yosys/kernel/hashlib.h

789 lines
18 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
inline unsigned int mkhash(unsigned int a, unsigned int b) {
return ((a << 5) + a) ^ b;
}
// traditionally 5381 is used as starting value for the djb2 hash
const unsigned int mkhash_init = 5381;
// The ADD version of DJB2
// (usunsigned int mkhashe 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 {
static inline bool cmp(const T &a, const T &b) {
return a == b;
}
static inline unsigned int hash(const T &a) {
return a.hash();
}
};
template<> struct hash_ops<int> {
template<typename T>
static inline bool cmp(T a, T b) {
return a == b;
}
template<typename T>
static inline unsigned int hash(T a) {
return a;
}
};
template<> struct hash_ops<std::string> {
static inline bool cmp(const std::string &a, const std::string &b) {
return a == b;
}
static inline unsigned int hash(const std::string &a) {
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>> {
static inline bool cmp(std::pair<P, Q> a, std::pair<P, Q> b) {
return a == b;
}
static inline unsigned int hash(std::pair<P, Q> a) {
hash_ops<P> p_ops;
hash_ops<Q> q_ops;
return mkhash(p_ops.hash(a.first), q_ops.hash(a.second));
}
};
template<typename T> struct hash_ops<std::vector<T>> {
static inline bool cmp(std::vector<T> a, std::vector<T> b) {
return a == b;
}
static inline unsigned int hash(std::vector<T> a) {
hash_ops<T> t_ops;
unsigned int h = mkhash_init;
for (auto k : a)
h = mkhash(h, t_ops.hash(k));
return h;
}
};
struct hash_cstr_ops {
static inline bool cmp(const char *a, const char *b) {
for (int i = 0; a[i] || b[i]; i++)
if (a[i] != b[i])
return false;
return true;
}
static inline unsigned int hash(const char *a) {
unsigned int hash = mkhash_init;
while (*a)
hash = mkhash(hash, *(a++));
return hash;
}
};
struct hash_ptr_ops {
static inline bool cmp(const void *a, const void *b) {
return a == b;
}
static inline unsigned int hash(const void *a) {
return (unsigned long)a;
}
};
struct hash_obj_ops {
static inline bool cmp(const void *a, const void *b) {
return a == b;
}
template<typename T>
static inline unsigned int hash(const T *a) {
return a->hash();
}
};
inline int hashtable_size(int min_size)
{
static std::vector<int> zero_and_some_primes = {
0, 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 : zero_and_some_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 : zero_and_some_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
{
std::pair<K, T> udata;
int next;
entry_t() { }
entry_t(const std::pair<K, T> &udata, int next) : udata(udata), next(next) { }
};
std::vector<int> hashtable;
std::vector<entry_t> entries;
OPS ops;
#if 0
static inline void do_assert(bool cond) {
if (!cond) throw std::runtime_error("dict<> assert failed.");
}
#else
static inline void do_assert(bool) { }
#endif
int do_hash(const K &key) const
{
unsigned int hash = 0;
if (!hashtable.empty())
hash = ops.hash(key) % (unsigned int)(hashtable.size());
return hash;
}
void do_rehash()
{
hashtable.clear();
hashtable.resize(hashtable_size(entries.size() * hashtable_size_factor), -1);
for (int i = 0; i < int(entries.size()); i++) {
do_assert(-1 <= entries[i].next && entries[i].next < int(entries.size()));
int hash = do_hash(entries[i].udata.first);
entries[i].next = hashtable[hash];
hashtable[hash] = i;
}
}
int do_erase(int index, int hash)
{
do_assert(index < int(entries.size()));
if (hashtable.empty() || index < 0)
return 0;
int k = hashtable[hash];
if (k == index) {
hashtable[hash] = entries[index].next;
} else {
while (entries[k].next != index) {
k = entries[k].next;
do_assert(0 <= k && k < int(entries.size()));
}
entries[k].next = entries[index].next;
}
int back_idx = entries.size()-1;
if (index != back_idx)
{
int back_hash = do_hash(entries[back_idx].udata.first);
k = hashtable[back_hash];
if (k == back_idx) {
hashtable[back_hash] = index;
} else {
while (entries[k].next != back_idx) {
k = entries[k].next;
do_assert(0 <= k && k < int(entries.size()));
}
entries[k].next = index;
}
entries[index] = std::move(entries[back_idx]);
}
entries.pop_back();
if (entries.empty())
hashtable.clear();
return 1;
}
int do_lookup(const K &key, int &hash) const
{
if (hashtable.empty())
return -1;
if (entries.size() * hashtable_size_trigger > hashtable.size()) {
((dict*)this)->do_rehash();
hash = do_hash(key);
}
int index = hashtable[hash];
while (index >= 0 && !ops.cmp(entries[index].udata.first, key)) {
index = entries[index].next;
do_assert(-1 <= index && index < int(entries.size()));
}
return index;
}
int do_insert(const std::pair<K, T> &value, int &hash)
{
if (hashtable.empty()) {
entries.push_back(entry_t(value, -1));
do_rehash();
hash = do_hash(value.first);
} else {
entries.push_back(entry_t(value, hashtable[hash]));
