/*
|
* Copyright 2017 Google Inc.
|
*
|
* Use of this source code is governed by a BSD-style license that can be
|
* found in the LICENSE file.
|
*/
|
|
#ifndef SkArenaAllocList_DEFINED
|
#define SkArenaAllocList_DEFINED
|
|
#include "SkArenaAlloc.h"
|
#include "SkTypes.h"
|
|
/**
|
* A singly linked list of Ts stored in a SkArenaAlloc. The arena rather than the list owns
|
* the elements. This supports forward iteration and range based for loops.
|
*/
|
template <typename T>
|
class SkArenaAllocList {
|
private:
|
struct Node;
|
|
public:
|
SkArenaAllocList() = default;
|
|
void reset() { fHead = fTail = nullptr; }
|
|
template <typename... Args>
|
inline T& append(SkArenaAlloc* arena, Args... args);
|
|
class Iter {
|
public:
|
Iter() = default;
|
inline Iter& operator++();
|
T& operator*() const { return fCurr->fT; }
|
T* operator->() const { return &fCurr->fT; }
|
bool operator==(const Iter& that) const { return fCurr == that.fCurr; }
|
bool operator!=(const Iter& that) const { return !(*this == that); }
|
|
private:
|
friend class SkArenaAllocList;
|
explicit Iter(Node* node) : fCurr(node) {}
|
Node* fCurr = nullptr;
|
};
|
|
Iter begin() { return Iter(fHead); }
|
Iter end() { return Iter(); }
|
Iter tail() { return Iter(fTail); }
|
|
private:
|
struct Node {
|
template <typename... Args>
|
Node(Args... args) : fT(std::forward<Args>(args)...) {}
|
T fT;
|
Node* fNext = nullptr;
|
};
|
Node* fHead = nullptr;
|
Node* fTail = nullptr;
|
};
|
|
template <typename T>
|
template <typename... Args>
|
T& SkArenaAllocList<T>::append(SkArenaAlloc* arena, Args... args) {
|
SkASSERT(!fHead == !fTail);
|
auto* n = arena->make<Node>(std::forward<Args>(args)...);
|
if (!fTail) {
|
fHead = fTail = n;
|
} else {
|
fTail = fTail->fNext = n;
|
}
|
return fTail->fT;
|
}
|
|
template <typename T>
|
typename SkArenaAllocList<T>::Iter& SkArenaAllocList<T>::Iter::operator++() {
|
fCurr = fCurr->fNext;
|
return *this;
|
}
|
|
#endif
|
