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