/* -*- 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_inl_h

#define vm_ArrayObject_inl_h

#include "vm/ArrayObject.h"

#include "gc/GCTrace.h"

#include "vm/StringType.h"

#include "vm/JSObject-inl.h"

#include "vm/ObjectGroup-inl.h"

#include "vm/ObjectOperations-inl.h" // js::GetElement

#include "vm/TypeInference-inl.h"

namespace js {

inline void

ArrayObject::setLength(JSContext* cx, uint32_t length)

{

    MOZ_ASSERT(lengthIsWritable());

    MOZ_ASSERT_IF(length != getElementsHeader()->length, !denseElementsAreFrozen());

    if (length > INT32_MAX) {

        /* Track objects with overflowing lengths in type information. */

        MarkObjectGroupFlags(cx, this, OBJECT_FLAG_LENGTH_OVERFLOW);

    }

    getElementsHeader()->length = length;

}

/* static */ inline ArrayObject*

ArrayObject::createArrayInternal(JSContext* cx, gc::AllocKind kind, gc::InitialHeap heap,

                                 HandleShape shape, HandleObjectGroup group,

                                 AutoSetNewObjectMetadata&)

{

    const js::Class* clasp = group->clasp();

    MOZ_ASSERT(shape && group);

    MOZ_ASSERT(clasp == shape->getObjectClass());

    MOZ_ASSERT(clasp == &ArrayObject::class_);

    MOZ_ASSERT_IF(clasp->hasFinalize(), heap == gc::TenuredHeap);

    MOZ_ASSERT_IF(group->hasUnanalyzedPreliminaryObjects(),

                  heap == js::gc::TenuredHeap);

    // Arrays can use their fixed slots to store elements, so can't have shapes

    // which allow named properties to be stored in the fixed slots.

    MOZ_ASSERT(shape->numFixedSlots() == 0);

    size_t nDynamicSlots = dynamicSlotsCount(0, shape->slotSpan(), clasp);

    JSObject* obj = js::Allocate<JSObject>(cx, kind, nDynamicSlots, heap, clasp);

    if (!obj) {

        return nullptr;

    }

    ArrayObject* aobj = static_cast<ArrayObject*>(obj);

    aobj->initGroup(group);

    aobj->initShape(shape);

    // NOTE: Dynamic slots are created internally by Allocate<JSObject>.

    if (!nDynamicSlots) {

        aobj->initSlots(nullptr);

    }

    MOZ_ASSERT(clasp->shouldDelayMetadataBuilder());

    cx->realm()->setObjectPendingMetadata(cx, aobj);

    return aobj;

}

/* static */ inline ArrayObject*

ArrayObject::finishCreateArray(ArrayObject* obj, HandleShape shape, AutoSetNewObjectMetadata& metadata)

{

    size_t span = shape->slotSpan();

    if (span) {

        obj->initializeSlotRange(0, span);

    }

    gc::gcTracer.traceCreateObject(obj);

    return obj;

}

/* static */ inline ArrayObject*

ArrayObject::createArray(JSContext* cx, gc::AllocKind kind, gc::InitialHeap heap,

                         HandleShape shape, HandleObjectGroup group,

                         uint32_t length, AutoSetNewObjectMetadata& metadata)

{

    ArrayObject* obj = createArrayInternal(cx, kind, heap, shape, group, metadata);

    if (!obj) {

        return nullptr;

    }

    uint32_t capacity = gc::GetGCKindSlots(kind) - ObjectElements::VALUES_PER_HEADER;

    obj->setFixedElements();

    new (obj->getElementsHeader()) ObjectElements(capacity, length);

    return finishCreateArray(obj, shape, metadata);

}

/* static */ inline ArrayObject*

ArrayObject::createCopyOnWriteArray(JSContext* cx, gc::InitialHeap heap,

                                    HandleArrayObject sharedElementsOwner)

{

    MOZ_ASSERT(sharedElementsOwner->getElementsHeader()->isCopyOnWrite());

    MOZ_ASSERT(sharedElementsOwner->getElementsHeader()->ownerObject() == sharedElementsOwner);

    // Use the smallest allocation kind for the array, as it can't have any

    // fixed slots (see the assert in createArrayInternal) and will not be using

    // its fixed elements.

    gc::AllocKind kind = gc::AllocKind::OBJECT0_BACKGROUND;

    AutoSetNewObjectMetadata metadata(cx);

    RootedShape shape(cx, sharedElementsOwner->lastProperty());

    RootedObjectGroup group(cx, sharedElementsOwner->group());

    ArrayObject* obj = createArrayInternal(cx, kind, heap, shape, group, metadata);

    if (!obj) {

        return nullptr;

    }

    obj->elements_ = sharedElementsOwner->getDenseElementsAllowCopyOnWrite();

    return finishCreateArray(obj, shape, metadata);

}

} // namespace js

#endif // vm_ArrayObject_inl_h