Interface ICommittedPositionReader

Namespace

Stratara.Abstractions.CommitOrder

Assembly

Stratara.Abstractions.dll

Reads the event store in commit order, one partition at a time. The promise that distinguishes it from a plain "after sequence number" read: no entry whose position is at or below the Position of a returned batch can still commit later. A reader that keeps that promise can be resumed from a stored position without ever skipping an entry.

public interface ICommittedPositionReader

Extension Methods

FieldChangedEventExtensions.ApplyPropertyChanged<TAggregate>(TAggregate, FieldChangedEvent<TAggregate>)

EventStream.ApplyEvents(object, IReadOnlyList<IEvent>)

Remarks

What a position is depends on the implementation — a sequence number, a per-partition counter, a transaction id — and a stored position is only meaningful to the reader that produced it. A read that orders by sequence number alone does not keep the promise: a transaction can take the lower sequence number and commit after one that took a higher.

Properties

Name

The stable name positions are stored under. It names the ordering the positions belong to and the partition count they were written under, so a checkpoint is refused by a reader of another kind or under another count, and renaming a class changes nothing a checkpoint is keyed on.

string Name { get; }

Property Value

string

Methods

ReadAfterAsync(int, long, int, CancellationToken)

Returns up to batchSize entries of partition that come after afterPosition in commit order, together with the position to resume from.

Task<CommittedBatch> ReadAfterAsync(int partition, long afterPosition, int batchSize, CancellationToken cancellationToken = default)

Parameters

partition int

The partition to read, from 0 to the configured partition count − 1.

afterPosition long

The position returned by the previous batch, or 0 to start from the beginning.

batchSize int

The maximum number of entries to return.

cancellationToken CancellationToken

Propagated to the store.

Returns

Task<CommittedBatch>

The entries in commit order, and the position to store; an empty batch keeps the position it was asked for.