Merge pull request #352 from napi-rs/cast-and-buffer

Cast and buffer
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LongYinan 2020-12-10 15:03:02 +08:00 committed by GitHub
commit 0005fca934
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GPG key ID: 4AEE18F83AFDEB23
7 changed files with 83 additions and 10 deletions

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@ -1,6 +1,7 @@
use std::any::TypeId;
use std::convert::TryInto;
use std::ffi::CString;
use std::mem;
use std::os::raw::{c_char, c_void};
use std::ptr;
@ -275,7 +276,7 @@ impl Env {
value: raw_value,
value_type: ValueType::Object,
}),
data,
mem::ManuallyDrop::new(data),
))
}
@ -306,10 +307,55 @@ impl Env {
value: raw_value,
value_type: ValueType::Object,
}),
data,
mem::ManuallyDrop::new(data),
))
}
#[inline]
/// # Safety
/// Mostly same with `create_buffer_with_data`, but you must ensure data will be dropped **after** the `Buffer` is been GC.
///
/// And should manually trigger `Env::adjust_external_memory` after data is dropped.
pub unsafe fn create_buffer_with_manually_drop_data(&self, data: &[u8]) -> Result<JsBufferValue> {
let length = data.len();
let mut raw_value = ptr::null_mut();
let data_ptr = data.as_ptr();
check_status!(sys::napi_create_external_buffer(
self.0,
length,
data_ptr as *mut c_void,
None,
ptr::null_mut(),
&mut raw_value,
))?;
let mut changed = 0;
check_status!(sys::napi_adjust_external_memory(
self.0,
length as i64,
&mut changed
))?;
Ok(JsBufferValue::new(
JsBuffer(Value {
env: self.0,
value: raw_value,
value_type: ValueType::Object,
}),
mem::ManuallyDrop::new(Vec::from_raw_parts(data_ptr as *mut u8, length, length)),
))
}
#[inline]
/// This function gives V8 an indication of the amount of externally allocated memory that is kept alive by JavaScript objects (i.e. a JavaScript object that points to its own memory allocated by a native module).
///
/// Registering externally allocated memory will trigger global garbage collections more often than it would otherwise.
///
/// ***ATTENTION ⚠️***, do not use this with `create_buffer_with_data/create_arraybuffer_with_data`, since these two functions already called the `adjust_external_memory` internal.
pub fn adjust_external_memory(&mut self, size: i64) -> Result<i64> {
let mut changed = 0i64;
check_status!(unsafe { sys::napi_adjust_external_memory(self.0, size, &mut changed) })?;
Ok(changed)
}
#[inline]
/// This API allocates a node::Buffer object and initializes it with data copied from the passed-in buffer.
/// While this is still a fully-supported data structure, in most cases using a TypedArray will suffice.
@ -336,7 +382,7 @@ impl Env {
value: raw_value,
value_type: ValueType::Object,
}),
unsafe { Vec::from_raw_parts(copy_data as *mut u8, length, length) },
mem::ManuallyDrop::new(unsafe { Vec::from_raw_parts(copy_data as *mut u8, length, length) }),
))
}

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@ -55,11 +55,8 @@ impl JsBufferValue {
}
#[inline]
pub fn new(value: JsBuffer, data: Vec<u8>) -> Self {
JsBufferValue {
value,
data: mem::ManuallyDrop::new(data),
}
pub fn new(value: JsBuffer, data: mem::ManuallyDrop<Vec<u8>>) -> Self {
JsBufferValue { value, data }
}
#[inline]

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@ -607,4 +607,15 @@ impl JsUnknown {
pub fn get_type(&self) -> Result<ValueType> {
unsafe { type_of!(self.0.env, self.0.value) }
}
#[inline]
/// # Safety
/// This function should be called after `JsUnknown::get_type`
/// And the `V` must be match with the return value of `get_type`
pub unsafe fn cast<V>(self) -> V
where
V: NapiValue,
{
V::from_raw_unchecked(self.0.env, self.0.value)
}
}

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@ -6,7 +6,7 @@
//!
//! ## Feature flags
//!
//! ### napi1 ~ napi6
//! ### napi1 ~ napi7
//!
//! 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.

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@ -47,3 +47,14 @@ test('strict_equals', (t) => {
t.false(bindings.strictEquals(NaN, NaN))
t.true(bindings.strictEquals(a, a))
})
test('cast_unknown', (t) => {
const f = {}
const r = bindings.castUnknown(f)
t.is(f, r)
})
test('cast_unknown will not throw', (t) => {
const f = 1
t.notThrows(() => bindings.castUnknown(f))
})

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@ -26,10 +26,17 @@ pub fn strict_equals(ctx: CallContext) -> Result<JsBoolean> {
ctx.env.get_boolean(ctx.env.strict_equals(a, b)?)
}
#[js_function(1)]
pub fn cast_unknown(ctx: CallContext) -> Result<JsObject> {
let arg: JsUnknown = ctx.get(0)?;
Ok(unsafe { arg.cast::<JsObject>() })
}
pub fn register_js(exports: &mut JsObject) -> Result<()> {
exports.create_named_method("instanceof", instanceof)?;
exports.create_named_method("isTypedarray", is_typedarray)?;
exports.create_named_method("isDataview", is_dataview)?;
exports.create_named_method("strictEquals", strict_equals)?;
exports.create_named_method("castUnknown", cast_unknown)?;
Ok(())
}

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@ -2,7 +2,8 @@
"extends": "../tsconfig.json",
"include": ["."],
"compilerOptions": {
"outDir": "./dist"
"outDir": "./dist",
"rootDir": "__test__"
},
"exclude": ["dist"]
}