ENH: dummy fileOperation: placeholder for interfaces taking a reference

STYLE: align readOnProc/writeOnProc naming within masterUncollated

applications/test/fileHandler-dummy/Make/files

@@ -0,0 +1,3 @@
+Test-fileHandler-dummy.C
+
+EXE = $(FOAM_USER_APPBIN)/Test-fileHandler-dummy

applications/test/fileHandler-dummy/Make/options

@@ -0,0 +1,2 @@
+/* EXE_INC = */
+/* EXE_LIBS = */

applications/test/fileHandler-dummy/Test-fileHandler-dummy.C

@@ -0,0 +1,79 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2023 OpenCFD Ltd.
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM 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 General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Application
+    Test-fileHandler-dummy
+
+Description
+    Simple test of dummy fileOperation
+
+\*---------------------------------------------------------------------------*/
+
+#include "argList.H"
+#include "fileName.H"
+#include "fileOperation.H"
+#include "Switch.H"
+
+using namespace Foam;
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+// Main program:
+
+int main(int argc, char *argv[])
+{
+    argList::noBanner();
+    argList::noCheckProcessorDirectories();
+
+    argList::addBoolOption
+    (
+        "force",
+        "Force use of dummy handler (and provoke NotImplemented)"
+    );
+
+    #include "setRootCase.H"
+
+    const bool optForce = args.found("force");
+
+    const auto& dummy = fileOperation::null();
+
+    Info<< "default handler: " << fileHandler() << endl;
+    Info<< "dummy handler: " << dummy() << endl;
+
+    Switch hasFile(Switch::INVALID);
+
+    if (optForce || (dummy && dummy().good()))
+    {
+        hasFile = dummy().isFile("foo");
+    }
+
+    Info<< "check file: " << hasFile << endl;
+
+    Info<< "\nEnd\n" << endl;
+    return 0;
+}
+
+
+// ************************************************************************* //

src/OpenFOAM/Make/files

@@ -22,6 +22,7 @@ $(fileOps)/fileOperation/fileOperationBroadcast.C
 $(fileOps)/fileOperation/fileOperationNew.C
 $(fileOps)/fileOperation/fileOperationRanks.C
 $(fileOps)/fileOperationInitialise/fileOperationInitialise.C
+$(fileOps)/dummyFileOperation/dummyFileOperation.C
 $(fileOps)/uncollatedFileOperation/uncollatedFileOperation.C
 $(fileOps)/masterUncollatedFileOperation/masterUncollatedFileOperation.C
 $(fileOps)/collatedFileOperation/collatedFileOperation.C

src/OpenFOAM/global/fileOperations/collatedFileOperation/collatedFileOperation.H

@@ -176,6 +176,7 @@ public:
                Class collatedFileOperationInitialise Declaration
 \*---------------------------------------------------------------------------*/
 
+//! Internal class only
 class collatedFileOperationInitialise
 :
     public masterUncollatedFileOperationInitialise

