/* * Copyright (C) 2016 Apple Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #pragma once #if ENABLE(WEBASSEMBLY) namespace JSC { namespace Wasm { class PageCount { public: PageCount() : m_pageCount(UINT_MAX) { static_assert(maxPageCount < UINT_MAX, "We rely on this here."); } PageCount(uint32_t pageCount) : m_pageCount(pageCount) { } size_t bytes() { return m_pageCount * pageSize; } static bool isValid(uint32_t pageCount) { return pageCount <= maxPageCount; } static PageCount max() { return PageCount(maxPageCount); } explicit operator bool() const { return m_pageCount != UINT_MAX; } bool operator<(const PageCount& other) const { return m_pageCount < other.m_pageCount; } bool operator>(const PageCount& other) const { return m_pageCount > other.m_pageCount; } bool operator>=(const PageCount& other) const { return m_pageCount >= other.m_pageCount; } private: static constexpr uint32_t pageSize = 64 * KB; static constexpr uint32_t maxPageCount = static_cast<uint32_t>((1ull << 32) / pageSize); uint32_t m_pageCount; }; } } // namespace JSC::Wasm #endif // ENABLE(WASM)