Interface IReducers

Namespace
Cratis.Chronicle.Reducers
Assembly
Cratis.Chronicle.dll

Defines a system for working with reducer registrations for the Kernel.

public interface IReducers
Extension Methods

Methods

Discover()

Discover all reducers from the entry assembly and dependencies.

Task Discover()

Returns

Task

Awaitable task.

FastForward(ReducerId)

Fast forward a specific reducer by its identifier to the tail of the event log, skipping every event it has not yet handled without invoking it.

Task<FastForwardResult> FastForward(ReducerId reducerId)

Parameters

reducerId ReducerId

ReducerId to fast forward.

Returns

Task<FastForwardResult>

The FastForwardResult describing what happened.

FastForward<TReducer>()

Fast forward a reducer to the tail of the event log, skipping every event it has not yet handled without invoking it.

Task<FastForwardResult> FastForward<TReducer>() where TReducer : IReducer

Returns

Task<FastForwardResult>

The FastForwardResult describing what happened.

Type Parameters

TReducer

Type of reducer to fast forward.

GetAllHandlers()

Get all registered handlers.

IEnumerable<IReducerHandler> GetAllHandlers()

Returns

IEnumerable<IReducerHandler>

Collection of IReducerHandler.

GetClrType(ReducerId)

Get the CLR type for a specific reducer.

Type GetClrType(ReducerId reducerId)

Parameters

reducerId ReducerId

ReducerId to get for.

Returns

Type

The type.

GetFailedPartitionsFor(Type)

Get any failed partitions for a specific reducer.

Task<IEnumerable<FailedPartition>> GetFailedPartitionsFor(Type reducerType)

Parameters

reducerType Type

Type of reducer.

Returns

Task<IEnumerable<FailedPartition>>

Collection of FailedPartition, if any.

GetFailedPartitionsFor<TReducer>()

Get any failed partitions for a specific reducer.

Task<IEnumerable<FailedPartition>> GetFailedPartitionsFor<TReducer>() where TReducer : IReducer

Returns

Task<IEnumerable<FailedPartition>>

Collection of FailedPartition, if any.

Type Parameters

TReducer

Type of reducer.

GetHandlerById(ReducerId)

Get all registered reducers by its identifier.

IReducerHandler GetHandlerById(ReducerId reducerId)

Parameters

reducerId ReducerId

The identifier of the reducer to get.

Returns

IReducerHandler

IReducerHandler instance.

GetHandlerFor(Type)

Gets a specific handler by its reducer type.

IReducerHandler GetHandlerFor(Type reducerType)

Parameters

reducerType Type

The reducer type to get for.

Returns

IReducerHandler

IReducerHandler.

GetHandlerForReadModelType(Type)

Get a specific handler for a specific model type.

IReducerHandler GetHandlerForReadModelType(Type readModelType)

Parameters

readModelType Type

Model type to get for.

Returns

IReducerHandler

IReducerHandler instance.

GetHandlerFor<TReducer>()

Get a specific handler for a specific reducer.

IReducerHandler GetHandlerFor<TReducer>() where TReducer : IReducer

Returns

IReducerHandler

IReducerHandler.

Type Parameters

TReducer

Type of reducer to get for.

GetInstanceById(Type, ReadModelKey)

Get a reduced read model instance by key by replaying events in-process.

Task<object?> GetInstanceById(Type readModelType, ReadModelKey readModelKey)

Parameters

readModelType Type

The read model type to get an instance for.

readModelKey ReadModelKey

The read model key to get.

Returns

Task<object>

The reduced read model instance, or null if no events exist for the key.

GetInstances(Type, EventCount?)

Get reduced read model instances by replaying events in-process.

Task<IEnumerable<object>> GetInstances(Type readModelType, EventCount? eventCount = null)

Parameters

readModelType Type

The read model type to get instances for.

eventCount EventCount

Optional limit for number of events to replay from the beginning.

Returns

Task<IEnumerable<object>>

Collection of reduced read model instances.

GetStateFor(Type)

Gets a registered reducer's state.

Task<ReducerState> GetStateFor(Type reducerType)

Parameters

reducerType Type

The reducer CLR type.

Returns

Task<ReducerState>

The reducer state.

Exceptions

TypeBasedArtifactRegistrationNotSupported

The custom registry does not support type-based state lookup.

GetStateFor<TReducer>()

Get the state of a specific reactor.

Task<ReducerState> GetStateFor<TReducer>() where TReducer : IReducer

Returns

Task<ReducerState>

ReducerState.

Type Parameters

TReducer

Type of reactor get for.

HasFor(Type)

Check if there is a reducer for a specific read model type.

bool HasFor(Type readModelType)

Parameters

readModelType Type

The read model type to check for.

Returns

bool

True if it has, false if not.

HasFor<TReadModel>()

Check if there is a reducer for a specific read model type.

bool HasFor<TReadModel>()

Returns

bool

True if it has, false if not.

Type Parameters

TReadModel

The read model type to check for.

HasReducerFor(Type)

Check if there is a reducer for a specific model type.

bool HasReducerFor(Type readModelType)

Parameters

readModelType Type

Model type to check for.

Returns

bool

True if it has, false if not.

Register()

Register all reducers with Chronicle.

Task Register()

Returns

Task

Awaitable task.

Register(Type)

Registers a reducer with its inferred read model.

Task<IReducerHandler> Register(Type reducerType)

Parameters

reducerType Type

The reducer CLR type.

Returns

Task<IReducerHandler>

The registered handler.

Exceptions

TypeBasedArtifactRegistrationNotSupported

The custom registry does not support type-based registration.

Register<TReducer, TReadModel>()

Registers a TReducer reducer with Chronicle.

Task<IReducerHandler> Register<TReducer, TReadModel>() where TReducer : IReducerFor<TReadModel> where TReadModel : class

Returns

Task<IReducerHandler>

Awaitable task.

Type Parameters

TReducer

The reactor type.

TReadModel

The model type the reducer is for.

Replay(ReducerId)

Replay a specific reducer by its identifier.

Task<JobId> Replay(ReducerId reducerId)

Parameters

reducerId ReducerId

ReducerId to replay.

Returns

Task<JobId>

The JobId of the replay job that was started or resumed, or NotSet if the reducer is not replayable or its observer is not in a state it can replay from (disconnected, quarantined); reconnect or release it before replaying.

Replay(Type)

Replays a registered reducer CLR type.

Task<JobId> Replay(Type reducerType)

Parameters

reducerType Type

The reducer CLR type.

Returns

Task<JobId>

The replay job identifier.

Exceptions

TypeBasedArtifactRegistrationNotSupported

The custom registry does not support type-based replay.

Replay<TReducer>()

Replay a specific reducer.

Task<JobId> Replay<TReducer>() where TReducer : IReducer

Returns

Task<JobId>

The JobId of the replay job that was started or resumed, or NotSet if the reducer is not replayable or its observer is not in a state it can replay from (disconnected, quarantined); reconnect or release it before replaying.

Type Parameters

TReducer

Type of reducer to replay.