src/OpenFOAM/global/fileOperations/dummyFileOperation/dummyFileOperation.C

@@ -0,0 +1,385 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2023 OpenCFD Ltd.
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM 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 General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "dummyFileOperation.H"
+#include "dummyISstream.H"
+#include "Fstream.H"
+#include "objectRegistry.H"
+
+/* * * * * * * * * * * * * * * Static Member Data  * * * * * * * * * * * * * */
+
+namespace Foam
+{
+namespace fileOperations
+{
+    defineTypeName(dummyFileOperation);
+
+// No runtime selection
+}
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::fileOperations::dummyFileOperation::dummyFileOperation
+(
+    bool verbose
+)
+:
+    fileOperation
+    (
+        // Use COMM_SELF for now, but COMM_NULL is probably more appropriate
+        Tuple2<label, labelList>
+        (
+            UPstream::selfComm,
+            fileOperation::getGlobalIORanks()
+        )
+    )
+{}
+
+
+// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
+
+Foam::fileOperations::dummyFileOperation::~dummyFileOperation()
+{}
+
+
+// * * * * * * * * * * * * * Filesystem Operations * * * * * * * * * * * * * //
+
+bool Foam::fileOperations::dummyFileOperation::mkDir
+(
+    const fileName& dir,
+    mode_t mode
+) const
+{
+    NotImplemented;
+    return false;
+}
+
+
+bool Foam::fileOperations::dummyFileOperation::chMod
+(
+    const fileName& fName,
+    mode_t mode
+) const
+{
+    NotImplemented;
+    return false;
+}
+
+
+mode_t Foam::fileOperations::dummyFileOperation::mode
+(
+    const fileName& fName,
+    const bool followLink
+) const
+{
+    NotImplemented;
+    return mode_t(0);
+}
+
+
+Foam::fileName::Type Foam::fileOperations::dummyFileOperation::type
+(
+    const fileName& fName,
+    const bool followLink
+) const
+{
+    NotImplemented;
+    return fileName::Type::UNDEFINED;
+}
+
+
+bool Foam::fileOperations::dummyFileOperation::exists
+(
+    const fileName& fName,
+    const bool checkGzip,
+    const bool followLink
+) const
+{
+    NotImplemented;
+    return false;
+}
+
+
+bool Foam::fileOperations::dummyFileOperation::isDir
+(
+    const fileName& fName,
+    const bool followLink
+) const
+{
+    NotImplemented;
+    return false;
+}
+
+
+bool Foam::fileOperations::dummyFileOperation::isFile
+(
+    const fileName& fName,
+    const bool checkGzip,
+    const bool followLink
+) const
+{
+    NotImplemented;
+    return false;
+}
+
+
+off_t Foam::fileOperations::dummyFileOperation::fileSize
+(
+    const fileName& fName,
+    const bool followLink
+) const
+{
+    NotImplemented;
+    return off_t(0);
+}
+
+
+time_t Foam::fileOperations::dummyFileOperation::lastModified
+(
+    const fileName& fName,
+    const bool followLink
+) const
+{
+    NotImplemented;
+    return time_t(0);
+}
+
+
+double Foam::fileOperations::dummyFileOperation::highResLastModified
+(
+    const fileName& fName,
+    const bool followLink
+) const
+{
+    NotImplemented;
+    return 0;
+}
+
+
+
+Foam::fileNameList Foam::fileOperations::dummyFileOperation::readDir
+(
+    const fileName& dir,
+    const fileName::Type type,
+    const bool filtergz,
+    const bool followLink
+) const
+{
+    NotImplemented;
+    return fileNameList();
+}
+
+
+bool Foam::fileOperations::dummyFileOperation::cp
+(
+    const fileName& src,
