Crate napi[−][src]
Expand description
High level NodeJS N-API binding
napi-rs provides minimal overhead to write N-API modules in Rust
.
Feature flags
napi1 ~ napi8
Because NodeJS
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; #[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
Macros
Deprecated register nodejs module
Structs
Notice
The hook will be removed if AsyncCleanupHook
was dropped
.
If you want keep the hook until node process exited, call the AsyncCleanupHook::forget
.
Function call context
Created by Env::add_env_cleanup_hook
And used by Env::remove_env_cleanup_hook
Env
is used to represent a context that the underlying N-API implementation can use to persist VM-specific state.
Represent JsError
.
Return this Error in js_function
, napi-rs will throw it as JsError
for you.
If you want throw it as TypeError
or RangeError
, you can use JsTypeError/JsRangeError::from(Error).throw_into(env)
Enums
Traits
Functions
This function could be used for create_buffer_with_borrowed_data
and want do noting when Buffer finalized.