public void Should_honour_cancellation_even_if_prior_execution_has_cached()
{
const string valueToReturn = "valueToReturn";
const string executionKey = "SomeExecutionKey";
CachePolicy <string> cache = Policy.Cache <string>(new StubCacheProvider(), TimeSpan.MaxValue);
CancellationTokenSource tokenSource = new CancellationTokenSource();
int delegateInvocations = 0;
Func <CancellationToken, string> func = ct =>
{
// delegate does not observe cancellation token; test is whether CacheEngine does.
delegateInvocations++;
return(valueToReturn);
};
cache.Execute(func, new Context(executionKey), tokenSource.Token).Should().Be(valueToReturn);
delegateInvocations.Should().Be(1);
tokenSource.Cancel();
cache.Invoking(policy => policy.Execute(func, new Context(executionKey), tokenSource.Token))
.ShouldThrow <OperationCanceledException>();
delegateInvocations.Should().Be(1);
}
public void Should_honour_cancellation_during_delegate_execution_and_not_put_to_cache()
{
const string valueToReturn = "valueToReturn";
const string executionKey = "SomeExecutionKey";
ISyncCacheProvider stubCacheProvider = new StubCacheProvider();
CachePolicy <string> cache = Policy.Cache <string>(stubCacheProvider, TimeSpan.MaxValue);
CancellationTokenSource tokenSource = new CancellationTokenSource();
Func <CancellationToken, string> func = ct =>
{
tokenSource.Cancel(); // simulate cancellation raised during delegate execution
ct.ThrowIfCancellationRequested();
return(valueToReturn);
};
cache.Invoking(policy => policy.Execute(func, new Context(executionKey), tokenSource.Token))
.ShouldThrow <OperationCanceledException>();
stubCacheProvider.Get(executionKey).Should().BeNull();
}
public void Should_honour_cancellation_during_delegate_execution_and_not_put_to_cache()
{
const string valueToReturn = "valueToReturn";
const string operationKey = "SomeOperationKey";
ISyncCacheProvider stubCacheProvider = new StubCacheProvider();
CachePolicy cache = Policy.Cache(stubCacheProvider, TimeSpan.MaxValue);
CancellationTokenSource tokenSource = new CancellationTokenSource();
Func <Context, CancellationToken, string> func = (ctx, ct) =>
{
tokenSource.Cancel(); // simulate cancellation raised during delegate execution
ct.ThrowIfCancellationRequested();
return(valueToReturn);
};
cache.Invoking(policy => policy.Execute(func, new Context(operationKey), tokenSource.Token))
.ShouldThrow <OperationCanceledException>();
(bool cacheHit, object fromCache) = stubCacheProvider.TryGet(operationKey);
cacheHit.Should().BeFalse();
fromCache.Should().BeNull();
}