+    const fileName& dst,
+    const bool followLink
+) const
+{
+    NotImplemented;
+    return false;
+}
+
+
+bool Foam::fileOperations::dummyFileOperation::ln
+(
+    const fileName& src,
+    const fileName& dst
+) const
+{
+    NotImplemented;
+    return false;
+}
+
+
+bool Foam::fileOperations::dummyFileOperation::mv
+(
+    const fileName& src,
+    const fileName& dst,
+    const bool followLink
+) const
+{
+    NotImplemented;
+    return false;
+}
+
+
+bool Foam::fileOperations::dummyFileOperation::mvBak
+(
+    const fileName& fName,
+    const std::string& ext
+) const
+{
+    NotImplemented;
+    return false;
+}
+
+
+bool Foam::fileOperations::dummyFileOperation::rm
+(
+    const fileName& fName
+) const
+{
+    NotImplemented;
+    return false;
+}
+
+
+bool Foam::fileOperations::dummyFileOperation::rmDir
+(
+    const fileName& dir,
+    const bool silent,
+    const bool emptyOnly
+) const
+{
+    NotImplemented;
+    return false;
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+Foam::fileName Foam::fileOperations::dummyFileOperation::filePath
+(
+    const bool checkGlobal,
+    const IOobject& io,
+    const word& typeName,
+    const bool search
+) const
+{
+    NotImplemented;
+    return fileName();
+}
+
+
+Foam::fileName Foam::fileOperations::dummyFileOperation::dirPath
+(
+    const bool checkGlobal,
+    const IOobject& io,
+    const bool search
+) const
+{
+    NotImplemented;
+    return fileName();
+}
+
+
+Foam::fileNameList Foam::fileOperations::dummyFileOperation::readObjects
+(
+    const objectRegistry& db,
+    const fileName& instance,
+    const fileName& local,
+    word& newInstance
+) const
+{
+    NotImplemented;
+    return fileNameList();
+}
+
+
+bool Foam::fileOperations::dummyFileOperation::readHeader
+(
+    IOobject& io,
+    const fileName& fName,
+    const word& typeName
+) const
+{
+    NotImplemented;
+    io.resetHeader();
+    return false;
+}
+
+
+Foam::autoPtr<Foam::ISstream>
+Foam::fileOperations::dummyFileOperation::readStream
+(
+    regIOobject& io,
+    const fileName& fName,
+    const word& typeName,
+    const bool readOnProc
+) const
+{
+    NotImplemented;
+    return autoPtr<ISstream>(new dummyISstream());
+}
+
+
+bool Foam::fileOperations::dummyFileOperation::read
+(
+    regIOobject& io,
+    const bool masterOnly,
+    const IOstreamOption::streamFormat format,
+    const word& typeName
+) const
+{
+    NotImplemented;
+    return false;
+}
+
+
+Foam::autoPtr<Foam::ISstream>
+Foam::fileOperations::dummyFileOperation::NewIFstream
+(
+    const fileName& filePath
+) const
+{
+    NotImplemented;
+    return autoPtr<ISstream>(new dummyISstream());
+}
+
+
+Foam::autoPtr<Foam::OSstream>
+Foam::fileOperations::dummyFileOperation::NewOFstream
+(
+    const fileName& pathName,
+    IOstreamOption streamOpt,
+    const bool writeOnProc
+) const
+{
+    NotImplemented;
+    return autoPtr<OSstream>(new OFstream(nullptr));  // ie, /dev/null
+}
+
+
+Foam::autoPtr<Foam::OSstream>
+Foam::fileOperations::dummyFileOperation::NewOFstream
+(
+    IOstreamOption::atomicType atomic,
+    const fileName& pathName,
+    IOstreamOption streamOpt,
+    const bool writeOnProc
+) const
+{
+    NotImplemented;
+    return autoPtr<OSstream>(new OFstream(nullptr));  // ie, /dev/null
+}
+
+
+// ************************************************************************* //