hashtable[hash] = entries.size() - 1;
}
return entries.size() - 1;
}
public:
class const_iterator : public std::iterator<std::forward_iterator_tag, std::pair<K, T>>
{
friend class dict;
protected:
const dict *ptr;
int index;
const_iterator(const dict *ptr, int index) : ptr(ptr), index(index) { }
public:
const_iterator() { }
const_iterator operator++() { index--; return *this; }
bool operator<(const const_iterator &other) const { return index > other.index; }
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; }
};
class iterator : public std::iterator<std::forward_iterator_tag, std::pair<K, T>>
{
friend class dict;
protected:
dict *ptr;
int index;
iterator(dict *ptr, int index) : ptr(ptr), index(index) { }
public:
iterator() { }
iterator operator++() { index--; return *this; }
bool operator<(const iterator &other) const { return index > other.index; }
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; }
operator const_iterator() const { return const_iterator(ptr, index); }
};
dict()
{
}
dict(const dict &other)
{
entries = other.entries;
do_rehash();
}
dict(dict &&other)
{
swap(other);
}
dict &operator=(const dict &other) {
entries = other.entries;
do_rehash();
return *this;
}
dict &operator=(dict &&other) {
clear();
swap(other);
return *this;
}
dict(const std::initializer_list<std::pair<K, T>> &list)
{
for (auto &it : list)
insert(it);
}
template<class InputIterator>
dict(InputIterator first, InputIterator last)
{
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 = do_hash(value.first);
int i = do_lookup(value.first, hash);
if (i >= 0)
return std::pair<iterator, bool>(iterator(this, i), false);
i = do_insert(value, hash);
return std::pair<iterator, bool>(iterator(this, i), true);
}
int erase(const K &key)
{
int hash = do_hash(key);
int index = do_lookup(key, hash);
return do_erase(index, hash);
}
iterator erase(iterator it)
{
int hash = do_hash(it->first);
do_erase(it.index, hash);
return ++it;
}
int count(const K &key) const
{
int hash = do_hash(key);
int i = do_lookup(key, hash);
return i < 0 ? 0 : 1;
}
int count(const K &key, const_iterator it) const
{
int hash = do_hash(key);
int i = do_lookup(key, hash);
return i < 0 || i > it.index ? 0 : 1;
}
iterator find(const K &key)
{
int hash = do_hash(key);
int i = do_lookup(key, hash);
if (i < 0)
return end();
return iterator(this, i);
}
const_iterator find(const K &key) const
{
int hash = do_hash(key);
int i = do_lookup(key, hash);
if (i < 0)
return end();
return const_iterator(this, i);
}
T& at(const K &key)
{
int hash = do_hash(key);
int i = do_lookup(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 = do_hash(key);
int i = do_lookup(key, hash);
if (i < 0)
throw std::out_of_range("dict::at()");
return entries[i].udata.second;
}
T& operator[](const K &key)
{
int hash = do_hash(key);
int i = do_lookup(key, hash);
if (i < 0)
i = do_insert(std::pair<K, T>(key, T()), hash);
return entries[i].udata.second;
}
void swap(dict &other)
{
hashtable.swap(other.hashtable);
entries.swap(other.entries);
}
bool operator==(const dict &other) const {
if (size() != other.size())
return false;
for (auto &it : entries) {
auto oit = other.find(it.udata.first);
if (oit == other.end() || oit->second != it.udata.second)
return false;
}
return true;
}
bool operator!=(const dict &other) const {
return !(*this == other);
}
size_t size() const { return entries.size(); }
bool empty() const { return entries.empty(); }
void clear() { hashtable.clear(); entries.clear(); }
iterator begin() { return iterator(this, int(entries.size())-1); }
iterator end() { return iterator(nullptr, -1); }
const_iterator begin() const { return const_iterator(this, int(entries.size())-1); }
const_iterator end() const { return const_iterator(nullptr, -1); }
};
template<typename K, typename OPS = hash_ops<K>>
class pool
{
struct entry_t
{
K udata;
int next;
entry_t() { }
entry_t(const K &udata, int next) : udata(udata), next(next) { }
};
std::vector<int> hashtable;
std::vector<entry_t> entries;
OPS ops;
#if 0
static inline void do_assert(bool cond) {
if (!cond) throw std::runtime_error("pool<> assert failed.");
}
#else
static inline void do_assert(bool) { }
#endif
int do_hash(const K &key) const
{
unsigned int hash = 0;
if (!hashtable.empty())
hash = ops.hash(key) % (unsigned int)(hashtable.size());
return hash;
}
void do_rehash()
{
hashtable.clear();
hashtable.resize(hashtable_size(entries.size() * hashtable_size_factor), -1);
for (int i = 0; i < int(entries.size()); i++) {
do_assert(-1 <= entries[i].next && entries[i].next < int(entries.size()));
int hash = do_hash(entries[i].udata);
entries[i].next = hashtable[hash];
hashtable[hash] = i;
}
}
int do_erase(int index, int hash)
{
do_assert(index < int(entries.size()));
