Files
Craftimizer/Solver/Solver.cs
T
2023-10-02 12:16:43 -07:00

572 lines
20 KiB
C#

using Craftimizer.Simulator;
using Craftimizer.Simulator.Actions;
using System.Diagnostics;
using System.Diagnostics.Contracts;
using System.Numerics;
using System.Runtime.CompilerServices;
using System.Text;
using Node = Craftimizer.Solver.ArenaNode<Craftimizer.Solver.SimulationNode>;
namespace Craftimizer.Solver;
// https://github.com/alostsock/crafty/blob/cffbd0cad8bab3cef9f52a3e3d5da4f5e3781842/crafty/src/simulator.rs
public sealed class Solver
{
private SolverConfig config;
private Node rootNode;
private RootScores rootScores;
public float MaxScore => rootScores.MaxScore;
public Solver(SolverConfig config, SimulationState state)
{
this.config = config;
var sim = new Simulator(state, config.MaxStepCount);
rootNode = new(new(
state,
null,
sim.CompletionState,
sim.AvailableActionsHeuristic(config.StrictActions)
));
rootScores = new();
}
private static SimulationNode Execute(Simulator simulator, SimulationState state, ActionType action, bool strict)
{
(_, var newState) = simulator.Execute(state, action);
return new(
newState,
action,
simulator.CompletionState,
simulator.AvailableActionsHeuristic(strict)
);
}
private static Node ExecuteActions(Simulator simulator, Node startNode, ReadOnlySpan<ActionType> actions, bool strict)
{
foreach (var action in actions)
{
var state = startNode.State;
if (state.IsComplete)
return startNode;
if (!state.AvailableActions.HasAction(action))
return startNode;
state.AvailableActions.RemoveAction(action);
startNode = startNode.Add(Execute(simulator, state.State, action, strict));
}
return startNode;
}
[Pure]
private SolverSolution Solution()
{
var actions = new List<ActionType>();
var node = rootNode;
while (node.Children.Count != 0)
{
node = node.ChildAt(ChildMaxScore(ref node.ChildScores))!;
if (node.State.Action != null)
actions.Add(node.State.Action.Value);
}
//var at = node.ChildIdx;
//ref var sum = ref node.ParentScores!.Value.Data[at.arrayIdx].ScoreSum.Span[at.subIdx];
//ref var max = ref node.ParentScores!.Value.Data[at.arrayIdx].MaxScore.Span[at.subIdx];
//ref var visits = ref node.ParentScores!.Value.Data[at.arrayIdx].Visits.Span[at.subIdx];
//Console.WriteLine($"{sum} {max} {visits}");
return new(actions, node.State.State);
}
[Pure]
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static (int arrayIdx, int subIdx) ChildMaxScore(ref NodeScoresBuffer scores)
{
var length = scores.Count;
var vecLength = Vector<float>.Count;
var max = (0, 0);
var maxScore = 0f;
for (var i = 0; length > 0; ++i)
{
var iterCount = Math.Min(vecLength, length);
ref var chunk = ref scores.Data[i];
var m = new Vector<float>(chunk.MaxScore.Span);
var idx = Intrinsics.HMaxIndex(m, iterCount);
if (m[idx] >= maxScore)
{
max = (i, idx);
maxScore = m[idx];
}
length -= iterCount;
}
return max;
}
// Calculates the best child node to explore next
// Exploitation: ((1 - w) * (s / v)) + (w * m)
// Exploration: sqrt(c * ln(V) / v)
// w = maxScoreWeightingConstant
// s = score sum
// m = max score
// v = visits
// V = parentVisits
// c = explorationConstant
// Somewhat based off of https://en.wikipedia.org/wiki/Monte_Carlo_tree_search#Exploration_and_exploitation
// Here, w_i = (1-w)*score sum
// n_i = visits
// max score is tacked onto it
// N_i = parent visits
// c = exploration constant (but crafty places it inside the sqrt..?)
