Class CachingCorsPolicyService

Namespace

Fdyay.IdentityServer.Services

Assembly

Fdyay.IdentityServer.Core.dll

Answers from CorsPolicyCache where it can, and from the decorated service otherwise.

public sealed class CachingCorsPolicyService : ICorsPolicyService

Inheritance

object

CachingCorsPolicyService

Implements

ICorsPolicyService

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Remarks

A CORS decision is taken on the preflight and again on the request that follows it, for every cross-origin call an application makes, so a policy service that reads a database is asked far more often than the data it reads changes. This is the decorator that stops that.

It caches a permission, and that has a cost the host is buying deliberately. InMemoryCorsPolicyService excludes disabled clients precisely so a decommissioned client's script stops reaching the protocol endpoints; with this in front of it, it stops reaching them up to one cache duration later. Nothing here is registered unless a host asks for it, the duration is theirs to choose, and Clear() ends the window early.

Constructors

CachingCorsPolicyService(ICorsPolicyService, CorsPolicyCache, TimeProvider, ILogger<CachingCorsPolicyService>)

A cache in front of inner.

public CachingCorsPolicyService(ICorsPolicyService inner, CorsPolicyCache cache, TimeProvider time, ILogger<CachingCorsPolicyService> logger)

Parameters

inner ICorsPolicyService

The policy service asked when an origin is not held.

cache CorsPolicyCache

Where allowed origins are held, and for how long.

time TimeProvider

The clock an entry's expiry is measured by.

logger ILogger<CachingCorsPolicyService>

Where an answer from the cache is logged.

Methods

IsOriginAllowedAsync(string, CancellationToken)

Returns true if the origin is allowed.

public Task<bool> IsOriginAllowedAsync(string origin, CancellationToken cancellationToken = default)

Parameters

origin string

cancellationToken CancellationToken

Returns

Task<bool>

Remarks

True from the cache while the origin is held; otherwise the inner service's answer, held only when it allows.