Optimize range search result sort in segcore (#24837)

Signed-off-by: Yudong Cai <yudong.cai@zilliz.com>
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Cai Yudong 2023-06-13 19:22:38 +08:00 committed by GitHub
parent 028cbee519
commit 1b3c4b26f1
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6 changed files with 94 additions and 88 deletions

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@ -12,37 +12,43 @@
#include <queue>
#include <vector>
#include <functional>
#include <iostream>
#include "common/Utils.h"
#include "common/RangeSearchHelper.h"
namespace milvus {
namespace {
using ResultPair = std::pair<float, int64_t>;
}
/* Sort and return TOPK items as final range search result */
DatasetPtr
SortRangeSearchResult(DatasetPtr data_set,
int64_t topk,
int64_t nq,
const std::string_view metric_type) {
ReGenRangeSearchResult(DatasetPtr data_set,
int64_t topk,
int64_t nq,
const std::string& metric_type) {
/**
* nq: number of queries;
* lims: the size of lims is nq + 1, lims[i+1] - lims[i] refers to the size of RangeSearch result queries[i]
* for example, the nq is 5. In the selected range,
* the size of RangeSearch result for each nq is [1, 2, 3, 4, 5],
* the lims will be [0, 1, 3, 6, 10, 15];
* for example, the nq is 5. In the selected range,
* the size of RangeSearch result for each nq is [1, 2, 3, 4, 5],
* the lims will be [0, 1, 3, 6, 10, 15];
* ids: the size of ids is lim[nq],
* { i(0,0), i(0,1), , i(0,k0-1),
* {
* i(0,0), i(0,1), , i(0,k0-1),
* i(1,0), i(1,1), , i(1,k1-1),
* ,
* i(n-1,0), i(n-1,1), , i(n-1,kn-1)},
* ... ...
* i(n-1,0), i(n-1,1), , i(n-1,kn-1)
* }
* i(0,0), i(0,1), , i(0,k0-1) means the ids of RangeSearch result queries[0], k0 equals lim[1] - lim[0];
* dist: the size of ids is lim[nq],
* { d(0,0), d(0,1), , d(0,k0-1),
* {
* d(0,0), d(0,1), , d(0,k0-1),
* d(1,0), d(1,1), , d(1,k1-1),
* ,
* d(n-1,0), d(n-1,1), , d(n-1,kn-1)},
* ... ...
* d(n-1,0), d(n-1,1), , d(n-1,kn-1)
* }
* d(0,0), d(0,1), , d(0,k0-1) means the distances of RangeSearch result queries[0], k0 equals lim[1] - lim[0];
*/
auto lims = GetDatasetLims(data_set);
@ -51,50 +57,53 @@ SortRangeSearchResult(DatasetPtr data_set,
// use p_id and p_dist to GenResultDataset after sorted
auto p_id = new int64_t[topk * nq];
memset(p_id, -1, sizeof(int64_t) * topk * nq);
auto p_dist = new float[topk * nq];
std::fill_n(p_id, topk * nq, -1);
std::fill_n(p_dist, topk * nq, std::numeric_limits<float>::max());
/*
* get result for one nq
* IP: 1.0 range_filter radius
* |------------+---------------| min_heap descending_order
* L2: 0.0 range_filter radius
* |------------+---------------| max_heap ascending_order
*
*/
* get result for one nq
* IP: 1.0 range_filter radius
* |------------+---------------| min_heap descending_order
* |___ ___|
* V
* topk
*
* L2: 0.0 range_filter radius
* |------------+---------------| max_heap ascending_order
* |___ ___|
* V
* topk
*/
std::function<bool(const ResultPair&, const ResultPair&)> cmp =
std::less<>();
if (IsMetricType(metric_type, knowhere::metric::IP)) {
if (PositivelyRelated(metric_type)) {
cmp = std::greater<>();
}
std::priority_queue<ResultPair, std::vector<ResultPair>, decltype(cmp)>
sub_result(cmp);
// The subscript of p_id and p_dist
int cnt = 0;
#pragma omp parallel for
for (int i = 0; i < nq; i++) {
// if RangeSearch answer size of one nq is less than topk, set the capacity to size
int size = lims[i + 1] - lims[i];
int capacity = topk > size ? size : topk;
std::priority_queue<ResultPair, std::vector<ResultPair>, decltype(cmp)>
pq(cmp);
auto capacity = std::min<int64_t>(lims[i + 1] - lims[i], topk);
for (int j = lims[i]; j < lims[i + 1]; j++) {
auto current = ResultPair(dist[j], id[j]);
if (sub_result.size() == capacity) {
if (cmp(sub_result.top(), current)) {
current = sub_result.top();
}
sub_result.pop();
auto curr = ResultPair(dist[j], id[j]);
if (pq.size() < capacity) {
pq.push(curr);
} else if (cmp(curr, pq.top())) {
pq.pop();
pq.push(curr);
}
sub_result.push(current);
}
for (int i = capacity + cnt - 1; i > cnt - 1; i--) {
p_dist[i] = sub_result.top().first;
p_id[i] = sub_result.top().second;
sub_result.pop();
for (int j = capacity - 1; j >= 0; j--) {
auto& node = pq.top();
p_dist[i * topk + j] = node.first;
p_id[i * topk + j] = node.second;
pq.pop();
}
cnt += topk;
}
return GenResultDataset(nq, topk, p_id, p_dist);
}
@ -102,22 +111,27 @@ SortRangeSearchResult(DatasetPtr data_set,
void
CheckRangeSearchParam(float radius,
float range_filter,
const std::string_view metric_type) {
const std::string& metric_type) {
/*
* IP: 1.0 range_filter radius
* |------------+---------------| min_heap descending_order
* L2: 1.0 radius range_filter
* |------------+---------------| max_heap ascending_order
* |------------+---------------| range_filter > radius
* L2: 0.0 range_filter radius
* |------------+---------------| range_filter < radius
*
*/
if (metric_type == knowhere::metric::IP) {
if (range_filter < radius) {
PanicInfo("range_filter must more than radius when IP");
if (PositivelyRelated(metric_type)) {
if (range_filter <= radius) {
PanicInfo(
"range_filter must be greater than or equal to radius for IP "
"and COSINE");
}
} else {
if (range_filter > radius) {
PanicInfo("range_filter must less than radius except IP");
if (range_filter >= radius) {
PanicInfo(
"range_filter must be less than or equal to radius for "
"L2/HAMMING/JACCARD/TANIMOTO");
}
}
}
} // namespace milvus

