Database.EventStore

Event

data Event

Contains event information like its type and data. Only used for write queries.

Instances

Eq Event

Show Event

data EventData

Holds event data.

Instances

Eq EventData

Show EventData

createEvent

Arguments

:: Text

Event type

-> Maybe UUID

Event ID, generated if Nothing

-> EventData

Event data

-> Event

withJson :: Value -> EventData

Creates a event using JSON format

withJsonAndMetadata :: Value -> Value -> EventData

Create a event with metadata using JSON format

Connection

data Connection

Represents a connection to a single EventStore node.

data ConnectionException

Constructors

MaxAttempt HostName Int Int

HostName Port MaxAttempt's value

Instances

Show ConnectionException

Exception ConnectionException

Typeable * ConnectionException

data Credentials

Holds login and password information.

Instances

Eq Credentials

Show Credentials

data Settings

Global Connection settings

Constructors

Settings

Fields

s_heartbeatInterval :: NominalDiffTime

s_heartbeatTimeout :: NominalDiffTime

s_requireMaster :: Bool

s_credentials :: Maybe Credentials

s_retry :: Retry

s_reconnect_delay_secs :: Int

In seconds

s_logger :: Maybe (Log -> IO ())

data Retry

Represents reconnection strategy.

atMost :: Int -> Retry

Indicates how many times we should try to reconnect to the server. A value less than or equal to 0 means no retry.

keepRetrying :: Retry

Indicates we should try to reconnect to the server until the end of the Universe.

credentials

Arguments

:: ByteString

Login

-> ByteString

Password

-> Credentials

defaultSettings :: Settings

Default global settings.

connect

Arguments

:: Settings

-> String

HostName

-> Int

Port

-> IO Connection

Creates a new Connection to a single node. It maintains a full duplex connection to the EventStore. An EventStore Connection operates quite differently than say a SQL connection. Normally when you use a SQL connection you want to keep the connection open for a much longer of time than when you use a SQL connection.

Another difference is that with the EventStore Connection all operation are handled in a full async manner (even if you call the synchronous behaviors). Many threads can use an EvenStore Connection at the same time or a single thread can make many asynchronous requests. To get the most performance out of the connection it is generally recommend to use it in this way.

shutdown :: Connection -> IO ()

Asynchronously closes the Connection.

Read Operations

data StreamMetadataResult

Represents stream metadata as a series of properties for system data and a StreamMetadata object for user metadata.

Constructors

StreamMetadataResult

Fields

streamMetaResultStream :: !Text

The name of the stream.

streamMetaResultVersion :: !Int32

The version of the metadata format.

streamMetaResultData :: !StreamMetadata

A StreamMetadata containing user-specified metadata.

NotFoundStreamMetadataResult

When the stream is either not found or 'no stream'.

Fields

streamMetaResultStream :: !Text

The name of the stream.

DeletedStreamMetadataResult

When the stream is soft-deleted.

Fields

streamMetaResultStream :: !Text

The name of the stream.

Instances

Show StreamMetadataResult

readEvent

Arguments

:: Connection

-> Text

Stream name

-> Int32

Event number

-> Bool

Resolve Link Tos

-> IO (Async ReadResult)

Reads a single event from given stream.

readAllEventsBackward

Arguments

:: Connection

-> Position

-> Int32

Batch size

-> Bool

Resolve Link Tos

-> IO (Async AllEventsSlice)

Reads events from the $all stream backward

readAllEventsForward

Arguments

:: Connection

-> Position

-> Int32

Batch size

-> Bool

Resolve Link Tos

-> IO (Async AllEventsSlice)

Reads events from the $all stream forward.

readStreamEventsBackward

Arguments

:: Connection

-> Text

Stream name

-> Int32

From event number

-> Int32

Batch size

-> Bool

Resolve Link Tos

-> IO (Async StreamEventsSlice)

Reads events from a given stream backward.

readStreamEventsForward

Arguments

:: Connection

-> Text

Stream name

-> Int32

From event number

-> Int32

Batch size

-> Bool

Resolve Link Tos

-> IO (Async StreamEventsSlice)

Reads events from a given stream forward.

getStreamMetadata :: Connection -> Text -> IO (Async StreamMetadataResult)

Asynchronously gets the metadata of a stream.

