private bool EnsureSolutionIsViable(ref SolverErrorCode optionalErrorCode)
{
foreach (int desiredInstanceCount in this.desiredContainerInstanceCounts)
{
for (int k = 0; k < this.ResourceCount; k++)
{
if (desiredInstanceCount > this.machineConstraintsPerResource[k].Count(c => c > 0))
{
optionalErrorCode = SolverErrorCode.ContainerRequiresAtLeastOneResourceThatIsNotAvailable;
}
if (desiredInstanceCount > this.machineConstraintsPerResource[k].Length)
{
optionalErrorCode = SolverErrorCode.MoreContainerInstancesThanMachinesAvailable;
return(false);
}
}
}
return(true);
}
public SolverResult Solve()
{
double baselineScore = 0, initialStateScore = 0, score = 0;
int iterativeSwappingIterations = 0, fullScanIterations = 0, interContainerIterations = 0;
SolutionQuality result;
SolverErrorCode errorCode = SolverErrorCode.None;
this.stopwatch = Stopwatch.StartNew();
Dictionary <ResourceKind, AllocationMetric[]> initialGuessMetrics = null, solutionMetrics = null;
this.initialState = this.InitializeMatrix();
this.variables = this.InitializeMatrix();
if (this.EnsureSolutionIsViable(ref errorCode))
{
this.ComputeAverageAvailableResource();
if (this.parameters.CurrentAllocations == null)
{
if (this.parameters.InitialRandomGuessIterations > 0)
{
this.variables = this.GenerateSamples(iterations: this.parameters.InitialRandomGuessIterations);
}
else
{
this.variables = this.GenerateInitialAllocation();
}
}
else
{
this.initialState = this.PopulateInitialState();
initialStateScore = ComputeVariance(this.Rows, this.Columns, this.ResourceCount, this.variables, this.containerCoefficientsPerResource, this.machineConstraintsPerResource, this.averageAvailableResource, this.resourceWeight);
this.variables = this.GreedyPlacementOverInitialState(this.initialState);
}
baselineScore = ComputeVariance(this.Rows, this.Columns, this.ResourceCount, this.variables, this.containerCoefficientsPerResource, this.machineConstraintsPerResource, this.averageAvailableResource, this.resourceWeight);
initialGuessMetrics = this.CaptureMetrics();
if (this.parameters.AllowedChurnPercentage.HasValue)
{
int[] currentAllocationsCounts = null;
if (this.parameters.CurrentAllocations?.Length > 0)
{
currentAllocationsCounts = this.GetInitialAllocationCounts();
}
this.maxDeallocationCount = CalculateMaxDeallocationCounts(
this.parameters.AllowedChurnPercentage.Value,
this.desiredContainerInstanceCounts,
currentAllocationsCounts);
}
iterativeSwappingIterations = this.IterativeSwapBestWorstMachinesForContainers(this.parameters.BestWorstSwappingIterations);
fullScanIterations = this.PerformFullScanSwapping(this.parameters.FullScanIterations);
interContainerIterations = this.FullScanSwappingContainers(this.parameters.FullScanSwapContainerIterations);
score = ComputeVariance(this.Rows, this.Columns, this.ResourceCount, this.variables, this.containerCoefficientsPerResource, this.machineConstraintsPerResource, this.averageAvailableResource, this.resourceWeight);
solutionMetrics = this.CaptureMetrics();
bool satisfiesContainerInstanceCount = this.AllContainerInstanceCountSatisfied();
bool satisfiesConstraints = this.AllConstraintsAreSatisfied();
if (satisfiesContainerInstanceCount && satisfiesConstraints)
{
result = SolutionQuality.FoundExact;
}
else if (double.IsNegativeInfinity(score) || double.IsNaN(score))
{
errorCode = SolverErrorCode.AdjustingErrorNegativeInfinityOrNaN;
result = SolutionQuality.Unfeasible;
}
else if (this.hardConstraintResourceIndex.HasValue && !this.AreHardConstraintsSatisfied())
{
errorCode = SolverErrorCode.HardConstraintUnsatisfied;
result = SolutionQuality.Unfeasible;
}
else
{
errorCode = SolverErrorCode.NotEnoughResourcesToAllocateAllInstances;
result = SolutionQuality.Partial;
}
}
else
{
result = SolutionQuality.Unfeasible;
}
this.stopwatch.Stop();
AllocationPlan allocationPlan = this.GetAllocationPlan();
score = ComputeVariance(this.Rows, this.Columns, this.ResourceCount, this.variables, this.containerCoefficientsPerResource, this.machineConstraintsPerResource, this.averageAvailableResource, this.resourceWeight);
return(new SolverResult(
result,
errorCode,
baselineScore,
initialStateScore,
score,
iterativeSwappingIterations,
fullScanIterations,
interContainerIterations,
this.stopwatch.Elapsed,
this.variables,
allocationPlan.Allocations,
allocationPlan.NewAllocations,
allocationPlan.Deallocations,
initialGuessMetrics,
solutionMetrics));
}
