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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_GCVector_h
#define js_GCVector_h
#include "mozilla/Assertions.h" // MOZ_ASSERT
#include "mozilla/Attributes.h" // MOZ_STACK_CLASS
#include "mozilla/MemoryReporting.h" // MallocSizeOf
#include "mozilla/Vector.h"
#include <stddef.h> // size_t
#include <utility> // forward, move
#include "js/AllocPolicy.h"
#include "js/GCPolicyAPI.h"
#include "js/RootingAPI.h"
class JSTracer;
struct JSContext;
namespace JS {
// A GCVector is a Vector with an additional trace method that knows how
// to visit all of the items stored in the Vector. For vectors 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.
//
// Note that although this Vector'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 = js::TempAllocPolicy>
class GCVector {
mozilla::Vector<T, MinInlineCapacity, AllocPolicy> vector;
public:
using ElementType = T;
explicit GCVector(AllocPolicy alloc = AllocPolicy())
: vector(std::move(alloc)) {}
GCVector(GCVector&& vec) : vector(std::move(vec.vector)) {}
GCVector& operator=(GCVector&& vec) {
vector = std::move(vec.vector);
return *this;
}
size_t length() const { return vector.length(); }
bool empty() const { return vector.empty(); }
size_t capacity() const { return vector.capacity(); }
T* begin() { return vector.begin(); }
const T* begin() const { return vector.begin(); }
T* end() { return vector.end(); }
const T* end() const { return vector.end(); }
T& operator[](size_t i) { return vector[i]; }
const T& operator[](size_t i) const { return vector[i]; }
T& back() { return vector.back(); }
const T& back() const { return vector.back(); }
bool initCapacity(size_t cap) { return vector.initCapacity(cap); }
[[nodiscard]] bool reserve(size_t req) { return vector.reserve(req); }
void shrinkBy(size_t amount) { return vector.shrinkBy(amount); }
void shrinkTo(size_t newLen) { return vector.shrinkTo(newLen); }
[[nodiscard]] bool growBy(size_t amount) { return vector.growBy(amount); }
[[nodiscard]] bool resize(size_t newLen) { return vector.resize(newLen); }
void clear() { return vector.clear(); }
void clearAndFree() { return vector.clearAndFree(); }
template <typename U>
bool append(U&& item) {
return vector.append(std::forward<U>(item));
}
void erase(T* it) { vector.erase(it); }
void erase(T* begin, T* end) { vector.erase(begin, end); }
template <typename Pred>
void eraseIf(Pred pred) {
vector.eraseIf(pred);
}
template <typename U>
void eraseIfEqual(const U& u) {
vector.eraseIfEqual(u);
}
template <typename... Args>
[[nodiscard]] bool emplaceBack(Args&&... args) {
return vector.emplaceBack(std::forward<Args>(args)...);
}
template <typename... Args>
void infallibleEmplaceBack(Args&&... args) {
vector.infallibleEmplaceBack(std::forward<Args>(args)...);
}
template <typename U>
void infallibleAppend(U&& aU) {
return vector.infallibleAppend(std::forward<U>(aU));
}
void infallibleAppendN(const T& aT, size_t aN) {
return vector.infallibleAppendN(aT, aN);
}
template <typename U>
void infallibleAppend(const U* aBegin, const U* aEnd) {
return vector.infallibleAppend(aBegin, aEnd);
}
template <typename U>
void infallibleAppend(const U* aBegin, size_t aLength) {
return vector.infallibleAppend(aBegin, aLength);
}
template <typename U>
[[nodiscard]] bool appendAll(const U& aU) {
return vector.append(aU.begin(), aU.end());
}
template <typename T2, size_t MinInlineCapacity2, typename AllocPolicy2>
[[nodiscard]] bool appendAll(
GCVector<T2, MinInlineCapacity2, AllocPolicy2>&& aU) {
