| /* -*- 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 jshashutil_h |
| #define jshashutil_h |
| |
| #include "jscntxt.h" |
| |
| #include "gc/Zone.h" |
| |
| namespace js { |
| |
| /* |
| * Used to add entries to a js::HashMap or HashSet where the key depends on a GC |
| * thing that may be moved by generational or compacting GC between the call to |
| * lookupForAdd() and relookupOrAdd(). |
| */ |
| template <class T> |
| struct DependentAddPtr |
| { |
| typedef typename T::AddPtr AddPtr; |
| typedef typename T::Entry Entry; |
| |
| template <class Lookup> |
| DependentAddPtr(const ExclusiveContext* cx, const T& table, const Lookup& lookup) |
| : addPtr(table.lookupForAdd(lookup)) |
| , originalGcNumber(cx->zone()->gcNumber()) |
| {} |
| |
| template <class KeyInput, class ValueInput> |
| bool add(ExclusiveContext* cx, T& table, const KeyInput& key, const ValueInput& value) { |
| bool gcHappened = originalGcNumber != cx->zone()->gcNumber(); |
| if (gcHappened) |
| addPtr = table.lookupForAdd(key); |
| if (!table.relookupOrAdd(addPtr, key, value)) { |
| ReportOutOfMemory(cx); |
| return false; |
| } |
| return true; |
| } |
| |
| |
| bool found() const { return addPtr.found(); } |
| explicit operator bool() const { return found(); } |
| const Entry& operator*() const { return *addPtr; } |
| const Entry* operator->() const { return &*addPtr; } |
| |
| private: |
| AddPtr addPtr ; |
| const uint64_t originalGcNumber; |
| |
| DependentAddPtr() = delete; |
| DependentAddPtr(const DependentAddPtr&) = delete; |
| DependentAddPtr& operator=(const DependentAddPtr&) = delete; |
| }; |
| |
| } // namespace js |
| |
| #endif |