golem-rust 2.0.0-dev.6

Golem Rust tooling library that facilitates writing Golem backends in Rust
Documentation 
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// Copyright 2024-2026 Golem Cloud
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use crate::await_promise;
use crate::bindings::golem::api::host::PromiseId;
use serde::Serialize;
use serde::de::DeserializeOwned;

/// Awaits a promise blocking the execution of the agent. The agent is going to be
/// suspended until the promise is completed.
///
/// The completed promise's payload is decoded as JSON.
///
/// Use `await_promise_json` for an async version of this function, allowing to interleave
/// awaiting of the promise with other operations.
pub fn blocking_await_promise_json<T: DeserializeOwned>(
    promise_id: &PromiseId,
) -> Result<T, serde_json::Error> {
    let promise = crate::bindings::golem::api::host::get_promise(promise_id);
    promise.subscribe().block();
    let bytes = promise.get().unwrap();
    serde_json::from_slice(&bytes)
}

/// Awaits a promise.
///
/// The completed promise's payload is decoded as JSON.
///
/// If only promises or timeouts are awaited simultaneously, the agent is going to be
/// suspended until any of them completes.
pub async fn await_promise_json<T: DeserializeOwned>(
    promise_id: &PromiseId,
) -> Result<T, serde_json::Error> {
    let bytes = await_promise(promise_id).await;
    serde_json::from_slice(&bytes)
}

/// Completes a promise with a JSON payload
pub fn complete_promise_json<T: Serialize>(
    promise_id: &PromiseId,
    value: T,
) -> Result<bool, serde_json::Error> {
    let bytes = serde_json::to_vec(&value)?;
    Ok(crate::bindings::golem::api::host::complete_promise(
        promise_id, &bytes,
    ))
}