[inspector] introduced v8::debug::EntriesPreview for inspector

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 7122 matching lines @@
   auto self = Utils::OpenHandle(this);
   i::Handle<i::Object> result;
   i::Handle<i::Object> argv[] = {Utils::OpenHandle(*key)};
   has_pending_exception = !i::Execution::Call(isolate, isolate->map_delete(),
                                               self, arraysize(argv), argv)
                                .ToHandle(&result);
   RETURN_ON_FAILED_EXECUTION_PRIMITIVE(bool);
   return Just(result->IsTrue(isolate));
 }
 
-
-Local<Array> Map::AsArray() const {
-  i::Handle<i::JSMap> obj = Utils::OpenHandle(this);
-  i::Isolate* isolate = obj->GetIsolate();
+namespace {
+i::Handle<i::JSArray> MapAsArray(i::Isolate* isolate, i::Object* table_obj,
+                                 int offset, int kind) {
   i::Factory* factory = isolate->factory();
-  LOG_API(isolate, Map, AsArray);
-  ENTER_V8(isolate);
-  i::Handle<i::OrderedHashMap> table(i::OrderedHashMap::cast(obj->table()));
-  int length = table->NumberOfElements() * 2;
+  i::Handle<i::OrderedHashMap> table(i::OrderedHashMap::cast(table_obj));
+  if (offset >= table->NumberOfElements()) return factory->NewJSArray(0);
+  int length = (table->NumberOfElements() - offset) *
+               (kind == i::JSMapIterator::kKindEntries ? 2 : 1);
   i::Handle<i::FixedArray> result = factory->NewFixedArray(length);
   int result_index = 0;
   {
     i::DisallowHeapAllocation no_gc;
     int capacity = table->UsedCapacity();
     i::Oddball* the_hole = isolate->heap()->the_hole_value();
     for (int i = 0; i < capacity; ++i) {
       i::Object* key = table->KeyAt(i);
       if (key == the_hole) continue;
-      result->set(result_index++, key);
-      result->set(result_index++, table->ValueAt(i));
+      if (offset-- > 0) continue;
+      if (kind == i::JSMapIterator::kKindEntries ||
+          kind == i::JSMapIterator::kKindKeys) {
+        result->set(result_index++, key);
+      }
+      if (kind == i::JSMapIterator::kKindEntries ||
+          kind == i::JSMapIterator::kKindValues) {
+        result->set(result_index++, table->ValueAt(i));
+      }
     }
   }
   DCHECK_EQ(result_index, result->length());
   DCHECK_EQ(result_index, length);
-  i::Handle<i::JSArray> result_array =
-      factory->NewJSArrayWithElements(result, i::FAST_ELEMENTS, length);
-  return Utils::ToLocal(result_array);
+  return factory->NewJSArrayWithElements(result, i::FAST_ELEMENTS, length);
+}
+}  // namespace
+
+Local<Array> Map::AsArray() const {
+  i::Handle<i::JSMap> obj = Utils::OpenHandle(this);
+  i::Isolate* isolate = obj->GetIsolate();
+  LOG_API(isolate, Map, AsArray);
+  ENTER_V8(isolate);
+  return Utils::ToLocal(
+      MapAsArray(isolate, obj->table(), 0, i::JSMapIterator::kKindEntries));
 }
 
 
 Local<v8::Set> v8::Set::New(Isolate* isolate) {
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
   LOG_API(i_isolate, Set, New);
   ENTER_V8_NO_SCRIPT_NO_EXCEPTION(i_isolate);
   i::Handle<i::JSSet> obj = i_isolate->factory()->NewJSSet();
   return Utils::ToLocal(obj);
 }
@@ skipping 45 matching lines @@
   auto self = Utils::OpenHandle(this);
   i::Handle<i::Object> result;
   i::Handle<i::Object> argv[] = {Utils::OpenHandle(*key)};
   has_pending_exception = !i::Execution::Call(isolate, isolate->set_delete(),
                                               self, arraysize(argv), argv)
                                .ToHandle(&result);
   RETURN_ON_FAILED_EXECUTION_PRIMITIVE(bool);
   return Just(result->IsTrue(isolate));
 }
 
