1 files changed, 62 insertions, 0 deletions
diff --git a/js/src/vm/ArrayObject.h b/js/src/vm/ArrayObject.h
new file mode 100644
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+++ b/js/src/vm/ArrayObject.h
@@ -0,0 +1,62 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef vm_ArrayObject_h
+#define vm_ArrayObject_h
+
+#include "vm/NativeObject.h"
+
+namespace js {
+
+class AutoSetNewObjectMetadata;
+
+class ArrayObject : public NativeObject {
+ public:
+  // Array(x) eagerly allocates dense elements if x <= this value. Without
+  // the subtraction the max would roll over to the next power-of-two (4096)
+  // due to the way that growElements() and goodAllocated() work.
+  static const uint32_t EagerAllocationMaxLength =
+      2048 - ObjectElements::VALUES_PER_HEADER;
+
+  static const JSClass class_;
+
+  bool lengthIsWritable() const {
+    return !getElementsHeader()->hasNonwritableArrayLength();
+  }
+
+  uint32_t length() const { return getElementsHeader()->length; }
+
+  void setNonWritableLength(JSContext* cx) {
+    shrinkCapacityToInitializedLength(cx);
+    getElementsHeader()->setNonwritableArrayLength();
+  }
+
+  void setLength(uint32_t length) {
+    MOZ_ASSERT(lengthIsWritable());
+    MOZ_ASSERT_IF(length != getElementsHeader()->length,
+                  !denseElementsAreFrozen());
+    getElementsHeader()->length = length;
+  }
+
+  // Try to add a new dense element to this array. The array must be extensible.
+  //
+  // Returns DenseElementResult::Incomplete if `index >= length`, if the array
+  // has sparse elements, if we're adding a sparse element, or if the array
+  // already contains a dense element at this index.
+  inline DenseElementResult addDenseElementNoLengthChange(JSContext* cx,
+                                                          uint32_t index,
+                                                          const Value& val);
+
+  // Make an array object with the specified initial state.
+  static MOZ_ALWAYS_INLINE ArrayObject* create(
+      JSContext* cx, gc::AllocKind kind, gc::Heap heap,
+      Handle<SharedShape*> shape, uint32_t length, uint32_t slotSpan,
+      AutoSetNewObjectMetadata& metadata, gc::AllocSite* site = nullptr);
+};
+
+}  // namespace js
+
+#endif  // vm_ArrayObject_h