public async Task GetOrAddAsyncWithImmediateExpirationAndCallbackInTheDelegateDoesExpireItemsAndFireTheCallback()
{
var millisecondsCacheDuration = 1000;
var callbackHasFired = false;
var validResult = await sut.GetOrAddAsync(
TestKey,
entry =>
{
return(Task.FromResult(new ComplexTestObject()));
}, LazyCacheEntryOptions
.WithImmediateAbsoluteExpiration(TimeSpan.FromMilliseconds(millisecondsCacheDuration))
.RegisterPostEvictionCallback((key, value, reason, state) => callbackHasFired = true));
// trigger expiry
Thread.Sleep(TimeSpan.FromMilliseconds(millisecondsCacheDuration + 1000));
Assert.That(validResult, Is.Not.Null);
Assert.That(callbackHasFired, Is.True);
}
public async Task AutoRefresh()
{
var key = "someKey";
var refreshInterval = TimeSpan.FromSeconds(1);
var timesGenerated = 0;
// this is the Func what we are caching
ComplexTestObject GetStuff()
{
timesGenerated++;
return(new ComplexTestObject());
}
// this sets up options that will recreate the entry on eviction
MemoryCacheEntryOptions GetOptions()
{
var options = new LazyCacheEntryOptions()
.SetAbsoluteExpiration(refreshInterval, ExpirationMode.ImmediateEviction);
options.RegisterPostEvictionCallback((keyEvicted, value, reason, state) =>
{
if (reason == EvictionReason.Expired || reason == EvictionReason.TokenExpired)
{
sut.GetOrAdd(key, _ => GetStuff(), GetOptions());
}
});
return(options);
}
for (var i = 0; i < 3; i++)
{
var thing = sut.GetOrAdd(key, () => GetStuff(), GetOptions());
Assert.That(thing, Is.Not.Null);
await Task.Delay(2 *refreshInterval);
}
// refreshed every second in 6 seconds so generated 6 times
// even though we only fetched it every other second which would be 3 times
Assert.That(timesGenerated, Is.EqualTo(6));
}
