
 //     if (zoneName.empty())
 //     {
@@ -59,8 +58,8 @@ Foam::word Foam::surfMesh::meshSubDir = "surfMesh";
 //     }
 //
 //     // Set single default zone
-//     zones.resize(1);
-//     zones[0] = surfZone
+//     surfZones_.resize(1);
+//     surfZones_[0] = surfZone
 //     (
 //         zoneName,
 //         nFaces(),       // zone size
@@ -100,18 +99,22 @@ Foam::surfMesh::surfMesh(const IOobject& io, const word& surfName)
             *this,
             IOobject::MUST_READ,
             IOobject::NO_WRITE
-        ),
+        )
+    ),
+    MeshReference(this->storedIOFaces(), this->storedIOPoints()),
+
+    surfZones_
+    (
         IOobject
         (
             "surfZones",
             time().findInstance(meshDir(), "surfZones"),
             meshSubDir,
             *this,
-            IOobject::MUST_READ,
+            IOobject::READ_IF_PRESENT,
             IOobject::NO_WRITE
         )
-    ),
-    MeshReference(this->storedIOFaces(), this->storedIOPoints())
+    )
 {}
 
 
@@ -142,7 +145,12 @@ Foam::surfMesh::surfMesh
             *this,
             IOobject::NO_READ,
             io.writeOpt()
-        ),
+        )
+    ),
+    MeshReference(this->storedIOFaces(), this->storedIOPoints()),
+
+    surfZones_
+    (
         IOobject
         (
             "surfZones",
@@ -152,8 +160,7 @@ Foam::surfMesh::surfMesh
             IOobject::NO_READ,
             io.writeOpt()
         )
-    ),
-    MeshReference(this->storedIOFaces(), this->storedIOPoints())
+    )
 {
     DebugInfo
         <<"IOobject: " << io.path() << nl
@@ -194,7 +201,12 @@ Foam::surfMesh::surfMesh
             *this,
             io.readOpt(),
             io.writeOpt()
-        ),
+        )
+    ),
+    MeshReference(this->storedIOFaces(), this->storedIOPoints()),
+
+    surfZones_
+    (
         IOobject
         (
             "surfZones",
@@ -204,8 +216,7 @@ Foam::surfMesh::surfMesh
             io.readOpt(),
             io.writeOpt()
         )
-    ),
-    MeshReference(this->storedIOFaces(), this->storedIOPoints())
+    )
 {
     DebugInfo
         <<"IOobject: " << io.path() << nl
@@ -224,8 +235,7 @@ Foam::surfMesh::surfMesh
 
 Foam::surfMesh::~surfMesh()
 {
-    // clearOut();
-    // resetMotion();
+    clearOut(); // Clear addressing
 }
 
 
@@ -272,7 +282,7 @@ void Foam::surfMesh::copyContents
 
     this->storedIOPoints() = surf.points();
     this->storedIOFaces() = surf.surfFaces();
-    this->storedIOZones() = surf.surfZones();
+    surfZones_ = surf.surfZones();
 
     this->updateRefs();
 
@@ -291,9 +301,9 @@ void Foam::surfMesh::transfer
 {
     clearOut(); // Clear addressing
 
-    this->storedIOPoints().transfer(surf.storedPoints());
-    this->storedIOFaces().transfer(surf.storedFaces());
-    this->storedIOZones().transfer(surf.storedZones());
+    this->storedPoints().transfer(surf.storedPoints());
+    this->storedFaces().transfer(surf.storedFaces());
+    this->storedZones().transfer(surf.storedZones());
 
     this->updateRefs();
 
@@ -366,18 +376,17 @@ const Foam::faceList& Foam::surfMesh::faces() const
 
 void Foam::surfMesh::checkZones()
 {
-    // extra safety, ensure we have at some zones
+    // Extra safety, ensure we have at some zones
     // and they cover all the faces - fix start silently
-    surfZoneList& zones = Allocator::storedIOZones();
 
-    if (zones.size() <= 1)
+    if (surfZones_.size() <= 1)
     {
         removeZones();
         return;
     }
 
     label count = 0;
-    for (surfZone& zn : zones)
+    for (surfZone& zn : surfZones_)
     {
         zn.start() = count;
         count += zn.size();
@@ -390,7 +399,7 @@ void Foam::surfMesh::checkZones()
             << " ... extending final zone"
             << endl;
 