Write Operations

data StreamACL

Represents an access control list for a stream.

Constructors

StreamACL

Fields

streamACLReadRoles :: ![Text]

Roles and users permitted to read the stream.

streamACLWriteRoles :: ![Text]

Roles and users permitted to write to the stream.

streamACLDeleteRoles :: ![Text]

Roles and users permitted to delete to the stream.

streamACLMetaReadRoles :: ![Text]

Roles and users permitted to read stream metadata.

streamACLMetaWriteRoles :: ![Text]

Roles and users permitted to write stream metadata.

Instances

Show StreamACL

data StreamMetadata

Represents stream metadata with strongly typed properties for system values and a dictionary-like interface for custom values.

Constructors

StreamMetadata

Fields

streamMetadataMaxCount :: !(Maybe Int32)

The maximum number of events allowed in the stream.

streamMetadataMaxAge :: !(Maybe TimeSpan)

The maximum age of events allowed in the stream.

streamMetadataTruncateBefore :: !(Maybe Int32)

The event number from which previous events can be scavenged. This is used to implement soft-deletion of streams.

streamMetadataCacheControl :: !(Maybe TimeSpan)

The amount of time for which the stream head is cachable.

streamMetadataACL :: !StreamACL

The access control list for the stream.

streamMetadataCustom :: !Object

An enumerable of key-value pairs of keys to JSON text for user-provider metadata.

Instances

Show StreamMetadata

FromJSON StreamMetadata

streamMetadataGetCustomPropertyValue :: StreamMetadata -> Text -> Maybe Value

Gets a custom property value from metadata.

streamMetadataGetCustomProperty :: FromJSON a => StreamMetadata -> Text -> Maybe a

Get a custom property value from metadata.

emptyStreamACL :: StreamACL

StreamACL with no role or users whatsoever.

emptyStreamMetadata :: StreamMetadata

StreamMetadata with everything set to Nothing, using emptyStreamACL and an empty Object.

deleteStream

Arguments

:: Connection

-> Text

Stream name

-> ExpectedVersion

-> Maybe Bool

Hard delete

-> IO (Async DeleteResult)

Deletes given stream.

sendEvent

Arguments

:: Connection

-> Text

Stream name

-> ExpectedVersion

-> Event

-> IO (Async WriteResult)

Sends a single Event to given stream.

sendEvents

Arguments

:: Connection

-> Text

Stream name

-> ExpectedVersion

-> [Event]

-> IO (Async WriteResult)

Sends a list of Event to given stream.

setStreamMetadata :: Connection -> Text -> ExpectedVersion -> StreamMetadata -> IO (Async WriteResult)

Asynchronously sets the metadata for a stream.

Builder

type Builder a = Endo a

Stream ACL Builder

type StreamACLBuilder = Builder StreamACL

buildStreamACL :: StreamACLBuilder -> StreamACL

Builds a StreamACL from a StreamACLBuilder.

modifyStreamACL :: StreamACLBuilder -> StreamACL -> StreamACL

Modifies a StreamACL using a StreamACLBuilder.

setReadRoles :: [Text] -> StreamACLBuilder

Sets role names with read permission for the stream.

setReadRole :: Text -> StreamACLBuilder

Sets a single role name with read permission for the stream.

setWriteRoles :: [Text] -> StreamACLBuilder

Sets role names with write permission for the stream.

setWriteRole :: Text -> StreamACLBuilder

Sets a single role name with write permission for the stream.

setDeleteRoles :: [Text] -> StreamACLBuilder

Sets role names with delete permission for the stream.

setDeleteRole :: Text -> StreamACLBuilder

Sets a single role name with delete permission for the stream.

setMetaReadRoles :: [Text] -> StreamACLBuilder

Sets role names with metadata read permission for the stream.

setMetaReadRole :: Text -> StreamACLBuilder

Sets a single role name with metadata read permission for the stream.

setMetaWriteRoles :: [Text] -> StreamACLBuilder

Sets role names with metadata write permission for the stream.

setMetaWriteRole :: Text -> StreamACLBuilder

Sets a single role name with metadata write permission for the stream.

