motiejus/turbonss
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bit methods need tests.

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This commit is contained in:
Davi Reis 2012-03-14 12:40:50 -03:00
parent 9c4bb27dc4
commit b63f618204
1 changed files with 20 additions and 8 deletions
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28
cxxmph/mph_map.h
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@ -106,8 +106,12 @@ class mph_map {
const_iterator slow_find(const key_type& k, uint32_t perfect_hash) const;
static const uint8_t kNestCollision = 3; // biggest 2 bit value
void set_nest_value(const uint32_t* h, uint8_t value) {
auto index = get_nest_index(h);
assert(get_nest_index(h) < nests_.size() * 4);
set_2bit_value(&(nests_[0]), get_nest_index(h), value);
assert(get_nest_index(h) >> 2 < nests_.size());
assert(value < 4);
set_2bit_value(&nests_[0], index, value);
assert(get_2bit_value(&nests_[0], index) == value);
}
uint32_t get_nest_value(const uint32_t* h) const {
assert(get_nest_index(h) < nests_.size() * 4);
@ -151,8 +155,6 @@ MPH_MAP_METHOD_DECL(insert_return_type, insert)(const value_type& x) {
}
values_.push_back(x);
present_.push_back(true);
auto nests_size = nextpoweroftwo(ceil(values_.size() / 4.0) + 1)*10;
nests_.resize(nests_size, std::numeric_limits<uint8_t>::max());
uint32_t h[4];
index_.hash_vector(x.first, h);
set_nest_value(h, kNestCollision);
@ -191,13 +193,20 @@ MPH_MAP_METHOD_DECL(void_type, pack)() {
assert(used_nests.size() > get_nest_index(h));
if (used_nests[get_nest_index(h)]) {
set_nest_value(h, kNestCollision);
assert(get_nest_value(h) == kNestCollision);
++collisions;
} else {
set_nest_value(h, index_.cuckoo_nest(h));
assert(index_.perfect_hash(it->first) == index_.cuckoo_hash(h, index_.cuckoo_nest(h)));
assert(get_nest_value(h) == index_.cuckoo_nest(h));
assert(index_.perfect_hash(it->first) == index_.cuckoo_hash(h, get_nest_value(h)));
used_nests[get_nest_index(h)] = true;
}
}
for (iterator it = begin(), it_end = end(); it != it_end; ++it) {
uint32_t h[4];
index_.hash_vector(it->first, h);
assert(get_nest_value(h) == kNestCollision || index_.perfect_hash(it->first) == index_.cuckoo_hash(h, get_nest_value(h)));
}
fprintf(stderr, "Collision ratio: %f\n", collisions*1.0/size());
values_.swap(new_values);
present_.swap(new_present);
@ -266,19 +275,22 @@ MPH_MAP_METHOD_DECL(const_iterator, slow_find)(const key_type& k, uint32_t perfe
}
MPH_MAP_METHOD_DECL(iterator, find)(const key_type& k) {
return slow_find(k, index_.perfect_hash(k));
/*
// return slow_find(k, index_.perfect_hash(k));
uint32_t h[4];
index_.hash_vector(k, h);
auto nest = get_nest_value(h);
if (__builtin_expect(nest != kNestCollision, 1)) {
auto vit = values_.begin() + index_.cuckoo_hash(h, nest);
if (equal_(k, vit->first)) return make_iterator(vit);
assert(index_.perfect_hash(k) == index_.cuckoo_hash(h, nest));
if (equal_(k, vit->first)) {
fprintf(stderr, "fast\n");
return make_iterator(vit);
}
}
nest = index_.cuckoo_nest(h);
fprintf(stderr, "slow\n");
// assert(index_.perfect_hash(k) == index_.cuckoo_hash(h, nest));
return slow_find(k, index_.cuckoo_hash(h, nest));
*/
}
MPH_MAP_METHOD_DECL(iterator, slow_find)(const key_type& k, uint32_t perfect_hash) {