yosys/kernel/hashlib.h

903 lines
21 KiB
C++

// This is free and unencumbered software released into the public domain.
//
// Anyone is free to copy, modify, publish, use, compile, sell, or
// distribute this software, either in source code form or as a compiled
// binary, for any purpose, commercial or non-commercial, and by any
// means.
// -------------------------------------------------------
// Written by Clifford Wolf <clifford@clifford.at> in 2014
// -------------------------------------------------------
#ifndef HASHLIB_H
#include <stdexcept>
#include <string>
#include <vector>
namespace hashlib {
const int hashtable_size_trigger = 2;
const int hashtable_size_factor = 3;
// The XOR version of DJB2
// (traditionally 5381 is used as starting value for the djb2 hash)
inline unsigned int mkhash(unsigned int a, unsigned int b) {
return ((a << 5) + a) ^ b;
}
// The ADD version of DJB2
// (use this version for cache locality in b)
inline unsigned int mkhash_add(unsigned int a, unsigned int b) {
return ((a << 5) + a) + b;
}
inline unsigned int mkhash_xorshift(unsigned int a) {
if (sizeof(a) == 4) {
a ^= a << 13;
a ^= a >> 17;
a ^= a << 5;
} else if (sizeof(a) == 8) {
a ^= a << 13;
a ^= a >> 7;
a ^= a << 17;
} else
throw std::runtime_error("mkhash_xorshift() only implemented for 32 bit and 64 bit ints");
return a;
}
template<typename T> struct hash_ops {
bool cmp(const T &a, const T &b) const {
return a == b;
}
unsigned int hash(const T &a) const {
return a.hash();
}
};
template<> struct hash_ops<int> {
template<typename T>
bool cmp(T a, T b) const {
return a == b;
}
unsigned int hash(unsigned int a) const {
return a;
}
};
template<> struct hash_ops<std::string> {
bool cmp(const std::string &a, const std::string &b) const {
return a == b;
}
unsigned int hash(const std::string &a) const {
unsigned int v = 0;
for (auto c : a)
v = mkhash(v, c);
return v;
}
};
template<typename P, typename Q> struct hash_ops<std::pair<P, Q>> {
bool cmp(std::pair<P, Q> a, std::pair<P, Q> b) const {
return a == b;
}
unsigned int hash(std::pair<P, Q> a) const {
hash_ops<P> p_ops;
hash_ops<Q> q_ops;
return mkhash(p_ops.hash(a.first), q_ops.hash(a.second));
}
};
struct hash_cstr_ops {
bool cmp(const char *a, const char *b) const {
for (int i = 0; a[i] || b[i]; i++)
if (a[i] != b[i])
return false;
return true;
}
unsigned int hash(const char *a) const {
unsigned int hash = 5381;
while (*a)
hash = mkhash(hash, *(a++));
return hash;
}
};
struct hash_ptr_ops {
bool cmp(const void *a, const void *b) const {
return a == b;
}
unsigned int hash(const void *a) const {
return (unsigned long)a;
}
};
struct hash_obj_ops {
bool cmp(const void *a, const void *b) const {
return a == b;
}
template<typename T>
unsigned int hash(const T *a) const {
return a->hash();
}
};
inline int hashtable_size(int min_size)
{
static std::vector<int> primes = {
23, 29, 37, 47, 59, 79, 101, 127, 163, 211, 269, 337, 431, 541, 677,
853, 1069, 1361, 1709, 2137, 2677, 3347, 4201, 5261, 6577, 8231, 10289,
12889, 16127, 20161, 25219, 31531, 39419, 49277, 61603, 77017, 96281,
120371, 150473, 188107, 235159, 293957, 367453, 459317, 574157, 717697,
897133, 1121423, 1401791, 1752239, 2190299, 2737937, 3422429, 4278037,
5347553, 6684443, 8355563, 10444457, 13055587, 16319519, 20399411,
25499291, 31874149, 39842687, 49803361, 62254207, 77817767, 97272239,
121590311, 151987889, 189984863, 237481091, 296851369, 371064217
};
for (auto p : primes)
if (p > min_size) return p;
if (sizeof(int) == 4)
throw std::length_error("hash table exceeded maximum size. use a ILP64 abi for larger tables.");
for (auto p : primes)
if (100129 * p > min_size) return 100129 * p;
throw std::length_error("hash table exceeded maximum size.");
}
template<typename K, typename T, typename OPS = hash_ops<K>>
class dict
{
struct entry_t
{
int link;
std::pair<K, T> udata;
entry_t() : link(-1) { }
entry_t(const std::pair<K, T> &udata) : link(1), udata(udata) { }
