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Fixed find, now minimal also beats STL.

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This commit is contained in:
Davi Reis 2012-03-22 00:58:02 -03:00
parent 57ce26c5b1
commit c112b11abe
2 changed files with 8 additions and 23 deletions
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2
cxxmph/mph_index.h
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@ -64,7 +64,7 @@ class MPHIndex {
// Advanced users functions. Please avoid unless you know what you are doing.
uint32_t perfect_hash_size() const { return n_; }
template <class SeededHashFcn, class Key> // must agree with Reset
uint32_t perfect_hash(const Key& x) const;
uint32_t perfect_hash(const Key& x) const; // way faster than the minimal
uint32_t minimal_perfect_hash_size() const { return size(); }
template <class SeededHashFcn, class Key> // must agree with Reset
uint32_t minimal_perfect_hash(const Key& x) const;

27
cxxmph/mph_map.h
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@ -69,8 +69,8 @@ class mph_map {
void erase(iterator pos);
void erase(const key_type& k);
pair<iterator, bool> insert(const value_type& x);
iterator find(const key_type& k) { return slow_find(k, index_.minimal_perfect_hash(k)); }
const_iterator find(const key_type& k) const { return slow_find(k, index_.minimal_perfect_hash(k)); };
iterator find(const key_type& k);
const_iterator find(const key_type& k) const;
typedef int32_t my_int32_t; // help macros
int32_t index(const key_type& k) const;
data_type& operator[](const key_type &k);
@ -103,11 +103,6 @@ class mph_map {
return hollow_const_iterator<std::vector<value_type>>(&values_, &present_, it);
}
// Experimental functions, not always faster
iterator fast_find(const key_type& k);
iterator slow_find(const key_type& k, uint32_t minimal_perfect_hash);
const_iterator slow_find(const key_type& k, uint32_t minimal_perfect_hash) const;
void pack();
std::vector<value_type> values_;
std::vector<bool> present_;
@ -117,11 +112,6 @@ class mph_map {
slack_type slack_;
size_type size_;
typename seeded_hash<HashFcn>::hash_function hasher128_;
mutable uint64_t fast_;
mutable uint64_t fast_taken_;
mutable uint64_t slow_;
mutable uint64_t very_slow_;
};
MPH_MAP_TMPL_SPEC
@ -135,7 +125,6 @@ MPH_MAP_TMPL_SPEC MPH_MAP_CLASS_SPEC::mph_map() : size_(0) {
}
MPH_MAP_TMPL_SPEC MPH_MAP_CLASS_SPEC::~mph_map() {
// fprintf(stderr, "Fast taken: %d Fast: %d Slow %d very_slow %d ratio %f\n", fast_taken_, fast_, slow_, very_slow_, fast_*1.0/slow_);
}
MPH_MAP_METHOD_DECL(insert_return_type, insert)(const value_type& x) {
@ -154,10 +143,6 @@ MPH_MAP_METHOD_DECL(insert_return_type, insert)(const value_type& x) {
else slack_.insert(std::make_pair(h, values_.size() - 1));
if (should_pack) pack();
it = find(x.first);
slow_ = 0;
very_slow_ = 0;
fast_ = 0;
fast_taken_ = 0;
return make_pair(it, true);
}
@ -212,30 +197,30 @@ MPH_MAP_METHOD_DECL(void_type, erase)(const key_type& k) {
erase(it);
}
MPH_MAP_METHOD_DECL(const_iterator, slow_find)(const key_type& k, uint32_t minimal_perfect_hash) const {
MPH_MAP_METHOD_DECL(const_iterator, find)(const key_type& k) const {
if (__builtin_expect(index_.minimal_perfect_hash_size(), 1)) {
auto minimal_perfect_hash = index_.minimal_perfect_hash(k);
if (__builtin_expect(present_[minimal_perfect_hash], true)) {
auto vit = values_.begin() + minimal_perfect_hash;
if (equal_(k, vit->first)) return make_iterator(vit);
}
}
if (__builtin_expect(!slack_.empty(), 0)) {
++very_slow_;
auto sit = slack_.find(hasher128_.hash128(k, 0));
if (sit != slack_.end()) return make_iterator(values_.begin() + sit->second);
}
return end();
}
MPH_MAP_METHOD_DECL(iterator, slow_find)(const key_type& k, uint32_t minimal_perfect_hash) {
MPH_MAP_METHOD_DECL(iterator, find)(const key_type& k) {
if (__builtin_expect(index_.minimal_perfect_hash_size(), 1)) {
auto minimal_perfect_hash = index_.minimal_perfect_hash(k);
if (__builtin_expect(present_[minimal_perfect_hash], true)) {
auto vit = values_.begin() + minimal_perfect_hash;
if (equal_(k, vit->first)) return make_iterator(vit);
}
}
if (__builtin_expect(!slack_.empty(), 0)) {
++very_slow_;
auto sit = slack_.find(hasher128_.hash128(k, 0));
if (sit != slack_.end()) return make_iterator(values_.begin() + sit->second);
}