Crate napi_h

source ·
Expand description

High level Node.js N-API binding

napi-rs provides minimal overhead to write N-API modules in Rust.

§Feature flags

§napi1 ~ napi8

Because Node.js N-API has versions. So there are feature flags to choose what version of N-API you want to build for. For example, if you want build a library which can be used by node@10.17.0, you should choose the napi5 or lower.

The details of N-API versions and support matrix: n_api_version_matrix

§tokio_rt

With tokio_rt feature, napi-rs provides a tokio runtime in an additional thread. And you can easily run tokio future in it and return promise.

use futures::prelude::*;
use napi::{CallContext, Error, JsObject, JsString, Result, Status};
use tokio;

#[napi]
pub async fn tokio_readfile(js_filepath: String) -> Result<JsBuffer> {
    ctx.env.execute_tokio_future(
        tokio::fs::read(js_filepath)
          .map(|v| v.map_err(|e| Error::new(Status::Unknown, format!("failed to read file, {}", e)))),
        |&mut env, data| env.create_buffer_with_data(data),
    )
}

§latin1

Decode latin1 string from JavaScript using encoding_rs.

With this feature, you can use JsString.as_latin1_string function

§serde-json

Enable Serialize/Deserialize data cross JavaScript Object and Rust struct.

#[derive(Serialize, Debug, Deserialize)]
struct AnObject {
    a: u32,
    b: Vec<f64>,
    c: String,
}

#[napi]
fn deserialize_from_js(arg0: JsUnknown) -> Result<JsUndefined> {
    let de_serialized: AnObject = ctx.env.from_js_value(arg0)?;
    ...
}

#[napi]
fn serialize(env: Env) -> Result<JsUnknown> {
    let value = AnyObject { a: 1, b: vec![0.1, 2.22], c: "hello" };
    env.to_js_value(&value)
}

Re-exports§

Modules§

Structs§

Enums§

Traits§

Functions§

  • This function could be used for create_buffer_with_borrowed_data and want do noting when Buffer finalized.

Type Aliases§

Attribute Macros§

  • Marks a function or static variable as a library/executable constructor. This uses OS-specific linker sections to call a specific function at load time.