程式碼來自: https://github.com/nmslib/hnswlib
閱讀順序：
- 記憶體池結構和管理 https://zhuanlan.zhihu.com/p/642713540
- addPoint(不帶level引數)
- addPoint(帶level引數)
- addPoint用到的其他函式
- searchKNN和他用到的函式
#pragma once
#include "visited_list_pool.h"
#include "hnswlib.h"
#include <atomic>
#include <random>
#include <stdlib.h>
#include <assert.h>
#include <unordered_set>
#include <list>
#include <memory>
namespace hnswlib {
typedef unsigned int tableint;
typedef unsigned int linklistsizeint;
template<typename dist_t>
class HierarchicalNSW : public AlgorithmInterface<dist_t> {
public:
static const tableint MAX_LABEL_OPERATION_LOCKS = 65536;
static const unsigned char DELETE_MARK = 0x01;
size_t max_elements_{0};
mutable std::atomic<size_t> cur_element_count{0}; // current number of elements
size_t size_data_per_element_{0};
size_t size_links_per_element_{0};
mutable std::atomic<size_t> num_deleted_{0}; // number of deleted elements
size_t M_{0};
size_t maxM_{0};
size_t maxM0_{0};
size_t ef_construction_{0};
size_t ef_{ 0 };
double mult_{0.0}, revSize_{0.0};
int maxlevel_{0};
std::unique_ptr<VisitedListPool> visited_list_pool_{nullptr};
//unique_ptr是智慧指標，它只能指向一個物件,即當它指向其他物件時,之前所指向的物件會被摧毀。其次,當 unique_ptr 超出作用域時,指向的物件也會被摧毀
// Locks operations with element by label value
mutable std::vector<std::mutex> label_op_locks_;
std::mutex global;
std::vector<std::mutex> link_list_locks_;
tableint enterpoint_node_{0};
size_t size_links_level0_{0};
size_t offsetData_{0}, offsetLevel0_{0}, label_offset_{ 0 };
char *data_level0_memory_{nullptr};
char **linkLists_{nullptr};
std::vector<int> element_levels_; // keeps level of each element
size_t data_size_{0};
DISTFUNC<dist_t> fstdistfunc_;
void *dist_func_param_{nullptr};
mutable std::mutex label_lookup_lock; // lock for label_lookup_
std::unordered_map<labeltype, tableint> label_lookup_;
std::default_random_engine level_generator_;
std::default_random_engine update_probability_generator_;
mutable std::atomic<long> metric_distance_computations{0};
mutable std::atomic<long> metric_hops{0};
bool allow_replace_deleted_ = false; // flag to replace deleted elements (marked as deleted) during insertions
std::mutex deleted_elements_lock; // lock for deleted_elements
std::unordered_set<tableint> deleted_elements; // contains internal ids of deleted elements
HierarchicalNSW(SpaceInterface<dist_t> *s) {
}
HierarchicalNSW(
SpaceInterface<dist_t> *s,
const std::string &location,
bool nmslib = false,
size_t max_elements = 0,
bool allow_replace_deleted = false)
: allow_replace_deleted_(allow_replace_deleted) {
loadIndex(location, s, max_elements);
}
HierarchicalNSW(
SpaceInterface<dist_t> *s,
size_t max_elements,
size_t M = 16,
size_t ef_construction = 200,
size_t random_seed = 100,
bool allow_replace_deleted = false)
: label_op_locks_(MAX_LABEL_OPERATION_LOCKS),
link_list_locks_(max_elements),
element_levels_(max_elements),
allow_replace_deleted_(allow_replace_deleted) {
max_elements_ = max_elements;
num_deleted_ = 0;
data_size_ = s->get_data_size();
fstdistfunc_ = s->get_dist_func();
dist_func_param_ = s->get_dist_func_param();
if ( M <= 10000 ) {
M_ = M;
} else {
HNSWERR << "warning: M parameter exceeds 10000 which may lead to adverse effects." << std::endl;
HNSWERR << " Cap to 10000 will be applied for the rest of the processing." << std::endl;
M_ = 10000;
}
maxM_ = M_;
maxM0_ = M_ * 2;
ef_construction_ = std::max(ef_construction, M_);
ef_ = 10;
level_generator_.seed(random_seed);
update_probability_generator_.seed(random_seed + 1);
size_links_level0_ = maxM0_ * sizeof(tableint) + sizeof(linklistsizeint);
size_data_per_element_ = size_links_level0_ + data_size_ + sizeof(labeltype);
offsetData_ = size_links_level0_;
label_offset_ = size_links_level0_ + data_size_;
offsetLevel0_ = 0;
data_level0_memory_ = (char *) malloc(max_elements_ * size_data_per_element_);
if (data_level0_memory_ == nullptr)
throw std::runtime_error("Not enough memory");
cur_element_count = 0;
visited_list_pool_ = std::unique_ptr<VisitedListPool>(new VisitedListPool(1, max_elements));
// initializations for special treatment of the first node
enterpoint_node_ = -1;
maxlevel_ = -1;
linkLists_ = (char **) malloc(sizeof(void *) * max_elements_);
if (linkLists_ == nullptr)
throw std::runtime_error("Not enough memory: HierarchicalNSW failed to allocate linklists");
size_links_per_element_ = maxM_ * sizeof(tableint) + sizeof(linklistsizeint);
mult_ = 1 / log(1.0 * M_);
revSize_ = 1.0 / mult_;
}
~HierarchicalNSW() {
clear();
}
void clear() {
free(data_level0_memory_);
data_level0_memory_ = nullptr;
for (tableint i = 0; i < cur_element_count; i++) {
if (element_levels_[i] > 0)
free(linkLists_[i]);
}
free(linkLists_);
linkLists_ = nullptr;
cur_element_count = 0;
visited_list_pool_.reset(nullptr);
}
struct CompareByFirst {
constexpr bool operator()(std::pair<dist_t, tableint> const& a,
std::pair<dist_t, tableint> const& b) const noexcept {
return a.first < b.first;
}
};
void setEf(size_t ef) {
ef_ = ef;
}
inline std::mutex& getLabelOpMutex(labeltype label) const {
// calculate hash
size_t lock_id = label & (MAX_LABEL_OPERATION_LOCKS - 1);
return label_op_locks_[lock_id];
}
inline labeltype getExternalLabel(tableint internal_id) const {
labeltype return_label;
memcpy(&return_label, (data_level0_memory_ + internal_id * size_data_per_element_ + label_offset_), sizeof(labeltype));
return return_label;
}
inline void setExternalLabel(tableint internal_id, labeltype label) const {
memcpy((data_level0_memory_ + internal_id * size_data_per_element_ + label_offset_), &label, sizeof(labeltype));
}
inline labeltype *getExternalLabeLp(tableint internal_id) const {
return (labeltype *) (data_level0_memory_ + internal_id * size_data_per_element_ + label_offset_);
}
inline char *getDataByInternalId(tableint internal_id) const {
return (data_level0_memory_ + internal_id * size_data_per_element_ + offsetData_);
}
int getRandomLevel(double reverse_size) {
std::uniform_real_distribution<double> distribution(0.0, 1.0);
double r = -log(distribution(level_generator_)) * reverse_size;
return (int) r;
}
size_t getMaxElements() {
return max_elements_;
}
size_t getCurrentElementCount() {
return cur_element_count;
}
size_t getDeletedCount() {
return num_deleted_;
}
std::priority_queue<std::pair<dist_t, tableint>, std::vector<std::pair<dist_t, tableint>>, CompareByFirst>
searchBaseLayer(tableint ep_id, const void *data_point, int layer) {//找一層中的data_point的KNN（從ep_id開始找
VisitedList *vl = visited_list_pool_->getFreeVisitedList();
//vl_type == unsigned short int
vl_type *visited_array = vl->mass;
vl_type visited_array_tag = vl->curV;
//visited_array[ep_id]=visited_array_tag 意思就是 visited[ep_id]=true.
