0029303: Data Exchange - add RWObj_CafWriter tool for wavefront OBJ file

Unstable test case v3d/memory/bug26538 has been adjusted.

src/Message/FILES

@@ -21,6 +21,7 @@ Message_CompositeAlerts.hxx
 Message_ExecStatus.hxx
 Message_Gravity.hxx
 Message_HArrayOfMsg.hxx
+Message_LazyProgressScope.hxx
 Message_Level.cxx
 Message_Level.hxx
 Message_ListIteratorOfListOfMsg.hxx

src/Message/Message_LazyProgressScope.hxx

@@ -0,0 +1,80 @@
+// Copyright (c) 2017-2021 OPEN CASCADE SAS
+//
+// This file is part of Open CASCADE Technology software library.
+//
+// This library is free software; you can redistribute it and/or modify it under
+// the terms of the GNU Lesser General Public License version 2.1 as published
+// by the Free Software Foundation, with special exception defined in the file
+// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
+// distribution for complete text of the license and disclaimer of any warranty.
+//
+// Alternatively, this file may be used under the terms of Open CASCADE
+// commercial license or contractual agreement.
+
+#ifndef _Message_LazyProgressScope_HeaderFiler
+#define _Message_LazyProgressScope_HeaderFiler
+
+#include <Message_ProgressScope.hxx>
+
+//! Progress scope with lazy updates and abort fetches.
+//!
+//! Although Message_ProgressIndicator implementation is encouraged to spare GUI updates,
+//! even optimized implementation might show a noticeable overhead on a very small update step (e.g. per triangle).
+//!
+//! The class splits initial (displayed) number of overall steps into larger chunks specified in constructor,
+//! so that displayed progress is updated at larger steps.
+class Message_LazyProgressScope : protected Message_ProgressScope
+{
+public:
+
+  //! Main constructor.
+  //! @param theRange [in] progress range to scope
+  //! @param theName  [in] name of this scope
+  //! @param theMax   [in] number of steps within this scope
+  //! @param thePatchStep [in] number of steps to update progress
+  //! @param theIsInf [in] infinite flag
+  Message_LazyProgressScope (const Message_ProgressRange& theRange,
+                             const char* theName,
+                             const Standard_Real theMax,
+                             const Standard_Real thePatchStep,
+                             const Standard_Boolean theIsInf = Standard_False)
+  : Message_ProgressScope (theRange, theName, theMax, theIsInf),
+    myPatchStep (thePatchStep),
+    myPatchProgress (0.0),
+    myIsLazyAborted (Standard_False) {}
+
+  //! Increment progress with 1.
+  void Next()
+  {
+    if (++myPatchProgress < myPatchStep)
+    {
+      return;
+    }
+
+    myPatchProgress = 0.0;
+    Message_ProgressScope::Next (myPatchStep);
+    IsAborted();
+  }
+
+  //! Return TRUE if progress has been aborted - return the cached state lazily updated.
+  Standard_Boolean More() const
+  {
+    return !myIsLazyAborted;
+  }
+
+  //! Return TRUE if progress has been aborted - fetches actual value from the Progress.
+  Standard_Boolean IsAborted()
+  {
+    myIsLazyAborted = myIsLazyAborted || !Message_ProgressScope::More();
+    return myIsLazyAborted;
+  }
+
+protected:
+
+  Standard_Real    myPatchStep;
+  Standard_Real    myPatchProgress;
+  Standard_Boolean myIsLazyAborted;
+
+};
+
+#endif // _Message_LazyProgressScope_HeaderFiler