Stream Metadata Builder

type StreamMetadataBuilder = Builder StreamMetadata

buildStreamMetadata :: StreamMetadataBuilder -> StreamMetadata

Builds a StreamMetadata from a StreamMetadataBuilder.

modifyStreamMetadata :: StreamMetadataBuilder -> StreamMetadata -> StreamMetadata

Modifies a StreamMetadata using a StreamMetadataBuilder

setMaxCount :: Int32 -> StreamMetadataBuilder

Sets the maximum number of events allowed in the stream.

setMaxAge :: TimeSpan -> StreamMetadataBuilder

Sets the maximum age of events allowed in the stream.

setTruncateBefore :: Int32 -> StreamMetadataBuilder

Sets the event number from which previous events can be scavenged.

setCacheControl :: TimeSpan -> StreamMetadataBuilder

Sets the amount of time for which the stream head is cachable.

setACL :: StreamACL -> StreamMetadataBuilder

modifyACL :: StreamACLBuilder -> StreamMetadataBuilder

setCustomProperty :: ToJSON a => Text -> a -> StreamMetadataBuilder

Sets a custom metadata property.

TimeSpan

data TimeSpan

.NET TimeSpan: TimeSpan represents a duration of time. A TimeSpan can be negative or positive. Sorry

Instances

Eq TimeSpan

Ord TimeSpan

Show TimeSpan

ToJSON TimeSpan

FromJSON TimeSpan

timeSpanTicks :: Int64 -> TimeSpan

timeSpanHoursMinsSecs :: Int64 -> Int64 -> Int64 -> TimeSpan

timeSpanDaysHoursMinsSecs :: Int64 -> Int64 -> Int64 -> Int64 -> TimeSpan

timeSpanDaysHoursMinsSecsMillis :: Int64 -> Int64 -> Int64 -> Int64 -> Int64 -> TimeSpan

timeSpanGetTicks :: TimeSpan -> Int64

timeSpanGetDays :: TimeSpan -> Int64

timeSpanGetHours :: TimeSpan -> Int64

timeSpanGetMinutes :: TimeSpan -> Int64

timeSpanGetSeconds :: TimeSpan -> Int64

timeSpanGetMillis :: TimeSpan -> Int64

timeSpanFromSeconds :: Double -> TimeSpan

timeSpanFromMinutes :: Double -> TimeSpan

timeSpanFromHours :: Double -> TimeSpan

timeSpanFromDays :: Double -> TimeSpan

timeSpanTotalMillis :: TimeSpan -> Int64

Transaction

data Transaction

Represents a multi-request transaction with the EventStore.

transactionStart

Arguments

:: Connection

-> Text

Stream name

-> ExpectedVersion

-> IO (Async Transaction)

Starts a transaction on given stream.

transactionCommit :: Transaction -> IO (Async WriteResult)

Asynchronously commits this transaction.

transactionRollback :: Transaction -> IO ()

Rollback this transaction.

transactionSendEvents :: Transaction -> [Event] -> IO (Async ())

Asynchronously writes to a transaction in the EventStore.

Volatile Subscription

data DropReason

Represents the reason subscription drop happened.

Constructors

D_Unsubscribed

D_AccessDenied

D_NotFound

D_PersistentSubscriptionDeleted

Instances

Enum DropReason

Eq DropReason

Show DropReason

class Identifiable a

Represents a subscription that is directly identifiable. Regular and Persistent fit that description while Catchup doesn't. Because Catchup reads all events from a particular checkpoint and when it's finished, it issues a subscription request.

Instances

Identifiable Persistent

Identifiable Regular

data Subscription a

Represents a subscription to a stream.

type family NextEvent a :: *

Value's type returned when calling subNextEvent

Equations

NextEvent Regular = Either DropReason ResolvedEvent

NextEvent Persistent = Either DropReason ResolvedEvent

NextEvent Catchup = Either CatchupError ResolvedEvent

data Regular

Represents a subscription to a single stream or $all stream in the EventStore.

Instances

Identifiable Regular

data Catchup

Represents catch-up subscription.

data Persistent

Represents a persistent subscription.