-
-Local<Array> Set::AsArray() const {
-  i::Handle<i::JSSet> obj = Utils::OpenHandle(this);
-  i::Isolate* isolate = obj->GetIsolate();
+namespace {
+i::Handle<i::JSArray> SetAsArray(i::Isolate* isolate, i::Object* table_obj,
+                                 int offset) {
   i::Factory* factory = isolate->factory();
-  LOG_API(isolate, Set, AsArray);
-  ENTER_V8(isolate);
-  i::Handle<i::OrderedHashSet> table(i::OrderedHashSet::cast(obj->table()));
-  int length = table->NumberOfElements();
+  i::Handle<i::OrderedHashSet> table(i::OrderedHashSet::cast(table_obj));
+  int length = table->NumberOfElements() - offset;
+  if (length <= 0) return factory->NewJSArray(0);
   i::Handle<i::FixedArray> result = factory->NewFixedArray(length);
   int result_index = 0;
   {
     i::DisallowHeapAllocation no_gc;
     int capacity = table->UsedCapacity();
     i::Oddball* the_hole = isolate->heap()->the_hole_value();
     for (int i = 0; i < capacity; ++i) {
       i::Object* key = table->KeyAt(i);
       if (key == the_hole) continue;
+      if (offset-- > 0) continue;
       result->set(result_index++, key);
     }
   }
   DCHECK_EQ(result_index, result->length());
   DCHECK_EQ(result_index, length);
-  i::Handle<i::JSArray> result_array =
-      factory->NewJSArrayWithElements(result, i::FAST_ELEMENTS, length);
-  return Utils::ToLocal(result_array);
+  return factory->NewJSArrayWithElements(result, i::FAST_ELEMENTS, length);
+}
+}  // namespace
+
+Local<Array> Set::AsArray() const {
+  i::Handle<i::JSSet> obj = Utils::OpenHandle(this);
+  i::Isolate* isolate = obj->GetIsolate();
+  LOG_API(isolate, Set, AsArray);
+  ENTER_V8(isolate);
+  return Utils::ToLocal(SetAsArray(isolate, obj->table(), 0));
 }
 
 
 MaybeLocal<Promise::Resolver> Promise::Resolver::New(Local<Context> context) {
   PREPARE_FOR_EXECUTION(context, Promise_Resolver, New, Resolver);
   i::Handle<i::Object> result;
   has_pending_exception =
       !i::Execution::Call(isolate, isolate->promise_internal_constructor(),
                           isolate->factory()->undefined_value(), 0, NULL)
            .ToHandle(&result);
@@ skipping 2076 matching lines @@
 
 int debug::EstimatedValueSize(Isolate* v8_isolate, v8::Local<v8::Value> value) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
   ENTER_V8(isolate);
   i::Handle<i::Object> object = Utils::OpenHandle(*value);
   if (object->IsSmi()) return i::kPointerSize;
   CHECK(object->IsHeapObject());
   return i::Handle<i::HeapObject>::cast(object)->Size();
 }
 
+v8::MaybeLocal<v8::Array> debug::EntriesPreview(Isolate* v8_isolate,
+                                                v8::Local<v8::Value> value,
+                                                bool* is_key_value) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
+  ENTER_V8(isolate);
+  if (value->IsMap()) {
+    *is_key_value = true;
+    return value.As<Map>()->AsArray();
+  }
+  if (value->IsSet()) {
+    *is_key_value = false;
+    return value.As<Set>()->AsArray();
+  }
+
+  i::Handle<i::Object> object = Utils::OpenHandle(*value);
+  if (object->IsJSWeakCollection()) {
+    *is_key_value = object->IsJSWeakMap();
+    return Utils::ToLocal(i::JSWeakCollection::GetEntries(
+        i::Handle<i::JSWeakCollection>::cast(object), 0));
+  }
+  if (object->IsJSMapIterator()) {
+    i::Handle<i::JSMapIterator> iterator =
+        i::Handle<i::JSMapIterator>::cast(object);
+    int iterator_kind = i::Smi::cast(iterator->kind())->value();
+    *is_key_value = iterator_kind == i::JSMapIterator::kKindEntries;
+    if (!iterator->HasMore()) return v8::Array::New(v8_isolate);
+    return Utils::ToLocal(MapAsArray(isolate, iterator->table(),
+                                     i::Smi::cast(iterator->index())->value(),
+                                     iterator_kind));
+  }
+  if (object->IsJSSetIterator()) {
+    i::Handle<i::JSSetIterator> it = i::Handle<i::JSSetIterator>::cast(object);
+    *is_key_value = false;
+    if (!it->HasMore()) return v8::Array::New(v8_isolate);
+    return Utils::ToLocal(
+        SetAsArray(isolate, it->table(), i::Smi::cast(it->index())->value()));
+  }
+  return v8::MaybeLocal<v8::Array>();
+}
+
 Local<String> CpuProfileNode::GetFunctionName() const {
   const i::ProfileNode* node = reinterpret_cast<const i::ProfileNode*>(this);
   i::Isolate* isolate = node->isolate();
   const i::CodeEntry* entry = node->entry();
   i::Handle<i::String> name =
       isolate->factory()->InternalizeUtf8String(entry->name());
   if (!entry->has_name_prefix()) {
     return ToApiHandle<String>(name);
   } else {
     // We do not expect this to fail. Change this if it does.
@@ skipping 672 matching lines @@
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 }  // namespace internal
 }  // namespace v8