[Pure]
[MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
private (int arrayIdx, int subIdx) EvalBestChild(int parentVisits, ref NodeScoresBuffer scores)
{
var length = scores.Count;
var vecLength = Vector<float>.Count;
var C = MathF.Sqrt(config.ExplorationConstant * MathF.Log(parentVisits));
var w = config.MaxScoreWeightingConstant;
var W = 1f - w;
var CVector = new Vector<float>(C);
var max = (0, 0);
var maxScore = 0f;
for (var i = 0; length > 0; ++i)
{
var iterCount = Math.Min(vecLength, length);
ref var chunk = ref scores.Data[i];
var s = new Vector<float>(chunk.ScoreSum.Span);
var vInt = new Vector<int>(chunk.Visits.Span);
var m = new Vector<float>(chunk.MaxScore.Span);
vInt = Vector.Max(vInt, Vector<int>.One);
var v = Vector.ConvertToSingle(vInt);
var exploitation = W * (s / v) + w * m;
var exploration = CVector * Intrinsics.ReciprocalSqrt(v);
var evalScores = exploitation + exploration;
var idx = Intrinsics.HMaxIndex(evalScores, iterCount);
if (evalScores[idx] >= maxScore)
{
max = (i, idx);
maxScore = evalScores[idx];
}
length -= iterCount;
}
return max;
}
[Pure]
public Node Select()
{
var node = rootNode;
var nodeVisits = rootScores.Visits;
while (true)
{
var expandable = !node.State.AvailableActions.IsEmpty;
var likelyTerminal = node.Children.Count == 0;
if (expandable || likelyTerminal)
return node;
// select the node with the highest score
var at = EvalBestChild(nodeVisits, ref node.ChildScores);
nodeVisits = node.ChildScores.GetVisits(at);
node = node.ChildAt(at)!;
}
}
public (Node ExpandedNode, float Score) ExpandAndRollout(Random random, Simulator simulator, Node initialNode)
{
ref var initialState = ref initialNode.State;
// expand once
if (initialState.IsComplete)
return (initialNode, initialState.CalculateScore(config) ?? 0);
var poppedAction = initialState.AvailableActions.PopRandom(random);
var expandedNode = initialNode.Add(Execute(simulator, initialState.State, poppedAction, true));
// playout to a terminal state
var currentState = expandedNode.State.State;
var currentCompletionState = expandedNode.State.SimulationCompletionState;
var currentActions = expandedNode.State.AvailableActions;
byte actionCount = 0;
Span<ActionType> actions = stackalloc ActionType[Math.Min(config.MaxStepCount - currentState.ActionCount, config.MaxRolloutStepCount)];
while (SimulationNode.GetCompletionState(currentCompletionState, currentActions) == CompletionState.Incomplete &&
actionCount < actions.Length)
{
var nextAction = currentActions.SelectRandom(random);
actions[actionCount++] = nextAction;
(_, currentState) = simulator.Execute(currentState, nextAction);
currentCompletionState = simulator.CompletionState;
if (currentCompletionState != CompletionState.Incomplete)
break;
currentActions = simulator.AvailableActionsHeuristic(true);
}
// store the result if a max score was reached
var score = SimulationNode.CalculateScoreForState(currentState, currentCompletionState, config) ?? 0;
if (currentCompletionState == CompletionState.ProgressComplete)
{
if (score >= config.ScoreStorageThreshold && score >= MaxScore)
{
var terminalNode = ExecuteActions(simulator, expandedNode, actions[..actionCount], true);
return (terminalNode, score);
}
}
return (expandedNode, score);
}
public void Backpropagate(Node startNode, float score)
{
while (true)
{
if (startNode == rootNode)
{
rootScores.Visit(score);
break;
}
startNode.ParentScores!.Value.Visit(startNode.ChildIdx, score);
startNode = startNode.Parent!;
}
}
private void ShowAllNodes()
{
static void ShowNodes(StringBuilder b, Node node, Stack<Node> path)
{
path.Push(node);
b.AppendLine($"{new string(' ', path.Count)}{node.State.Action}");
{
for (var i = 0; i < node.Children.Count; ++i)
{
var n = node.ChildAt((i >> 3, i & 7))!;
ShowNodes(b, n, path);
}
path.Pop();
}
}
var b = new StringBuilder();
ShowNodes(b, rootNode, new());
Console.WriteLine(b.ToString());
}
private bool AllNodesComplete()
{
static bool NodesIncomplete(Node node, Stack<Node> path)
{
path.Push(node);
if (node.Children.Count == 0)
