fix(napi): arraybuffer implement

close https://github.com/napi-rs/napi-rs/issues/68

napi/src/env.rs

@@ -264,22 +264,22 @@ impl Env {
     ))
   }
 
-  pub fn create_arraybuffer(&self, length: u64) -> Result<JsArrayBuffer> {
+  pub fn create_arraybuffer(&self, length: u64) -> Result<JsArrayBufferValue> {
     let mut raw_value = ptr::null_mut();
-    let mut data = Vec::with_capacity(length as usize);
-    let mut data_ptr = data.as_mut_ptr();
+    let mut data: Vec<u8> = Vec::with_capacity(length as usize);
+    let mut data_ptr = data.as_mut_ptr() as *mut c_void;
     check_status(unsafe {
       sys::napi_create_arraybuffer(self.0, length, &mut data_ptr, &mut raw_value)
     })?;
-    mem::forget(data);
-    let mut array_buffer = JsArrayBuffer::from_raw_unchecked(self.0, raw_value);
-    array_buffer.data = data_ptr as *const u8;
-    array_buffer.len = length;
-    Ok(array_buffer)
+
+    Ok(JsArrayBufferValue::new(
+      JsArrayBuffer::from_raw_unchecked(self.0, raw_value),
+      data,
+    ))
   }
 
-  pub fn create_arraybuffer_with_data(&self, data: Vec<u8>) -> Result<JsArrayBuffer> {
-    let length = data.len() as u64;
+  pub fn create_arraybuffer_with_data(&self, data: Vec<u8>) -> Result<JsArrayBufferValue> {
+    let mut length = data.len() as u64;
     let mut raw_value = ptr::null_mut();
     let data_ptr = data.as_ptr();
     check_status(unsafe {
@@ -288,17 +288,21 @@ impl Env {
         data_ptr as *mut c_void,
         length,
         Some(drop_buffer),
-        &length as *const _ as *mut c_void,
+        &mut length as *mut u64 as *mut c_void,
         &mut raw_value,
       )
     })?;
     let mut changed = 0;
     check_status(unsafe { sys::napi_adjust_external_memory(self.0, length as i64, &mut changed) })?;
-    mem::forget(data);
-    let mut array_buffer = JsArrayBuffer::from_raw_unchecked(self.0, raw_value);
-    array_buffer.data = data_ptr as *const u8;
-    array_buffer.len = length;
-    Ok(array_buffer)
+
+    Ok(JsArrayBufferValue::new(
+      JsArrayBuffer(Value {
+        env: self.0,
+        value: raw_value,
+        value_type: ValueType::Object,
+      }),
+      data,
+    ))
   }
 
   pub fn create_function(&self, name: &str, callback: Callback) -> Result<JsFunction> {

napi/src/js_values/arraybuffer.rs

@@ -1,182 +1,69 @@
-use std::convert::TryFrom;
+use std::mem;
+use std::ops::Deref;
 use std::ptr;
 
-use super::{JsNumber, JsObject, JsString, JsUnknown, NapiValue, Status, Value, ValueType};
+use super::Value;
 use crate::error::check_status;
-use crate::{sys, Error, Result};
+use crate::{sys, JsUnknown, Ref, Result};
+
+#[repr(transparent)]
+#[derive(Debug, Clone, Copy)]
+pub struct JsArrayBuffer(pub(crate) Value);
 
 #[derive(Debug)]
-pub struct JsArrayBuffer {
-  pub value: JsObject,
-  pub data: *const u8,
-  pub len: u64,
+pub struct JsArrayBufferValue {
+  pub(crate) value: JsArrayBuffer,
+  data: mem::ManuallyDrop<Vec<u8>>,
 }
 
