Expose StringView directly from Inspector

Inspector.sendNotification and Inspector.sentResponse now expose the StringView
directly, avoid multiple copies of the data.

Author: karlseguin

src/binding.cpp

@@ -6,7 +6,9 @@
 #include "include/v8.h"
 #include "src/api/api.h"
 #include "src/inspector/protocol/Runtime.h"
+#include "src/inspector/string-util.h"
 #include "src/inspector/v8-string-conversions.h"
+
 #include "src/debug/debug-interface.h"
 
 #include "inspector.h"
@@ -1724,15 +1726,15 @@ static inline v8_inspector::StringView toStringView(const std::string &str) {
     return toStringView(str.c_str(), str.length());
 }
 
-static v8::Local<v8::String> fromStringView(v8::Isolate* isolate, const v8_inspector::StringView stringView) {
-  int length = static_cast<int>(stringView.length());
-  v8::Local<v8::String> message = (
-        stringView.is8Bit()
-          ? v8::String::NewFromOneByte(isolate, stringView.characters8(), v8::NewStringType::kNormal, length)
-          : v8::String::NewFromTwoByte(isolate, stringView.characters16(), v8::NewStringType::kNormal, length)
-      ).ToLocalChecked();
-  return message;
-}
+// static v8::Local<v8::String> fromStringView(v8::Isolate* isolate, const v8_inspector::StringView stringView) {
+//   int length = static_cast<int>(stringView.length());
+//   v8::Local<v8::String> message = (
+//         stringView.is8Bit()
+//           ? v8::String::NewFromOneByte(isolate, stringView.characters8(), v8::NewStringType::kNormal, length)
+//           : v8::String::NewFromTwoByte(isolate, stringView.characters16(), v8::NewStringType::kNormal, length)
+//       ).ToLocalChecked();
+//   return message;
+// }
 
 /// Allocates a string as utf8 on the allocator without \0 terminator, for use in Zig.
 /// The strings pointer and length should therefore be returned together
@@ -1996,24 +1998,23 @@ void v8_inspector__Channel__IMPL__SET_DATA(v8_inspector__Channel__IMPL *self, vo
 // NOTE: zig project should provide those implementations with C-ABI functions
 void v8_inspector__Channel__IMPL__sendResponse(
     v8_inspector__Channel__IMPL* self, void* data,
-    int callId, v8::Local<v8::String> resp);
+    int callId, v8_inspector::StringView resp);
 void v8_inspector__Channel__IMPL__sendNotification(
-    v8_inspector__Channel__IMPL* self, void *data,
-    v8::Local<v8::String> notif);
+    v8_inspector__Channel__IMPL *self, void *data,
+    v8_inspector::StringView notif);
 void v8_inspector__Channel__IMPL__flushProtocolNotifications(
     v8_inspector__Channel__IMPL* self, void *data);
 
 // c++ implementation (just wrappers around the C/zig functions)
 } // extern "C"
 void v8_inspector__Channel__IMPL::sendResponse(
     int callId, std::unique_ptr<v8_inspector::StringBuffer> message) {
-  const v8::Local<v8::String> resp = fromStringView(this->isolate, message->string());
-  return v8_inspector__Channel__IMPL__sendResponse(this, this->data, callId, resp);
+  return v8_inspector__Channel__IMPL__sendResponse(this, this->data, callId, message->string());
 }
 void v8_inspector__Channel__IMPL::sendNotification(
     std::unique_ptr<v8_inspector::StringBuffer> message) {
-  const v8::Local<v8::String> notif = fromStringView(this->isolate, message->string());
-   return v8_inspector__Channel__IMPL__sendNotification(this, this->data, notif);
+  // const v8::Local<v8::String> msg = v8_inspector::toV8String(this->isolate, message->string());
+   return v8_inspector__Channel__IMPL__sendNotification(this, this->data, message->string());
 }
 void v8_inspector__Channel__IMPL::flushProtocolNotifications() {
   return v8_inspector__Channel__IMPL__flushProtocolNotifications(this, this->data);
@@ -2026,14 +2027,15 @@ extern "C" {
 void v8_inspector__Channel__sendResponse(
     v8_inspector::V8Inspector::Channel* self, int callId,
     v8_inspector::StringBuffer* message) {
+
   self->sendResponse(
       callId,
       static_cast<std::unique_ptr<v8_inspector::StringBuffer>>(message));
 }
 void v8_inspector__Channel__sendNotification(
     v8_inspector::V8Inspector::Channel* self,
     v8_inspector::StringBuffer* message) {
-  self->sendNotification(
+    self->sendNotification(
       static_cast<std::unique_ptr<v8_inspector::StringBuffer>>(message));
 }
 void v8_inspector__Channel__flushProtocolNotifications(
@@ -2146,4 +2148,13 @@ void v8_inspector__Client__consoleAPIMessage(
                           columnNumber, stackTrace);
 }
 
