ladybird/AK/IDAllocator.h

56 lines
1.1 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Forward.h>
#include <AK/HashTable.h>
#include <AK/Random.h>
namespace AK {
// This class manages a pool of random ID's in the range N (default of 1) to INT32_MAX
class IDAllocator {
public:
IDAllocator() = default;
explicit IDAllocator(int minimum_value)
: m_minimum_value(minimum_value)
{
}
~IDAllocator() = default;
int allocate()
{
VERIFY(m_allocated_ids.size() < (INT32_MAX - 2));
int id = 0;
for (;;) {
id = static_cast<int>(get_random_uniform(NumericLimits<int>::max()));
if (id < m_minimum_value)
continue;
if (m_allocated_ids.set(id) == AK::HashSetResult::InsertedNewEntry)
break;
}
return id;
}
void deallocate(int id)
{
m_allocated_ids.remove(id);
}
private:
HashTable<int> m_allocated_ids;
int m_minimum_value { 1 };
};
}
#if USING_AK_GLOBALLY
using AK::IDAllocator;
#endif