Crate napi

Crate napi 

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Expand description

High level Node.js N-API binding

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

§Feature flags

§napi1 ~ napi10

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: Node-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::bindgen_prelude::*;
use tokio;

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

§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§

pub extern crate anyhow;
pub extern crate ctor;
pub extern crate futures_core;
pub extern crate tokio;
pub extern crate tokio_stream;
pub use crate::bindgen_prelude::KeyCollectionMode;
pub use crate::bindgen_prelude::KeyConversion;
pub use crate::bindgen_prelude::KeyFilter;
pub use napi_sys as sys;

Modules§

bindgen_prelude
iterator
threadsafe_function

Structs§

AsyncCleanupHook
Notice The hook will be removed if AsyncCleanupHook was dropped. If you want keep the hook until node process exited, call the AsyncCleanupHook::forget.
AsyncWorkPromise
CallContext
Function call context
CleanupEnvHook
Created by Env::add_env_cleanup_hook And used by Env::remove_env_cleanup_hook
De
Env
Env is used to represent a context that the underlying N-API implementation can use to persist VM-specific state.
Error
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)
ExtendedErrorInfo
JSON
JsArrayBufferDeprecated
JsArrayBufferValueDeprecated
JsBigIntDeprecated
JsBooleanDeprecated
JsBufferDeprecated
JsBufferValueDeprecated
JsDataView
JsDataViewValue
JsDate
JsDeferred
JsError
JsExternal
Represent the Node-API External value
JsFunctionDeprecated
JsGlobal
JsNullDeprecated
JsNumber
JsObjectDeprecated
JsRangeError
JsString
JsStringLatin1
JsStringUtf8
JsStringUtf16
JsSymbol
represent Symbol value in JavaScript
JsSyntaxError
JsTimeout
JsTypeError
JsTypedArrayDeprecated
JsTypedArrayValueDeprecated
JsUndefinedDeprecated
NodeVersion
Property
PropertyAttributes
PropertyClosures
Ref
Ser
SymbolRef
A reference to a JavaScript Symbol.
Unknown
Represents a raw JavaScript value
UnknownRef
A reference to a unknown JavaScript value.

Enums§

Either
Status
ValueType

Traits§

JsValue
NapiRaw
NapiValue
ScopedTask
Basically it’s the same as the Task trait
Task

Functions§

noop_finalize
This function could be used for BufferSlice::from_external and want do noting when Buffer finalized.

Type Aliases§

Callback
ContextlessResult
Result