From 33693f32b6171e51a5171b110dae4a4460468a34 Mon Sep 17 00:00:00 2001
From: Mark Olesen <Mark.Olesen@esi-group.com>
Date: Wed, 4 May 2022 18:39:59 +0200
Subject: [PATCH] ENH: wrapped IOField, IOList, IOmapDistributePolyMesh

- Uses a refPtr to reference external content.
  Useful (for example) when writing data without copying.
  Reading into external locations is not implemented
  (no current requirement for that).

    * IOFieldRef -> IOField
    * IOListRef -> IOList
    * IOmapDistributePolyMeshRef -> IOmapDistributePolyMesh

  Eg,

    labelList addressing = ...;

    io.rename("cellProcAddressing");
    IOListRef<label>(io, addressing).write();

  Or,
    primitivePatch patch = ...;
    IOFieldRef<vector>(io, patch.localPoints()).write();
---
 applications/test/IOField/Test-IOField.C      | 34 ++++++++-
 src/OpenFOAM/Make/files                       |  2 +-
 src/OpenFOAM/db/IOobjects/IOField/IOField.C   | 23 +++++-
 src/OpenFOAM/db/IOobjects/IOField/IOField.H   | 72 ++++++++++++++++++-
 src/OpenFOAM/db/IOobjects/IOList/IOList.C     | 25 ++++++-
 src/OpenFOAM/db/IOobjects/IOList/IOList.H     | 70 +++++++++++++++++-
 src/OpenFOAM/db/IOobjects/IOMap/IOMap.C       |  3 +-
 .../IOobjects/IOMap/{IOMapName.C => IOMaps.C} |  0
 .../mapDistribute/IOmapDistributePolyMesh.C   | 46 +++++++++++-
 .../mapDistribute/IOmapDistributePolyMesh.H   | 69 ++++++++++++++++++
 10 files changed, 333 insertions(+), 11 deletions(-)
 rename src/OpenFOAM/db/IOobjects/IOMap/{IOMapName.C => IOMaps.C} (100%)

diff --git a/applications/test/IOField/Test-IOField.C b/applications/test/IOField/Test-IOField.C
index 97a4774b61..729a7c85e5 100644
--- a/applications/test/IOField/Test-IOField.C
+++ b/applications/test/IOField/Test-IOField.C
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2017 OpenFOAM Foundation
-    Copyright (C) 2019-2021 OpenCFD Ltd.
+    Copyright (C) 2019-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -34,6 +34,7 @@ Description
 
 #include "argList.H"
 #include "IOField.H"
+#include "IOList.H"
 #include "primitiveFields.H"
 #include "polyMesh.H"
 #include "Time.H"
@@ -181,6 +182,7 @@ int main(int argc, char *argv[])
     argList::addBoolOption("bool", "Use bool for tests");
     argList::addBoolOption("scalar", "Use scalar for tests");
     argList::addBoolOption("label", "Use label for tests (default)");
+    argList::addBoolOption("ref", "Test writing by ref");
 
     #include "addTimeOptions.H"
 
@@ -232,6 +234,36 @@ int main(int argc, char *argv[])
         doTests<label>(io, sz);
     }
 
+    if (args.found("ref"))
+    {
+        Info<< nl << "Testing writing referenced external data" << nl << endl;
+
+        IOobject ioOutput
+        (
+            args.executable(),
+            "constant",
+            runTime,
+            IOobject::NO_READ,
+            IOobject::NO_WRITE,
+            false
+        );
+
+        labelList ints(identity(200));
+
+        ioOutput.rename(args.executable() + "-labels");
+        Info<< "write " << ioOutput.objectRelPath() << endl;
+        {
+            IOListRef<label>(ioOutput, ints).write();
+        }
+
+        ioOutput.rename(args.executable() + "-points");
+        Info<< "write " << ioOutput.objectRelPath() << endl;
+        {
+            IOFieldRef<vector>(ioOutput, mesh.points()).write();
+        }
+
+    }
+
 
     Pout<< "\nEnd\n" << endl;
 
diff --git a/src/OpenFOAM/Make/files b/src/OpenFOAM/Make/files
index edd6b51add..ab3eea8736 100644
--- a/src/OpenFOAM/Make/files
+++ b/src/OpenFOAM/Make/files
@@ -317,7 +317,7 @@ $(IOdictionary)/localIOdictionary.C
 $(IOdictionary)/unwatchedIOdictionary.C
 $(IOdictionary)/IOdictionary.C
 