Instances

Identifiable Persistent

subscribe

Arguments

:: Connection

-> Text

Stream name

-> Bool

Resolve Link Tos

-> IO (Async (Subscription Regular))

Subcribes to given stream.

subscribeToAll

Arguments

:: Connection

-> Bool

Resolve Link Tos

-> IO (Async (Subscription Regular))

Subcribes to $all stream.

subNextEvent :: Subscription a -> IO (NextEvent a)

Awaits for the next event.

subId :: Identifiable a => Subscription a -> UUID

Gets the ID of the subscription.

subStreamId :: Subscription a -> Text

The name of the stream to which the subscription is subscribed.

subIsSubscribedToAll :: Subscription a -> Bool

True if this subscription is to $all stream.

subResolveLinkTos :: Subscription Regular -> Bool

Determines whether or not any link events encontered in the stream will be resolved.

subLastCommitPos :: Identifiable a => Subscription a -> Int64

The last commit position seen on the subscription (if this a subscription to $all stream).

subLastEventNumber :: Identifiable a => Subscription a -> Maybe Int32

The last event number seen on the subscription (if this is a subscription to a single stream).

subUnsubscribe :: Subscription a -> IO ()

Asynchronously unsubscribe from the the stream.

Catch-up Subscription

data CatchupError

Errors that could arise during a catch-up subscription. Text value represents the stream name.

Constructors

CatchupStreamDeleted Text

CatchupUnexpectedStreamStatus Text ReadStreamResult

CatchupSubscriptionDropReason Text DropReason

Instances

Show CatchupError

Exception CatchupError

Typeable * CatchupError

subscribeFrom

Arguments

:: Connection

-> Text

Stream name

-> Bool

Resolve Link Tos

-> Maybe Int32

Last checkpoint

-> Maybe Int32

Batch size

-> IO (Subscription Catchup)

Subscribes to given stream. If last checkpoint is defined, this will readStreamEventsForward from that event number, otherwise from the beginning. Once last stream event reached up, a subscription request will be sent using subscribe.

subscribeToAllFrom

Arguments

:: Connection

-> Bool

Resolve Link Tos

-> Maybe Position

Last checkpoint

-> Maybe Int32

Batch size

-> IO (Subscription Catchup)

Same as subscribeFrom but applied to $all stream.

waitTillCatchup :: Subscription Catchup -> IO ()

Waits until Catchup subscription catch-up its stream.

hasCaughtUp :: Subscription Catchup -> IO Bool

Non blocking version of waitTillCatchup.

Persistent Subscription

data PersistentSubscriptionSettings

Constructors

PersistentSubscriptionSettings

Fields

psSettingsResolveLinkTos :: !Bool

Whether or not the persistent subscription should resolve linkTo events to their linked events.

psSettingsStartFrom :: !Int32

Where the subscription should start from (position).

psSettingsExtraStats :: !Bool

Whether or not in depth latency statistics should be tracked on this subscription.

psSettingsMsgTimeout :: !TimeSpan

The amount of time after which a message should be considered to be timeout and retried.

psSettingsMaxRetryCount :: !Int32

The maximum number of retries (due to timeout) before a message get considered to be parked.

psSettingsLiveBufSize :: !Int32

The size of the buffer listening to live messages as they happen.

psSettingsReadBatchSize :: !Int32

The number of events read at a time when paging in history.

psSettingsHistoryBufSize :: !Int32

The number of events to cache when paging through history.

psSettingsCheckPointAfter :: !TimeSpan

The amount of time to try checkpoint after.

psSettingsMinCheckPointCount :: !Int32

The minimum number of messages to checkpoint.

psSettingsMaxCheckPointCount :: !Int32

The maximum number of message to checkpoint. If this number is reached, a checkpoint will be forced.

psSettingsMaxSubsCount :: !Int32

The maximum number of subscribers allowed.

psSettingsNamedConsumerStrategy :: !SystemConsumerStrategy

The strategy to use for distributing events to client consumers.

Instances

Eq PersistentSubscriptionSettings

Show PersistentSubscriptionSettings

data SystemConsumerStrategy

System supported consumer strategies for use with persistent subscriptions.

Constructors

DispatchToSingle

Distributes events to a single client until it is full. Then round robin to the next client.

