public void BatchingTopologicalSort_throws_with_formatted_message_when_cycle_cannot_be_broken()
{
const string message = "Formatted cycle";
var vertexOne = new Vertex {
Id = 1
};
var vertexTwo = new Vertex {
Id = 2
};
var vertexThree = new Vertex {
Id = 3
};
var edgeOne = new Edge {
Id = 1
};
var edgeTwo = new Edge {
Id = 2
};
var edgeThree = new Edge {
Id = 3
};
var graph = new Multigraph <Vertex, Edge>();
graph.AddVertices(new[] { vertexOne, vertexTwo, vertexThree });
// 1 -> {2}
graph.AddEdge(vertexOne, vertexTwo, edgeOne);
// 2 -> {3}
graph.AddEdge(vertexTwo, vertexThree, edgeTwo);
// 3 -> {1}
graph.AddEdge(vertexThree, vertexOne, edgeThree);
Dictionary <Vertex, Tuple <Vertex, Vertex, IEnumerable <Edge> > > cycleData = null;
Func <IEnumerable <Tuple <Vertex, Vertex, IEnumerable <Edge> > >, string> formatter = data =>
{
cycleData = data.ToDictionary(entry => entry.Item1);
return(message);
};
Assert.Equal(
Strings.CircularDependency(message),
Assert.Throws <InvalidOperationException>(() => graph.BatchingTopologicalSort(formatter)).Message);
Assert.Equal(3, cycleData.Count());
Assert.Equal(vertexTwo, cycleData[vertexOne].Item2);
Assert.Equal(new[] { edgeOne }, cycleData[vertexOne].Item3);
Assert.Equal(vertexThree, cycleData[vertexTwo].Item2);
Assert.Equal(new[] { edgeTwo }, cycleData[vertexTwo].Item3);
Assert.Equal(vertexOne, cycleData[vertexThree].Item2);
Assert.Equal(new[] { edgeThree }, cycleData[vertexThree].Item3);
}
private static IEnumerable <IEntityType> Sort(IEnumerable <IEntityType> entityTypes)
{
var entityTypeGraph = new Multigraph <IEntityType, int>();
entityTypeGraph.AddVertices(entityTypes);
foreach (var entityType in entityTypes.Where(et => et.BaseType != null))
{
entityTypeGraph.AddEdge(entityType.BaseType !, entityType, 0);
}
return(entityTypeGraph.BatchingTopologicalSort().SelectMany(b => b.OrderBy(et => et.Name)));
}
// To avoid violating store constraints the modification commands must be sorted
// according to these rules:
//
// 1. Commands adding rows or modifying the candidate key values (when supported) must precede
// commands adding or modifying rows that will be referencing the former
// 2. Commands deleting rows or modifying the foreign key values must precede
// commands deleting rows or modifying the candidate key values (when supported) of rows
// that are currently being referenced by the former
// 3. Commands deleting rows or modifying the foreign key values must precede
// commands adding or modifying the foreign key values to the same values
// if foreign key is unique
/// <summary>
/// This is an internal API that supports the Entity Framework Core infrastructure and not subject to
/// the same compatibility standards as public APIs. It may be changed or removed without notice in
/// any release. You should only use it directly in your code with extreme caution and knowing that
/// doing so can result in application failures when updating to a new Entity Framework Core release.
/// </summary>
protected virtual IReadOnlyList <List <ModificationCommand> > TopologicalSort([NotNull] IEnumerable <ModificationCommand> commands)
{
var modificationCommandGraph = new Multigraph <ModificationCommand, IAnnotatable>();
modificationCommandGraph.AddVertices(commands);
// The predecessors map allows to populate the graph in linear time
var predecessorsMap = CreateKeyValuePredecessorMap(modificationCommandGraph);
AddForeignKeyEdges(modificationCommandGraph, predecessorsMap);
AddUniqueValueEdges(modificationCommandGraph);
return(modificationCommandGraph.BatchingTopologicalSort(FormatCycle));
}
// To avoid violating store constraints the modification commands must be sorted
// according to these rules:
//
// 1. Commands adding rows or modifying the candidate key values (when supported) must precede
// commands adding or modifying rows that will be referencing the former
// 2. Commands deleting rows or modifying the foreign key values must precede
// commands deleting rows or modifying the candidate key values (when supported) of rows
// that are currently being referenced by the former
// 3. Commands deleting rows or modifying the foreign key values must precede
// commands adding or modifying the foreign key values to the same values
// if foreign key is unique
protected virtual IReadOnlyList <List <ModificationCommand> > TopologicalSort([NotNull] IEnumerable <ModificationCommand> commands)
{
var modificationCommandGraph = new Multigraph <ModificationCommand, IForeignKey>();
modificationCommandGraph.AddVertices(commands);
// The predecessors map allows to populate the graph in linear time
var predecessorsMap = CreateKeyValuePredecessorMap(modificationCommandGraph);
AddForeignKeyEdges(modificationCommandGraph, predecessorsMap);
var sortedCommands
= modificationCommandGraph.BatchingTopologicalSort(data => { return(string.Join(", ", data.Select(d => d.Item3.First()))); });
return(sortedCommands);
}
// To avoid violating store constraints the modification commands must be sorted
// according to these rules:
//
// 1. Commands adding rows or modifying the candidate key values (when supported) must precede
// commands adding or modifying rows that will be referencing the former
// 2. Commands deleting rows or modifying the foreign key values must precede
// commands deleting rows or modifying the candidate key values (when supported) of rows
// that are currently being referenced by the former
// 3. Commands deleting rows or modifying the foreign key values must precede
// commands adding or modifying the foreign key values to the same values
// if foreign key is unique
/// <summary>
/// This API supports the Entity Framework Core infrastructure and is not intended to be used
/// directly from your code. This API may change or be removed in future releases.
/// </summary>
protected virtual IReadOnlyList<List<ModificationCommand>> TopologicalSort([NotNull] IEnumerable<ModificationCommand> commands)
{
var modificationCommandGraph = new Multigraph<ModificationCommand, IForeignKey>();
modificationCommandGraph.AddVertices(commands);
// The predecessors map allows to populate the graph in linear time
var predecessorsMap = CreateKeyValuePredecessorMap(modificationCommandGraph);
AddForeignKeyEdges(modificationCommandGraph, predecessorsMap);
var sortedCommands
= modificationCommandGraph.BatchingTopologicalSort(data => { return string.Join(", ", data.Select(d => d.Item3.First())); });
return sortedCommands;
}
