blvm-node 0.1.90

//! WASM module loader trait.
//!
//! blvm-node defines this interface. Implementations (e.g. from blvm-sdk) are
//! injected by the binary/compositor. blvm-node does not depend on blvm-sdk.

use std::collections::HashMap;
use std::path::Path;
use std::sync::Arc;

use crate::module::ipc::protocol::{CliSpec, InvocationResultPayload};
use crate::module::traits::{EventType, ModuleError};

/// Sync host callback for `host_node_call`. JSON method name and JSON args in; JSON text out.
pub type WasmHostNodeCall =
    std::sync::Arc<dyn Fn(&str, &str) -> Result<String, String> + Send + Sync>;

/// Opaque handle to a loaded WASM module instance.
/// blvm-node stores this; the concrete type comes from the loader implementation.
pub trait WasmModuleInstance: Send + Sync {
    /// Invoke a CLI subcommand (sync; host calls into module).
    fn invoke_cli(
        &self,
        subcommand: &str,
        args: Vec<String>,
    ) -> Result<InvocationResultPayload, ModuleError>;

    /// Invoke an RPC method (sync; host calls into module).
    fn invoke_rpc(
        &self,
        method: &str,
        params: serde_json::Value,
    ) -> Result<serde_json::Value, ModuleError>;

    /// Get CLI spec (for getmoduleclispecs). Returns None if not available.
    fn cli_spec(&self) -> Option<CliSpec>;

    /// Event names this guest subscribes to (`event_types` export, JSON array of `EventType` names).
    fn event_types(&self) -> Result<Vec<EventType>, ModuleError>;

    /// Deliver one JSON `ModuleMessage` to `on_event`. Returns the guest string (empty or an error).
    fn on_event(&self, event_json: &str) -> Result<String, ModuleError>;

    /// Last string returned by [`Self::on_event`], if a call has completed.
    fn last_on_event_result(&self) -> Option<String>;

    /// Install the `host_node_call` callback. The node sets this after permissions are registered.
    fn set_host_node_call(&self, call: WasmHostNodeCall);
}

/// Loads WASM modules from path with storage and config.
/// Implemented by blvm-sdk; injected into blvm-node by the binary (e.g. blvm).
pub trait WasmModuleLoader: Send + Sync {
    fn load(
        &self,
        path: &Path,
        data_dir: &Path,
        config: HashMap<String, String>,
    ) -> Result<Arc<dyn WasmModuleInstance>, String>;
}