+size_t v8__StringView__Length(const v8_inspector::StringView* self) {
+    return self->length();
+}
+
+const uint8_t* v8__StringView__Bytes(const v8_inspector::StringView* self) {
+    return self->characters8();
+}
+
 } // extern "C"
+

src/binding.h

@@ -1227,3 +1227,7 @@ void v8_inspector__RemoteObject__setPreview(RemoteObject* self, ObjectPreview* p
 bool v8_inspector__RemoteObject__hasCustomPreview(RemoteObject* self);
 const CustomPreview* v8_inspector__RemoteObject__getCustomPreview(RemoteObject* self);
 void v8_inspector__RemoteObject__setCustomPreview(RemoteObject* self, CustomPreview* customPreview);
+
+
+uint32_t v8__StringView__Length(const StringView* self);
+const uint8_t* v8__StringView__Bytes(const StringView* self);

src/v8.zig

@@ -2245,6 +2245,18 @@ pub const Primitive = struct {
     }
 };
 
+pub const StringView = struct {
+    handle: *const c.StringView,
+
+    pub fn length(self: StringView) usize {
+        return c.v8__StringView__Length(self.handle);
+    }
+
+    pub fn bytes(self: StringView) [*c]const u8 {
+        return c.v8__StringView__Bytes(self.handle);
+    }
+};
+
 pub fn initUndefined(isolate: Isolate) Primitive {
     return .{
         .handle = c.v8__Undefined(isolate.handle).?,
@@ -2906,8 +2918,8 @@ pub const InspectorChannel = struct {
     onNotif: onNotifFn = undefined,
     onResp: onRespFn = undefined,
 
-    pub const onNotifFn = *const fn (ctx: *anyopaque, msg: *const c.String) void;
-    pub const onRespFn = *const fn (ctx: *anyopaque, call_id: u32, msg: *const c.String) void;
+    pub const onNotifFn = *const fn (ctx: *anyopaque, msg: StringView) void;
+    pub const onRespFn = *const fn (ctx: *anyopaque, call_id: u32, msg: StringView) void;
 
     pub fn init(
         ctx: *anyopaque,
@@ -2932,20 +2944,20 @@ pub const InspectorChannel = struct {
         c.v8_inspector__Channel__IMPL__SET_DATA(self.handle, inspector);
     }
 
-    fn resp(self: InspectorChannel, call_id: u32, msg: *const c.String) void {
-        self.onResp(self.ctx, call_id, msg);
+    fn resp(self: InspectorChannel, call_id: u32, msg: *const c.StringView) void {
+        self.onResp(self.ctx, call_id, .{.handle = msg});
     }
 
-    fn notif(self: InspectorChannel, msg: *const c.String) void {
-        self.onNotif(self.ctx, msg);
+    fn notif(self: InspectorChannel, msg: *const c.StringView) void {
+        self.onNotif(self.ctx, .{.handle = msg});
     }
 };
 
 pub export fn v8_inspector__Channel__IMPL__sendResponse(
     _: *c.InspectorChannelImpl,
     data: *anyopaque,
     call_id: c_int,
-    msg: *const c.String,
+    msg: *const c.StringView,
 ) callconv(.C) void {
     const inspector = Inspector.fromData(data);
     inspector.channel.resp(@as(u32, @intCast(call_id)), msg);
@@ -2954,7 +2966,7 @@ pub export fn v8_inspector__Channel__IMPL__sendResponse(
 pub export fn v8_inspector__Channel__IMPL__sendNotification(
     _: *c.InspectorChannelImpl,
     data: *anyopaque,
-    msg: *const c.String,
+    msg: *const c.StringView,
 ) callconv(.C) void {
     const inspector = Inspector.fromData(data);
     inspector.channel.notif(msg);