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#include <QtCore/qarraydata.h>
#include <QtCore/private/qtools_p.h>

#include <stdlib.h>

QT_BEGIN_NAMESPACE

#if defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__  >= 406) && !defined(Q_CC_INTEL)
  #pragma GCC diagnostic push
  #pragma GCC diagnostic ignored "-Wmissing-field-initializers"
#endif

const QArrayData QArrayData::shared_null[2] = {
    { Q_REFCOUNT_INITIALIZE_STATIC, 0, 0, 0, sizeof(QArrayData) }, // shared null
    /* zero initialized terminator */};

static const QArrayData qt_array[3] = {
    { Q_REFCOUNT_INITIALIZE_STATIC, 0, 0, 0, sizeof(QArrayData) }, // shared empty
    { { Q_BASIC_ATOMIC_INITIALIZER(0) }, 0, 0, 0, sizeof(QArrayData) }, // unsharable empty
    /* zero initialized terminator */};

#if defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__  >= 406) && !defined(Q_CC_INTEL)
  #pragma GCC diagnostic pop
#endif

static const QArrayData &qt_array_empty = qt_array[0];
static const QArrayData &qt_array_unsharable_empty = qt_array[1];

QArrayData *QArrayData::allocate(size_t objectSize, size_t alignment,
        size_t capacity, AllocationOptions options)
{
    // Alignment is a power of two
    Q_ASSERT(alignment >= Q_ALIGNOF(QArrayData)
            && !(alignment & (alignment - 1)));

    // Don't allocate empty headers
    if (!(options & RawData) && !capacity)
        return !(options & Unsharable)
            ? const_cast<QArrayData *>(&qt_array_empty)
            : const_cast<QArrayData *>(&qt_array_unsharable_empty);

    size_t headerSize = sizeof(QArrayData);

    // Allocate extra (alignment - Q_ALIGNOF(QArrayData)) padding bytes so we
    // can properly align the data array. This assumes malloc is able to
    // provide appropriate alignment for the header -- as it should!
    // Padding is skipped when allocating a header for RawData.
    if (!(options & RawData))
        headerSize += (alignment - Q_ALIGNOF(QArrayData));

    // Allocate additional space if array is growing
    if (options & Grow)
        capacity = qAllocMore(objectSize * capacity, headerSize) / int(objectSize);

    size_t allocSize = headerSize + objectSize * capacity;

    QArrayData *header = static_cast<QArrayData *>(::malloc(allocSize));
    if (header) {
        quintptr data = (quintptr(header) + sizeof(QArrayData) + alignment - 1)
                & ~(alignment - 1);

        header->ref.atomic.store(bool(!(options & Unsharable)));
        header->size = 0;
        header->alloc = capacity;
        header->capacityReserved = bool(options & CapacityReserved);
        header->offset = data - quintptr(header);
    }

    return header;
}

void QArrayData::deallocate(QArrayData *data, size_t objectSize,
        size_t alignment)
{
    // Alignment is a power of two
    Q_ASSERT(alignment >= Q_ALIGNOF(QArrayData)
            && !(alignment & (alignment - 1)));
    Q_UNUSED(objectSize) Q_UNUSED(alignment)

    if (data == &qt_array_unsharable_empty)
        return;

    Q_ASSERT_X(!data->ref.isStatic(), "QArrayData::deallocate", "Static data can not be deleted");
    ::free(data);
}

QT_END_NAMESPACE