RoundRobin

Distribute events to each client in a round robin fashion.

Instances

Eq SystemConsumerStrategy

Show SystemConsumerStrategy

data NakAction

Constructors

NA_Unknown

NA_Park

NA_Retry

NA_Skip

NA_Stop

Instances

Enum NakAction

Eq NakAction

Show NakAction

notifyEventsProcessed :: Subscription Persistent -> [UUID] -> IO ()

Acknowledges those event ids have been successfully processed.

notifyEventsFailed :: Subscription Persistent -> NakAction -> Maybe Text -> [UUID] -> IO ()

Acknowledges those event ids have failed to be processed successfully.

defaultPersistentSubscriptionSettings :: PersistentSubscriptionSettings

System default persistent subscription settings.

createPersistentSubscription :: Connection -> Text -> Text -> PersistentSubscriptionSettings -> IO (Async ())

Asynchronously create a persistent subscription group on a stream.

updatePersistentSubscription :: Connection -> Text -> Text -> PersistentSubscriptionSettings -> IO (Async ())

Asynchronously update a persistent subscription group on a stream.

deletePersistentSubscription :: Connection -> Text -> Text -> IO (Async ())

Asynchronously delete a persistent subscription group on a stream.

connectToPersistentSubscription :: Connection -> Text -> Text -> Int32 -> IO (Async (Subscription Persistent))

Asynchronously connect to a persistent subscription given a group on a stream.

Results

data AllEventsSlice

The result of a read operation from the $all stream.

Constructors

AllEventsSlice

Fields

allEventsSliceResult :: !ReadAllResult

Representing the status of the read attempt.

allEventsSliceFrom :: !Position

Representing the position where the next slice should be read from.

allEventsSliceNext :: !Position

Representing the position where the next slice should be read from.

allEventsSliceIsEOS :: !Bool

Representing whether or not this is the end of the $all stream.

allEventsSliceEvents :: ![ResolvedEvent]

The events read.

allEventsSliceDirection :: !ReadDirection

The direction of read request.

Instances

Show AllEventsSlice

newtype DeleteResult

Returned after deleting a stream. Position of the write.

Constructors

DeleteResult

Fields

deleteStreamPosition :: Position

Instances

Eq DeleteResult

Show DeleteResult

data WriteResult

Returned after writing to a stream.

Constructors

WriteResult

Fields

writeNextExpectedVersion :: !Int32

Next expected version of the stream.

writePosition :: !Position

Position of the write.

Instances

Eq WriteResult

Show WriteResult

data ReadResult

Result of a single event read operation to the EventStore.

Constructors

ReadResult

Fields

readResultStatus :: !ReadEventResult

Attempt status

readResultStreamId :: !Text

Stream name

readResultEventNumber :: !Int32

Event number

readResultResolvedEvent :: !(Maybe ResolvedEvent)

Instances

Show ReadResult

data RecordedEvent

Represents a previously written event.

Constructors

RecordedEvent

Fields

recordedEventStreamId :: !Text

The event stream that this event belongs to.

recordedEventId :: !UUID

Unique identifier representing this event.

recordedEventNumber :: !Int32

Number of this event in the stream.

recordedEventType :: !Text

Type of this event.

recordedEventData :: !ByteString

Representing the data of this event.

recordedEventMetadata :: !(Maybe ByteString)

Representing the metadada associated with this event.

recordedEventIsJson :: !Bool

Indicates whether the content is internally marked as json.

recordedEventCreated :: !(Maybe UTCTime)

Representing when this event was created in the system.

Instances

Show RecordedEvent

data StreamEventsSlice

Represents the result of a single read operation to the EventStore.

Constructors

StreamEventsSlice

Fields

streamEventsSliceResult :: !ReadStreamResult

Representing the status of the read attempt.

streamEventsSliceStreamId :: !Text

The name of the stream read.

streamEventsSliceStart :: !Int32

The starting point (represented as a sequence number) of the read operation.

streamEventsSliceNext :: !Int32

The next event number that can be read.

streamEventsSliceLast :: !Int32

The last event number in the stream.

streamEventsSliceIsEOS :: !Bool

Representing whether or not this is the end of the stream.

streamEventsSliceEvents :: ![ResolvedEvent]

The events read represented as ResolvedEvent

streamEventsSliceDirection :: !ReadDirection

The direction of the read request.

