WIP: use v8::Value for strings in fast API

Cargo.toml

@@ -25,10 +25,10 @@ deno_ops = { version = "0.192.0", path = "./ops" }
 serde_v8 = { version = "0.225.0", path = "./serde_v8" }
 deno_core_testing = { path = "./testing" }
 
-v8 = { version = "0.106.0", default-features = false }
+v8 = { version = "130.0.1", default-features = false }
 deno_ast = { version = "=0.40.0", features = ["transpiling"] }
 deno_unsync = "0.4.0"
-deno_core_icudata = "0.0.73"
+deno_core_icudata = "0.74.0"
 
 anyhow = "1"
 bencher = "0.1"
@@ -92,3 +92,6 @@ codegen-units = 1
 incremental = true
 lto = true
 opt-level = 'z' # Optimize for size
+
+[patch.crates-io]
+v8 = { path = "../rusty_v8" }

core/benches/ops/sync.rs

@@ -301,6 +301,11 @@ fn bench_op_string(b: &mut Bencher) {
   bench_op(b, BENCH_COUNT, "op_string", 1, "accum += op_string('this is a reasonably long string that we would like to get the length of!');");
 }
 
+/// A string function with a numeric return value.
+fn bench_op_string_constring(b: &mut Bencher) {
+  bench_op(b, BENCH_COUNT, "op_string", 1, "accum += op_string('this is a reasonably long string that we would like to get the length of!' + String(accum));");
+}
+
 /// A string function with a numeric return value.
 fn bench_op_string_large_1000(b: &mut Bencher) {
   bench_op(
@@ -510,6 +515,7 @@ benchmark_group!(
   bench_op_string_bytestring,
   bench_op_string_bytestring_no_side_effects,
   bench_op_string,
+  bench_op_string_constring,
   bench_op_string_large_1000,
   bench_op_string_large_1000000,
   bench_op_string_onebyte,

core/ops_builtin_v8.rs

@@ -18,6 +18,7 @@ use crate::OpState;
 use anyhow::Error;
 use serde::Deserialize;
 use serde::Serialize;
+use std::borrow::Cow;
 use std::cell::RefCell;
 use std::rc::Rc;
 use v8::ValueDeserializerHelper;
@@ -67,13 +68,13 @@ pub fn op_leak_tracing_submit(
   scope: &mut v8::HandleScope,
   #[smi] kind: u8,
   #[smi] id: i32,
-  #[string] trace: &str,
+  #[string] trace: Cow<'_, str>,
 ) {
   let context_state = JsRealm::state_from_scope(scope);
   context_state.activity_traces.submit(
     RuntimeActivityType::from_u8(kind),
     id as _,
-    trace,
+    &trace,
   );
 }
 

core/runtime/ops.rs

@@ -235,10 +235,39 @@ pub fn to_string_ptr(string: &v8::fast_api::FastApiOneByteString) -> String {
   }
 }
 
-pub fn to_cow_byte_ptr(
-  string: &v8::fast_api::FastApiOneByteString,
-) -> Cow<[u8]> {
-  string.as_bytes().into()
+#[inline(always)]
+pub fn to_string_view<'a>(
+  scope: &mut v8::Isolate,
+  value: v8::Local<'a, v8::Value>,
+) -> Option<v8::ValueView<'a>> {
+  if !value.is_string() {
+    return None;
+  }
+
+  // SAFETY: We checked is_string above.
+  let string: v8::Local<'a, v8::String> = unsafe { std::mem::transmute(value) };
+
+  let string_view = v8::ValueView::new(scope, string);
+
+  Some(string_view)
+}
+
+#[inline(always)]
+pub fn to_str_from_view<'a, const N: usize>(
+  string: &'a v8::ValueView<'_>,
+  buffer: &'a mut [MaybeUninit<u8>; N],
+) -> Cow<'a, str> {
+  string.to_rust_cow_lossy(buffer)
+}
+
+#[inline(always)]
+pub fn to_cow_one_byte_from_view<'a>(
+  string: &'a v8::ValueView<'_>,
+) -> Result<Cow<'a, [u8]>, &'static str> {
+  match string.data() {
+    v8::ValueViewData::OneByte(data) => Ok(Cow::Borrowed(data)),
+    v8::ValueViewData::TwoByte(_) => Err("expected one-byte String"),
+  }
 }
 
 /// Converts a [`v8::Value`] to an owned string.
@@ -276,7 +305,7 @@ pub fn to_cow_one_byte(
   string: &v8::Value,
 ) -> Result<Cow<'static, [u8]>, &'static str> {
   if !string.is_string() {
-    return Err("expected String");
+    return Err("expected string");
   }
 
   // SAFETY: We checked is_string above
@@ -288,7 +317,7 @@ pub fn to_cow_one_byte(
   }
 
   if !string.is_onebyte() && !string.contains_only_onebyte() {
-    return Err("expected one-byte String");
+    return Err("expected one-byte string");
   }
 
   // Create an uninitialized buffer of `capacity` bytes. We need to be careful here to avoid

core/runtime/setup.rs

@@ -19,7 +19,7 @@ fn v8_init(
 ) {
   #[cfg(feature = "include_icu_data")]
   {
-    v8::icu::set_common_data_73(deno_core_icudata::ICU_DATA).unwrap();
+    v8::icu::set_common_data_74(deno_core_icudata::ICU_DATA).unwrap();
   }
 
   let base_flags = concat!(