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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
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* vim: set ts=8 sts=2 et sw=2 tw=80:
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#ifndef js_TraceableFifo_h
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#define js_TraceableFifo_h
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#include "ds/Fifo.h"
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#include "js/RootingAPI.h"
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#include "js/TracingAPI.h"
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namespace js {
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// A TraceableFifo is a Fifo with an additional trace method that knows how to
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// visit all of the items stored in the Fifo. For Fifos that contain GC things,
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// this is usually more convenient than manually iterating and marking the
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// contents.
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//
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// Most types of GC pointers as keys and values can be traced with no extra
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// infrastructure. For structs and non-gc-pointer members, ensure that there is
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// a specialization of GCPolicy<T> with an appropriate trace method available
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// to handle the custom type. Generic helpers can be found in
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// js/public/TracingAPI.h. Generic helpers can be found in
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// js/public/TracingAPI.h.
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//
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// Note that although this Fifo's trace will deal correctly with moved items, it
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// does not itself know when to barrier or trace items. To function properly it
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// must either be used with Rooted, or barriered and traced manually.
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template <typename T, size_t MinInlineCapacity = 0,
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typename AllocPolicy = TempAllocPolicy>
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class TraceableFifo : public js::Fifo<T, MinInlineCapacity, AllocPolicy> {
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using Base = js::Fifo<T, MinInlineCapacity, AllocPolicy>;
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public:
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explicit TraceableFifo(AllocPolicy alloc = AllocPolicy())
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: Base(std::move(alloc)) {}
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TraceableFifo(TraceableFifo&& rhs) : Base(std::move(rhs)) {}
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TraceableFifo& operator=(TraceableFifo&& rhs) = default;
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TraceableFifo(const TraceableFifo&) = delete;
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TraceableFifo& operator=(const TraceableFifo&) = delete;
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void trace(JSTracer* trc) {
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for (size_t i = 0; i < this->front_.length(); ++i) {
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JS::GCPolicy<T>::trace(trc, &this->front_[i], "fifo element");
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}
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for (size_t i = 0; i < this->rear_.length(); ++i) {
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JS::GCPolicy<T>::trace(trc, &this->rear_[i], "fifo element");
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}
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}
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};
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template <typename Wrapper, typename T, size_t Capacity, typename AllocPolicy>
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class WrappedPtrOperations<TraceableFifo<T, Capacity, AllocPolicy>, Wrapper> {
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using TF = TraceableFifo<T, Capacity, AllocPolicy>;
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const TF& fifo() const { return static_cast<const Wrapper*>(this)->get(); }
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public:
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size_t length() const { return fifo().length(); }
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bool empty() const { return fifo().empty(); }
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const T& front() const { return fifo().front(); }
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};
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template <typename Wrapper, typename T, size_t Capacity, typename AllocPolicy>
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class MutableWrappedPtrOperations<TraceableFifo<T, Capacity, AllocPolicy>,
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Wrapper>
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: public WrappedPtrOperations<TraceableFifo<T, Capacity, AllocPolicy>,
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Wrapper> {
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using TF = TraceableFifo<T, Capacity, AllocPolicy>;
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TF& fifo() { return static_cast<Wrapper*>(this)->get(); }
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public:
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T& front() { return fifo().front(); }
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template <typename U>
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bool pushBack(U&& u) {
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return fifo().pushBack(std::forward<U>(u));
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}
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template <typename... Args>
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bool emplaceBack(Args&&... args) {
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return fifo().emplaceBack(std::forward<Args...>(args...));
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}
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void popFront() { fifo().popFront(); }
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void clear() { fifo().clear(); }
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};
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} // namespace js
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#endif // js_TraceableFifo_h