std::priority_queue<std::pair<dist_t, tableint>, std::vector<std::pair<dist_t, tableint>>, CompareByFirst> top_candidates;
std::priority_queue<std::pair<dist_t, tableint>, std::vector<std::pair<dist_t, tableint>>, CompareByFirst> candidateSet;
//max-heap...
dist_t lowerBound;//lowerBound就是ResultSet裡面的最大距離
if (!isMarkedDeleted(ep_id)) {//進入點沒被刪直接走就行了
dist_t dist = fstdistfunc_(data_point, getDataByInternalId(ep_id), dist_func_param_);
top_candidates.emplace(dist, ep_id);
lowerBound = dist;
candidateSet.emplace(-dist, ep_id);//插入負號變成小根堆
} else {//進入點被刪了表明這個進入點不能加入KNN裡面，但是還是得從這個地方走，所以把當前的最近距離設定為inf
lowerBound = std::numeric_limits<dist_t>::max();
candidateSet.emplace(-lowerBound, ep_id);
}
visited_array[ep_id] = visited_array_tag;
while (!candidateSet.empty()) {//遍歷這一層圖
std::pair<dist_t, tableint> curr_el_pair = candidateSet.top();
if ((-curr_el_pair.first) > lowerBound && top_candidates.size() == ef_construction_) {//candidate裡面距離都大於當前最小距離而且ResultSet選滿了
break;
}
candidateSet.pop();
tableint curNodeNum = curr_el_pair.second;
std::unique_lock <std::mutex> lock(link_list_locks_[curNodeNum]);
int *data; // = (int *)(linkList0_ + curNodeNum * size_links_per_element0_);
if (layer == 0) {
data = (int*)get_linklist0(curNodeNum);
} else {
data = (int*)get_linklist(curNodeNum, layer);
// data = (int *) (linkLists_[curNodeNum] + (layer - 1) * size_links_per_element_);
}
size_t size = getListCount((linklistsizeint*)data);
tableint *datal = (tableint *) (data + 1);
//找好當前的點
//SSE是intel出的新CPU的新的更快的指令集
#ifdef USE_SSE
_mm_prefetch((char *) (visited_array + *(data + 1)), _MM_HINT_T0);
_mm_prefetch((char *) (visited_array + *(data + 1) + 64), _MM_HINT_T0);
_mm_prefetch(getDataByInternalId(*datal), _MM_HINT_T0);
_mm_prefetch(getDataByInternalId(*(datal + 1)), _MM_HINT_T0);
#endif
for (size_t j = 0; j < size; j++) {
tableint candidate_id = *(datal + j);
// if (candidate_id == 0) continue;
#ifdef USE_SSE
_mm_prefetch((char *) (visited_array + *(datal + j + 1)), _MM_HINT_T0);
_mm_prefetch(getDataByInternalId(*(datal + j + 1)), _MM_HINT_T0);
#endif
if (visited_array[candidate_id] == visited_array_tag) continue;
visited_array[candidate_id] = visited_array_tag;
char *currObj1 = (getDataByInternalId(candidate_id));
//當前點的neighbour
dist_t dist1 = fstdistfunc_(data_point, currObj1, dist_func_param_);
if (top_candidates.size() < ef_construction_ || lowerBound > dist1) {
candidateSet.emplace(-dist1, candidate_id);
#ifdef USE_SSE
_mm_prefetch(getDataByInternalId(candidateSet.top().second), _MM_HINT_T0);
#endif
if (!isMarkedDeleted(candidate_id))
top_candidates.emplace(dist1, candidate_id);
if (top_candidates.size() > ef_construction_)
top_candidates.pop();
if (!top_candidates.empty())
lowerBound = top_candidates.top().first;
}
}
}
visited_list_pool_->releaseVisitedList(vl);
return top_candidates;
}
// bare_bone_search means there is no check for deletions and stop condition is ignored in return of extra performance
template <bool bare_bone_search = true, bool collect_metrics = false>
std::priority_queue<std::pair<dist_t, tableint>, std::vector<std::pair<dist_t, tableint>>, CompareByFirst>
searchBaseLayerST(
tableint ep_id,//enter point
const void *data_point,//query point
size_t ef,//find ef candidates
BaseFilterFunctor* isIdAllowed = nullptr,
BaseSearchStopCondition<dist_t>* stop_condition = nullptr) const {
VisitedList *vl = visited_list_pool_->getFreeVisitedList();
vl_type *visited_array = vl->mass;
vl_type visited_array_tag = vl->curV;
//加入了對於stopcondition和刪除的判斷，增加barebonesearch加快搜尋速度，其他和上面searchBaseLayer是一樣的,沒啥好看的
std::priority_queue<std::pair<dist_t, tableint>, std::vector<std::pair<dist_t, tableint>>, CompareByFirst> top_candidates;
std::priority_queue<std::pair<dist_t, tableint>, std::vector<std::pair<dist_t, tableint>>, CompareByFirst> candidate_set;
dist_t lowerBound;
if (bare_bone_search ||
(!isMarkedDeleted(ep_id) && ((!isIdAllowed) || (*isIdAllowed)(getExternalLabel(ep_id))))) {
char* ep_data = getDataByInternalId(ep_id);
dist_t dist = fstdistfunc_(data_point, ep_data, dist_func_param_);
lowerBound = dist;
top_candidates.emplace(dist, ep_id);
if (!bare_bone_search && stop_condition) {
stop_condition->add_point_to_result(getExternalLabel(ep_id), ep_data, dist);
}
candidate_set.emplace(-dist, ep_id);
} else {
lowerBound = std::numeric_limits<dist_t>::max();
candidate_set.emplace(-lowerBound, ep_id);
}
visited_array[ep_id] = visited_array_tag;
while (!candidate_set.empty()) {
std::pair<dist_t, tableint> current_node_pair = candidate_set.top();
dist_t candidate_dist = -current_node_pair.first;
bool flag_stop_search;
if (bare_bone_search) {
flag_stop_search = candidate_dist > lowerBound;
} else {
if (stop_condition) {
flag_stop_search = stop_condition->should_stop_search(candidate_dist, lowerBound);
} else {
flag_stop_search = candidate_dist > lowerBound && top_candidates.size() == ef;
}
}
if (flag_stop_search) {
break;
}
candidate_set.pop();
tableint current_node_id = current_node_pair.second;
int *data = (int *) get_linklist0(current_node_id);
size_t size = getListCount((linklistsizeint*)data);
// bool cur_node_deleted = isMarkedDeleted(current_node_id);
if (collect_metrics) {
metric_hops++;
metric_distance_computations+=size;
}
#ifdef USE_SSE
