public PoolingProjector(IPassiveEventStore eventStore, T projection, ILogger <T> logger)
{
_eventStore = eventStore;
_projection = projection;
_logger = logger;
EventPageSize = 10;
PoolingTimer = TimeSpan.FromSeconds(2);
}
When_a_subscription_starts_after_zero_checkpoint_and_another_subscription_starts_after_null_checkpoint_while_the_first_subscription_is_loading_the_first_page_from_the_event_store()
{
Given(() =>
{
IPassiveEventStore eventStore = A.Fake <IPassiveEventStore>();
A.CallTo(() => eventStore.GetFrom(A <long?> .Ignored)).ReturnsLazily(call =>
{
long checkpoint = call.GetArgument <long?>(0) ?? 0;
aSubscriptionStartedLoading.Set();
if (!secondSubscriptionCreated.Wait(TimeSpan.FromSeconds(10)))
{
throw new InvalidOperationException("The second subscription has not been created in 10 seconds.");
}
// Give the second subscription enough time to access the cache.
Thread.Sleep(TimeSpan.FromSeconds(1));
return(checkpoint > 0
? new Transaction[0]
: new[] { new TransactionBuilder().WithCheckpoint(1).Build() });
});
var adapter = new PollingEventStoreAdapter(eventStore, 11, pollingInterval, 100, () => DateTime.UtcNow);
WithSubject(_ => adapter.Subscribe);
});
When(() =>
{
Subject(0, new Subscriber
{
HandleTransactions = (transactions, info) => Task.FromResult(0)
}, "firstId");
if (!aSubscriptionStartedLoading.Wait(TimeSpan.FromSeconds(10)))
{
throw new InvalidOperationException("The first subscription has not started loading in 10 seconds.");
}
Subject(null, new Subscriber
{
HandleTransactions = (transactions, info) =>
{
secondSubscriptionReceivedTheTransaction.Set();
return(Task.FromResult(0));
}
}, "secondId");
secondSubscriptionCreated.Set();
});
}
/// <summary>
/// Creates an adapter that observes an implementation of <see cref="IPassiveEventStore"/> and efficiently handles
/// multiple subscribers.
/// </summary>
/// <param name="eventStore">
/// The persistency implementation that the NEventStore is configured with.
/// </param>
/// <param name="cacheSize">
/// The size of the LRU cache that will hold transactions already loaded from the event store. The larger the cache,
/// the higher the chance multiple subscribers can reuse the same transactions without hitting the underlying event store.
/// Set to <c>0</c> to disable the cache alltogether.
/// </param>
/// <param name="pollInterval">
/// The amount of time to wait before polling again after the event store has not yielded any transactions anymore.
/// </param>
/// <param name="maxPageSize">
/// The size of the page of transactions the adapter should load from the event store for every query.
/// </param>
/// <param name="getUtcNow">
/// Provides the current date and time in UTC.
/// </param>
public PollingEventStoreAdapter(IPassiveEventStore eventStore, int cacheSize, TimeSpan pollInterval, int maxPageSize,
Func <DateTime> getUtcNow)
{
this.eventStore = eventStore;
this.pollInterval = pollInterval;
this.maxPageSize = maxPageSize;
this.getUtcNow = getUtcNow;
if (cacheSize > 0)
{
transactionCacheByPreviousCheckpoint = new LruCache <long, Transaction>(cacheSize);
}
}
/// <summary>
/// Creates an adapter that observes an implementation of <see cref="IPassiveEventStore"/> and efficiently handles
/// multiple subscribers.
/// </summary>
/// <param name="eventStore">
/// The persistency implementation that the NEventStore is configured with.
/// </param>
/// <param name="cacheSize">
/// The size of the LRU cache that will hold transactions already loaded from the event store. The larger the cache,
/// the higher the chance multiple subscribers can reuse the same transactions without hitting the underlying event store.
/// Set to <c>0</c> to disable the cache alltogether.
/// </param>
/// <param name="pollInterval">
/// The amount of time to wait before polling again after the event store has not yielded any transactions anymore.
/// </param>
/// <param name="maxPageSize">
/// The size of the page of transactions the adapter should load from the event store for every query.
/// </param>
/// <param name="getUtcNow">
/// Obsolete. Only kept in there to prevent breaking changes.
/// </param>
/// <param name="logger">
/// An optional method for logging internal diagnostic messages as well as any exceptions that happen.
/// </param>
/// <remarks>
/// Diagnostic information is only logged if this code is compiled with the LIQUIDPROJECTIONS_DIAGNOSTICS compiler symbol.
/// </remarks>
public PollingEventStoreAdapter(IPassiveEventStore eventStore, int cacheSize, TimeSpan pollInterval, int maxPageSize,
Func <DateTime> getUtcNow, LogMessage logger = null)
{
this.eventStore = eventStore;
this.pollInterval = pollInterval;
this.maxPageSize = maxPageSize;
#if LIQUIDPROJECTIONS_DIAGNOSTICS
this.logDebug = logger ?? (_ =>
{
});
#else
this.logDebug = _ => {};
#endif
this.logError = logger ?? (_ =>
{
});
if (cacheSize > 0)
{
cachedTransactionsByPrecedingCheckpoint = new LruCache <long, Transaction>(cacheSize);
}
}
