zmusic/thirdparty/opnmidi/opnmidi_bankmap.h
Christoph Oelckers a4eae42ec5 - initial commit
2020-01-02 17:52:30 +01:00

127 lines
3.7 KiB
C++

/*
* libOPNMIDI is a free MIDI to WAV conversion library with OPN2 (YM2612) emulation
*
* MIDI parser and player (Original code from ADLMIDI): Copyright (c) 2010-2014 Joel Yliluoma <bisqwit@iki.fi>
* ADLMIDI Library API: Copyright (c) 2015-2018 Vitaly Novichkov <admin@wohlnet.ru>
*
* Library is based on the ADLMIDI, a MIDI player for Linux and Windows with OPL3 emulation:
* http://iki.fi/bisqwit/source/adlmidi.html
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef OPNMIDI_BANKMAP_H
#define OPNMIDI_BANKMAP_H
#include <list>
#include <utility>
#include <stdint.h>
#include <stddef.h>
#include "opnmidi_ptr.hpp"
/**
* A simple hash map which accepts bank numbers as keys, can be reserved to a
* fixed size, offers O(1) search and insertion, has a hash function to
* optimize for the worst case, and has some good cache locality properties.
*/
template <class T>
class BasicBankMap
{
public:
typedef size_t key_type; /* the bank identifier */
typedef T mapped_type;
typedef std::pair<key_type, T> value_type;
BasicBankMap();
void reserve(size_t capacity);
size_t size() const
{ return m_size; }
size_t capacity() const
{ return m_capacity; }
bool empty() const
{ return m_size == 0; }
class iterator;
iterator begin() const;
iterator end() const;
struct do_not_expand_t {};
iterator find(key_type key);
void erase(iterator it);
std::pair<iterator, bool> insert(const value_type &value);
std::pair<iterator, bool> insert(const value_type &value, do_not_expand_t);
void clear();
T &operator[](key_type key);
private:
struct Slot;
enum { minimum_allocation = 4 };
enum
{
hash_bits = 8, /* worst case # of collisions: 128^2/2^hash_bits */
hash_buckets = 1 << hash_bits,
};
public:
class iterator
{
public:
iterator();
value_type &operator*() const { return slot->value; }
value_type *operator->() const { return &slot->value; }
iterator &operator++();
bool operator==(const iterator &o) const;
bool operator!=(const iterator &o) const;
void to_ptrs(void *ptrs[3]);
static iterator from_ptrs(void *const ptrs[3]);
private:
Slot **buckets;
Slot *slot;
size_t index;
iterator(Slot **buckets, Slot *slot, size_t index);
#ifdef _MSC_VER
template<class _T>
friend class BasicBankMap;
#else
friend class BasicBankMap<T>;
#endif
};
private:
struct Slot {
Slot *next, *prev;
value_type value;
Slot() : next(NULL), prev(NULL) {}
};
AdlMIDI_SPtrArray<Slot *> m_buckets;
std::list< AdlMIDI_SPtrArray<Slot> > m_allocations;
Slot *m_freeslots;
size_t m_size;
size_t m_capacity;
static size_t hash(key_type key);
Slot *allocate_slot();
Slot *ensure_allocate_slot();
void free_slot(Slot *slot);
Slot *bucket_find(size_t index, key_type key);
void bucket_add(size_t index, Slot *slot);
void bucket_remove(size_t index, Slot *slot);
};
#include "opnmidi_bankmap.tcc"
#endif // OPNMIDI_BANKMAP_H