Add builtins-encoder.h

src/builtins/builtins-encoder.h

+#ifndef V8_BUILTINS_BUILTINS_ENCODER_H_
+#define V8_BUILTINS_BUILTINS_ENCODER_H_
+
+#include "src/builtins/builtins.h"
+#include "src/builtins/builtins-utils-inl.h"
+
+namespace v8 {
+  namespace internal {
+
+    //提取字段
+    inline Handle<Object> EncodeGetProperty(v8::internal::Isolate* isolate, v8::internal::Handle<v8::internal::Object> object, const char* name) {
+      Handle<String> h_name = isolate->factory()->InternalizeUtf8String(name);
+      Handle<Object> result;
+      bool succ = Object::GetProperty(isolate, object, h_name).ToHandle(&result);
+      if (result.is_null() || !succ) {
+        return isolate->factory()->undefined_value();
+      }
+      return result;
+    }
+
+    //对象转cstring
+    inline std::unique_ptr<char[]> EncodeToCString(v8::internal::Isolate* isolate, v8::internal::Handle<v8::internal::Object> object) {
+      if (!object->IsString()) return std::unique_ptr<char[]>(nullptr);
+      Handle<String> string = Handle<String>::cast(object);
+      return string->ToCString();
+    }
+
+    //TypedArray 或 ArrayBuffer 对象转指针
+    inline std::tuple<uint8_t*, size_t> EncodeToBuffer(v8::internal::Isolate* isolate, v8::internal::Handle<v8::internal::Object> object) {
+      Handle<JSArrayBuffer> jsab;
+      //size_t size;
+      if (object->IsJSTypedArray()) {
+        auto jsta = JSTypedArray::Validate(isolate, object, "EncodeToBuffer").ToHandleChecked();
+        jsab = jsta->GetBuffer();
+        //size = jsta->GetByteLength();
+      }
+      else if (object->IsJSArrayBuffer()) {
+        jsab = Handle<JSArrayBuffer>::cast(object);
+        if (jsab->IsNullOrUndefined()) {
+          isolate->Throw(*isolate->factory()->NewTypeError(
+            MessageTemplate::kInvalidArrayBufferLength));
+        }
+      }
+      if (jsab->IsNullOrUndefined()) return std::tuple<uint8_t*, size_t>(nullptr, 0);
+      std::shared_ptr<v8::internal::BackingStore> store = jsab->GetBackingStore();
+      return std::tuple<uint8_t*, size_t>((uint8_t*)store->buffer_start(), store->byte_length());
+    }
+
+    inline Handle<JSObject> EncodeNewJSObject(v8::internal::Isolate* isolate) {
+      return isolate->factory()->NewJSObject(isolate->object_function(), AllocationType::kOld);
+    }
+
+    inline void EncodeAddPropertyObject(Isolate* isolate, Handle<JSObject> object, const char* key, Handle<Object> value) {
+      JSObject::AddProperty(isolate, object, key, value, PropertyAttributes::NONE);
+    }
+
+    inline void EncodeAddPropertyNumber(Isolate* isolate, Handle<JSObject> object, const char* key, double value) {
+      Handle<Object> valueObj = isolate->factory()->NewNumber(value);
+      JSObject::AddProperty(isolate, object, key, valueObj, PropertyAttributes::NONE);
+    }
+
+    inline void EncodeAddPropertyString(Isolate* isolate, Handle<JSObject> object, const char* key, const char* value) {
+      Handle<String> strObj = isolate->factory()->InternalizeUtf8String(value);
+      //字段设置为 PropertyAttributes::DontEnum 时，无法通过键值对遍历 Object.keys(retObj)
+      JSObject::AddProperty(isolate, object, key, strObj, PropertyAttributes::NONE);
+    }
+
+    inline Handle<JSArrayBuffer> EncodeNewJSArrayBuffer(v8::internal::Isolate* isolate, size_t size) {
+      MaybeHandle<JSArrayBuffer> arrbuffOjb =
+        isolate->factory()->NewJSArrayBufferAndBackingStore(
+          size, InitializedFlag::kZeroInitialized);
+      Handle<JSArrayBuffer> result;
+      if (!arrbuffOjb.ToHandle(&result)) {
+        isolate->Throw(*isolate->factory()->NewTypeError(
+          MessageTemplate::kInvalidArrayBufferLength));
+        return result;
+      }
+      return result;
+    }
+
+  }  // namespace internal
+}  // namespace v8
+
+#endif  // V8_BUILTINS_BUILTINS_ENCODER_H_