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