_mm_prefetch((char *) (visited_array + *(data + 1)), _MM_HINT_T0);
_mm_prefetch((char *) (visited_array + *(data + 1) + 64), _MM_HINT_T0);
_mm_prefetch(data_level0_memory_ + (*(data + 1)) * size_data_per_element_ + offsetData_, _MM_HINT_T0);
_mm_prefetch((char *) (data + 2), _MM_HINT_T0);
#endif
for (size_t j = 1; j <= size; j++) {
int candidate_id = *(data + j);
// if (candidate_id == 0) continue;
#ifdef USE_SSE
_mm_prefetch((char *) (visited_array + *(data + j + 1)), _MM_HINT_T0);
_mm_prefetch(data_level0_memory_ + (*(data + j + 1)) * size_data_per_element_ + offsetData_,
_MM_HINT_T0); ////////////
#endif
if (!(visited_array[candidate_id] == visited_array_tag)) {
visited_array[candidate_id] = visited_array_tag;
char *currObj1 = (getDataByInternalId(candidate_id));
dist_t dist = fstdistfunc_(data_point, currObj1, dist_func_param_);
bool flag_consider_candidate;
if (!bare_bone_search && stop_condition) {
flag_consider_candidate = stop_condition->should_consider_candidate(dist, lowerBound);
} else {
flag_consider_candidate = top_candidates.size() < ef || lowerBound > dist;
}
if (flag_consider_candidate) {
candidate_set.emplace(-dist, candidate_id);
#ifdef USE_SSE
_mm_prefetch(data_level0_memory_ + candidate_set.top().second * size_data_per_element_ +
offsetLevel0_, ///////////
_MM_HINT_T0); ////////////////////////
#endif
if (bare_bone_search ||
(!isMarkedDeleted(candidate_id) && ((!isIdAllowed) || (*isIdAllowed)(getExternalLabel(candidate_id))))) {
top_candidates.emplace(dist, candidate_id);
if (!bare_bone_search && stop_condition) {
stop_condition->add_point_to_result(getExternalLabel(candidate_id), currObj1, dist);
}
}
bool flag_remove_extra = false;
if (!bare_bone_search && stop_condition) {
flag_remove_extra = stop_condition->should_remove_extra();
} else {
flag_remove_extra = top_candidates.size() > ef;
}
while (flag_remove_extra) {
tableint id = top_candidates.top().second;
top_candidates.pop();
if (!bare_bone_search && stop_condition) {
stop_condition->remove_point_from_result(getExternalLabel(id), getDataByInternalId(id), dist);
flag_remove_extra = stop_condition->should_remove_extra();
} else {
flag_remove_extra = top_candidates.size() > ef;
}
}
if (!top_candidates.empty())
lowerBound = top_candidates.top().first;
}
}
}
}
visited_list_pool_->releaseVisitedList(vl);
return top_candidates;
}
void getNeighborsByHeuristic2(//啟發式篩選鄰居，建立類似RNG的圖，https://www.jianshu.com/p/12bf1018c590 有說怎麼篩,或者看論文
std::priority_queue<std::pair<dist_t, tableint>, std::vector<std::pair<dist_t, tableint>>, CompareByFirst> &top_candidates,
const size_t M) {
if (top_candidates.size() < M) {
return;
}
std::priority_queue<std::pair<dist_t, tableint>> queue_closest;
std::vector<std::pair<dist_t, tableint>> return_list;//todo:你怎麼這裡不搞CBFl
while (top_candidates.size() > 0) {
queue_closest.emplace(-top_candidates.top().first, top_candidates.top().second);
top_candidates.pop();
}//搞成小根堆
while (queue_closest.size()) {//依次取距離最近的
if (return_list.size() >= M)
break;
std::pair<dist_t, tableint> curent_pair = queue_closest.top();
dist_t dist_to_query = -curent_pair.first;//到query點(要連的那個點的距離
queue_closest.pop();
bool good = true;
for (std::pair<dist_t, tableint> second_pair : return_list) {
dist_t curdist =
fstdistfunc_(getDataByInternalId(second_pair.second),
getDataByInternalId(curent_pair.second),
dist_func_param_);//另外的距離
if (curdist < dist_to_query) {//cut
good = false;
break;
}
}
if (good) {
return_list.push_back(curent_pair);
}
}
//又轉回去 注意是這裡是引用所以把原來的改了就行
for (std::pair<dist_t, tableint> curent_pair : return_list) {
top_candidates.emplace(-curent_pair.first, curent_pair.second);
}
}
linklistsizeint *get_linklist0(tableint internal_id) const {
return (linklistsizeint *) (data_level0_memory_ + internal_id * size_data_per_element_ + offsetLevel0_);
}
linklistsizeint *get_linklist0(tableint internal_id, char *data_level0_memory_) const {
return (linklistsizeint *) (data_level0_memory_ + internal_id * size_data_per_element_ + offsetLevel0_);
}
linklistsizeint *get_linklist(tableint internal_id, int level) const {
return (linklistsizeint *) (linkLists_[internal_id] + (level - 1) * size_links_per_element_);
}
linklistsizeint *get_linklist_at_level(tableint internal_id, int level) const {
return level == 0 ? get_linklist0(internal_id) : get_linklist(internal_id, level);
}
tableint mutuallyConnectNewElement(
const void *data_point,//新加入的點的資料
tableint cur_c,//新加入的點的內部編號
std::priority_queue<std::pair<dist_t, tableint>, std::vector<std::pair<dist_t, tableint>>, CompareByFirst> &top_candidates,//候選鄰居
int level,//層數
bool isUpdate) {
size_t Mcurmax = level ? maxM_ : maxM0_;
getNeighborsByHeuristic2(top_candidates, M_);
if (top_candidates.size() > M_)
throw std::runtime_error("Should be not be more than M_ candidates returned by the heuristic");
std::vector<tableint> selectedNeighbors;
selectedNeighbors.reserve(M_);
while (top_candidates.size() > 0) {
selectedNeighbors.push_back(top_candidates.top().second);//內部編號
top_candidates.pop();
}
tableint next_closest_entry_point = selectedNeighbors.back();
{//往當前點的鄰接表裡面加入他的鄰居
// lock only during the update
// because during the addition the lock for cur_c is already acquired
std::unique_lock <std::mutex> lock(link_list_locks_[cur_c], std::defer_lock);