bool is_free() const { return link < 0; }
int get_next() const { return (link > 0 ? link : -link) - 2; }
bool get_last() const { return get_next() == -1; }
void set_next_used(int next) { link = next + 2; }
void set_next_free(int next) { link = -(next + 2); }
};
std::vector<int> hashtable;
std::vector<entry_t> entries;
int free_list, counter, begin_n;
int begin_seek_count;
OPS ops;
void init()
{
free_list = -1;
counter = 0;
begin_n = -1;
begin_seek_count = 0;
}
void init_from(const dict<K, T, OPS> &other)
{
hashtable.clear();
entries.clear();
counter = other.size();
begin_n = counter - 1;
entries.reserve(counter);
for (auto &it : other)
entries.push_back(entry_t(it));
rehash();
}
int mkhash(const K &key) const
{
unsigned int hash = 0;
if (!hashtable.empty())
hash = ops.hash(key) % (unsigned int)(hashtable.size());
return hash;
}
void upd_begin_n(bool do_refree = true)
{
if (begin_n < -1) {
begin_n = -(begin_n+2);
while (begin_n >= 0 && entries[begin_n].is_free()) { begin_seek_count++; begin_n--; }
if (do_refree && begin_seek_count > int(entries.size() / 2)) refree();
}
}
void refree()
{
free_list = -1;
begin_n = -1;
int last_free = -1;
for (int i = 0; i < int(entries.size()); i++)
if (entries[i].is_free()) {
if (last_free != -1)
entries[last_free].set_next_free(i);
else
free_list = i;
last_free = i;
} else
begin_n = i;
if (last_free != -1)
entries[last_free].set_next_free(-1);
begin_seek_count = 0;
}
void rehash()
{
upd_begin_n(false);
entries.resize(begin_n + 1);
free_list = -1;
begin_n = -1;
hashtable.clear();
hashtable.resize(hashtable_size(entries.size() * hashtable_size_factor), -1);
int last_free = -1;
for (int i = 0; i < int(entries.size()); i++)
if (entries[i].is_free()) {
if (last_free != -1)
entries[last_free].set_next_free(i);
else
free_list = i;
last_free = i;
} else {
int hash = mkhash(entries[i].udata.first);
entries[i].set_next_used(hashtable[hash]);
hashtable[hash] = i;
begin_n = i;
}
if (last_free != -1)
entries[last_free].set_next_free(-1);
begin_seek_count = 0;
}
int do_erase(const K &key, int hash)
{
int last_index = -1;
int index = hashtable.empty() ? -1 : hashtable[hash];
while (1) {
if (index < 0)
return 0;
if (ops.cmp(entries[index].udata.first, key)) {
if (last_index < 0)
hashtable[hash] = entries[index].get_next();
else
entries[last_index].set_next_used(entries[index].get_next());
entries[index].udata = std::pair<K, T>();
entries[index].set_next_free(free_list);
free_list = index;
if (--counter == 0)
clear();
else if (index == begin_n)
begin_n = -(begin_n+2);
return 1;
}
last_index = index;
index = entries[index].get_next();
}
}
int lookup_index(const K &key, int hash) const
{
int index = hashtable.empty() ? -1 : hashtable[hash];
while (1) {
if (index < 0)
return -1;
if (ops.cmp(entries[index].udata.first, key))
return index;
index = entries[index].get_next();
}
}
int insert_at(const std::pair<K, T> &value, int hash)
{
if (free_list < 0)
{
free_list = entries.size();
entries.push_back(entry_t());
if (entries.size() * hashtable_size_trigger > hashtable.size()) {
int i = free_list;
entries[i].udata = value;
entries[i].set_next_used(0);
begin_n = i;
counter++;
rehash();
return i;
}
}
int i = free_list;
free_list = entries[i].get_next();
entries[i].udata = value;
entries[i].set_next_used(hashtable[hash]);
hashtable[hash] = i;
if ((begin_n < -1 && -(begin_n+2) <= i) || (begin_n >= -1 && begin_n <= i))
begin_n = i;
counter++;
return i;
}
public:
class iterator
{
dict<K, T, OPS> *ptr;
int index;
public:
iterator() { }
iterator(dict<K, T, OPS> *ptr, int index) : ptr(ptr), index(index) { }
iterator operator++() { do index--; while (index >= 0 && ptr->entries[index].is_free()); return *this; }
bool operator==(const iterator &other) const { return index == other.index; }
bool operator!=(const iterator &other) const { return index != other.index; }
std::pair<K, T> &operator*() { return ptr->entries[index].udata; }
