Class ConcurrencyOptions

Namespace

Cratis.Chronicle.EventSequences.Concurrency

Assembly

Cratis.Chronicle.dll

Represents options for configuring concurrency strategies.

public class ConcurrencyOptions

Inheritance

object

ConcurrencyOptions

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>)

Constructors

ConcurrencyOptions()

public ConcurrencyOptions()

Fields

CheckFirstAppendIntoAScopeByDefault

The value CheckFirstAppendIntoAScope takes when nothing configures it.

public const bool CheckFirstAppendIntoAScopeByDefault = false

Field Value

bool

Remarks

False keeps the behavior every released version has had: the first append into a narrowed scope is not checked. It is scheduled to become true in the next major version, and flipping this one value is the whole change - OptimisticConcurrencyStrategy and the options property both read it, so nothing else has to move.

Properties

AllowRouteScopeStreamMismatch

Gets or sets a value indicating whether a definition-linked explicit scope may guard a different stream than a single-route append.

public bool AllowRouteScopeStreamMismatch { get; set; }

Property Value

bool

Remarks

False by default. Labelled independent conditions are not subject to this check.

CheckFirstAppendIntoAScope

Gets or sets a value indicating whether the first append into a concurrency scope is checked.

public bool CheckFirstAppendIntoAScope { get; set; }

Property Value

bool

Remarks

A concurrency check needs something to compare against, and OptimisticConcurrencyStrategy gets it by reading the tail through the scope's own narrowing. When nothing matches that narrowing yet there is no tail to read. With this false - the default, and what every released version does - the scope carries no expectation and the kernel skips the check, so the first append into each scope goes through unchecked. That is the append most exposed to a race, because it opens a new narrowed partition on a stream other writers are already using.

With this true the strategy says what a first append actually expects - that no event matching the narrowing exists - and the kernel checks it, rejecting the append with a concurrency violation if one appeared in the meantime. Turning it on will reject appends that succeed with it off, which is why it is opt-in rather than the default. It is scheduled to become the default in the next major version.

This governs the strategy. A single append can ask for the same check without turning this on, by building a scope with ExpectingNoMatchingEvent().

DefaultStrategy

Gets or sets the default concurrency strategy to use when no specific strategy is provided.

public Type DefaultStrategy { get; set; }

Property Value

Type

SkipIncompleteExplicitScopes

Gets or sets a value indicating whether incomplete caller-supplied scopes retain the legacy unchecked behavior.

public bool SkipIncompleteExplicitScopes { get; set; }

Property Value

bool

Remarks

False by default. Incomplete narrowed explicit scopes otherwise expect no matching event.