if (isUpdate) {
lock.lock();
}
linklistsizeint *ll_cur;//當前點的link_list位置指標，返回的位置裝的是鄰接矩陣裡面鄰居的個數
if (level == 0)
ll_cur = get_linklist0(cur_c);
else
ll_cur = get_linklist(cur_c, level);
if (*ll_cur && !isUpdate) {
throw std::runtime_error("The newly inserted element should have blank link list");
}
setListCount(ll_cur, selectedNeighbors.size());
tableint *data = (tableint *) (ll_cur + 1);
for (size_t idx = 0; idx < selectedNeighbors.size(); idx++) {
if (data[idx] && !isUpdate)
throw std::runtime_error("Possible memory corruption");
if (level > element_levels_[selectedNeighbors[idx]])
throw std::runtime_error("Trying to make a link on a non-existent level");
data[idx] = selectedNeighbors[idx];
}
}
//往鄰居的鄰接表裡面加當前點
for (size_t idx = 0; idx < selectedNeighbors.size(); idx++) {
std::unique_lock <std::mutex> lock(link_list_locks_[selectedNeighbors[idx]]);
linklistsizeint *ll_other;
if (level == 0)
ll_other = get_linklist0(selectedNeighbors[idx]);
else
ll_other = get_linklist(selectedNeighbors[idx], level);
size_t sz_link_list_other = getListCount(ll_other);
if (sz_link_list_other > Mcurmax)
throw std::runtime_error("Bad value of sz_link_list_other");
if (selectedNeighbors[idx] == cur_c)
throw std::runtime_error("Trying to connect an element to itself");
if (level > element_levels_[selectedNeighbors[idx]])//todo:為什麼是大於不是不等於
throw std::runtime_error("Trying to make a link on a non-existent level");
tableint *data = (tableint *) (ll_other + 1);
bool is_cur_c_present = false;
if (isUpdate) {
for (size_t j = 0; j < sz_link_list_other; j++) {
if (data[j] == cur_c) {
is_cur_c_present = true;
break;
}
}
}
// If cur_c is already present in the neighboring connections of `selectedNeighbors[idx]` then no need to modify any connections or run the heuristics.
if (!is_cur_c_present) {
if (sz_link_list_other < Mcurmax) {
data[sz_link_list_other] = cur_c;
setListCount(ll_other, sz_link_list_other + 1);
} else {
// finding the "weakest" element to replace it with the new one
dist_t d_max = fstdistfunc_(getDataByInternalId(cur_c), getDataByInternalId(selectedNeighbors[idx]),
dist_func_param_);
// Heuristic:
std::priority_queue<std::pair<dist_t, tableint>, std::vector<std::pair<dist_t, tableint>>, CompareByFirst> candidates;
candidates.emplace(d_max, cur_c);
for (size_t j = 0; j < sz_link_list_other; j++) {
candidates.emplace(
fstdistfunc_(getDataByInternalId(data[j]), getDataByInternalId(selectedNeighbors[idx]),
dist_func_param_), data[j]);
}
//把待加邊和已加邊全部放入candidates，用這個HEURISTIC找出來
getNeighborsByHeuristic2(candidates, Mcurmax);
int indx = 0;
while (candidates.size() > 0) {
data[indx] = candidates.top().second;
candidates.pop();
indx++;
}
setListCount(ll_other, indx);
// Nearest K:
/*int indx = -1;
for (int j = 0; j < sz_link_list_other; j++) {
dist_t d = fstdistfunc_(getDataByInternalId(data[j]), getDataByInternalId(rez[idx]), dist_func_param_);
if (d > d_max) {
indx = j;
d_max = d;
}
}
if (indx >= 0) {
data[indx] = cur_c;
} */
}
}
}
return next_closest_entry_point;
}
void resizeIndex(size_t new_max_elements) {//重新分配一坨更大的空間
if (new_max_elements < cur_element_count)
throw std::runtime_error("Cannot resize, max element is less than the current number of elements");
visited_list_pool_.reset(new VisitedListPool(1, new_max_elements));
element_levels_.resize(new_max_elements);
std::vector<std::mutex>(new_max_elements).swap(link_list_locks_);
// Reallocate base layer
char * data_level0_memory_new = (char *) realloc(data_level0_memory_, new_max_elements * size_data_per_element_);
if (data_level0_memory_new == nullptr)
throw std::runtime_error("Not enough memory: resizeIndex failed to allocate base layer");
data_level0_memory_ = data_level0_memory_new;
// Reallocate all other layers
char ** linkLists_new = (char **) realloc(linkLists_, sizeof(void *) * new_max_elements);
if (linkLists_new == nullptr)
throw std::runtime_error("Not enough memory: resizeIndex failed to allocate other layers");
linkLists_ = linkLists_new;
max_elements_ = new_max_elements;
}
size_t indexFileSize() const {
size_t size = 0;
size += sizeof(offsetLevel0_);
size += sizeof(max_elements_);
size += sizeof(cur_element_count);
size += sizeof(size_data_per_element_);
size += sizeof(label_offset_);
size += sizeof(offsetData_);
size += sizeof(maxlevel_);
size += sizeof(enterpoint_node_);
size += sizeof(maxM_);
size += sizeof(maxM0_);
size += sizeof(M_);
size += sizeof(mult_);
size += sizeof(ef_construction_);
size += cur_element_count * size_data_per_element_;
for (size_t i = 0; i < cur_element_count; i++) {
unsigned int linkListSize = element_levels_[i] > 0 ? size_links_per_element_ * element_levels_[i] : 0;
size += sizeof(linkListSize);
size += linkListSize;
}
return size;
}
void saveIndex(const std::string &location) {//把index存到ROM裡面
std::ofstream output(location, std::ios::binary);
std::streampos position;
writeBinaryPOD(output, offsetLevel0_);
writeBinaryPOD(output, max_elements_);
writeBinaryPOD(output, cur_element_count);
writeBinaryPOD(output, size_data_per_element_);
writeBinaryPOD(output, label_offset_);
writeBinaryPOD(output, offsetData_);
writeBinaryPOD(output, maxlevel_);
writeBinaryPOD(output, enterpoint_node_);
writeBinaryPOD(output, maxM_);
writeBinaryPOD(output, maxM0_);