 impl JsArrayBuffer {
-  pub(crate) fn from_raw_unchecked(env: sys::napi_env, value: sys::napi_value) -> Self {
-    Self {
-      value: JsObject(Value {
-        env,
-        value,
-        value_type: ValueType::Object,
-      }),
-      data: ptr::null(),
-      len: 0,
-    }
-  }
-
-  #[inline]
-  pub fn into_unknown(self) -> Result<JsUnknown> {
-    JsUnknown::from_raw(self.value.0.env, self.value.0.value)
-  }
-
-  #[inline]
-  pub fn coerce_to_number(self) -> Result<JsNumber> {
-    let mut new_raw_value = ptr::null_mut();
-    check_status(unsafe {
-      sys::napi_coerce_to_number(self.value.0.env, self.value.0.value, &mut new_raw_value)
-    })?;
-    Ok(JsNumber(Value {
-      env: self.value.0.env,
-      value: new_raw_value,
-      value_type: ValueType::Number,
-    }))
-  }
-
-  #[inline]
-  pub fn coerce_to_string(self) -> Result<JsString> {
-    let mut new_raw_value = ptr::null_mut();
-    check_status(unsafe {
-      sys::napi_coerce_to_string(self.value.0.env, self.value.0.value, &mut new_raw_value)
-    })?;
-    Ok(JsString(Value {
-      env: self.value.0.env,
-      value: new_raw_value,
-      value_type: ValueType::String,
-    }))
-  }
-  #[inline]
-  pub fn coerce_to_object(self) -> Result<JsObject> {
-    let mut new_raw_value = ptr::null_mut();
-    check_status(unsafe {
-      sys::napi_coerce_to_object(self.value.0.env, self.value.0.value, &mut new_raw_value)
-    })?;
-    Ok(JsObject(Value {
-      env: self.value.0.env,
-      value: new_raw_value,
-      value_type: ValueType::Object,
-    }))
-  }
-
-  #[inline]
-  #[cfg(napi5)]
-  pub fn is_date(&self) -> Result<bool> {
-    let mut is_date = true;
-    check_status(unsafe { sys::napi_is_date(self.value.0.env, self.value.0.value, &mut is_date) })?;
-    Ok(is_date)
-  }
-
-  #[inline]
-  pub fn is_error(&self) -> Result<bool> {
-    let mut result = false;
-    check_status(unsafe { sys::napi_is_error(self.value.0.env, self.value.0.value, &mut result) })?;
-    Ok(result)
-  }
-
-  #[inline]
-  pub fn is_typedarray(&self) -> Result<bool> {
-    let mut result = false;
-    check_status(unsafe {
-      sys::napi_is_typedarray(self.value.0.env, self.value.0.value, &mut result)
-    })?;
-    Ok(result)
-  }
-
-  #[inline]
-  pub fn is_dataview(&self) -> Result<bool> {
-    let mut result = false;
-    check_status(unsafe {
-      sys::napi_is_dataview(self.value.0.env, self.value.0.value, &mut result)
-    })?;
-    Ok(result)
-  }
-
-  #[inline]
-  pub fn is_array(&self) -> Result<bool> {
-    let mut is_array = false;
-    check_status(unsafe {
-      sys::napi_is_array(self.value.0.env, self.value.0.value, &mut is_array)
-    })?;
-    Ok(is_array)
-  }
-
-  #[inline]
-  pub fn is_buffer(&self) -> Result<bool> {
-    let mut is_buffer = false;
-    check_status(unsafe {
-      sys::napi_is_buffer(self.value.0.env, self.value.0.value, &mut is_buffer)
-    })?;
-    Ok(is_buffer)
-  }
-
-  #[inline]
-  pub fn instanceof<Constructor: NapiValue>(&self, constructor: Constructor) -> Result<bool> {
-    let mut result = false;
-    check_status(unsafe {
-      sys::napi_instanceof(
-        self.value.0.env,
-        self.value.0.value,
-        constructor.raw(),
-        &mut result,
-      )
-    })?;
-    Ok(result)
-  }
-}
-
-impl NapiValue for JsArrayBuffer {
-  fn raw(&self) -> sys::napi_value {
-    self.value.0.value
-  }
-
-  fn from_raw(env: sys::napi_env, value: sys::napi_value) -> Result<Self> {
+  pub fn into_value(self) -> Result<JsArrayBufferValue> {
     let mut data = ptr::null_mut();
     let mut len: u64 = 0;
-    check_status(unsafe { sys::napi_get_arraybuffer_info(env, value, &mut data, &mut len) })?;
-    Ok(JsArrayBuffer {
-      value: JsObject(Value {
-        env,
-        value,
-        value_type: ValueType::Object,
+    check_status(unsafe {
+      sys::napi_get_arraybuffer_info(self.0.env, self.0.value, &mut data, &mut len)
+    })?;
+    Ok(JsArrayBufferValue {
+      data: mem::ManuallyDrop::new(unsafe {
+        Vec::from_raw_parts(data as *mut _, len as usize, len as usize)
       }),
-      data: data as *const u8,
-      len,
+      value: self,
     })
   }
 
-  fn from_raw_unchecked(env: sys::napi_env, value: sys::napi_value) -> Self {
-    let mut data = ptr::null_mut();
-    let mut len: u64 = 0;
-    let status = unsafe { sys::napi_get_arraybuffer_info(env, value, &mut data, &mut len) };
-    debug_assert!(
-      Status::from(status) == Status::Ok,
-      "napi_get_arraybuffer_info failed"
-    );
-    JsArrayBuffer {
-      value: JsObject(Value {
-        env,
-        value,
-        value_type: ValueType::Object,
-      }),
-      data: data as *const u8,
-      len,
-    }
+  #[inline]
+  pub fn into_ref(self) -> Result<Ref<JsArrayBufferValue>> {
+    Ref::new(self.0, 1, self.into_value()?)
   }
 }
 
