import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

js/src/vm/ArrayObject.h

@@ -0,0 +1,77 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * 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 Class class_;
+
+    bool lengthIsWritable() const {
+        return !getElementsHeader()->hasNonwritableArrayLength();
+    }
+
+    uint32_t length() const {
+        return getElementsHeader()->length;
+    }
+
+    inline void setLength(ExclusiveContext* cx, uint32_t length);
+
+    // Variant of setLength for use on arrays where the length cannot overflow int32_t.
+    void setLengthInt32(uint32_t length) {
+        MOZ_ASSERT(lengthIsWritable());
+        MOZ_ASSERT(length <= INT32_MAX);
+        getElementsHeader()->length = length;
+    }
+
+    // Make an array object with the specified initial state.
+    static inline ArrayObject*
+    createArray(ExclusiveContext* cx,
+                gc::AllocKind kind,
+                gc::InitialHeap heap,
+                HandleShape shape,
+                HandleObjectGroup group,
+                uint32_t length,
+                AutoSetNewObjectMetadata& metadata);
+
+    // Make a copy-on-write array object which shares the elements of an
+    // existing object.
+    static inline ArrayObject*
+    createCopyOnWriteArray(ExclusiveContext* cx,
+                           gc::InitialHeap heap,
+                           HandleArrayObject sharedElementsOwner);
+
+  private:
+    // Helper for the above methods.
+    static inline ArrayObject*
+    createArrayInternal(ExclusiveContext* cx,
+                        gc::AllocKind kind,
+                        gc::InitialHeap heap,
+                        HandleShape shape,
+                        HandleObjectGroup group,
+                        AutoSetNewObjectMetadata&);
+
+    static inline ArrayObject*
+    finishCreateArray(ArrayObject* obj, HandleShape shape, AutoSetNewObjectMetadata& metadata);
+};
+
+} // namespace js
+
+#endif // vm_ArrayObject_h
+