writeBinaryPOD(output, M_);
writeBinaryPOD(output, mult_);
writeBinaryPOD(output, ef_construction_);
output.write(data_level0_memory_, cur_element_count * size_data_per_element_);
for (size_t i = 0; i < cur_element_count; i++) {
unsigned int linkListSize = element_levels_[i] > 0 ? size_links_per_element_ * element_levels_[i] : 0;
writeBinaryPOD(output, linkListSize);
if (linkListSize)
output.write(linkLists_[i], linkListSize);
}
output.close();
}
void loadIndex(const std::string &location, SpaceInterface<dist_t> *s, size_t max_elements_i = 0) {//在外存載入index
std::ifstream input(location, std::ios::binary);
if (!input.is_open())
throw std::runtime_error("Cannot open file");
clear();
// get file size:
input.seekg(0, input.end);
std::streampos total_filesize = input.tellg();
input.seekg(0, input.beg);
readBinaryPOD(input, offsetLevel0_);
readBinaryPOD(input, max_elements_);
readBinaryPOD(input, cur_element_count);
size_t max_elements = max_elements_i;
if (max_elements < cur_element_count)
max_elements = max_elements_;
max_elements_ = max_elements;
readBinaryPOD(input, size_data_per_element_);
readBinaryPOD(input, label_offset_);
readBinaryPOD(input, offsetData_);
readBinaryPOD(input, maxlevel_);
readBinaryPOD(input, enterpoint_node_);
readBinaryPOD(input, maxM_);
readBinaryPOD(input, maxM0_);
readBinaryPOD(input, M_);
readBinaryPOD(input, mult_);
readBinaryPOD(input, ef_construction_);
data_size_ = s->get_data_size();
fstdistfunc_ = s->get_dist_func();
dist_func_param_ = s->get_dist_func_param();
auto pos = input.tellg();
/// Optional - check if index is ok:
input.seekg(cur_element_count * size_data_per_element_, input.cur);
for (size_t i = 0; i < cur_element_count; i++) {
if (input.tellg() < 0 || input.tellg() >= total_filesize) {
throw std::runtime_error("Index seems to be corrupted or unsupported");
}
unsigned int linkListSize;
readBinaryPOD(input, linkListSize);
if (linkListSize != 0) {
input.seekg(linkListSize, input.cur);
}
}
// throw exception if it either corrupted or old index
if (input.tellg() != total_filesize)
throw std::runtime_error("Index seems to be corrupted or unsupported");
input.clear();
/// Optional check end
input.seekg(pos, input.beg);
data_level0_memory_ = (char *) malloc(max_elements * size_data_per_element_);
if (data_level0_memory_ == nullptr)
throw std::runtime_error("Not enough memory: loadIndex failed to allocate level0");
input.read(data_level0_memory_, cur_element_count * size_data_per_element_);
size_links_per_element_ = maxM_ * sizeof(tableint) + sizeof(linklistsizeint);
size_links_level0_ = maxM0_ * sizeof(tableint) + sizeof(linklistsizeint);
std::vector<std::mutex>(max_elements).swap(link_list_locks_);
std::vector<std::mutex>(MAX_LABEL_OPERATION_LOCKS).swap(label_op_locks_);
visited_list_pool_.reset(new VisitedListPool(1, max_elements));
linkLists_ = (char **) malloc(sizeof(void *) * max_elements);
if (linkLists_ == nullptr)
throw std::runtime_error("Not enough memory: loadIndex failed to allocate linklists");
element_levels_ = std::vector<int>(max_elements);
revSize_ = 1.0 / mult_;
ef_ = 10;
for (size_t i = 0; i < cur_element_count; i++) {
label_lookup_[getExternalLabel(i)] = i;
unsigned int linkListSize;
readBinaryPOD(input, linkListSize);
if (linkListSize == 0) {
element_levels_[i] = 0;
linkLists_[i] = nullptr;
} else {
element_levels_[i] = linkListSize / size_links_per_element_;
linkLists_[i] = (char *) malloc(linkListSize);
if (linkLists_[i] == nullptr)
throw std::runtime_error("Not enough memory: loadIndex failed to allocate linklist");
input.read(linkLists_[i], linkListSize);
}
}
for (size_t i = 0; i < cur_element_count; i++) {
if (isMarkedDeleted(i)) {
num_deleted_ += 1;
if (allow_replace_deleted_) deleted_elements.insert(i);
}
}
input.close();
return;
}
template<typename data_t>
std::vector<data_t> getDataByLabel(labeltype label) const {//沒用過
// lock all operations with element by label
std::unique_lock <std::mutex> lock_label(getLabelOpMutex(label));
std::unique_lock <std::mutex> lock_table(label_lookup_lock);
auto search = label_lookup_.find(label);
if (search == label_lookup_.end() || isMarkedDeleted(search->second)) {
throw std::runtime_error("Label not found");
}
tableint internalId = search->second;
lock_table.unlock();
char* data_ptrv = getDataByInternalId(internalId);
size_t dim = *((size_t *) dist_func_param_);
std::vector<data_t> data;
data_t* data_ptr = (data_t*) data_ptrv;
for (size_t i = 0; i < dim; i++) {
data.push_back(*data_ptr);
data_ptr += 1;
}
return data;
}
/*
* Marks an element with the given label deleted, does NOT really change the current graph.
*/
void markDelete(labeltype label) {
// lock all operations with element by label
std::unique_lock <std::mutex> lock_label(getLabelOpMutex(label));
std::unique_lock <std::mutex> lock_table(label_lookup_lock);
auto search = label_lookup_.find(label);
if (search == label_lookup_.end()) {
throw std::runtime_error("Label not found");
}
tableint internalId = search->second;
lock_table.unlock();
markDeletedInternal(internalId);
}
/*
* Uses the last 16 bits of the memory for the linked list size to store the mark,
* whereas maxM0_ has to be limited to the lower 16 bits, however, still large enough in almost all cases.