src/OpenFOAM/global/fileOperations/dummyFileOperation/dummyFileOperation.H

@@ -0,0 +1,290 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2023 OpenCFD Ltd.
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM 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 General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Class
+    Foam::fileOperations::dummyFileOperation
+
+Description
+    Dummy fileOperation, to be used as a placeholder for interfaces
+    taking a reference to a fileOperation.
+    Will mostly behave like a no-op, but at the moment no guarantees
+    of any particular behaviour other than good() returning false.
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef Foam_fileOperations_dummyFileOperation_H
+#define Foam_fileOperations_dummyFileOperation_H
+
+#include "fileOperation.H"
+#include "OSspecific.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+namespace fileOperations
+{
+
+/*---------------------------------------------------------------------------*\
+                     Class dummyFileOperation Declaration
+\*---------------------------------------------------------------------------*/
+
+class dummyFileOperation
+:
+    public fileOperation
+{
+public:
+
+    //- Runtime type information
+    TypeNameNoDebug("dummy");
+
+
+    // Constructors
+
+        //- Default construct
+        explicit dummyFileOperation(bool verbose = false);
+
+
+    //- Destructor
+    virtual ~dummyFileOperation();
+
+
+    // Member Functions
+
+        //- This fileOperation is not really valid for anything.
+        virtual bool good() const { return false; }
+
+        //- No managed communicator
+        virtual void storeComm() const {}
+
+
+        // OSSpecific equivalents
+
+            //- Make directory
+            virtual bool mkDir(const fileName&, mode_t=0777) const;
+
+            //- Set the file mode
+            virtual bool chMod(const fileName&, const mode_t) const;
+
+            //- Return the file mode
+            virtual mode_t mode
+            (
+                const fileName&,
+                const bool followLink = true
+            ) const;
+
+            //- Return the file type: DIRECTORY, FILE or SYMLINK
+            virtual fileName::Type type
+            (
+                const fileName&,
+                const bool followLink = true
+            ) const;
+
+            //- Does the name exist (as DIRECTORY or FILE) in the file system?
+            //  Optionally enable/disable check for gzip file.
+            virtual bool exists
+            (
+                const fileName&,
+                const bool checkGzip=true,
+                const bool followLink = true
+            ) const;
+
+            //- Does the name exist as a DIRECTORY in the file system?
+            virtual bool isDir
+            (
+                const fileName&,
+                const bool followLink = true
+            ) const;
+
+            //- Does the name exist as a FILE in the file system?
+            //  Optionally enable/disable check for gzip file.
+            virtual bool isFile
+            (
+                const fileName&,
+                const bool checkGzip=true,
+                const bool followLink = true
+            ) const;
+
+            //- Return size of file
+            virtual off_t fileSize
+            (
+                const fileName&,
+                const bool followLink = true
+            ) const;
+
+            //- Return time of last file modification
+            virtual time_t lastModified
+            (
+                const fileName&,
+                const bool followLink = true
+            ) const;
+
+            //- Return time of last file modification
+            virtual double highResLastModified
+            (
+                const fileName&,
+                const bool followLink = true
+            ) const;
+
+            //- Read a directory and return the entries as a string list
+            virtual fileNameList readDir
+            (
+                const fileName&,
+                const fileName::Type=fileName::FILE,
+                const bool filtergz=true,
+                const bool followLink = true
+            ) const;
+
+            //- Copy, recursively if necessary, the source to the destination
+            virtual bool cp
+            (
+                const fileName& src,
+                const fileName& dst,
+                const bool followLink = true
+            ) const;
+
+             //- Create a softlink. dst should not exist. Returns true if
+            //  successful.
+            virtual bool ln(const fileName& src, const fileName& dst) const;
+
+            //- Rename src to dst
+            virtual bool mv
+            (
+                const fileName& src,
+                const fileName& dst,
+                const bool followLink = false
+            ) const;
+
+            //- Rename to a corresponding backup file
+            //  If the backup file already exists, attempt with
+            //  "01" .. "99" suffix
+            virtual bool mvBak
+            (
+                const fileName&,
+                const std::string& ext = "bak"
+            ) const;
+
+            //- Remove a file, returning true if successful otherwise false
+            virtual bool rm(const fileName&) const;
+
+            //- Remove a directory and its contents
+            //  \param dir the directory to remove
+            //  \param silent do not report missing directory
+            //  \param emptyOnly only remove empty directories (recursive)
+            virtual bool rmDir
+            (
+                const fileName& dir,
+                const bool silent = false,
+                const bool emptyOnly = false
+            ) const;
+
+
+        // (reg)IOobject functionality
+
+            //- Search for an object. checkGlobal
+            virtual fileName filePath
+            (
+                const bool checkGlobal,
+                const IOobject& io,
+                const word& typeName,
+                const bool search
+            ) const;
+
+            //- Search for a directory. checkGlobal
+            virtual fileName dirPath
+            (
+                const bool checkGlobal,
+                const IOobject& io,
+                const bool search
+            ) const;
+
+            //- Search directory for objects. Used in IOobjectList.
+            virtual fileNameList readObjects
+            (
+                const objectRegistry& db,
+                const fileName& instance,
+                const fileName& local,
+                word& newInstance
+            ) const;
+
+            //- Read object header from supplied file
+            virtual bool readHeader
+            (
+                IOobject&,
+                const fileName&,
+                const word& typeName
+            ) const;
+
+            //- Reads header for regIOobject and returns an ISstream
+            //- to read the contents.
+            virtual autoPtr<ISstream> readStream
+            (
+                regIOobject&,
+                const fileName&,
+                const word& typeName,
+                const bool readOnProc = true
+            ) const;
+
+            //- Top-level read
+            virtual bool read
+            (
+                regIOobject&,
+                const bool masterOnly,
+                const IOstreamOption::streamFormat format,
+                const word& typeName
+            ) const;
+
+            //- Generate an ISstream that reads a file
+            virtual autoPtr<ISstream> NewIFstream(const fileName&) const;
+
+            //- Generate an OSstream that writes a file
+            virtual autoPtr<OSstream> NewOFstream
+            (
+                const fileName& pathname,
+                IOstreamOption streamOpt = IOstreamOption(),
+                const bool writeOnProc = true
+            ) const;
+
+            //- Generate an OSstream that writes a file
+            virtual autoPtr<OSstream> NewOFstream
+            (
+                IOstreamOption::atomicType,
+                const fileName& pathname,
+                IOstreamOption streamOpt = IOstreamOption(),
+                const bool writeOnProc = true
+            ) const;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace fileOperations
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/OpenFOAM/global/fileOperations/fileOperation/fileOperation.H

@@ -143,6 +143,14 @@ public:
         typedef IntRange<int> procRangeType;
 
 
+private:
+
+    // Private Static Data
+
+        //- Storage of the dummy file handler (demand-driven)
+        static refPtr<fileOperation> dummyHandlerPtr_;
+
+
 protected:
 