Instances

Show StreamEventsSlice

data Position

A structure referring to a potential logical record position in the EventStore transaction file.

Constructors

Position

Fields

positionCommit :: !Int64

Commit position of the record

positionPrepare :: !Int64

Prepare position of the record

Instances

Eq Position

Show Position

data ReadDirection

Represents the direction of read operation (both from $all an usual streams).

Constructors

Forward

From beginning to end

Backward

From end to beginning

Instances

Eq ReadDirection

Show ReadDirection

data ReadAllResult

Enumeration detailing the possible outcomes of reading a slice of $all stream.

Constructors

RA_SUCCESS

RA_NOT_MODIFIED

RA_ERROR

RA_ACCESS_DENIED

Instances

Enum ReadAllResult

Eq ReadAllResult

Show ReadAllResult

data ReadEventResult

Enumeration representing the status of a single event read operation.

Constructors

RE_SUCCESS

RE_NOT_FOUND

RE_NO_STREAM

RE_STREAM_DELETED

RE_ERROR

RE_ACCESS_DENIED

Instances

Enum ReadEventResult

Eq ReadEventResult

Show ReadEventResult

data ResolvedEvent

A structure representing a single event or an resolved link event.

Constructors

ResolvedEvent

Fields

resolvedEventRecord :: !(Maybe RecordedEvent)

The event, or the resolved link event if this ResolvedEvent is a link event.

resolvedEventLink :: !(Maybe RecordedEvent)

The link event if this ResolvedEvent is a link event.

Instances

Show ResolvedEvent

data ReadStreamResult

Enumeration detailing the possible outcomes of reading a slice of a stream

Constructors

RS_SUCCESS

RS_NO_STREAM

RS_STREAM_DELETED

RS_NOT_MODIFIED

RS_ERROR

RS_ACCESS_DENIED

Instances

Enum ReadStreamResult

Eq ReadStreamResult

Show ReadStreamResult

data OperationException

Constructors

WrongExpectedVersion Text ExpectedVersion

Stream and Expected Version

StreamDeleted Text

Stream

InvalidTransaction

AccessDenied Text

Stream

InvalidServerResponse Word8 Word8

Expected, Found

ProtobufDecodingError String

ServerError (Maybe Text)

Reason

InvalidOperation Text

Instances

Show OperationException

Exception OperationException

Typeable * OperationException

eventResolved :: ResolvedEvent -> Bool

Indicates whether this ResolvedEvent is a resolved link event.

resolvedEventOriginal :: ResolvedEvent -> Maybe RecordedEvent

Returns the event that was read or which triggered the subscription.

If this ResolvedEvent represents a link event, the link will be the original event, otherwise it will be the event.

resolvedEventOriginalStreamId :: ResolvedEvent -> Maybe Text

The stream name of the original event.

resolvedEventOriginalId :: ResolvedEvent -> Maybe UUID

The ID of the original event.

positionStart :: Position

Representing the start of the transaction file.

positionEnd :: Position

Representing the end of the transaction file.

Misc

data ExpectedVersion

Constants used for expected version control.

The use of expected version can be a bit tricky especially when discussing idempotency assurances given by the EventStore.

The EventStore will assure idempotency for all operations using any value in ExpectedVersion except for anyStream. When using anyStream the EventStore will do its best to assure idempotency but will not guarantee idempotency.

Instances

Eq ExpectedVersion

Show ExpectedVersion

anyStream :: ExpectedVersion

This write should not conflict with anything and should always succeed.

noStream :: ExpectedVersion

The stream being written to should not yet exist. If it does exist treat that as a concurrency problem.

emptyStream :: ExpectedVersion

The stream should exist and should be empty. If it does not exist or is not empty, treat that as a concurrency problem.

exactStream :: Int32 -> ExpectedVersion

States that the last event written to the stream should have a sequence number matching your expected value.

Re-export

module Control.Concurrent.Async

(<>) :: Monoid m => m -> m -> m infixr 6

An infix synonym for mappend.

Since: 4.5.0.0