*/
void markDeletedInternal(tableint internalId) {
assert(internalId < cur_element_count);
if (!isMarkedDeleted(internalId)) {
unsigned char *ll_cur = ((unsigned char *)get_linklist0(internalId))+2;
*ll_cur |= DELETE_MARK;
num_deleted_ += 1;
if (allow_replace_deleted_) {
std::unique_lock <std::mutex> lock_deleted_elements(deleted_elements_lock);
deleted_elements.insert(internalId);
}
} else {
throw std::runtime_error("The requested to delete element is already deleted");
}
}
/*
* Removes the deleted mark of the node, does NOT really change the current graph.
*
* Note: the method is not safe to use when replacement of deleted elements is enabled,
* because elements marked as deleted can be completely removed by addPoint
*/
void unmarkDelete(labeltype label) {
// lock all operations with element by label
std::unique_lock <std::mutex> lock_label(getLabelOpMutex(label));
std::unique_lock <std::mutex> lock_table(label_lookup_lock);
auto search = label_lookup_.find(label);
if (search == label_lookup_.end()) {
throw std::runtime_error("Label not found");
}
tableint internalId = search->second;
lock_table.unlock();
unmarkDeletedInternal(internalId);
}
/*
* Remove the deleted mark of the node.
*/
void unmarkDeletedInternal(tableint internalId) {
assert(internalId < cur_element_count);
if (isMarkedDeleted(internalId)) {
unsigned char *ll_cur = ((unsigned char *)get_linklist0(internalId)) + 2;
*ll_cur &= ~DELETE_MARK;
num_deleted_ -= 1;
if (allow_replace_deleted_) {
std::unique_lock <std::mutex> lock_deleted_elements(deleted_elements_lock);
deleted_elements.erase(internalId);
}
} else {
throw std::runtime_error("The requested to undelete element is not deleted");
}
}
/*
* Checks the first 16 bits of the memory to see if the element is marked deleted.
*/
bool isMarkedDeleted(tableint internalId) const {
unsigned char *ll_cur = ((unsigned char*)get_linklist0(internalId)) + 2;
return *ll_cur & DELETE_MARK;
}
unsigned short int getListCount(linklistsizeint * ptr) const {
return *((unsigned short int *)ptr);
}
void setListCount(linklistsizeint * ptr, unsigned short int size) const {
*((unsigned short int*)(ptr))=*((unsigned short int *)&size);
}
/*
* Adds point. Updates the point if it is already in the index.
* If replacement of deleted elements is enabled: replaces previously deleted point if any, updating it with new point
*/
// inserted data ,inserted label, useless for me
void addPoint(const void *data_point, labeltype label, bool replace_deleted = false) { // no delete for me
if ((allow_replace_deleted_ == false) && (replace_deleted == true)) {
throw std::runtime_error("Replacement of deleted elements is disabled in constructor");
}
// lock all operations with element by label
std::unique_lock <std::mutex> lock_label(getLabelOpMutex(label));
if (!replace_deleted) {
addPoint(data_point, label, -1);
return;
}
//-----------------------------------
// check if there is vacant place
tableint internal_id_replaced;
std::unique_lock <std::mutex> lock_deleted_elements(deleted_elements_lock);
bool is_vacant_place = !deleted_elements.empty();
if (is_vacant_place) {
internal_id_replaced = *deleted_elements.begin();
deleted_elements.erase(internal_id_replaced);
}
lock_deleted_elements.unlock();
// if there is no vacant place then add or update point
// else add point to vacant place
if (!is_vacant_place) {
addPoint(data_point, label, -1);
} else {
// we assume that there are no concurrent operations on deleted element
labeltype label_replaced = getExternalLabel(internal_id_replaced);
setExternalLabel(internal_id_replaced, label);
std::unique_lock <std::mutex> lock_table(label_lookup_lock);
label_lookup_.erase(label_replaced);
label_lookup_[label] = internal_id_replaced;
lock_table.unlock();
unmarkDeletedInternal(internal_id_replaced);
updatePoint(data_point, internal_id_replaced, 1.0);
}
}
void updatePoint(const void *dataPoint, tableint internalId, float updateNeighborProbability) {//笑死，根本不想看
// update the feature vector associated with existing point with new vector
memcpy(getDataByInternalId(internalId), dataPoint, data_size_);
int maxLevelCopy = maxlevel_;
tableint entryPointCopy = enterpoint_node_;
// If point to be updated is entry point and graph just contains single element then just return.
if (entryPointCopy == internalId && cur_element_count == 1)
return;
int elemLevel = element_levels_[internalId];
std::uniform_real_distribution<float> distribution(0.0, 1.0);
for (int layer = 0; layer <= elemLevel; layer++) {
std::unordered_set<tableint> sCand;
std::unordered_set<tableint> sNeigh;
std::vector<tableint> listOneHop = getConnectionsWithLock(internalId, layer);
if (listOneHop.size() == 0)
continue;
sCand.insert(internalId);
for (auto&& elOneHop : listOneHop) {
sCand.insert(elOneHop);
if (distribution(update_probability_generator_) > updateNeighborProbability)
continue;
sNeigh.insert(elOneHop);
std::vector<tableint> listTwoHop = getConnectionsWithLock(elOneHop, layer);
for (auto&& elTwoHop : listTwoHop) {
sCand.insert(elTwoHop);
}
}
for (auto&& neigh : sNeigh) {
// if (neigh == internalId)
// continue;
std::priority_queue<std::pair<dist_t, tableint>, std::vector<std::pair<dist_t, tableint>>, CompareByFirst> candidates;
size_t size = sCand.find(neigh) == sCand.end() ? sCand.size() : sCand.size() - 1; // sCand guaranteed to have size >= 1
size_t elementsToKeep = std::min(ef_construction_, size);
for (auto&& cand : sCand) {
if (cand == neigh)
continue;
dist_t distance = fstdistfunc_(getDataByInternalId(neigh), getDataByInternalId(cand), dist_func_param_);
if (candidates.size() < elementsToKeep) {
candidates.emplace(distance, cand);
} else {
if (distance < candidates.top().first) {
candidates.pop();
candidates.emplace(distance, cand);
}
}
}
// Retrieve neighbours using heuristic and set connections.
