SharedDispatch

SharedDispatch

The SharedDispatch class is responsible for dispatch features shared by CentralDispatch and WorkerDispatch.

Constructor

new SharedDispatch()

Members

callbacks :Array.<Array.<function()>>

List of callback registrations for promises waiting for a response from a call to a service on another worker. A callback registration is an array of [resolve,reject] Promise functions. Calls to local services don't enter this list.

Type:
  • Array.<Array.<function()>>

nextResponseId :int

The next response ID to be used.

Type:
  • int

Methods

(protected) _deliverResponse(responseId, message)

Deliver call response from a worker. This should only be called as the result of a message from a worker.

Parameters:
Name Type Description
responseId int

the response ID of the callback set to call.
message DispatchResponseMessage

the message containing the response value(s).

(abstract, protected) _getServiceProvider(service) → {Object}

Fetch the service provider object for a particular service name.

Parameters:
Name Type Description
service string

the name of the service to look up
Returns:
  • the means to contact the service, if found
Type
Object

(private) _isRemoteService(service) → {boolean}

Check if a particular service lives on another worker.

Parameters:
Name Type Description
service string

the service to check.
Returns:
  • true if the service is remote (calls must cross a Worker boundary), false otherwise.
Type
boolean

(abstract, private) _onDispatchMessage(worker, message) → {Promise|undefined}

Handle a call message sent to the dispatch service itself

Parameters:
Name Type Description
worker Worker

the worker which sent the message.
message DispatchCallMessage

the message to be handled.
Returns:
  • a promise for the results of this operation, if appropriate
Type
Promise | undefined

(protected) _onMessage(worker, event)

Handle a message event received from a connected worker.

Parameters:
Name Type Description
worker Worker

the worker which sent the message, or the global object if running in a worker.
event MessageEvent

the message event to be handled.

_remoteCall(provider, service, method, …argsopt) → {Promise}

Like call, but force the call to be posted through a particular communication channel.

Parameters:
Name Type Attributes Description
provider object

send the call through this object's postMessage function.
service string

the name of the service.
method string

the name of the method.
args * <optional>
<repeatable>

the arguments to be copied to the method, if any.
Returns:
  • a promise for the return value of the service method.
Type
Promise

_remoteTransferCall(provider, service, method, transferopt, …argsopt) → {Promise}

Like transferCall, but force the call to be posted through a particular communication channel.

Parameters:
Name Type Attributes Description
provider object

send the call through this object's postMessage function.
service string

the name of the service.
method string

the name of the method.
transfer Array <optional>

objects to be transferred instead of copied. Must be present in args to be useful.
args * <optional>
<repeatable>

the arguments to be copied to the method, if any.
Returns:
  • a promise for the return value of the service method.
Type
Promise

(protected) _storeCallbacks(resolve, reject) → {*}

Store callback functions pending a response message.

Parameters:
Name Type Description
resolve function

function to call if the service method returns.
reject function

function to call if the service method throws.
Returns:
  • a unique response ID for this set of callbacks. See _deliverResponse.
Type
*

call(service, method, …argsopt) → {Promise}

Call a particular method on a particular service, regardless of whether that service is provided locally or on a worker. If the service is provided by a worker, the args will be copied using the Structured Clone algorithm, except for any items which are also in the transfer list. Ownership of those items will be transferred to the worker, and they should not be used after this call.

Example
dispatcher.call('vm', 'setData', 'cat', 42);
     // this finds the worker for the 'vm' service, then on that worker calls:
     vm.setData('cat', 42);
Parameters:
Name Type Attributes Description
service string

the name of the service.
method string

the name of the method.
args * <optional>
<repeatable>

the arguments to be copied to the method, if any.
Returns:
  • a promise for the return value of the service method.
Type
Promise

transferCall(service, method, transferopt, …argsopt) → {Promise}

Call a particular method on a particular service, regardless of whether that service is provided locally or on a worker. If the service is provided by a worker, the args will be copied using the Structured Clone algorithm, except for any items which are also in the transfer list. Ownership of those items will be transferred to the worker, and they should not be used after this call.

Example
dispatcher.transferCall('vm', 'setData', [myArrayBuffer], 'cat', myArrayBuffer);
     // this finds the worker for the 'vm' service, transfers `myArrayBuffer` to it, then on that worker calls:
     vm.setData('cat', myArrayBuffer);
Parameters:
Name Type Attributes Description
service string

the name of the service.
method string

the name of the method.
transfer Array <optional>

objects to be transferred instead of copied. Must be present in args to be useful.
args * <optional>
<repeatable>

the arguments to be copied to the method, if any.
Returns:
  • a promise for the return value of the service method.
Type
Promise