{
if (!node.State.AvailableActions.IsEmpty)
return true;
}
else
{
for (var i = 0; i < node.Children.Count; ++i)
{
var n = node.ChildAt((i >> 3, i & 7))!;
if (NodesIncomplete(n, path))
return true;
}
path.Pop();
}
return false;
}
return !NodesIncomplete(rootNode, new());
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private void Search(int iterations, CancellationToken token)
{
Simulator simulator = new(rootNode.State.State, config.MaxStepCount);
var random = rootNode.State.State.Input.Random;
var n = 0;
for (var i = 0; i < iterations || MaxScore == 0; i++)
{
if (token.IsCancellationRequested)
break;
var selectedNode = Select();
var (endNode, score) = ExpandAndRollout(random, simulator, selectedNode);
if (MaxScore == 0)
{
if (endNode == selectedNode)
{
if (n++ > 5000)
{
n = 0;
if (AllNodesComplete())
{
//Console.WriteLine("All nodes solved for. Can't find a valid solution.");
//ShowAllNodes();
return;
}
}
}
else
n = 0;
}
Backpropagate(endNode, score);
}
}
public static SolverSolution SearchStepwiseFurcated(SolverConfig config, SimulationState state, Action<ActionType>? actionCallback, CancellationToken token)
{
var definiteActionCount = 0;
var bestSims = new List<(float Score, SolverSolution Result)>();
var sim = new Simulator(state, config.MaxStepCount);
var activeStates = new List<SolverSolution>() { new(new(), state) };
while (activeStates.Count != 0)
{
if (token.IsCancellationRequested)
break;
var s = Stopwatch.StartNew();
var tasks = new Task<(float MaxScore, int FurcatedActionIdx, SolverSolution Solution)>[config.ForkCount];
for (var i = 0; i < config.ForkCount; i++)
{
var stateIdx = (int)((float)i / config.ForkCount * activeStates.Count);
var st = activeStates[stateIdx];
tasks[i] = Task.Run(() =>
{
var solver = new Solver(config, activeStates[stateIdx].State);
solver.Search(config.Iterations / config.ForkCount, token);
return (solver.MaxScore, stateIdx, solver.Solution());
}, token);
}
Task.WaitAll(tasks, token);
s.Stop();
if (token.IsCancellationRequested)
break;
var bestActions = tasks.Select(t => t.Result).OrderByDescending(r => r.MaxScore).Take(config.FurcatedActionCount).ToArray();
var bestAction = bestActions[0];
if (bestAction.MaxScore >= config.ScoreStorageThreshold)
{
var (maxScore, furcatedActionIdx, solution) = bestAction;
var (activeActions, activeState) = activeStates[furcatedActionIdx];
activeActions.AddRange(solution.Actions);
return solution with { Actions = activeActions };
}
var newStates = new List<SolverSolution>(config.FurcatedActionCount);
for (var i = 0; i < bestActions.Length; ++i)
{
var (maxScore, furcatedActionIdx, (solutionActions, solutionNode)) = bestActions[i];
if (solutionActions.Count == 0)
continue;
var (activeActions, activeState) = activeStates[furcatedActionIdx];
var chosenAction = solutionActions[0];
var newActions = new List<ActionType>(activeActions) { chosenAction };
var newState = sim.Execute(activeState, chosenAction).NewState;
if (sim.IsComplete)
bestSims.Add((maxScore, new(newActions, newState)));
else
newStates.Add(new(newActions, newState));
}
if (bestSims.Count == 0 && newStates.Count != 0)
{
var definiteCount = definiteActionCount;
var equalCount = int.MaxValue;
var refActions = newStates[0].Actions;
for (var i = 1; i < newStates.Count; ++i)
{
var cmpActions = newStates[i].Actions;
var possibleCount = Math.Min(Math.Min(refActions.Count, cmpActions.Count), equalCount);
var completelyEqual = true;
for (var j = definiteCount; j < possibleCount; ++j)
{
if (refActions[j] != cmpActions[j])
{
equalCount = j;
completelyEqual = false;
break;
}
}
if (completelyEqual)
equalCount = possibleCount;
}
if (definiteCount != equalCount)
{
for (var i = definiteCount; i < equalCount; ++i)
actionCallback?.Invoke(refActions[i]);
definiteActionCount = equalCount;
}
}
activeStates = newStates;
Console.WriteLine($"{s.Elapsed.TotalMilliseconds:0.00}ms {config.Iterations / config.ForkCount / s.Elapsed.TotalSeconds / 1000:0.00} kI/s/t");
}
if (bestSims.Count == 0)
return new(new(), state);