return vector.appendAll(aU.begin(), aU.end());
}
[[nodiscard]] bool appendN(const T& val, size_t count) {
return vector.appendN(val, count);
}
template <typename U>
[[nodiscard]] bool append(const U* aBegin, const U* aEnd) {
return vector.append(aBegin, aEnd);
}
template <typename U>
[[nodiscard]] bool append(const U* aBegin, size_t aLength) {
return vector.append(aBegin, aLength);
}
void popBack() { return vector.popBack(); }
T popCopy() { return vector.popCopy(); }
size_t sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const {
return vector.sizeOfExcludingThis(mallocSizeOf);
}
size_t sizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const {
return vector.sizeOfIncludingThis(mallocSizeOf);
}
void trace(JSTracer* trc) {
for (auto& elem : vector) {
GCPolicy<T>::trace(trc, &elem, "vector element");
}
}
bool traceWeak(JSTracer* trc) {
T* src = begin();
T* dst = begin();
while (src != end()) {
if (GCPolicy<T>::traceWeak(trc, src)) {
if (src != dst) {
*dst = std::move(*src);
}
dst++;
}
src++;
}
MOZ_ASSERT(dst <= end());
shrinkBy(end() - dst);
return !empty();
}
bool needsSweep() const { return !this->empty(); }
void sweep() {
T* src = begin();
T* dst = begin();
while (src != end()) {
if (!GCPolicy<T>::needsSweep(src)) {
if (src != dst) {
*dst = std::move(*src);
}
dst++;
}
src++;
}
MOZ_ASSERT(dst <= end());
shrinkBy(end() - dst);
}
};
// AllocPolicy is optional. It has a default value declared in TypeDecls.h
template <typename T, typename AllocPolicy>
class MOZ_STACK_CLASS StackGCVector : public GCVector<T, 8, AllocPolicy> {
public:
using Base = GCVector<T, 8, AllocPolicy>;
private:
// Inherit constructor from GCVector.
using Base::Base;
};
} // namespace JS
namespace js {
template <typename Wrapper, typename T, size_t Capacity, typename AllocPolicy>
class WrappedPtrOperations<JS::GCVector<T, Capacity, AllocPolicy>, Wrapper> {
using Vec = JS::GCVector<T, Capacity, AllocPolicy>;
const Vec& vec() const { return static_cast<const Wrapper*>(this)->get(); }
public:
const AllocPolicy& allocPolicy() const { return vec().allocPolicy(); }
size_t length() const { return vec().length(); }
bool empty() const { return vec().empty(); }
size_t capacity() const { return vec().capacity(); }
const T* begin() const { return vec().begin(); }
const T* end() const { return vec().end(); }
const T& back() const { return vec().back(); }
JS::Handle<T> operator[](size_t aIndex) const {
return JS::Handle<T>::fromMarkedLocation(&vec().operator[](aIndex));
}
};
template <typename Wrapper, typename T, size_t Capacity, typename AllocPolicy>
class MutableWrappedPtrOperations<JS::GCVector<T, Capacity, AllocPolicy>,
Wrapper>
: public WrappedPtrOperations<JS::GCVector<T, Capacity, AllocPolicy>,
Wrapper> {
using Vec = JS::GCVector<T, Capacity, AllocPolicy>;
const Vec& vec() const { return static_cast<const Wrapper*>(this)->get(); }
Vec& vec() { return static_cast<Wrapper*>(this)->get(); }
public:
const AllocPolicy& allocPolicy() const { return vec().allocPolicy(); }
AllocPolicy& allocPolicy() { return vec().allocPolicy(); }
const T* begin() const { return vec().begin(); }
T* begin() { return vec().begin(); }
const T* end() const { return vec().end(); }
T* end() { return vec().end(); }
const T& back() const { return vec().back(); }
T& back() { return vec().back(); }
JS::Handle<T> operator[](size_t aIndex) const {
return JS::Handle<T>::fromMarkedLocation(&vec().operator[](aIndex));
}
JS::MutableHandle<T> operator[](size_t aIndex) {
return JS::MutableHandle<T>::fromMarkedLocation(&vec().operator[](aIndex));
}
