src/MassTransit.Abstractions/Internals/GraphValidation/DependencyGraph.cs - develop - vshmidt/masstransit

src/MassTransit.Abstractions/Internals/GraphValidation/DependencyGraph.cs

78 строк2 KB

Chris Patterson

Adding multiple framework support for net461, netstandard2.0, netstandard2.1, and net6.0 where appropriate

07 май 2022, 04:26

07 май 2022, 04:2671bb847

namespace MassTransit.Internals.GraphValidation
{
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;


    public class DependencyGraph<T>
        where T : notnull
    {
        readonly AdjacencyList<T, DependencyGraphNode<T>> _adjacencyList;

        public DependencyGraph(int capacity)
        {
            _adjacencyList = new AdjacencyList<T, DependencyGraphNode<T>>(DefaultNodeFactory, capacity);
        }

        static DependencyGraphNode<T> DefaultNodeFactory(int index, T value)
        {
            return new DependencyGraphNode<T>(index, value);
        }

        public void Add(T source)
        {
            _adjacencyList.GetNode(source);
        }

        public void Add(T source, T target)
        {
            _adjacencyList.AddEdge(source, target, 0);
        }

        public void Add(T source, IEnumerable<T> targets)
        {
            foreach (var target in targets)
                _adjacencyList.AddEdge(source, target, 0);
        }

        public IEnumerable<T> GetItemsInOrder()
        {
            var sort = new TopologicalSort<T, DependencyGraphNode<T>>(_adjacencyList);

            return sort.Result.Select(x => x.Value);
        }

        public IEnumerable<T> GetItemsInOrder(T source)
        {
            var sort = new TopologicalSort<T, DependencyGraphNode<T>>(_adjacencyList, source);

            return sort.Result.Select(x => x.Value);
        }

        public void EnsureGraphIsAcyclic()
        {
            var tarjan = new Tarjan<T, DependencyGraphNode<T>>(_adjacencyList);

            if (tarjan.Result.Count == 0)
                return;

            var message = new StringBuilder();
            foreach (IList<DependencyGraphNode<T>> cycle in tarjan.Result)
            {
                message.Append("(");
                for (var i = 0; i < cycle.Count; i++)
                {
                    if (i > 0)
                        message.Append(",");

                    message.Append(cycle[i].Value);
                }

                message.Append(")");
            }

            throw new CyclicGraphException("The dependency graph contains cycles: " + message);
        }
    }
}