172 lines
5.3 KiB
C
172 lines
5.3 KiB
C
|
/* Internal hash table implementation. Used as a base for set, map etc.
|
||
|
*
|
||
|
* This file is part of OctaSTD. See COPYING.md for futher information.
|
||
|
*/
|
||
|
|
||
|
#ifndef OCTA_INTERNAL_HASHTABLE_H
|
||
|
#define OCTA_INTERNAL_HASHTABLE_H
|
||
|
|
||
|
#include <string.h>
|
||
|
|
||
|
#include "octa/types.h"
|
||
|
#include "octa/utility.h"
|
||
|
#include "octa/memory.h"
|
||
|
|
||
|
namespace octa {
|
||
|
|
||
|
namespace detail {
|
||
|
template<
|
||
|
typename B, /* contains methods specific to each ht type */
|
||
|
typename E, /* element type */
|
||
|
typename K, /* key type */
|
||
|
typename T, /* value type */
|
||
|
typename H, /* hash func */
|
||
|
typename C, /* equality check */
|
||
|
typename A /* allocator */
|
||
|
> struct Hashtable {
|
||
|
static constexpr octa::Size CHUNKSIZE = 64;
|
||
|
|
||
|
struct Chain {
|
||
|
E value;
|
||
|
Chain *next;
|
||
|
};
|
||
|
struct Chunk {
|
||
|
Chain chains[CHUNKSIZE];
|
||
|
Chunk *next;
|
||
|
};
|
||
|
|
||
|
octa::Size p_size;
|
||
|
octa::Size p_len;
|
||
|
|
||
|
Chunk *p_chunks;
|
||
|
Chain *p_unused;
|
||
|
|
||
|
|
||
|
using CPA = octa::AllocatorRebind<A, Chain *>;
|
||
|
using CHA = octa::AllocatorRebind<A, Chunk>;
|
||
|
|
||
|
using AllocPair = octa::detail::CompressedPair<CPA, CHA>;
|
||
|
using FuncPair = octa::detail::CompressedPair<H, C>;
|
||
|
using FAPair = octa::detail::CompressedPair<AllocPair, FuncPair>;
|
||
|
using DataPair = octa::detail::CompressedPair<Chain **, FAPair>;
|
||
|
|
||
|
DataPair p_data;
|
||
|
|
||
|
const H &get_hash() const { return p_data.second().second().first(); }
|
||
|
const C &get_eq() const { return p_data.second().second().second(); }
|
||
|
|
||
|
CPA &get_cpalloc() { return p_data.second().first().first(); }
|
||
|
CHA &get_challoc() { return p_data.second().first().second(); }
|
||
|
|
||
|
Hashtable(octa::Size size, const H &hf, const C &eqf, const A &alloc):
|
||
|
p_size(size), p_len(0), p_chunks(nullptr), p_unused(nullptr),
|
||
|
p_data(nullptr, FAPair(AllocPair(alloc, alloc), FuncPair(hf, eqf))) {
|
||
|
p_data.first() = octa::allocator_allocate(get_cpalloc(), size);
|
||
|
memset(p_data.first(), 0, size * sizeof(Chain *));
|
||
|
}
|
||
|
|
||
|
~Hashtable() {
|
||
|
octa::allocator_deallocate(get_cpalloc(), p_data.first(), p_size);
|
||
|
delete_chunks();
|
||
|
}
|
||
|
|
||
|
Chain *insert(octa::Size h) {
|
||
|
if (!p_unused) {
|
||
|
Chunk *chunk = octa::allocator_allocate(get_challoc(), 1);
|
||
|
octa::allocator_construct(get_challoc(), chunk);
|
||
|
chunk->next = p_chunks;
|
||
|
p_chunks = chunk;
|
||
|
for (Size i = 0; i < (CHUNKSIZE - 1); ++i)
|
||
|
chunk->chains[i].next = &chunk->chains[i + 1];
|
||
|
chunk->chains[CHUNKSIZE - 1].next = p_unused;
|
||
|
p_unused = chunk->chains;
|
||
|
}
|
||
|
Chain *c = p_unused;
|
||
|
p_unused = p_unused->next;
|
||
|
c->next = p_data.first()[h];
|
||
|
p_data.first()[h] = c;
|
||
|
++p_len;
|
||
|
return c;
|
||
|
}
|
||
|
|
||
|
template<typename U>
|
||
|
T &insert(octa::Size h, const U &key) {
|
||
|
Chain *c = insert(h);
|
||
|
B::set_key(c->value, key);
|
||
|
return B::get_data(c->value);
|
||
|
}
|
||
|
|
||
|
template<typename U>
|
||
|
bool remove(const U &key) {
|
||
|
octa::Size h = get_hash()(key) & (p_size - 1);
|
||
|
Chain *c = p_data.first()[h];
|
||
|
Chain **p = &c;
|
||
|
while (c) {
|
||
|
if (get_eq()(key, B::get_key(c->value))) {
|
||
|
*p = c->next;
|
||
|
c->value.~E();
|
||
|
new (&c->value) E;
|
||
|
c->next = p_unused;
|
||
|
p_unused = c;
|
||
|
--p_len;
|
||
|
return true;
|
||
|
}
|
||
|
c = c->next;
|
||
|
p = &c;
|
||
|
}
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
void delete_chunks() {
|
||
|
for (Chunk *nc; p_chunks; p_chunks = nc) {
|
||
|
nc = p_chunks->next;
|
||
|
octa::allocator_destroy(get_challoc(), p_chunks);
|
||
|
octa::allocator_deallocate(get_challoc(), p_chunks, 1);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
void clear() {
|
||
|
if (!p_len) return;
|
||
|
memset(p_data.first(), 0, p_size * sizeof(Chain *));
|
||
|
p_len = 0;
|
||
|
p_unused = nullptr;
|
||
|
delete_chunks();
|
||
|
}
|
||
|
|
||
|
template<typename U>
|
||
|
T *access_base(const U &key, octa::Size &h) const {
|
||
|
h = get_hash()(key) & (p_size - 1);
|
||
|
for (Chain *c = p_data.first()[h]; c; c = c->next) {
|
||
|
if (get_eq()(key, B::get_key(c->value)))
|
||
|
return &B::get_data(c->value);
|
||
|
}
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
template<typename U>
|
||
|
T *access(const U &key) const {
|
||
|
octa::Size h;
|
||
|
return access_base(key, h);
|
||
|
}
|
||
|
|
||
|
template<typename U, typename V>
|
||
|
T &access(const U &key, const V &val) {
|
||
|
octa::Size h;
|
||
|
T *found = access_base(key, h);
|
||
|
if (found) return *found;
|
||
|
return (insert(h, key) = val);
|
||
|
}
|
||
|
|
||
|
void swap(Hashtable &h) {
|
||
|
octa::swap(p_size, h.p_size);
|
||
|
octa::swap(p_len, h.p_len);
|
||
|
octa::swap(p_chunks, h.p_chunks);
|
||
|
octa::swap(p_unused, h.p_unused);
|
||
|
octa::swap(p_data, h.p_data);
|
||
|
}
|
||
|
};
|
||
|
} /* namespace detail */
|
||
|
|
||
|
} /* namespace octa */
|
||
|
|
||
|
#endif
|