-        zones.last().size() += count - nFaces();
+        surfZones_.last().size() += count - nFaces();
     }
     else if (size() < count)
     {
@@ -404,15 +413,15 @@ void Foam::surfMesh::checkZones()
 // Add boundary patches. Constructor helper
 void Foam::surfMesh::addZones
 (
-    const surfZoneList& srfZones,
+    const surfZoneList& zones,
     const bool validate
 )
 {
-    surfZoneList& zones = Allocator::storedIOZones();
+    removeZones();
 
-    forAll(zones, zonei)
+    forAll(surfZones_, zonei)
     {
-        zones[zonei] = surfZone(srfZones[zonei], zonei);
+        surfZones_[zonei] = surfZone(zones[zonei], zonei);
     }
 
     if (validate)

src/surfMesh/surfMesh/surfMesh.H

@@ -43,6 +43,7 @@ SourceFiles
 #include "MeshedSurfaceIOAllocator.H"
 #include "PrimitivePatch.H"
 #include "SubField.H"
+#include "surfZoneIOList.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -64,7 +65,7 @@ class surfMesh
 {
 public:
 
-    // Public data types
+    // Public Data Types
 
         //- Enumeration defining the state of the mesh after a read update.
         //  Used for post-processing applications, where the mesh
@@ -94,6 +95,12 @@ private:
         MeshReference;
 
 
+    // Demand driven private data
+
+        //- The surface zones
+        surfZoneIOList surfZones_;
+
+
     // Private Member Functions
 
         //- No copy construct
@@ -119,10 +126,10 @@ protected:
             return Allocator::storedIOFaces();
         }
 
-        //- Non-const access to the zones
+        //- Non-const access to the surface zones
         surfZoneList& storedZones()
         {
-            return Allocator::storedIOZones();
+            return surfZones_;
         }
 
         //- Update references to storedFaces
@@ -236,10 +243,9 @@ public:
         //- Return surface zones
         virtual const surfZoneList& surfZones() const
         {
-            return Allocator::storedIOZones();
+            return surfZones_;
         }
 
-
         //- Return face area vectors (normals)
         inline const vectorField& Sf() const
         {
@@ -264,7 +270,7 @@ public:
         //- Add surface zones, optionally validating the zone coverage
         void addZones
         (
-            const surfZoneList& srfZones,
+            const surfZoneList& zones,
             bool validate = true
         );
 

src/surfMesh/surfMesh/surfMeshClear.C

@@ -36,7 +36,7 @@ void Foam::surfMesh::removeZones()
     DebugInFunction << "Removing surface zones." << endl;
 
     // Remove the surface zones
-    storedZones().clear();
+    surfZones_.clear();
 
     clearOut();
 }
@@ -54,7 +54,7 @@ void Foam::surfMesh::clearGeom()
 
 void Foam::surfMesh::clearAddressing()
 {
-    DebugInFunction << "clearing topology" << endl;
+    DebugInFunction << "Clearing topology" << endl;
 
     MeshReference::clearPatchMeshAddr();
 }

src/surfMesh/surfMesh/surfMeshIO.C

@@ -40,6 +40,7 @@ void Foam::surfMesh::setInstance
 
     instance() = inst;
     Allocator::setInstance(inst);
+    surfZones_.instance()  = inst;
 
     setWriteOption(wOpt);
 }
@@ -49,6 +50,7 @@ void Foam::surfMesh::setWriteOption(IOobject::writeOption wOpt)
 {
     writeOpt() = wOpt;
     Allocator::setWriteOption(wOpt);
+    surfZones_.writeOpt()  = wOpt;
 }
 
 
@@ -116,7 +118,7 @@ Foam::surfMesh::readUpdateState Foam::surfMesh::readUpdate()
                 facesInst,
                 meshSubDir,
                 *this,
-                IOobject::MUST_READ,
+                IOobject::READ_IF_PRESENT,
                 IOobject::NO_WRITE,
                 false
             )
@@ -125,16 +127,15 @@ Foam::surfMesh::readUpdateState Foam::surfMesh::readUpdate()
         // Check that zone types and names are unchanged
         bool zonesChanged = false;
 
-        surfZoneList& zones = this->storedIOZones();
-        if (zones.size() != newZones.size())
+        if (surfZones_.size() != newZones.size())
         {
             zonesChanged = true;
         }
         else
         {
-            forAll(zones, zoneI)
+            forAll(surfZones_, zoneI)
             {
-                if (zones[zoneI].name() != newZones[zoneI].name())
+                if (surfZones_[zoneI].name() != newZones[zoneI].name())