Safe Haskell	None

IHP.DataSync.ChangeNotifications

Synopsis

channelName :: TableWithRLS -> ByteString
data ChangeNotification
- = DidInsert {
  - id :: !UUID
  }
- | DidUpdate {
  - id :: !UUID
  - changeSet :: !ChangeSet
  }
- | DidUpdateLarge {
  - id :: !UUID
  - payloadId :: !UUID
  }
- | DidDelete {
  - id :: !UUID
  }
data Change = Change {
- col :: !Text
- new :: !Value
}
data ChangeSet
- = InlineChangeSet {
  - changeSet :: ![Change]
  }
- | ExternalChangeSet {
  - largePgNotificationId :: !UUID
  }
createNotificationFunction :: TableWithRLS -> Query
installTableChangeTriggers :: (?modelContext :: ModelContext) => TableWithRLS -> IO ()
makeCachedInstallTableChangeTriggers :: (?modelContext :: ModelContext) => IO (TableWithRLS -> IO ())
retrieveChanges :: (?modelContext :: ModelContext) => ChangeSet -> IO [Change]

Documentation

channelName :: TableWithRLS -> ByteString Source #

Returns the event name of the event that the pg notify trigger dispatches

data ChangeNotification Source #

Constructors

DidInsert
Fields id :: !UUID
DidUpdate
Fields id :: !UUID changeSet :: !ChangeSet
DidUpdateLarge
Fields id :: !UUID payloadId :: !UUID
DidDelete
Fields id :: !UUID

Instances

Instances details

FromJSON ChangeNotification Source #
Instance details Defined in IHP.DataSync.ChangeNotifications Methods parseJSON :: Value -> Parser ChangeNotification # parseJSONList :: Value -> Parser [ChangeNotification] # omittedField :: Maybe ChangeNotification #
ToJSON ChangeNotification Source #
Instance details Defined in IHP.DataSync.ChangeNotifications Methods toJSON :: ChangeNotification -> Value # toEncoding :: ChangeNotification -> Encoding # toJSONList :: [ChangeNotification] -> Value # toEncodingList :: [ChangeNotification] -> Encoding # omitField :: ChangeNotification -> Bool #
Show ChangeNotification Source #
Instance details Defined in IHP.DataSync.ChangeNotifications Methods showsPrec :: Int -> ChangeNotification -> ShowS # show :: ChangeNotification -> String showList :: [ChangeNotification] -> ShowS #
Eq ChangeNotification Source #
Instance details Defined in IHP.DataSync.ChangeNotifications Methods (==) :: ChangeNotification -> ChangeNotification -> Bool # (/=) :: ChangeNotification -> ChangeNotification -> Bool #

data Change Source #

Constructors

Change
Fields col :: !Text new :: !Value

Instances

Instances details

FromJSON Change Source #
Instance details Defined in IHP.DataSync.ChangeNotifications Methods parseJSON :: Value -> Parser Change # parseJSONList :: Value -> Parser [Change] # omittedField :: Maybe Change #
ToJSON Change Source #
Instance details Defined in IHP.DataSync.ChangeNotifications Methods toJSON :: Change -> Value # toEncoding :: Change -> Encoding # toJSONList :: [Change] -> Value # toEncodingList :: [Change] -> Encoding # omitField :: Change -> Bool #
Show Change Source #
Instance details Defined in IHP.DataSync.ChangeNotifications Methods showsPrec :: Int -> Change -> ShowS # show :: Change -> String showList :: [Change] -> ShowS #
Eq Change Source #
Instance details Defined in IHP.DataSync.ChangeNotifications Methods (==) :: Change -> Change -> Bool # (/=) :: Change -> Change -> Bool #

data ChangeSet Source #

Constructors

InlineChangeSet
Fields changeSet :: ![Change]
ExternalChangeSet	When the patch fits into the 8000 bytes limit of `pg_notify`
Fields largePgNotificationId :: !UUID

Instances

Instances details

FromJSON ChangeSet Source #
Instance details Defined in IHP.DataSync.ChangeNotifications Methods parseJSON :: Value -> Parser ChangeSet # parseJSONList :: Value -> Parser [ChangeSet] # omittedField :: Maybe ChangeSet #
ToJSON ChangeSet Source #
Instance details Defined in IHP.DataSync.ChangeNotifications Methods toJSON :: ChangeSet -> Value # toEncoding :: ChangeSet -> Encoding # toJSONList :: [ChangeSet] -> Value # toEncodingList :: [ChangeSet] -> Encoding # omitField :: ChangeSet -> Bool #
Show ChangeSet Source #
Instance details Defined in IHP.DataSync.ChangeNotifications Methods showsPrec :: Int -> ChangeSet -> ShowS # show :: ChangeSet -> String showList :: [ChangeSet] -> ShowS #
Eq ChangeSet Source #	The patch is over 8000 bytes, so we have stored it in the `large_pg_notifications` table
Instance details Defined in IHP.DataSync.ChangeNotifications Methods (==) :: ChangeSet -> ChangeSet -> Bool # (/=) :: ChangeSet -> ChangeSet -> Bool #

createNotificationFunction :: TableWithRLS -> Query Source #

Returns the sql code to set up a database trigger. Mainly used by watchInsertOrUpdateTable.

installTableChangeTriggers :: (?modelContext :: ModelContext) => TableWithRLS -> IO () Source #

makeCachedInstallTableChangeTriggers :: (?modelContext :: ModelContext) => IO (TableWithRLS -> IO ()) Source #

retrieveChanges :: (?modelContext :: ModelContext) => ChangeSet -> IO [Change] Source #

The pg_notify function has a payload limit of 8000 bytes. When a record update is larger than the payload size we store the patch in the large_pg_notifications table and pass over the id to the patch.

This function retrieves the patch from the large_pg_notifications table, or directly returns the patch when it's less than 8000 bytes.