std::pair<K, T> *operator->() { return &ptr->entries[index].udata; }
const std::pair<K, T> &operator*() const { return ptr->entries[index].udata; }
const std::pair<K, T> *operator->() const { return &ptr->entries[index].udata; }
};
class const_iterator
{
const dict<K, T, OPS> *ptr;
int index;
public:
const_iterator() { }
const_iterator(const dict<K, T, OPS> *ptr, int index) : ptr(ptr), index(index) { }
const_iterator operator++() { do index--; while (index >= 0 && ptr->entries[index].is_free()); return *this; }
bool operator==(const const_iterator &other) const { return index == other.index; }
bool operator!=(const const_iterator &other) const { return index != other.index; }
const std::pair<K, T> &operator*() const { return ptr->entries[index].udata; }
const std::pair<K, T> *operator->() const { return &ptr->entries[index].udata; }
};
dict()
{
init();
}
dict(const dict<K, T, OPS> &other)
{
init_from(other);
}
dict(dict<K, T, OPS> &&other)
{
init();
swap(other);
}
dict<K, T, OPS> &operator=(const dict<K, T, OPS> &other) {
if (this != &other)
init_from(other);
return *this;
}
dict<K, T, OPS> &operator=(dict<K, T, OPS> &&other) {
clear();
swap(other);
return *this;
}
dict(const std::initializer_list<std::pair<K, T>> &list)
{
init();
for (auto &it : list)
insert(it);
}
template<class InputIterator>
dict(InputIterator first, InputIterator last)
{
init();
insert(first, last);
}
template<class InputIterator>
void insert(InputIterator first, InputIterator last)
{
for (; first != last; ++first)
insert(*first);
}
std::pair<iterator, bool> insert(const std::pair<K, T> &value)
{
int hash = mkhash(value.first);
int i = lookup_index(value.first, hash);
if (i >= 0)
return std::pair<iterator, bool>(iterator(this, i), false);
i = insert_at(value, hash);
return std::pair<iterator, bool>(iterator(this, i), true);
}
int erase(const K &key)
{
int hash = mkhash(key);
return do_erase(key, hash);
}
iterator erase(iterator it)
{
int hash = mkhash(it->first);
do_erase(it->first, hash);
return ++it;
}
int count(const K &key) const
{
int hash = mkhash(key);
int i = lookup_index(key, hash);
return i < 0 ? 0 : 1;
}
iterator find(const K &key)
{
int hash = mkhash(key);
int i = lookup_index(key, hash);
if (i < 0)
return end();
return iterator(this, i);
}
const_iterator find(const K &key) const
{
int hash = mkhash(key);
int i = lookup_index(key, hash);
if (i < 0)
return end();
return const_iterator(this, i);
}
T& at(const K &key)
{
int hash = mkhash(key);
int i = lookup_index(key, hash);
if (i < 0)
throw std::out_of_range("dict::at()");
return entries[i].udata.second;
}
const T& at(const K &key) const
{
int hash = mkhash(key);
int i = lookup_index(key, hash);
if (i < 0)
throw std::out_of_range("dict::at()");
return entries[i].udata.second;
}
T& operator[](const K &key)
{
int hash = mkhash(key);
int i = lookup_index(key, hash);
if (i < 0)
i = insert_at(std::pair<K, T>(key, T()), hash);
return entries[i].udata.second;
}
void swap(dict<K, T, OPS> &other)
{
hashtable.swap(other.hashtable);
entries.swap(other.entries);
std::swap(free_list, other.free_list);
std::swap(counter, other.counter);
std::swap(begin_n, other.begin_n);
std::swap(begin_seek_count, other.begin_seek_count);
}
bool operator==(const dict<K, T, OPS> &other) const {
if (counter != other.counter)
return false;
if (counter == 0)
return true;
if (entries.size() < other.entries.size())
for (auto &it : *this) {
auto oit = other.find(it.first);
if (oit == other.end() || oit->second != it.second)
return false;
}
else
for (auto &oit : other) {
auto it = find(oit.first);
if (it == end() || it->second != oit.second)
return false;
}
return true;
}
bool operator!=(const dict<K, T, OPS> &other) const {
return !(*this == other);
}
size_t size() const { return counter; }
bool empty() const { return counter == 0; }
void clear() { hashtable.clear(); entries.clear(); init(); }
iterator begin() { upd_begin_n(); return iterator(this, begin_n); }
