New feature: Added switch which enables storing only first and last iteration residuals in solvePerformance

src/foam/matrices/solution/solution.C

@@ -127,6 +127,15 @@ void Foam::solution::read(const dictionary& dict)
     {
         solverPerformance_ = dict.subDict("solverPerformance");
     }
+
+    if (dict.found("residuals"))
+    {
+        storeAllResiduals_ =
+            dict.subDict("residuals").lookupOrDefault
+            (
+                "storeAllResiduals", false
+            );
+    }
 }
 
 
@@ -153,7 +162,8 @@ Foam::solution::solution(const objectRegistry& obr, const fileName& dictName)
     eqnRelaxDefault_(0),
     solvers_(dictionary::null),
     solverPerformance_(dictionary::null),
-    prevTimeIndex_(0)
+    prevTimeIndex_(0),
+    storeAllResiduals_(false)
 {
     if (!headerOk())
     {

src/foam/matrices/solution/solution.H

@@ -82,6 +82,10 @@ class solution
         //- Previously used time-index, used for reset between iterations
         mutable label prevTimeIndex_;
 
+        //- Switch for storing residuals of every iteration inside a single
+        //  timestep
+        bool storeAllResiduals_;
+
 
     // Private Member Functions
 

src/foam/matrices/solution/solutionTemplates.C

@@ -65,8 +65,20 @@ void Foam::solution::setSolverPerformance
         solverPerformance_.readIfPresent(name, perfs);
     }
 
-    // Append to list
-    perfs.setSize(perfs.size() + 1, sp);
+    // If storeAllResiduals_ is true, we are storing residual of every iteration
+    // inside a single time step. Otherwise, only the first iteration residual
+    // and the current iteration residual are required, so the current
+    // iteration residual replaces the previous one and only the first iteration
+    // residual is always present, VS 2018-02-11
+    if (storeAllResiudals_ || perfs.size() < 2)
+    {
+        // Append to list
+        perfs.setSize(perfs.size() + 1, sp);
+    }
+    else
+    {
+        perfs.last() = sp;
+    }
 
     solverPerformance_.set(name, perfs);
 }