98 lines
4.0 KiB
C++
98 lines
4.0 KiB
C++
/*************************************************************************/
|
|
/* pooled_list.h */
|
|
/*************************************************************************/
|
|
/* This file is part of: */
|
|
/* GODOT ENGINE */
|
|
/* https://godotengine.org */
|
|
/*************************************************************************/
|
|
/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur. */
|
|
/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md). */
|
|
/* */
|
|
/* Permission is hereby granted, free of charge, to any person obtaining */
|
|
/* a copy of this software and associated documentation files (the */
|
|
/* "Software"), to deal in the Software without restriction, including */
|
|
/* without limitation the rights to use, copy, modify, merge, publish, */
|
|
/* distribute, sublicense, and/or sell copies of the Software, and to */
|
|
/* permit persons to whom the Software is furnished to do so, subject to */
|
|
/* the following conditions: */
|
|
/* */
|
|
/* The above copyright notice and this permission notice shall be */
|
|
/* included in all copies or substantial portions of the Software. */
|
|
/* */
|
|
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
|
|
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
|
|
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
|
|
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
|
|
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
|
|
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
|
|
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
|
|
/*************************************************************************/
|
|
|
|
#ifndef POOLED_LIST_H
|
|
#define POOLED_LIST_H
|
|
|
|
#include "core/templates/local_vector.h"
|
|
|
|
// Simple template to provide a pool with O(1) allocate and free.
|
|
// The freelist could alternatively be a linked list placed within the unused elements
|
|
// to use less memory, however a separate freelist is probably more cache friendly.
|
|
//
|
|
// NOTE: Take great care when using this with non POD types. The construction and destruction
|
|
// is done in the LocalVector, NOT as part of the pool. So requesting a new item does not guarantee
|
|
// a constructor is run, and free does not guarantee a destructor.
|
|
// You should generally handle clearing
|
|
// an item explicitly after a request, as it may contain 'leftovers'.
|
|
// This is by design for fastest use in the BVH. If you want a more general pool
|
|
// that does call constructors / destructors on request / free, this should probably be
|
|
// a separate template.
|
|
template <class T, bool force_trivial = false>
|
|
class PooledList {
|
|
LocalVector<T, uint32_t, force_trivial> list;
|
|
LocalVector<uint32_t, uint32_t, true> freelist;
|
|
|
|
// not all list members are necessarily used
|
|
int _used_size;
|
|
|
|
public:
|
|
PooledList() {
|
|
_used_size = 0;
|
|
}
|
|
|
|
int estimate_memory_use() const {
|
|
return (list.size() * sizeof(T)) + (freelist.size() * sizeof(uint32_t));
|
|
}
|
|
|
|
const T &operator[](uint32_t p_index) const {
|
|
return list[p_index];
|
|
}
|
|
T &operator[](uint32_t p_index) {
|
|
return list[p_index];
|
|
}
|
|
|
|
int size() const { return _used_size; }
|
|
|
|
T *request(uint32_t &r_id) {
|
|
_used_size++;
|
|
|
|
if (freelist.size()) {
|
|
// pop from freelist
|
|
int new_size = freelist.size() - 1;
|
|
r_id = freelist[new_size];
|
|
freelist.resize(new_size);
|
|
return &list[r_id];
|
|
}
|
|
|
|
r_id = list.size();
|
|
list.resize(r_id + 1);
|
|
return &list[r_id];
|
|
}
|
|
void free(const uint32_t &p_id) {
|
|
// should not be on free list already
|
|
CRASH_COND(p_id >= list.size());
|
|
freelist.push_back(p_id);
|
|
_used_size--;
|
|
}
|
|
};
|
|
|
|
#endif // POOLED_LIST_H
|