caf_sharing/proxy_sharing

A proxy to access Shared Maps from application code.

Source:

proxy_sharing.js, line 20

Extends

external:caf_components/gen_proxy

Members

$

Source:

proxy_sharing.js, line 205

A context containing proxies to all the visible Shared Maps for this CA.

Application code refers to these maps using aliases:

 this.$.sharing.$.myMap

and this is typically shortened as follows:

 const $$ = this.$.sharing.$
 $$.myMap.set('x', $$.myMap.get('y') + 1)

Methods

addReadOnlyMap(alias, name, optionsopt)

Source:

proxy_sharing.js, line 83

Creates a read-only mirror of a Shared Map or an Aggregate Map.

The Shared Map will be active before this CA processes another message.

The consistency model is monotonic read consistency: local replicas could be stale, but once we see a Shared Map version, we will never see previous ones.

Type of caf_map.options is {isAggregate: boolean}

Parameters:

Name	Type	Attributes	Description
`alias`	string		A short name that identifies this map in the `this.$.sharing.$` context.
`name`	string		A fully qualified name for the source of this Shared Map, i.e., scoped with the owner's CA name, like `caOwner-caLocalName-mapLocalName`.
`options`	mapOptionsType	<optional>	If `options.isAggregate` is `true` create an `AggregateMap`. If `options.bestEffort` is `true`, ignore errors when we cannot create a replica. In that case the map is set to `null`, and the client could retry adding it again later on. If `options.noExec` is true, it throws when calling `applyMethod()`.

addWritableMap(alias, name, optionsopt)

Source:

proxy_sharing.js, line 52

Creates, or reloads if already created, a writable Shared Map.

The map will be active before this CA processes another message.

Parameters:

Name	Type	Attributes	Description
`alias`	string		A short name that identifies this map in the `this.$.sharing.$` context.
`name`	string		A relative name for this map that will be scoped by this CA's name.
`options`	mapOptionsType	<optional>	With field `initialValue`, an optional initial value for the map. Note that this value is ignored if the map was already initialized.

applyDelta(alias, changes, loggeropt)

Source:

proxy_sharing.js, line 148

Applies a change set to a writable map, needed to replicate external Shared Maps.

Parameters:

Name	Type	Attributes	Description
`alias`	string		The local alias for this map.
`changes`	mapUpdateType		A set of changes to apply.
`logger`	Object	<optional>	An optional logger, i.e., `this.$.log`, to warn of ignored updates.

Throws:

Error when the change set version is not compatible.

deleteMap(alias)

Source:

proxy_sharing.js, line 98

Deletes a local reference to a Shared Map.

The contents of the map are not destroyed from persistent storage.

Parameters:

Name	Type	Description
`alias`	string	The local alias for this map.

fullName(name) → {string}

Source:

proxy_sharing.js, line 184

Gets the full name of a local writable Shared Map.

Maps are named after the CA that owns them, i.e., a complete name is caOwner-caLocalName-mapLocalName.

Parameters:

Name	Type	Description
`name`	string	A relative name for a Shared Map.

Returns:

A complete name for the Shared Map.

Type: string

pullUpdate(alias, versionopt) → {mapUpdateType|Array.<mapUpdateType>}

Source:

proxy_sharing.js, line 123

Returns an incremental update or a full dump of the Shared Map.

The type of mapUpdateType is {version: number, remove : Array<string>, add : Array<string|Object>} where add just flattens key/value pairs in a single array.

Multiple incremental updates can be provided in an array of mapUpdateType objects.

An up to date local replica will have an empty array as update.

Parameters:

Name	Type	Attributes	Description
`alias`	string		The local alias for this map.
`version`	number	<optional>	The current version of the local Shared Map, or `undefined` if a full dump is needed.

Returns:

A full dump of the map or a list with incremental updates (empty if up to date).

Type: mapUpdateType | Array.<mapUpdateType>