[−][src]Crate napi
High level NodeJS N-API binding
napi-rs provides minimal overhead to write N-API modules in Rust.
Feature flags
libuv
With libuv feature, you can execute a rust future in libuv in NodeJS, and return a promise object.
use std::thread; use std::fs; use futures::prelude::*; use futures::channel::oneshot; use napi::{CallContext, Result, JsString, JsObject, Status, Error}; #[js_function(1)] pub fn uv_read_file(ctx: CallContext) -> Result<JsObject> { let path = ctx.get::<JsString>(0)?; let (sender, receiver) = oneshot::channel(); let p = path.as_str()?.to_owned(); thread::spawn(|| { let res = fs::read(p).map_err(|e| Error::new(Status::Unknown, format!("{}", e))); sender.send(res).expect("Send data failed"); }); ctx.env.execute(receiver.map_err(|e| Error::new(Status::Unknown, format!("{}", e))).map(|x| x.and_then(|x| x)), |&mut env, data| { env.create_buffer_with_data(data) }) }
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; #[js_function(1)] pub fn tokio_readfile(ctx: CallContext) -> Result<JsObject> { let js_filepath = ctx.get::<JsString>(0)?; let path_str = js_filepath.as_str()?; ctx.env.execute_tokio_future( tokio::fs::read(path_str.to_owned()) .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), ) }
Tokio channel in napi-rs buffer size is default 100.
You can adjust it via NAPI_RS_TOKIO_CHANNEL_BUFFER_SIZE environment variable
NAPI_RS_TOKIO_CHANNEL_BUFFER_SIZE=1000 node ./app.js
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, } #[js_function(1)] fn deserialize_from_js(ctx: CallContext) -> Result<JsUndefined> { let arg0 = ctx.get::<JsUnknown>(0)?; let de_serialized: AnObject = ctx.env.from_js_value(arg0)?; ... } #[js_function] fn serialize(ctx: CallContext) -> Result<JsUnknown> { let value = AnyObject { a: 1, b: vec![0.1, 2.22], c: "hello" }; ctx.env.to_js_value(&value) }
Re-exports
pub use napi_sys as sys; |
Modules
| threadsafe_function |
Macros
| register_module | Deprecated Deprecated register nodejs module |
Structs
Enums
| Either | |
| KeyCollectionMode | |
| KeyConversion | |
| KeyFilter | |
| PropertyAttributes | |
| Status | |
| TypedArrayType | |
| ValueType |
Traits
| NapiValue | |
| Task |
Functions
| shutdown_tokio_rt⚠ |
Type Definitions
| Callback | |
| ContextlessResult | |
| Result |