if (hashtable.empty() || index < 0)
return 0;
int k = hashtable[hash];
if (k == index) {
hashtable[hash] = entries[index].next;
} else {
while (entries[k].next != index) {
k = entries[k].next;
do_assert(0 <= k && k < int(entries.size()));
}
entries[k].next = entries[index].next;
}
int back_idx = entries.size()-1;
if (index != back_idx)
{
int back_hash = do_hash(entries[back_idx].udata);
k = hashtable[back_hash];
if (k == back_idx) {
hashtable[back_hash] = index;
} else {
while (entries[k].next != back_idx) {
k = entries[k].next;
do_assert(0 <= k && k < int(entries.size()));
}
entries[k].next = index;
}
entries[index] = std::move(entries[back_idx]);
}
entries.pop_back();
if (entries.empty())
hashtable.clear();
return 1;
}
int do_lookup(const K &key, int &hash) const
{
if (hashtable.empty())
return -1;
if (entries.size() * hashtable_size_trigger > hashtable.size()) {
((pool*)this)->do_rehash();
hash = do_hash(key);
}
int index = hashtable[hash];
while (index >= 0 && !ops.cmp(entries[index].udata, key)) {
index = entries[index].next;
do_assert(-1 <= index && index < int(entries.size()));
}
return index;
}
int do_insert(const K &value, int &hash)
{
if (hashtable.empty()) {
entries.push_back(entry_t(value, -1));
do_rehash();
hash = do_hash(value);
} else {
entries.push_back(entry_t(value, hashtable[hash]));
hashtable[hash] = entries.size() - 1;
}
return entries.size() - 1;
}
public:
class const_iterator : public std::iterator<std::forward_iterator_tag, K>
{
friend class pool;
protected:
const pool *ptr;
int index;
const_iterator(const pool *ptr, int index) : ptr(ptr), index(index) { }
public:
const_iterator() { }
const_iterator operator++() { index--; 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].udata; }
const K *operator->() const { return &ptr->entries[index].udata; }
};
class iterator : public std::iterator<std::forward_iterator_tag, K>
{
friend class pool;
protected:
pool *ptr;
int index;
iterator(pool *ptr, int index) : ptr(ptr), index(index) { }
public:
iterator() { }
iterator operator++() { index--; 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].udata; }
K *operator->() { return &ptr->entries[index].udata; }
const K &operator*() const { return ptr->entries[index].udata; }
const K *operator->() const { return &ptr->entries[index].udata; }
operator const_iterator() const { return const_iterator(ptr, index); }
};
pool()
{
}
pool(const pool &other)
{
entries = other.entries;
do_rehash();
}
pool(pool &&other)
{
swap(other);
}
pool &operator=(const pool &other) {
entries = other.entries;
do_rehash();
return *this;
}
pool &operator=(pool &&other) {
clear();
swap(other);
return *this;
}
pool(const std::initializer_list<K> &list)
{
for (auto &it : list)
insert(it);
}
template<class InputIterator>
pool(InputIterator first, InputIterator last)
{
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 &value)
{
int hash = do_hash(value);
int i = do_lookup(value, hash);
if (i >= 0)
return std::pair<iterator, bool>(iterator(this, i), false);
i = do_insert(value, hash);
return std::pair<iterator, bool>(iterator(this, i), true);
}
int erase(const K &key)
{
int hash = do_hash(key);
int index = do_lookup(key, hash);
return do_erase(index, hash);
}
iterator erase(iterator it)
{
int hash = do_hash(*it);
do_erase(it.index, hash);
return ++it;
}
int count(const K &key) const
{
int hash = do_hash(key);
int i = do_lookup(key, hash);
return i < 0 ? 0 : 1;
}
int count(const K &key, const_iterator it) const
{
int hash = do_hash(key);
int i = do_lookup(key, hash);
return i < 0 || i > it.index ? 0 : 1;
}
iterator find(const K &key)
{
int hash = do_hash(key);
int i = do_lookup(key, hash);
if (i < 0)
return end();
return iterator(this, i);
}
const_iterator find(const K &key) const
{
int hash = do_hash(key);
int i = do_lookup(key, hash);
if (i < 0)
return end();
return const_iterator(this, i);
}
bool operator[](const K &key)
{
int hash = do_hash(key);
int i = do_lookup(key, hash);
return i >= 0;
}
void swap(pool &other)
{
hashtable.swap(other.hashtable);
entries.swap(other.entries);
}
bool operator==(const pool &other) const {
if (size() != other.size())
return false;
for (auto &it : entries)
if (!other.count(it.udata))
return false;
return true;
}
bool operator!=(const pool &other) const {
return !(*this == other);
}
size_t size() const { return entries.size(); }
bool empty() const { return entries.empty(); }
void clear() { hashtable.clear(); entries.clear(); }
iterator begin() { return iterator(this, int(entries.size())-1); }
iterator end() { return iterator(nullptr, -1); }
const_iterator begin() const { return const_iterator(this, int(entries.size())-1); }
const_iterator end() const { return const_iterator(nullptr, -1); }
};
} /* namespace hashlib */
#endif