iterator end() { return iterator(this, -1); }
const_iterator begin() const { ((dict*)this)->upd_begin_n(); return const_iterator(this, begin_n); }
const_iterator end() const { return const_iterator(this, -1); }
};
template<typename K, typename OPS = hash_ops<K>>
class pool
{
struct entry_t
{
int link;
K key;
entry_t() : link(-1) { }
entry_t(const K &key) : link(1), key(key) { }
bool is_free() const { return link < 0; }
int get_next() const { return (link > 0 ? link : -link) - 2; }
bool get_last() const { return get_next() == -1; }
void set_next_used(int next) { link = next + 2; }
void set_next_free(int next) { link = -(next + 2); }
};
std::vector<int> hashtable;
std::vector<entry_t> entries;
int free_list, counter, begin_n;
int begin_seek_count;
OPS ops;
void init()
{
free_list = -1;
counter = 0;
begin_n = -1;
begin_seek_count = 0;
}
void init_from(const pool<K, OPS> &other)
{
hashtable.clear();
entries.clear();
counter = other.size();
begin_n = counter - 1;
entries.reserve(counter);
for (auto &it : other)
entries.push_back(entry_t(it));
rehash();
}
int mkhash(const K &key) const
{
unsigned int hash = 0;
if (!hashtable.empty())
hash = ops.hash(key) % (unsigned int)(hashtable.size());
return hash;
}
void upd_begin_n(bool do_refree = true)
{
if (begin_n < -1) {
begin_n = -(begin_n+2);
while (begin_n >= 0 && entries[begin_n].is_free()) { begin_seek_count++; begin_n--; }
if (do_refree && begin_seek_count > int(entries.size() / 2)) refree();
}
}
void refree()
{
free_list = -1;
begin_n = -1;
int last_free = -1;
for (int i = 0; i < int(entries.size()); i++)
if (entries[i].is_free()) {
if (last_free != -1)
entries[last_free].set_next_free(i);
else
free_list = i;
last_free = i;
} else
begin_n = i;
if (last_free != -1)
entries[last_free].set_next_free(-1);
begin_seek_count = 0;
}
void rehash()
{
upd_begin_n(false);
entries.resize(begin_n + 1);
free_list = -1;
begin_n = -1;
hashtable.clear();
hashtable.resize(hashtable_size(entries.size() * hashtable_size_factor), -1);
int last_free = -1;
for (int i = 0; i < int(entries.size()); i++)
if (entries[i].is_free()) {
if (last_free != -1)
entries[last_free].set_next_free(i);
else
free_list = i;
last_free = i;
} else {
int hash = mkhash(entries[i].key);
entries[i].set_next_used(hashtable[hash]);
hashtable[hash] = i;
begin_n = i;
}
if (last_free != -1)
entries[last_free].set_next_free(-1);
begin_seek_count = 0;
}
int do_erase(const K &key, int hash)
{
int last_index = -1;
int index = hashtable.empty() ? -1 : hashtable[hash];
while (1) {
if (index < 0)
return 0;
if (ops.cmp(entries[index].key, key)) {
if (last_index < 0)
hashtable[hash] = entries[index].get_next();
else
entries[last_index].set_next_used(entries[index].get_next());
entries[index].key = K();
entries[index].set_next_free(free_list);
free_list = index;
if (--counter == 0)
clear();
else if (index == begin_n)
begin_n = -(begin_n+2);
return 1;
}
last_index = index;
index = entries[index].get_next();
}
}
int lookup_index(const K &key, int hash) const
{
int index = hashtable.empty() ? -1 : hashtable[hash];
while (1) {
if (index < 0)
return -1;
if (ops.cmp(entries[index].key, key))
return index;
index = entries[index].get_next();
}
}
int insert_at(const K &key, int hash)
{
if (free_list < 0)
{
free_list = entries.size();
entries.push_back(entry_t());
if (entries.size() * hashtable_size_trigger > hashtable.size()) {
int i = free_list;
entries[i].key = key;
entries[i].set_next_used(0);
begin_n = i;
counter++;
rehash();
return i;
}
}
int i = free_list;
free_list = entries[i].get_next();
entries[i].key = key;
entries[i].set_next_used(hashtable[hash]);
hashtable[hash] = i;
if ((begin_n < -1 && -(begin_n+2) <= i) || (begin_n >= -1 && begin_n <= i))
begin_n = i;
counter++;
return i;
}
public:
class iterator
{
pool<K, OPS> *ptr;
int index;
public:
iterator() { }
iterator(pool<K, OPS> *ptr, int index) : ptr(ptr), index(index) { }