-impl TryFrom<JsUnknown> for JsArrayBuffer {
-  type Error = Error;
-  fn try_from(value: JsUnknown) -> Result<JsArrayBuffer> {
-    JsArrayBuffer::from_raw(value.0.env, value.0.value)
+impl JsArrayBufferValue {
+  pub fn new(value: JsArrayBuffer, data: Vec<u8>) -> Self {
+    JsArrayBufferValue {
+      value,
+      data: mem::ManuallyDrop::new(data),
+    }
+  }
+
+  pub fn into_raw(self) -> JsArrayBuffer {
+    self.value
+  }
+
+  pub fn into_unknown(self) -> Result<JsUnknown> {
+    self.value.into_unknown()
+  }
+}
+
+impl AsRef<[u8]> for JsArrayBufferValue {
+  fn as_ref(&self) -> &[u8] {
+    self.data.as_slice()
+  }
+}
+
+impl Deref for JsArrayBufferValue {
+  type Target = [u8];
+
+  fn deref(&self) -> &[u8] {
+    self.data.as_slice()
   }
 }

napi/src/js_values/mod.rs

@@ -27,7 +27,7 @@ mod value;
 mod value_ref;
 mod value_type;
 
-pub use arraybuffer::JsArrayBuffer;
+pub use arraybuffer::*;
 #[cfg(napi6)]
 pub use bigint::JsBigint;
 pub use boolean::JsBoolean;
@@ -231,6 +231,7 @@ impl_js_value_methods!(JsUnknown);
 impl_js_value_methods!(JsUndefined);
 impl_js_value_methods!(JsNull);
 impl_js_value_methods!(JsBoolean);
+impl_js_value_methods!(JsArrayBuffer);
 impl_js_value_methods!(JsBuffer);
 impl_js_value_methods!(JsNumber);
 impl_js_value_methods!(JsString);
@@ -245,6 +246,7 @@ impl_napi_value_trait!(JsUndefined, Undefined);
 impl_napi_value_trait!(JsNull, Null);
 impl_napi_value_trait!(JsBoolean, Boolean);
 impl_napi_value_trait!(JsBuffer, Object);
+impl_napi_value_trait!(JsArrayBuffer, Object);
 impl_napi_value_trait!(JsNumber, Number);
 impl_napi_value_trait!(JsString, String);
 impl_napi_value_trait!(JsObject, Object);

test_module/__test__/arraybuffer.spec.ts

@@ -0,0 +1,8 @@
+import test from 'ava'
+
+const bindings = require('../index.node')
+
+test('should get arraybuffer length', (t) => {
+  const fixture = Buffer.from('wow, hello')
+  t.is(bindings.getArraybufferLength(fixture.buffer), fixture.buffer.byteLength)
+})

test_module/src/arraybuffer.rs

@@ -0,0 +1,37 @@
+use std::ffi::CStr;
+use std::str;
+
+use napi::{CallContext, JsArrayBuffer, JsNumber, JsString, Module, Result};
+
+#[js_function(1)]
+pub fn get_arraybuffer_length(ctx: CallContext) -> Result<JsNumber> {
+  let buffer = ctx.get::<JsArrayBuffer>(0)?.into_value()?;
+  ctx.env.create_uint32((&buffer).len() as u32)
+}
+
+#[js_function(1)]
+pub fn arraybuffer_to_string(ctx: CallContext) -> Result<JsString> {
+  let buffer = ctx.get::<JsArrayBuffer>(0)?.into_value()?;
+  ctx
+    .env
+    .create_string(str_from_null_terminated_utf8_safe(&buffer))
+}
+
+fn str_from_null_terminated_utf8_safe(s: &[u8]) -> &str {
+  if s.iter().any(|&x| x == 0) {
+    unsafe { str_from_null_terminated_utf8(s) }
+  } else {
+    str::from_utf8(s).unwrap()
+  }
+}
+
+// unsafe: s must contain a null byte
+unsafe fn str_from_null_terminated_utf8(s: &[u8]) -> &str {
+  CStr::from_ptr(s.as_ptr() as *const _).to_str().unwrap()
+}
+
+pub fn register_js(module: &mut Module) -> Result<()> {
+  module.create_named_method("getArraybufferLength", get_arraybuffer_length)?;
+  module.create_named_method("arraybufferToString", arraybuffer_to_string)?;
+  Ok(())
+}

test_module/src/lib.rs

@@ -18,6 +18,7 @@ mod napi6;
 #[cfg(napi4)]
 mod tokio_rt;
 
+mod arraybuffer;
 mod buffer;
 mod class;
 mod either;
@@ -43,6 +44,7 @@ fn init(module: &mut Module) -> Result<()> {
   serde::register_js(module)?;
   task::register_js(module)?;
   external::register_js(module)?;
+  arraybuffer::register_js(module)?;
   buffer::register_js(module)?;
   either::register_js(module)?;
   symbol::register_js(module)?;