BMInvoke¶
BMInvoke is the primary Remote Procedure Call (RPC) object in BM. It encapsulates a method call, an optional callback method for the return value, and the list of arguments to be passed to the remote function.
Whenever the client or host executes a remote command (such as registry.register or setCookie), it is packaged inside a BMInvoke object.
- Class ID: 4
Wire Format¶
After the object envelope, a BMInvoke contains the following fields in order:
| # | Field | Type | Description |
|---|---|---|---|
| 1 | id |
i32 | A sequential, incrementing ID identifying this specific invocation. Used for mapping return values back to the caller. |
| 2 | method |
UTF | The name of the remote method to execute (e.g., "registry.register" or "onHostConnected"). |
| 3 | returnMethod |
UTF | The callback method to execute on the remote device with the result. If no callback is expected, this is sent as an empty string (""). |
| 4 | argsLength |
i32 | The number of arguments being passed to the method. If there are no arguments, this is 0. |
| 5 | arguments |
object | If argsLength > 0, this is followed by exactly argsLength serialized objects. |
Total minimum size¶
Without any arguments: 5 (envelope) + 4 + 2 + 2 + 4 = 17 bytes
(assuming empty method and returnMethod).
Argument Serialization¶
The arguments in the arguments sequence are written using the standard object serialization mechanism.
Because the arguments are inherently dynamically typed in the protocol, BM wraps each argument in a BMParameter (Class ID 3). Therefore, if argsLength is greater than 0, you will typically see the standard object envelope (@) followed by the BMParameter class ID for each argument sequentially.