getNeighborsByHeuristic2(candidates, layer == 0 ? maxM0_ : maxM_);
{
std::unique_lock <std::mutex> lock(link_list_locks_[neigh]);
linklistsizeint *ll_cur;
ll_cur = get_linklist_at_level(neigh, layer);
size_t candSize = candidates.size();
setListCount(ll_cur, candSize);
tableint *data = (tableint *) (ll_cur + 1);
for (size_t idx = 0; idx < candSize; idx++) {
data[idx] = candidates.top().second;
candidates.pop();
}
}
}
}
repairConnectionsForUpdate(dataPoint, entryPointCopy, internalId, elemLevel, maxLevelCopy);
}
void repairConnectionsForUpdate(
const void *dataPoint,
tableint entryPointInternalId,
tableint dataPointInternalId,
int dataPointLevel,
int maxLevel) {
tableint currObj = entryPointInternalId;
if (dataPointLevel < maxLevel) {
dist_t curdist = fstdistfunc_(dataPoint, getDataByInternalId(currObj), dist_func_param_);
for (int level = maxLevel; level > dataPointLevel; level--) {
bool changed = true;
while (changed) {
changed = false;
unsigned int *data;
std::unique_lock <std::mutex> lock(link_list_locks_[currObj]);
data = get_linklist_at_level(currObj, level);
int size = getListCount(data);
tableint *datal = (tableint *) (data + 1);
#ifdef USE_SSE
_mm_prefetch(getDataByInternalId(*datal), _MM_HINT_T0);
#endif
for (int i = 0; i < size; i++) {
#ifdef USE_SSE
_mm_prefetch(getDataByInternalId(*(datal + i + 1)), _MM_HINT_T0);
#endif
tableint cand = datal[i];
dist_t d = fstdistfunc_(dataPoint, getDataByInternalId(cand), dist_func_param_);
if (d < curdist) {
curdist = d;
currObj = cand;
changed = true;
}
}
}
}
}
if (dataPointLevel > maxLevel)
throw std::runtime_error("Level of item to be updated cannot be bigger than max level");
for (int level = dataPointLevel; level >= 0; level--) {
std::priority_queue<std::pair<dist_t, tableint>, std::vector<std::pair<dist_t, tableint>>, CompareByFirst> topCandidates = searchBaseLayer(
currObj, dataPoint, level);
std::priority_queue<std::pair<dist_t, tableint>, std::vector<std::pair<dist_t, tableint>>, CompareByFirst> filteredTopCandidates;
while (topCandidates.size() > 0) {
if (topCandidates.top().second != dataPointInternalId)
filteredTopCandidates.push(topCandidates.top());
topCandidates.pop();
}
// Since element_levels_ is being used to get `dataPointLevel`, there could be cases where `topCandidates` could just contains entry point itself.
// To prevent self loops, the `topCandidates` is filtered and thus can be empty.
if (filteredTopCandidates.size() > 0) {
bool epDeleted = isMarkedDeleted(entryPointInternalId);
if (epDeleted) {
filteredTopCandidates.emplace(fstdistfunc_(dataPoint, getDataByInternalId(entryPointInternalId), dist_func_param_), entryPointInternalId);
if (filteredTopCandidates.size() > ef_construction_)
filteredTopCandidates.pop();
}
currObj = mutuallyConnectNewElement(dataPoint, dataPointInternalId, filteredTopCandidates, level, true);
}
}
}
std::vector<tableint> getConnectionsWithLock(tableint internalId, int level) {
std::unique_lock <std::mutex> lock(link_list_locks_[internalId]);
unsigned int *data = get_linklist_at_level(internalId, level);
int size = getListCount(data);
std::vector<tableint> result(size);
tableint *ll = (tableint *) (data + 1);
memcpy(result.data(), ll, size * sizeof(tableint));
return result;
}
//(typedef unsigned int tableint)
tableint addPoint(const void *data_point, labeltype label, int level) {
tableint cur_c = 0;
{
// Checking if the element with the same label already exists
// if so, updating it *instead* of creating a new element.
std::unique_lock <std::mutex> lock_table(label_lookup_lock);
//add lock and rewrite that label.
//TODO:check the lock here.
auto search = label_lookup_.find(label);
if (search != label_lookup_.end()) {
tableint existingInternalId = search->second;
if (allow_replace_deleted_) {
if (isMarkedDeleted(existingInternalId)) {
throw std::runtime_error(
"Can't use addPoint to update deleted elements if replacement of deleted elements is enabled.");
}
}
lock_table.unlock();
if (isMarkedDeleted(existingInternalId)) {
unmarkDeletedInternal(existingInternalId);
}
updatePoint(data_point, existingInternalId, 1.0);
return existingInternalId;
}
if (cur_element_count >= max_elements_) {
throw std::runtime_error("The number of elements exceeds the specified limit");
}
//unused above
//update cur_c
cur_c = cur_element_count;
cur_element_count++;
label_lookup_[label] = cur_c;
}
std::unique_lock <std::mutex> lock_el(link_list_locks_[cur_c]);
//update the neighbours of the node
//random at first ,then -=1
int curlevel = getRandomLevel(mult_);
if (level > 0)
curlevel = level;
element_levels_[cur_c] = curlevel;
std::unique_lock <std::mutex> templock(global);
int maxlevelcopy = maxlevel_;
if (curlevel <= maxlevelcopy)//如果大於，說明當前點的更新會造成整個圖的結構（enterpoint等）更改，所以要鎖掉global
templock.unlock();
//???
tableint currObj = enterpoint_node_;//currObj就是當前點
tableint enterpoint_copy = enterpoint_node_;
memset(data_level0_memory_ + cur_c * size_data_per_element_ + offsetLevel0_, 0, size_data_per_element_);
//^ initialize the memory pool of the level 0
// Initialisation of the data and label
memcpy(getExternalLabeLp(cur_c), &label, sizeof(labeltype));
memcpy(getDataByInternalId(cur_c), data_point, data_size_);
if (curlevel) {
linkLists_[cur_c] = (char *) malloc(size_links_per_element_ * curlevel + 1);
if (linkLists_[cur_c] == nullptr)
throw std::runtime_error("Not enough memory: addPoint failed to allocate linklist");
memset(linkLists_[cur_c], 0, size_links_per_element_ * curlevel + 1);
}
//^ initialize the memory pool of level from curlevel to 1,they are consecutive.linkLists is memory pool!!