     // Protected Static Data
@@ -272,6 +280,9 @@ public:
     //- The currently active file handler. Avoid accessing directly
     static refPtr<fileOperation> fileHandlerPtr_;
 
+    //- Reference to a dummy file handler.
+    static refPtr<fileOperation> null();
+
 
     // Constructors
 
@@ -501,6 +512,10 @@ public:
 
     // Member Functions
 
+        //- True if the fileOperation can be considered valid.
+        //- At the moment, primarily used to detect the dummy fileOperation.
+        virtual bool good() const { return true; }
+
         //- Transfer ownership of communicator to this fileOperation.
         //- Use with caution
         virtual void storeComm() const = 0;

src/OpenFOAM/global/fileOperations/fileOperation/fileOperationNew.C

@@ -26,15 +26,30 @@ License
 \*---------------------------------------------------------------------------*/
 
 #include "fileOperation.H"
+#include "dummyFileOperation.H"
 #include "uncollatedFileOperation.H"
 
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
 
+Foam::refPtr<Foam::fileOperation> Foam::fileOperation::dummyHandlerPtr_;
+
 Foam::refPtr<Foam::fileOperation> Foam::fileOperation::fileHandlerPtr_;
 
 
 // * * * * * * * * * * * * * Static Member Functions * * * * * * * * * * * * //
 
+Foam::refPtr<Foam::fileOperation> Foam::fileOperation::null()
+{
+    if (!dummyHandlerPtr_)
+    {
+        // verbose = false
+        dummyHandlerPtr_.reset(new fileOperations::dummyFileOperation(false));
+    }
+
+    return dummyHandlerPtr_;
+}
+
+
 const Foam::fileOperation& Foam::fileOperation::fileHandler()
 {
     if (!fileOperation::fileHandlerPtr_)

src/OpenFOAM/global/fileOperations/masterUncollatedFileOperation/masterUncollatedFileOperation.C

@@ -428,10 +428,12 @@ Foam::fileOperations::masterUncollatedFileOperation::localObjectPath
 void Foam::fileOperations::masterUncollatedFileOperation::readAndSend
 (
     const fileName& filePath,
-    const labelUList& procs,
+    const labelUList& recvProcs,
     PstreamBuffers& pBufs
 )
 {
+    if (recvProcs.empty()) return;
+
     IFstream ifs(filePath, IOstreamOption::BINARY);
 
     if (!ifs.good())
@@ -462,7 +464,7 @@ void Foam::fileOperations::masterUncollatedFileOperation::readAndSend
             std::istreambuf_iterator<char>()
         );
 
-        for (const label proci : procs)
+        for (const label proci : recvProcs)
         {
             UOPstream os(proci, pBufs);
             os.write(buf.data(), buf.length());
@@ -483,7 +485,7 @@ void Foam::fileOperations::masterUncollatedFileOperation::readAndSend
         List<char> buf(static_cast<label>(count));
         ifs.stdStream().read(buf.data(), count);
 
-        for (const label proci : procs)
+        for (const label proci : recvProcs)
         {
             UOPstream os(proci, pBufs);
             os.write(buf.cdata(), count);
@@ -505,37 +507,35 @@ Foam::fileOperations::masterUncollatedFileOperation::read
     IOobject& io,
     const label comm,
     const bool uniform,             // on comms master only
-    const fileNameList& filePaths,  // on comms master only
-    const boolList& procValid       // on comms master and sub-ranks
+    const fileNameList& filePaths,  // on comms master and sub-ranks
+    const boolUList& readOnProcs    // on comms master and sub-ranks
 )
 {
     autoPtr<ISstream> isPtr;
 
-    // const bool uniform = fileOperation::uniformFile(filePaths);
-
     PstreamBuffers pBufs(comm, UPstream::commsTypes::nonBlocking);
 
     if (UPstream::master(comm))
     {
         if (uniform)
         {
-            if (procValid[0])
+            if (readOnProcs[0])
             {
                 if (filePaths[0].empty())
                 {
                     FatalIOErrorInFunction(filePaths[0])
-                        << "cannot find file " << io.objectPath()
+                        << "Cannot find file " << io.objectPath()
                         << " fileHandler : comm:" << comm
                         << " ioRanks:" << UPstream::procID(comm)
                         << exit(FatalIOError);
                 }
 
