WebAssembly runtime

parcel_runtime::wasm is available with the wasm feature, enabled by default. For building a module and writing its manifest, see Custom functions.

install

pub fn install(
    module_bytes: &[u8],
    manifest: &FunctionManifest,
    owner: &str,
) -> Result<FunctionEntry, String>;

Parameter	Meaning
module_bytes	Compiled WebAssembly module bytes.
manifest	Function name, version, signature, and execution properties.
owner	Identifier of the owner whose contracts may call the function.

Loads and verifies the module, makes its implementation available to CEL and DataFusion, and returns the entry to insert into the compilation registry. Invalid modules, unsupported interfaces, or failed test batches return an error string.

For existing module_bytes and a parsed manifest:

let entry = parcel_runtime::wasm::install(&module_bytes, &manifest, "acme")?;
let mut registry = parcel_core::Registry::builtin();
registry.insert(entry);

WasmFunction

The only public field is entry: FunctionEntry, the function’s verified metadata.

impl WasmFunction {
    pub fn load(module_bytes: &[u8], entry: FunctionEntry) -> Result<WasmFunction, String>;
    pub fn call(&self, args: &[ArrayRef], rows: usize) -> Result<ArrayRef, String>;
    pub fn call_values(&self, args: &[cel::Value]) -> Result<cel::Value, String>;
}

Method	Arguments and result
load	Verifies module bytes against the owned entry and creates a callable instance.
call	Executes ordered Arrow argument arrays for rows rows and returns the output array.
call_values	Executes one ordered set of CEL arguments and returns a CEL value.

Calls can fail on argument mismatches, module execution errors, or resource limits. install is the higher-level entry point when preparing functions for contract compilation.

verify_pins

This function is at the parcel_runtime crate root:

pub fn verify_pins<'a>(
    pins: impl IntoIterator<Item = &'a FunctionPin>,
) -> Result<(), String>;

Checks that the runtime has the exact function implementations referenced by the supplied pins. Returns Ok(()) when all are available; otherwise returns the missing or mismatched function in an error message. Load custom implementations before checking their pins.