if ((signed)currObj != -1) {
if (curlevel < maxlevelcopy) {
dist_t curdist = fstdistfunc_(data_point, getDataByInternalId(currObj), dist_func_param_);
for (int level = maxlevelcopy; level > curlevel; level--) {
bool changed = true;
while (changed) {
changed = false;
unsigned int *data;
std::unique_lock <std::mutex> lock(link_list_locks_[currObj]);
data = get_linklist(currObj, level);//找到當前點當前層的資料
int size = getListCount(data);//鄰居個數
tableint *datal = (tableint *) (data + 1);//從datal開始是鄰接矩陣
for (int i = 0; i < size; i++) {
tableint cand = datal[i];//candidate
if (cand < 0 || cand > max_elements_)
throw std::runtime_error("cand error");//離譜的錯誤~
dist_t d = fstdistfunc_(data_point, getDataByInternalId(cand), dist_func_param_);
if (d < curdist) {
curdist = d;
currObj = cand;
changed = true;
}
}
}
}
}
//^ 如果當前層在比較下面，進入點在進入當前層之前，找到每一層最近的點然後到下一層
//ep:enter point
bool epDeleted = isMarkedDeleted(enterpoint_copy);
for (int level = std::min(curlevel, maxlevelcopy); level >= 0; level--) {
if (level > maxlevelcopy || level < 0) // possible? 什麼nb判斷，怕是隻有CPU短路了才會觸發（doge）
throw std::runtime_error("Level error");
//從當前層開始加邊了，但如果當前層太高了（大於最高層，從當前層到最高層後面再處理
std::priority_queue<std::pair<dist_t, tableint>, std::vector<std::pair<dist_t, tableint>>, CompareByFirst> top_candidates = searchBaseLayer(
currObj, data_point, level);
//----------------------------????
if (epDeleted) {
//emplace 就是push，但是不會複製，而是move
top_candidates.emplace(fstdistfunc_(data_point, getDataByInternalId(enterpoint_copy), dist_func_param_), enterpoint_copy);
if (top_candidates.size() > ef_construction_)
top_candidates.pop();
}
//---------------------------todo:???為什麼他都被刪了你還加進去啊
currObj = mutuallyConnectNewElement(data_point, cur_c, top_candidates, level, false);
// todo:check加邊
}
} else {
// Do nothing for the first element
enterpoint_node_ = 0;
maxlevel_ = curlevel;
}
// Releasing lock for the maximum level
if (curlevel > maxlevelcopy) {
enterpoint_node_ = cur_c;//當前點就是最高層的最近插入點的點，作為enterpoint
maxlevel_ = curlevel;
}
return cur_c;
}
std::priority_queue<std::pair<dist_t, labeltype >>
searchKnn(const void *query_data, size_t k, BaseFilterFunctor* isIdAllowed = nullptr) const {
std::priority_queue<std::pair<dist_t, labeltype >> result;
if (cur_element_count == 0) return result;
tableint currObj = enterpoint_node_;
dist_t curdist = fstdistfunc_(query_data, getDataByInternalId(enterpoint_node_), dist_func_param_);
for (int level = maxlevel_; level > 0; level--) {
bool changed = true;
while (changed) {
changed = false;
unsigned int *data;
data = (unsigned int *) get_linklist(currObj, level);
int size = getListCount(data);
metric_hops++;
metric_distance_computations+=size;
tableint *datal = (tableint *) (data + 1);
for (int i = 0; i < size; i++) {
tableint cand = datal[i];
if (cand < 0 || cand > max_elements_)
throw std::runtime_error("cand error");
dist_t d = fstdistfunc_(query_data, getDataByInternalId(cand), dist_func_param_);
if (d < curdist) {
curdist = d;
currObj = cand;
changed = true;
}
}
}
}
std::priority_queue<std::pair<dist_t, tableint>, std::vector<std::pair<dist_t, tableint>>, CompareByFirst> top_candidates;
bool bare_bone_search = !num_deleted_ && !isIdAllowed;
if (bare_bone_search) {
top_candidates = searchBaseLayerST<true>(
currObj, query_data, std::max(ef_, k), isIdAllowed);
} else {
top_candidates = searchBaseLayerST<false>(
currObj, query_data, std::max(ef_, k), isIdAllowed);
}
while (top_candidates.size() > k) {
top_candidates.pop();
}
while (top_candidates.size() > 0) {
std::pair<dist_t, tableint> rez = top_candidates.top();
result.push(std::pair<dist_t, labeltype>(rez.first, getExternalLabel(rez.second)));
top_candidates.pop();
}
return result;
}
std::vector<std::pair<dist_t, labeltype >>
searchStopConditionClosest(
const void *query_data,
BaseSearchStopCondition<dist_t>& stop_condition,
BaseFilterFunctor* isIdAllowed = nullptr) const {
std::vector<std::pair<dist_t, labeltype >> result;
if (cur_element_count == 0) return result;
tableint currObj = enterpoint_node_;
dist_t curdist = fstdistfunc_(query_data, getDataByInternalId(enterpoint_node_), dist_func_param_);
for (int level = maxlevel_; level > 0; level--) {
bool changed = true;
while (changed) {
changed = false;
unsigned int *data;
data = (unsigned int *) get_linklist(currObj, level);
int size = getListCount(data);
metric_hops++;
metric_distance_computations+=size;
tableint *datal = (tableint *) (data + 1);
for (int i = 0; i < size; i++) {
tableint cand = datal[i];
if (cand < 0 || cand > max_elements_)
throw std::runtime_error("cand error");
dist_t d = fstdistfunc_(query_data, getDataByInternalId(cand), dist_func_param_);
if (d < curdist) {
curdist = d;
currObj = cand;
changed = true;
}
}
}
}
std::priority_queue<std::pair<dist_t, tableint>, std::vector<std::pair<dist_t, tableint>>, CompareByFirst> top_candidates;
top_candidates = searchBaseLayerST<false>(currObj, query_data, 0, isIdAllowed, &stop_condition);
size_t sz = top_candidates.size();
result.resize(sz);
while (!top_candidates.empty()) {
result[--sz] = top_candidates.top();
top_candidates.pop();
}
stop_condition.filter_results(result);
return result;
}
void checkIntegrity() {
int connections_checked = 0;
std::vector <int > inbound_connections_num(cur_element_count, 0);
for (int i = 0; i < cur_element_count; i++) {
for (int l = 0; l <= element_levels_[i]; l++) {
linklistsizeint *ll_cur = get_linklist_at_level(i, l);
int size = getListCount(ll_cur);
tableint *data = (tableint *) (ll_cur + 1);
std::unordered_set<tableint> s;
for (int j = 0; j < size; j++) {
assert(data[j] < cur_element_count);
assert(data[j] != i);
inbound_connections_num[data[j]]++;
s.insert(data[j]);
connections_checked++;
}
assert(s.size() == size);
}
}
if (cur_element_count > 1) {
int min1 = inbound_connections_num[0], max1 = inbound_connections_num[0];
for (int i=0; i < cur_element_count; i++) {
assert(inbound_connections_num[i] > 0);
min1 = std::min(inbound_connections_num[i], min1);
max1 = std::max(inbound_connections_num[i], max1);
}
std::cout << "Min inbound: " << min1 << ", Max inbound:" << max1 << "\n";
}
std::cout << "integrity ok, checked " << connections_checked << " connections\n";
}
};
} // namespace hnswlib