public void Create_CreatesCandidateSet(int count)
{
// Arrange
var endpoints = new RouteEndpoint[count];
for (var i = 0; i < endpoints.Length; i++)
{
endpoints[i] = CreateEndpoint($"/{i}");
}
var builder = CreateDfaMatcherBuilder();
var candidates = builder.CreateCandidates(endpoints);
// Act
var candidateSet = new CandidateSet(candidates);
// Assert
for (var i = 0; i < candidateSet.Count; i++)
{
ref var state = ref candidateSet[i];
Assert.True(candidateSet.IsValidCandidate(i));
Assert.Same(endpoints[i], state.Endpoint);
Assert.Equal(candidates[i].Score, state.Score);
Assert.Null(state.Values);
candidateSet.SetValidity(i, false);
Assert.False(candidateSet.IsValidCandidate(i));
}
public override Task SelectAsync(
ProtoContext httpContext,
EndpointSelectorContext context,
CandidateSet candidateSet)
{
if (httpContext == null)
{
throw new ArgumentNullException(nameof(httpContext));
}
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
if (candidateSet == null)
{
throw new ArgumentNullException(nameof(candidateSet));
}
// Fast path: We can specialize for trivial numbers of candidates since there can
// be no ambiguities
switch (candidateSet.Count)
{
case 0:
{
// Do nothing
break;
}
case 1:
{
if (candidateSet.IsValidCandidate(0))
{
ref var state = ref candidateSet[0];
context.Endpoint = state.Endpoint;
context.RouteValues = state.Values;
}
break;
}
public Task ApplyAsync(ProtoContext httpContext, EndpointSelectorContext context, CandidateSet candidates)
{
throw new NotImplementedException();
}
public sealed override Task MatchAsync(ProtoContext httpContext, EndpointSelectorContext context)
{
if (httpContext == null)
{
throw new ArgumentNullException(nameof(httpContext));
}
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
// All of the logging we do here is at level debug, so we can get away with doing a single check.
var log = _logger.IsEnabled(LogLevel.Debug);
// The sequence of actions we take is optimized to avoid doing expensive work
// like creating substrings, creating route value dictionaries, and calling
// into policies like versioning.
var path = httpContext.Request.Path.Value;
// First tokenize the path into series of segments.
Span <PathSegment> buffer = stackalloc PathSegment[_maxSegmentCount];
var count = FastPathTokenizer.Tokenize(path, buffer);
var segments = buffer.Slice(0, count);
// FindCandidateSet will process the DFA and return a candidate set. This does
// some preliminary matching of the URL (mostly the literal segments).
var(candidates, policies) = FindCandidateSet(httpContext, path, segments);
if (candidates.Length == 0)
{
if (log)
{
Logger.CandidatesNotFound(_logger, path);
}
return(Task.CompletedTask);
}
if (log)
{
Logger.CandidatesFound(_logger, path, candidates);
}
// At this point we have a candidate set, defined as a list of endpoints in
// priority order.
//
// We don't yet know that any candidate can be considered a match, because
// we haven't processed things like route constraints and complex segments.
//
// Now we'll iterate each endpoint to capture route values, process constraints,
// and process complex segments.
// `candidates` has all of our internal state that we use to process the
// set of endpoints before we call the EndpointSelector.
//
// `candidateSet` is the mutable state that we pass to the EndpointSelector.
var candidateSet = new CandidateSet(candidates);
for (var i = 0; i < candidates.Length; i++)
{
// PERF: using ref here to avoid copying around big structs.
//
// Reminder!
// candidate: readonly data about the endpoint and how to match
// state: mutable storarge for our processing
ref var candidate = ref candidates[i];
ref var state = ref candidateSet[i];
/// <summary>
/// Asynchronously selects an <see cref="Endpoint"/> from the <see cref="CandidateSet"/>.
/// </summary>
/// <param name="httpContext">The <see cref="ProtoContext"/> associated with the current request.</param>
/// <param name="context">The <see cref="EndpointSelectorContext"/> associated with the current request.</param>
/// <param name="candidates">The <see cref="CandidateSet"/>.</param>
/// <returns>A <see cref="Task"/> that completes asynchronously once endpoint selection is complete.</returns>
/// <remarks>
/// An <see cref="EndpointSelector"/> should assign the <see cref="EndpointSelectorContext.Endpoint"/>
/// and <see cref="EndpointSelectorContext.RouteValues"/> properties once an endpoint is selected.
/// </remarks>
public abstract Task SelectAsync(
ProtoContext httpContext,
EndpointSelectorContext context,
CandidateSet candidates);