-                DynamicList<label> validProcs(Pstream::nProcs(comm));
-                for (const int proci : Pstream::allProcs(comm))
+                DynamicList<label> recvProcs(UPstream::nProcs(comm));
+                for (const int proci : UPstream::allProcs(comm))
                 {
-                    if (procValid[proci])
+                    if (readOnProcs[proci])
                     {
-                        validProcs.append(proci);
+                        recvProcs.push_back(proci);
                     }
                 }
 
@@ -545,20 +545,20 @@ Foam::fileOperations::masterUncollatedFileOperation::read
                 {
                     Pout<< "masterUncollatedFileOperation::readStream :"
                         << " For uniform file " << filePaths[0]
-                        << " sending to " << validProcs
+                        << " sending to " << recvProcs
                         << " in comm:" << comm << endl;
                 }
-                readAndSend(filePaths[0], validProcs, pBufs);
+                readAndSend(filePaths[0], recvProcs, pBufs);
             }
         }
         else
         {
-            if (procValid[0])
+            if (readOnProcs[0])
             {
                 if (filePaths[0].empty())
                 {
                     FatalIOErrorInFunction(filePaths[0])
-                        << "cannot find file " << io.objectPath()
+                        << "Cannot find file " << io.objectPath()
                         << " fileHandler : comm:" << comm
                         << " ioRanks:" << UPstream::procID(comm)
                         << exit(FatalIOError);
@@ -580,7 +580,7 @@ Foam::fileOperations::masterUncollatedFileOperation::read
             }
 
             // Read sub-rank files
-            for (const int proci : Pstream::subProcs(comm))
+            for (const int proci : UPstream::subProcs(comm))
             {
                 if (debug)
                 {
@@ -591,7 +591,7 @@ Foam::fileOperations::masterUncollatedFileOperation::read
 
                 const fileName& fPath = filePaths[proci];
 
-                if (procValid[proci] && !fPath.empty())
+                if (readOnProcs[proci] && !fPath.empty())
                 {
                     // Note: handle compression ourselves since size cannot
                     // be determined without actually uncompressing
@@ -609,14 +609,14 @@ Foam::fileOperations::masterUncollatedFileOperation::read
 
     if (!isPtr)
     {
-        if (procValid[Pstream::myProcNo(comm)])
+        if (readOnProcs[UPstream::myProcNo(comm)])
         {
             // This processor needs to return something
-            List<char> buf(pBufs.recvDataCount(Pstream::masterNo()));
+            List<char> buf(pBufs.recvDataCount(UPstream::masterNo()));
 
             if (!buf.empty())
             {
-                UIPstream is(Pstream::masterNo(), pBufs);
+                UIPstream is(UPstream::masterNo(), pBufs);
                 is.read(buf.data(), buf.size());
             }
 
@@ -633,7 +633,7 @@ Foam::fileOperations::masterUncollatedFileOperation::read
             isPtr.reset(new IListStream(std::move(buf)));
 
             // With the proper file name
-            isPtr->name() = filePaths[Pstream::myProcNo(comm)];
+            isPtr->name() = filePaths[UPstream::myProcNo(comm)];
 
             if (!io.readHeader(*isPtr))
             {
@@ -1971,7 +1971,7 @@ Foam::fileOperations::masterUncollatedFileOperation::readStream
         splitProcessorPath(fName, path, procDir, local, group, nProcs);
 
 
-        if (!Pstream::parRun())
+        if (!UPstream::parRun())
         {
             // Analyse the objectpath to find out the processor we're trying
             // to access
@@ -2078,16 +2078,16 @@ Foam::fileOperations::masterUncollatedFileOperation::readStream
         {
             // Use worldComm. Note: should not really need to gather filePaths
             // since we enforce sending from master anyway ...
-            fileNameList filePaths(Pstream::nProcs(UPstream::worldComm));
-            filePaths[Pstream::myProcNo(UPstream::worldComm)] = fName;
+            fileNameList filePaths(UPstream::nProcs(UPstream::worldComm));
+            filePaths[UPstream::myProcNo(UPstream::worldComm)] = fName;
             Pstream::gatherList
             (
                 filePaths,
-                Pstream::msgType(),
+                UPstream::msgType(),
                 UPstream::worldComm
             );
 