var result = bestSims.MaxBy(s => s.Score).Result;
for (var i = definiteActionCount; i < result.Actions.Count; ++i)
actionCallback?.Invoke(result.Actions[i]);
return result;
}
public static SolverSolution SearchStepwiseForked(SolverConfig config, SimulationState state, Action<ActionType>? actionCallback, CancellationToken token)
{
var actions = new List<ActionType>();
var sim = new Simulator(state, config.MaxStepCount);
while (true)
{
if (token.IsCancellationRequested)
break;
if (sim.IsComplete)
break;
var s = Stopwatch.StartNew();
var tasks = new Task<(float MaxScore, SolverSolution Solution)>[config.ForkCount];
for (var i = 0; i < config.ForkCount; ++i)
tasks[i] = Task.Run(() =>
{
var solver = new Solver(config, state);
solver.Search(config.Iterations / config.ForkCount, token);
return (solver.MaxScore, solver.Solution());
}, token);
Task.WaitAll(tasks, token);
s.Stop();
if (token.IsCancellationRequested)
break;
var (maxScore, solution) = tasks.Select(t => t.Result).MaxBy(r => r.MaxScore);
if (maxScore >= config.ScoreStorageThreshold)
{
actions.AddRange(solution.Actions);
return solution with { Actions = actions };
}
var chosenAction = solution.Actions[0];
actionCallback?.Invoke(chosenAction);
Console.WriteLine($"{s.Elapsed.TotalMilliseconds:0.00}ms {config.Iterations / config.ForkCount / s.Elapsed.TotalSeconds / 1000:0.00} kI/s/t");
(_, state) = sim.Execute(state, chosenAction);
actions.Add(chosenAction);
}
return new(actions, state);
}
public static SolverSolution SearchStepwise(SolverConfig config, SimulationState state, Action<ActionType>? actionCallback, CancellationToken token)
{
var actions = new List<ActionType>();
var sim = new Simulator(state, config.MaxStepCount);
while (true)
{
if (token.IsCancellationRequested)
break;
if (sim.IsComplete)
break;
var solver = new Solver(config, state);
var s = Stopwatch.StartNew();
solver.Search(config.Iterations, token);
s.Stop();
var solution = solver.Solution();
if (solver.MaxScore >= config.ScoreStorageThreshold)
{
actions.AddRange(solution.Actions);
return solution with { Actions = actions };
}
var chosenAction = solution.Actions[0];
actionCallback?.Invoke(chosenAction);
Console.WriteLine($"{s.Elapsed.TotalMilliseconds:0.00}ms {config.Iterations / s.Elapsed.TotalSeconds / 1000:0.00} kI/s");
(_, state) = sim.Execute(state, chosenAction);
actions.Add(chosenAction);
}
return new(actions, state);
}
public static SolverSolution SearchOneshotForked(SolverConfig config, SimulationState state, Action<ActionType>? actionCallback, CancellationToken token)
{
var tasks = new Task<(float MaxScore, SolverSolution Solution)>[config.ForkCount];
for (var i = 0; i < config.ForkCount; ++i)
tasks[i] = Task.Run(() =>
{
var solver = new Solver(config, state);
solver.Search(config.Iterations / config.ForkCount, token);
return (solver.MaxScore, solver.Solution());
}, token);
Task.WaitAll(tasks, CancellationToken.None);
var solution = tasks.Select(t => t.Result).MaxBy(r => r.MaxScore).Solution;
foreach (var action in solution.Actions)
actionCallback?.Invoke(action);
return solution;
}
public static SolverSolution SearchOneshot(SolverConfig config, SimulationState state, Action<ActionType>? actionCallback, CancellationToken token)
{
var solver = new Solver(config, state);
solver.Search(config.Iterations, token);
var solution = solver.Solution();
foreach (var action in solution.Actions)
actionCallback?.Invoke(action);
return solution;
}
public static SolverSolution Search(SolverConfig config, SimulationState state, Action<ActionType>? actionCallback = null, CancellationToken token = default)
{
Func<SolverConfig, SimulationState, Action<ActionType>?, CancellationToken, SolverSolution> func = config.Algorithm switch
{
SolverAlgorithm.Oneshot => SearchOneshot,
SolverAlgorithm.OneshotForked => SearchOneshotForked,
SolverAlgorithm.Stepwise => SearchStepwise,
SolverAlgorithm.StepwiseForked => SearchStepwiseForked,
SolverAlgorithm.StepwiseFurcated or _ => SearchStepwiseFurcated,
};
return func(config, state, actionCallback, token);
}
}