iterator operator++() { do index--; while (index >= 0 && ptr->entries[index].is_free()); return *this; }
bool operator==(const iterator &other) const { return index == other.index; }
bool operator!=(const iterator &other) const { return index != other.index; }
K &operator*() { return ptr->entries[index].key; }
K *operator->() { return &ptr->entries[index].key; }
const K &operator*() const { return ptr->entries[index].key; }
const K *operator->() const { return &ptr->entries[index].key; }
};
class const_iterator
{
const pool<K, OPS> *ptr;
int index;
public:
const_iterator() { }
const_iterator(const pool<K, OPS> *ptr, int index) : ptr(ptr), index(index) { }
const_iterator operator++() { do index--; while (index >= 0 && ptr->entries[index].is_free()); return *this; }
bool operator==(const const_iterator &other) const { return index == other.index; }
bool operator!=(const const_iterator &other) const { return index != other.index; }
const K &operator*() const { return ptr->entries[index].key; }
const K *operator->() const { return &ptr->entries[index].key; }
};
pool()
{
init();
}
pool(const pool<K, OPS> &other)
{
init_from(other);
}
pool(pool<K, OPS> &&other)
{
init();
swap(other);
}
pool<K, OPS> &operator=(const pool<K, OPS> &other) {
if (this != &other)
init_from(other);
return *this;
}
pool<K, OPS> &operator=(pool<K, OPS> &&other) {
clear();
swap(other);
return *this;
}
pool(const std::initializer_list<K> &list)
{
init();
for (auto &it : list)
insert(it);
}
template<class InputIterator>
pool(InputIterator first, InputIterator last)
{
init();
insert(first, last);
}
template<class InputIterator>
void insert(InputIterator first, InputIterator last)
{
for (; first != last; ++first)
insert(*first);
}
std::pair<iterator, bool> insert(const K &key)
{
int hash = mkhash(key);
int i = lookup_index(key, hash);
if (i >= 0)
return std::pair<iterator, bool>(iterator(this, i), false);
i = insert_at(key, hash);
return std::pair<iterator, bool>(iterator(this, i), true);
}
int erase(const K &key)
{
int hash = mkhash(key);
return do_erase(key, hash);
}
iterator erase(iterator it)
{
int hash = mkhash(*it);
do_erase(*it, hash);
return ++it;
}
int count(const K &key) const
{
int hash = mkhash(key);
int i = lookup_index(key, hash);
return i < 0 ? 0 : 1;
}
iterator find(const K &key)
{
int hash = mkhash(key);
int i = lookup_index(key, hash);
if (i < 0)
return end();
return iterator(this, i);
}
const_iterator find(const K &key) const
{
int hash = mkhash(key);
int i = lookup_index(key, hash);
if (i < 0)
return end();
return const_iterator(this, i);
}
bool operator[](const K &key) const
{
int hash = mkhash(key);
int i = lookup_index(key, hash);
return i >= 0;
}
void swap(pool<K, OPS> &other)
{
hashtable.swap(other.hashtable);
entries.swap(other.entries);
std::swap(free_list, other.free_list);
std::swap(counter, other.counter);
std::swap(begin_n, other.begin_n);
std::swap(begin_seek_count, other.begin_seek_count);
}
bool operator==(const pool<K, OPS> &other) const {
if (counter != other.counter)
return false;
if (counter == 0)
return true;
if (entries.size() < other.entries.size())
for (auto &it : *this) {
auto oit = other.find(it.first);
if (oit == other.end() || oit->second != it.second)
return false;
}
else
for (auto &oit : other) {
auto it = find(oit.first);
if (it == end() || it->second != oit.second)
return false;
}
return true;
}
bool operator!=(const pool<K, OPS> &other) const {
return !(*this == other);
}
size_t size() const { return counter; }
bool empty() const { return counter == 0; }
void clear() { hashtable.clear(); entries.clear(); init(); }
iterator begin() { upd_begin_n(); return iterator(this, begin_n); }
iterator end() { return iterator(this, -1); }
const_iterator begin() const { ((pool*)this)->upd_begin_n(); return const_iterator(this, begin_n); }
const_iterator end() const { return const_iterator(this, -1); }
};
} /* namespace hashlib */
#endif