Class MongoDBWatcher

Namespace: Cratis.Arc.MongoDB

Assembly: Cratis.Arc.MongoDB.dll

Represents an implementation of IMongoDBWatcher that maintains a single change stream connection per database per process.

[Singleton]
public class MongoDBWatcher : IMongoDBWatcher, IDisposable

Inheritance: object

MongoDBWatcher

Implements: IMongoDBWatcher

IDisposable

Inherited Members: object.GetType()

object.MemberwiseClone()

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

Extension Methods: MethodCalls.CallGenericMethod<TOut, T>(T, Expression<Func<T, Func<TOut>>>, params Type[])

MethodCalls.CallGenericMethod<TOut, T, T1>(T, Expression<Func<T, Func<T1, TOut>>>, T1, params Type[])

MethodCalls.CallGenericMethod<TOut, T, T1, T2>(T, Expression<Func<T, Func<T1, T2, TOut>>>, T1, T2, params Type[])

MethodCalls.CallGenericMethod<TOut, T, T1, T2, T3>(T, Expression<Func<T, Func<T1, T2, T3, TOut>>>, T1, T2, T3, params Type[])

ConverterExtensions.ConvertTo(object, Type)

ConceptExtensions.GetConceptValue(object)

ConceptExtensions.IsConcept(object)

JsonValueExtensions.ToJsonValue(object?)

ObservableExtensions.InvokeAndWrapWithSubject<TResult>(object, Func<CancellationToken, IObservable<TResult>>)

ObservableExtensions.InvokeAndWrapWithTransformSubject<TResult, TSource>(object, Func<CancellationToken, IObservable<TSource>>, Func<TSource, TResult>)

Remarks

The watch is partitioned by the resolved database name so a multi-tenant application — where the name resolver appends the tenant to the database name — gets one change stream per tenant database rather than sharing the first caller's. A single shared watcher that cached one database served every tenant the first tenant's data. With connection resolution the watch is also partitioned by server, since two tenants may resolve to databases of the same name on different servers.

Constructors

MongoDBWatcher(IMongoDBClientFactory, IMongoDatabaseNameResolver, ILogger<MongoDBWatcher>, IMongoDBConnections?)

Represents an implementation of IMongoDBWatcher that maintains a single change stream connection per database per process.

public MongoDBWatcher(IMongoDBClientFactory clientFactory, IMongoDatabaseNameResolver databaseNameResolver, ILogger<MongoDBWatcher> logger, IMongoDBConnections? connections = null)

Parameters

clientFactory IMongoDBClientFactory: The IMongoDBClientFactory for creating MongoDB clients.
databaseNameResolver IMongoDatabaseNameResolver: The IMongoDatabaseNameResolver for resolving the database name.
logger ILogger<MongoDBWatcher>: The logger.
connections IMongoDBConnections: Optional IMongoDBConnections, so watches follow configured connection resolution.

Remarks

Methods

Dispose()

public void Dispose()

GetChanges(string)

Gets the changes of the shared change stream for a database, starting the stream when it is not already open.

public IObservable<ChangeStreamDocument<BsonDocument>> GetChanges(string databaseName)

Parameters

databaseName string: Name of the database whose changes to get.

Returns

IObservable<ChangeStreamDocument<BsonDocument>>: A hot IObservable<T> of every change in the database, across all of its collections.

Remarks

Every subscription to one database shares a single change stream, so subscribing costs no database connection. A subscriber sees only changes that arrive after it subscribed.

Observe<TDocument>(Expression<Func<TDocument, bool>>?)

Start observing a collection using the shared database-level change stream.

public IMongoDBObserveBuilder<TDocument> Observe<TDocument>(Expression<Func<TDocument, bool>>? filter = null)

Parameters

filter Expression<Func<TDocument, bool>>: Optional filter expression for the documents to observe.

Returns

IMongoDBObserveBuilder<TDocument>: A IMongoDBObserveBuilder<TDocument> for chaining joins and finalizing the observation.

Type Parameters

TDocument: Type of document to observe.