[[nodiscard]] bool initCapacity(size_t aRequest) {
return vec().initCapacity(aRequest);
}
[[nodiscard]] bool reserve(size_t aRequest) {
return vec().reserve(aRequest);
}
void shrinkBy(size_t aIncr) { vec().shrinkBy(aIncr); }
[[nodiscard]] bool growBy(size_t aIncr) { return vec().growBy(aIncr); }
[[nodiscard]] bool resize(size_t aNewLength) {
return vec().resize(aNewLength);
}
[[nodiscard]] bool growByUninitialized(size_t aIncr) {
return vec().growByUninitialized(aIncr);
}
void infallibleGrowByUninitialized(size_t aIncr) {
vec().infallibleGrowByUninitialized(aIncr);
}
[[nodiscard]] bool resizeUninitialized(size_t aNewLength) {
return vec().resizeUninitialized(aNewLength);
}
void clear() { vec().clear(); }
void clearAndFree() { vec().clearAndFree(); }
template <typename U>
[[nodiscard]] bool append(U&& aU) {
return vec().append(std::forward<U>(aU));
}
template <typename... Args>
[[nodiscard]] bool emplaceBack(Args&&... aArgs) {
return vec().emplaceBack(std::forward<Args>(aArgs)...);
}
template <typename... Args>
void infallibleEmplaceBack(Args&&... args) {
vec().infallibleEmplaceBack(std::forward<Args>(args)...);
}
template <typename U>
[[nodiscard]] bool appendAll(U&& aU) {
return vec().appendAll(aU);
}
[[nodiscard]] bool appendN(const T& aT, size_t aN) {
return vec().appendN(aT, aN);
}
template <typename U>
[[nodiscard]] bool append(const U* aBegin, const U* aEnd) {
return vec().append(aBegin, aEnd);
}
template <typename U>
[[nodiscard]] bool append(const U* aBegin, size_t aLength) {
return vec().append(aBegin, aLength);
}
template <typename U>
void infallibleAppend(U&& aU) {
vec().infallibleAppend(std::forward<U>(aU));
}
void infallibleAppendN(const T& aT, size_t aN) {
vec().infallibleAppendN(aT, aN);
}
template <typename U>
void infallibleAppend(const U* aBegin, const U* aEnd) {
vec().infallibleAppend(aBegin, aEnd);
}
template <typename U>
void infallibleAppend(const U* aBegin, size_t aLength) {
vec().infallibleAppend(aBegin, aLength);
}
void popBack() { vec().popBack(); }
T popCopy() { return vec().popCopy(); }
template <typename U>
T* insert(T* aP, U&& aVal) {
return vec().insert(aP, std::forward<U>(aVal));
}
void erase(T* aT) { vec().erase(aT); }
void erase(T* aBegin, T* aEnd) { vec().erase(aBegin, aEnd); }
template <typename Pred>
void eraseIf(Pred pred) {
vec().eraseIf(pred);
}
template <typename U>
void eraseIfEqual(const U& u) {
vec().eraseIfEqual(u);
}
};
template <typename Wrapper, typename T, typename AllocPolicy>
class WrappedPtrOperations<JS::StackGCVector<T, AllocPolicy>, Wrapper>
: public WrappedPtrOperations<
typename JS::StackGCVector<T, AllocPolicy>::Base, Wrapper> {};
template <typename Wrapper, typename T, typename AllocPolicy>
class MutableWrappedPtrOperations<JS::StackGCVector<T, AllocPolicy>, Wrapper>
: public MutableWrappedPtrOperations<
typename JS::StackGCVector<T, AllocPolicy>::Base, Wrapper> {};
} // namespace js
namespace JS {
// An automatically rooted GCVector for stack use.
template <typename T>
class RootedVector : public Rooted<StackGCVector<T>> {
using Vec = StackGCVector<T>;
using Base = Rooted<Vec>;
public:
explicit RootedVector(JSContext* cx) : Base(cx, Vec(cx)) {}
};
// For use in rust code, an analog to RootedVector that doesn't require
// instances to be destroyed in LIFO order.
template <typename T>
class PersistentRootedVector : public PersistentRooted<StackGCVector<T>> {
using Vec = StackGCVector<T>;
using Base = PersistentRooted<Vec>;
public:
explicit PersistentRootedVector(JSContext* cx) : Base(cx, Vec(cx)) {}
};
} // namespace JS
#endif // js_GCVector_h