-db/IOobjects/IOMap/IOMapName.C
+db/IOobjects/IOMap/IOMaps.C
 db/IOobjects/decomposedBlockData/decomposedBlockData.C
 db/IOobjects/decomposedBlockData/decomposedBlockDataHeader.C
 db/IOobjects/GlobalIOField/GlobalIOFields.C
diff --git a/src/OpenFOAM/db/IOobjects/IOField/IOField.C b/src/OpenFOAM/db/IOobjects/IOField/IOField.C
index af07c9e91a..bb84a52e0c 100644
--- a/src/OpenFOAM/db/IOobjects/IOField/IOField.C
+++ b/src/OpenFOAM/db/IOobjects/IOField/IOField.C
@@ -167,12 +167,33 @@ Foam::IOField<Type>::IOField(const IOobject& io, const tmp<Field<Type>>& tfld)
 }
 
 
+template<class Type>
+Foam::IOFieldRef<Type>::IOFieldRef
+(
+    const IOobject& io,
+    const Field<Type>& content
+)
+:
+    regIOobject(io),
+    contentRef_(content)  // cref
+{}
+
+
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
 template<class Type>
 bool Foam::IOField<Type>::writeData(Ostream& os) const
 {
-    return (os << static_cast<const Field<Type>&>(*this)).good();
+    os << static_cast<const Field<Type>&>(*this);
+    return os.good();
+}
+
+
+template<class Type>
+bool Foam::IOFieldRef<Type>::writeData(Ostream& os) const
+{
+    os << contentRef_.cref();
+    return os.good();
 }
 
 
diff --git a/src/OpenFOAM/db/IOobjects/IOField/IOField.H b/src/OpenFOAM/db/IOobjects/IOField/IOField.H
index 163ee129df..7dc71fdf14 100644
--- a/src/OpenFOAM/db/IOobjects/IOField/IOField.H
+++ b/src/OpenFOAM/db/IOobjects/IOField/IOField.H
@@ -38,8 +38,9 @@ SourceFiles
 #ifndef Foam_IOField_H
 #define Foam_IOField_H
 
-#include "regIOobject.H"
 #include "Field.H"
+#include "regIOobject.H"
+#include "refPtr.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -100,7 +101,8 @@ public:
 
     // Member Functions
 
-        bool writeData(Ostream& os) const;
+        //- The writeData method for regIOobject write operation
+        virtual bool writeData(Ostream& os) const;
 
 
     // Member Operators
@@ -113,6 +115,72 @@ public:
 };
 
 
+/*---------------------------------------------------------------------------*\
+                         Class IOFieldRef Declaration
+\*---------------------------------------------------------------------------*/
+
+//- A IOField wrapper for writing external data.
+template<class Type>
+class IOFieldRef
+:
+    public regIOobject
+{
+    // Private Data
+
+        //- Reference to the external content
+        refPtr<Field<Type>> contentRef_;
+
+
+public:
+
+    //- The underlying content type
+    typedef Field<Type> content_type;
+
+
+    //- Type is identical to IOField
+    virtual const word& type() const
+    {
+        return IOField<Type>::typeName;
+    }
+
+
+    // Generated Methods
+
+        //- No default construct
+        IOFieldRef() = delete;
+
+        //- No copy construct
+        IOFieldRef(const IOFieldRef&) = delete;
+
+        //- No copy assignment
+        void operator=(const IOFieldRef&) = delete;
+
+
+    // Constructors
+
+        //- Construct from IOobject and const data reference
+        IOFieldRef(const IOobject& io, const Field<Type>& content);
+
+
+    //- Destructor
+    virtual ~IOFieldRef() = default;
+
+
+    // Member Functions
+
+        //- Allow cast to const content
+        //  Fatal if content is not set
+        operator const Field<Type>&() const
+        {
+            return contentRef_.cref();
+        }
+
+        //- The writeData method for regIOobject write operation
+        //  Fatal if content is not set
+        virtual bool writeData(Ostream& os) const;
+};
+
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 } // End namespace Foam
diff --git a/src/OpenFOAM/db/IOobjects/IOList/IOList.C b/src/OpenFOAM/db/IOobjects/IOList/IOList.C
index 9c96b75374..a058b52442 100644
--- a/src/OpenFOAM/db/IOobjects/IOList/IOList.C
+++ b/src/OpenFOAM/db/IOobjects/IOList/IOList.C
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2016-2018 OpenCFD Ltd.
+    Copyright (C) 2016-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -109,12 +109,33 @@ Foam::IOList<T>::IOList(const IOobject& io, List<T>&& content)
 }
 