-            boolList procValid
+            boolList readOnProcs
             (
                 UPstream::listGatherValues<bool>
                 (
@@ -2096,30 +2096,40 @@ Foam::fileOperations::masterUncollatedFileOperation::readStream
                 )
             );
             // NB: local proc validity information required on sub-ranks too!
-            procValid.resize(Pstream::nProcs(UPstream::worldComm));
-            procValid[Pstream::myProcNo(UPstream::worldComm)] = readOnProc;
+            readOnProcs.resize(UPstream::nProcs(UPstream::worldComm));
+            readOnProcs[UPstream::myProcNo(UPstream::worldComm)] = readOnProc;
 
-            return read(io, UPstream::worldComm, true, filePaths, procValid);
+            // Uniform in local comm
+            return read(io, UPstream::worldComm, true, filePaths, readOnProcs);
         }
         else
         {
             // Use local communicator
-            fileNameList filePaths(Pstream::nProcs(comm_));
-            filePaths[Pstream::myProcNo(comm_)] = fName;
-            Pstream::gatherList(filePaths, Pstream::msgType(), comm_);
-
-            boolList procValid
+            fileNameList filePaths(UPstream::nProcs(comm_));
+            filePaths[UPstream::myProcNo(comm_)] = fName;
+            Pstream::gatherList
             (
-                UPstream::listGatherValues<bool>(readOnProc, comm_)
+                filePaths,
+                UPstream::msgType(),
+                comm_
+            );
+
+            boolList readOnProcs
+            (
+                UPstream::listGatherValues<bool>
+                (
+                    readOnProc,
+                    comm_
+                )
             );
             // NB: local proc validity information required on sub-ranks too!
-            procValid.resize(Pstream::nProcs(comm_));
-            procValid[Pstream::myProcNo(comm_)] = readOnProc;
+            readOnProcs.resize(UPstream::nProcs(comm_));
+            readOnProcs[UPstream::myProcNo(comm_)] = readOnProc;
 
             // Uniform in local comm
             const bool uniform = fileOperation::uniformFile(filePaths);
 
-            return read(io, comm_, uniform, filePaths, procValid);
+            return read(io, comm_, uniform, filePaths, readOnProcs);
         }
     }
 }

src/OpenFOAM/global/fileOperations/masterUncollatedFileOperation/masterUncollatedFileOperation.H

@@ -454,7 +454,7 @@ protected:
         static void readAndSend
         (
             const fileName& filePath,
-            const labelUList& procs,
+            const labelUList& recvProcs,
             PstreamBuffers& pBufs
         );
 
@@ -464,8 +464,8 @@ protected:
             IOobject& io,
             const label comm,
             const bool uniform,             // on comms master only
-            const fileNameList& filePaths,  // on comms master only
-            const boolList& procValid       // on comms master only
+            const fileNameList& filePaths,  // on comms master and sub-ranks
+            const boolUList& readOnProcs    // on comms master and sub-ranks
         );
 
         //- Helper: check IO for local existence. Like filePathInfo but
@@ -791,6 +791,7 @@ public:
            Class masterUncollatedFileOperationInitialise Declaration
 \*---------------------------------------------------------------------------*/
 
+//! Internal class only
 class masterUncollatedFileOperationInitialise
 :
     public unthreadedInitialise

src/OpenFOAM/global/fileOperations/uncollatedFileOperation/hostUncollatedFileOperation.H

@@ -98,6 +98,7 @@ public:
             Class hostUncollatedFileOperationInitialise Declaration
 \*---------------------------------------------------------------------------*/
 
+//! Internal class only
 class hostUncollatedFileOperationInitialise
 :
     public masterUncollatedFileOperationInitialise

src/OpenFOAM/global/fileOperations/uncollatedFileOperation/uncollatedFileOperation.C

@@ -614,10 +614,10 @@ Foam::fileOperations::uncollatedFileOperation::readStream
     regIOobject& io,
     const fileName& fName,
     const word& typeName,
-    const bool writeOnProc
+    const bool readOnProc
 ) const
 {
-    if (!writeOnProc)
+    if (!readOnProc)
     {
         return autoPtr<ISstream>(new dummyISstream());
     }

src/OpenFOAM/global/fileOperations/uncollatedFileOperation/uncollatedFileOperation.H

@@ -285,7 +285,7 @@ public:
                 regIOobject&,
                 const fileName&,
                 const word& typeName,
-                const bool procValid = true
+                const bool readOnProc = true
             ) const;
 
             //- Top-level read