From 24286a4d71fb262a9aaab48ea5bc9d5efe61c171 Mon Sep 17 00:00:00 2001
From: Bert Belder <bertbelder@gmail.com>
Date: Tue, 31 Dec 2019 02:42:39 +0100
Subject: [PATCH] Add StartupData constructor (#156)

---
 src/binding.cc    |  3 +--
 src/isolate.rs    |  2 +-
 src/snapshot.rs   | 55 +++++++++++++++++++++++++++++++++++------------
 tests/test_api.rs | 16 ++++++++++++++
 4 files changed, 59 insertions(+), 17 deletions(-)

diff --git a/src/binding.cc b/src/binding.cc
index 2ae7b4bc..d0798861 100644
--- a/src/binding.cc
+++ b/src/binding.cc
@@ -583,8 +583,7 @@ void v8__FunctionCallbackInfo__GetReturnValue(
 }
 
 v8::Value* v8__FunctionCallbackInfo__GetArgument(
-    const v8::FunctionCallbackInfo<v8::Value>& self,
-    int i) {
+    const v8::FunctionCallbackInfo<v8::Value>& self, int i) {
   return local_to_ptr(self[i]);
 }
 
diff --git a/src/isolate.rs b/src/isolate.rs
index 2a3d3a18..2302bf70 100644
--- a/src/isolate.rs
+++ b/src/isolate.rs
@@ -336,7 +336,7 @@ impl CreateParams {
   /// - The call will abort if the data is invalid.
   pub fn set_snapshot_blob(&mut self, snapshot_blob: &mut StartupData) {
     unsafe {
-      v8__Isolate__CreateParams__SET__snapshot_blob(self, &mut *snapshot_blob)
+      v8__Isolate__CreateParams__SET__snapshot_blob(self, snapshot_blob)
     };
   }
 }
diff --git a/src/snapshot.rs b/src/snapshot.rs
index 0be5c93c..450c9b90 100644
--- a/src/snapshot.rs
+++ b/src/snapshot.rs
@@ -1,12 +1,15 @@
+use std::borrow::Borrow;
+use std::marker::PhantomData;
+use std::mem::MaybeUninit;
+use std::ops::Deref;
+use std::ops::DerefMut;
+
 use crate::external_references::ExternalReferences;
 use crate::support::int;
 use crate::support::intptr_t;
 use crate::Context;
 use crate::Isolate;
 use crate::Local;
-use std::mem::MaybeUninit;
-use std::ops::Deref;
-use std::ops::DerefMut;
 
 extern "C" {
   fn v8__SnapshotCreator__CONSTRUCT(
@@ -20,7 +23,7 @@ extern "C" {
   fn v8__SnapshotCreator__CreateBlob(
     this: *mut SnapshotCreator,
     function_code_handling: FunctionCodeHandling,
-  ) -> StartupData;
+  ) -> OwnedStartupData;
   fn v8__SnapshotCreator__SetDefaultContext(
     this: &mut SnapshotCreator,
     context: *mut Context,
@@ -28,29 +31,53 @@ extern "C" {
   fn v8__StartupData__DESTRUCT(this: &mut StartupData);
 }
 
-#[derive(Debug)]
 #[repr(C)]
-pub struct StartupData {
-  data: *mut u8,
+pub struct StartupData<'a> {
+  data: *const u8,
   raw_size: int,
+  _phantom: PhantomData<&'a [u8]>,
 }
 
-impl Deref for StartupData {
+impl<'a> StartupData<'a> {
+  pub fn new<D>(data: &'a D) -> Self
+  where
+    D: Borrow<[u8]>,
+  {
+    let data = data.borrow();
+    Self {
+      data: data.as_ptr(),
+      raw_size: data.len() as int,
+      _phantom: PhantomData,
+    }
+  }
+}
+
+impl<'a> Deref for StartupData<'a> {
   type Target = [u8];
   fn deref(&self) -> &Self::Target {
     unsafe { std::slice::from_raw_parts(self.data, self.raw_size as usize) }
   }
 }
 
-impl DerefMut for StartupData {
-  fn deref_mut(&mut self) -> &mut Self::Target {
-    unsafe { std::slice::from_raw_parts_mut(self.data, self.raw_size as usize) }
+#[repr(transparent)]
+pub struct OwnedStartupData(StartupData<'static>);
+
+impl Deref for OwnedStartupData {
+  type Target = StartupData<'static>;
+  fn deref(&self) -> &Self::Target {
+    &self.0
   }
 }
 
-impl Drop for StartupData {
+impl DerefMut for OwnedStartupData {
+  fn deref_mut(&mut self) -> &mut Self::Target {
+    &mut self.0
+  }
+}
+
+impl Drop for OwnedStartupData {
   fn drop(&mut self) {
-    unsafe { v8__StartupData__DESTRUCT(self) }
+    unsafe { v8__StartupData__DESTRUCT(&mut self.0) }
   }
 }
 
@@ -103,7 +130,7 @@ impl SnapshotCreator {
   pub fn create_blob(
     &mut self,
     function_code_handling: FunctionCodeHandling,
-  ) -> Option<StartupData> {
+  ) -> Option<OwnedStartupData> {
     let blob =
       unsafe { v8__SnapshotCreator__CreateBlob(self, function_code_handling) };
     if blob.data.is_null() {
diff --git a/tests/test_api.rs b/tests/test_api.rs
index 573b0d0b..73b12782 100644
--- a/tests/test_api.rs
+++ b/tests/test_api.rs
@@ -1437,6 +1437,22 @@ fn external_references() {
   drop(g);
 }
 
+#[test]
+fn startup_data() {
+  let data1 = b"abcd";
+  let sd1 = v8::StartupData::new(data1);
+  assert_eq!(&*sd1, data1);
+
+  let data2 = b"defg";
+  let vec2 = Vec::from(&data2[..]);
+  let sd2 = v8::StartupData::new(&vec2);
+  assert_eq!(&*sd2, data2);
+
+  let data3 = b"hijk";
+  let sd3 = Box::new(v8::StartupData::new(data3));
+  assert_eq!(&**sd3, data3);
+}
+
 #[test]
 fn uint8_array() {
   let g = setup();