 
+template<class T>
+Foam::IOListRef<T>::IOListRef
+(
+    const IOobject& io,
+    const List<T>& content
+)
+:
+    regIOobject(io),
+    contentRef_(content)
+{}
+
+
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
 template<class T>
 bool Foam::IOList<T>::writeData(Ostream& os) const
 {
-    return (os << *this).good();
+    os << static_cast<const List<T>&>(*this);
+    return os.good();
+}
+
+
+template<class T>
+bool Foam::IOListRef<T>::writeData(Ostream& os) const
+{
+    os << contentRef_.cref();
+    return os.good();
 }
 
 
diff --git a/src/OpenFOAM/db/IOobjects/IOList/IOList.H b/src/OpenFOAM/db/IOobjects/IOList/IOList.H
index 86cd0a1eb7..3894f96a3d 100644
--- a/src/OpenFOAM/db/IOobjects/IOList/IOList.H
+++ b/src/OpenFOAM/db/IOobjects/IOList/IOList.H
@@ -40,6 +40,7 @@ SourceFiles
 
 #include "List.H"
 #include "regIOobject.H"
+#include "refPtr.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -94,7 +95,8 @@ public:
 
     // Member Functions
 
-        bool writeData(Ostream& os) const;
+        //- The writeData method for regIOobject write operation
+        virtual bool writeData(Ostream& os) const;
 
 
     // Member Operators
@@ -107,6 +109,72 @@ public:
 };
 
 
+/*---------------------------------------------------------------------------*\
+                          Class IOListRef Declaration
+\*---------------------------------------------------------------------------*/
+
+//- A IOList wrapper for writing external data.
+template<class T>
+class IOListRef
+:
+    public regIOobject
+{
+    // Private Data
+
+        //- Reference to the external content
+        refPtr<List<T>> contentRef_;
+
+
+public:
+
+    //- The underlying content type
+    typedef List<T> content_type;
+
+
+    //- Type is identical to IOList
+    virtual const word& type() const
+    {
+        return IOList<T>::typeName;
+    }
+
+
+    // Generated Methods
+
+        //- No default construct
+        IOListRef() = delete;
+
+        //- No copy construct
+        IOListRef(const IOListRef&) = delete;
+
+        //- No copy assignment
+        void operator=(const IOListRef&) = delete;
+
+
+    // Constructors
+
+        //- Construct from IOobject and const data reference
+        IOListRef(const IOobject& io, const List<T>& content);
+
+
+    //- Destructor
+    virtual ~IOListRef() = default;
+
+
+    // Member Functions
+
+        //- Allow cast to const content
+        //  Fatal if content is not set
+        operator const List<T>&() const
+        {
+            return contentRef_.cref();
+        }
+
+        //- The writeData method for regIOobject write operation
+        //  Fatal if content is not set
+        virtual bool writeData(Ostream& os) const;
+};
+
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 } // End namespace Foam
diff --git a/src/OpenFOAM/db/IOobjects/IOMap/IOMap.C b/src/OpenFOAM/db/IOobjects/IOMap/IOMap.C
index fc1bdd57dc..b44711ee55 100644
--- a/src/OpenFOAM/db/IOobjects/IOMap/IOMap.C
+++ b/src/OpenFOAM/db/IOobjects/IOMap/IOMap.C
@@ -106,7 +106,8 @@ Foam::IOMap<T>::IOMap(const IOobject& io, Map<T>&& content)
 template<class T>
 bool Foam::IOMap<T>::writeData(Ostream& os) const
 {
-    return (os << *this).good();
+    os << *this;
+    return os.good();
 }
 
 
diff --git a/src/OpenFOAM/db/IOobjects/IOMap/IOMapName.C b/src/OpenFOAM/db/IOobjects/IOMap/IOMaps.C
similarity index 100%
rename from src/OpenFOAM/db/IOobjects/IOMap/IOMapName.C
rename to src/OpenFOAM/db/IOobjects/IOMap/IOMaps.C
diff --git a/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/IOmapDistributePolyMesh.C b/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/IOmapDistributePolyMesh.C
index 2af120a3d0..ab1b4be762 100644
--- a/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/IOmapDistributePolyMesh.C
+++ b/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/IOmapDistributePolyMesh.C
@@ -106,17 +106,59 @@ Foam::IOmapDistributePolyMesh::IOmapDistributePolyMesh
 }
 
 
+Foam::IOmapDistributePolyMeshRef::IOmapDistributePolyMeshRef
+(
+    const IOobject& io,
+    const mapDistributePolyMesh& map
+)
+:
+    regIOobject(io),
+    contentRef_(map)  // cref
+{}
+
+
+// Not sure if we need this yet...
+//
+/// Foam::IOmapDistributePolyMeshRef::IOmapDistributePolyMeshRef
+/// (
+///     const IOobject& io,
+///     mapDistributePolyMesh& map
+/// )
+/// :
+///     regIOobject(io),
+///     contentRef_()
+/// {
+///     contentRef_.ref(map);  // writable reference
+/// }
+
+
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
 bool Foam::IOmapDistributePolyMesh::readData(Istream& is)
 {
-    return (is >> *this).good();
+    is >> *this;
+    return is.good();
 }
 
 
 bool Foam::IOmapDistributePolyMesh::writeData(Ostream& os) const
 {
-    return (os << *this).good();
+    os << *this;
+    return os.good();
+}
+
+
+bool Foam::IOmapDistributePolyMeshRef::readData(Istream& is)
+{
+    is >> contentRef_.ref();
+    return is.good();
+}
+
+
+bool Foam::IOmapDistributePolyMeshRef::writeData(Ostream& os) const
+{
+    os << contentRef_.cref();
+    return os.good();
 }
 
 
diff --git a/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/IOmapDistributePolyMesh.H b/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/IOmapDistributePolyMesh.H
index 46d326006e..a3afb0f245 100644
--- a/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/IOmapDistributePolyMesh.H
+++ b/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/IOmapDistributePolyMesh.H
@@ -42,6 +42,7 @@ SourceFiles
 
 #include "mapDistributePolyMesh.H"
 #include "regIOobject.H"
+#include "refPtr.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -102,6 +103,74 @@ public:
 };
 
 
+/*---------------------------------------------------------------------------*\
+                 Class IOmapDistributePolyMeshRef Declaration
+\*---------------------------------------------------------------------------*/
+
+//- A IOmapDistributePolyMesh wrapper for using referenced external data.
+class IOmapDistributePolyMeshRef
+:
+    public regIOobject
+{
+    // Private Data
+
+        //- Reference to the external content
+        refPtr<mapDistributePolyMesh> contentRef_;
+
+public:
+
+    //- Type is identical to IOmapDistributePolyMesh
+    virtual const word& type() const
+    {
+        return IOmapDistributePolyMesh::typeName;
+    }
+
+
+    // Generated Methods
+
+        //- No default construct
+        IOmapDistributePolyMeshRef() = delete;
+
+        //- No copy construct
+        IOmapDistributePolyMeshRef(const IOmapDistributePolyMeshRef&) = delete;
+
+        //- No copy assignment
+        void operator=(const IOmapDistributePolyMeshRef&) = delete;
+
+
+    // Constructors
+
+        //- Construct from IOobject and const data reference
+        IOmapDistributePolyMeshRef
+        (
+            const IOobject& io,
+            const mapDistributePolyMesh& map
+        );
+
+
+    //- Destructor
+    virtual ~IOmapDistributePolyMeshRef() = default;
+
+
+    // Member Functions
+
+        //- Allow cast to const content
+        //  Fatal if content is not set
+        operator const mapDistributePolyMesh&() const
+        {
+            return contentRef_.cref();
+        }
+
+        //- The readData method for regIOobject read operation
+        //  Fatal if content is constant (or not set)
+        virtual bool readData(Istream& is);
+
+        //- The writeData method for regIOobject write operation
+        //  Fatal if content is not set
+        virtual bool writeData(Ostream& os) const;
+};
+
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 } // End namespace Foam