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@ -17,13 +17,14 @@
namespace milvus {
DatasetPtr
SortRangeSearchResult(DatasetPtr data_set,
int64_t topk,
int64_t nq,
const std::string_view metric_type);
ReGenRangeSearchResult(DatasetPtr data_set,
int64_t topk,
int64_t nq,
const std::string& metric_type);
void
CheckRangeSearchParam(float radius,
float range_filter,
const std::string_view metric_type);
const std::string& metric_type);
} // namespace milvus

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@ -192,7 +192,7 @@ VectorDiskAnnIndex<T>::Query(const DatasetPtr dataset,
"failed to range search, " +
MatchKnowhereError(res.error()));
}
return SortRangeSearchResult(
return ReGenRangeSearchResult(
res.value(), topk, num_queries, GetMetricType());
} else {
auto res = index_.Search(*dataset, search_config, bitset);

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@ -122,7 +122,7 @@ VectorMemIndex::Query(const DatasetPtr dataset,
"failed to range search, " +
MatchKnowhereError(res.error()));
}
return SortRangeSearchResult(
return ReGenRangeSearchResult(
res.value(), topk, num_queries, GetMetricType());
} else {
auto res = index_.Search(*dataset, search_conf, bitset);

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@ -77,7 +77,7 @@ BruteForceSearch(const dataset::SearchDataset& dataset,
"failed to range search, " +
MatchKnowhereError(res.error()));
}
auto result = SortRangeSearchResult(
auto result = ReGenRangeSearchResult(
res.value(), topk, nq, dataset.metric_type);
std::copy_n(
GetDatasetIDs(result), nq * topk, sub_result.get_seg_offsets());

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@ -22,12 +22,12 @@
#include "test_utils/indexbuilder_test_utils.h"
bool
cmp1(std::pair<float, int64_t> a, std::pair<float, int64_t> b) {
greater(std::pair<float, int64_t> a, std::pair<float, int64_t> b) {
return a.first > b.first;
}
bool
cmp2(std::pair<float, int64_t> a, std::pair<float, int64_t> b) {
less(std::pair<float, int64_t> a, std::pair<float, int64_t> b) {
return a.first < b.first;
}
@ -35,7 +35,7 @@ auto
RangeSearchSortResultBF(milvus::DatasetPtr data_set,
int64_t topk,
size_t nq,
std::string metric_type) {
std::string& metric_type) {
auto lims = milvus::GetDatasetLims(data_set);
auto id = milvus::GetDatasetIDs(data_set);
auto dist = milvus::GetDatasetDistance(data_set);
@ -43,32 +43,26 @@ RangeSearchSortResultBF(milvus::DatasetPtr data_set,
memset(p_id, -1, sizeof(int64_t) * topk * nq);
auto p_dist = new float[topk * nq];
std::fill_n(p_dist, topk * nq, std::numeric_limits<float>::max());
auto cmp_func = (milvus::PositivelyRelated(metric_type)) ? greater : less;
// cnt means the subscript of p_id and p_dist
int cnt = 0;
for (int i = 0; i < nq; i++) {
auto size = lims[i + 1] - lims[i];
int capacity = topk > size ? size : topk;
auto capacity = std::min<int64_t>(lims[i + 1] - lims[i], topk);
// sort each layer
std::vector<std::pair<float, int64_t>> list;
if (milvus::IsMetricType(metric_type, knowhere::metric::IP)) {
for (int j = lims[i]; j < lims[i + 1]; j++) {
list.push_back(std::pair<float, int64_t>(dist[j], id[j]));
}
std::sort(list.begin(), list.end(), cmp1);
for (int j = lims[i]; j < lims[i + 1]; j++) {
list.emplace_back(dist[j], id[j]);
}
std::sort(list.begin(), list.end(), cmp_func);
} else {
for (int j = lims[i]; j < lims[i + 1]; j++) {
list.push_back(std::pair<float, int64_t>(dist[j], id[j]));
}
std::sort(list.begin(), list.end(), cmp2);
for (int k = 0; k < capacity; k++) {
p_dist[i * topk + k] = list[k].first;
p_id[i * topk + k] = list[k].second;
}
for (int k = cnt; k < capacity + cnt; k++) {
p_dist[k] = list[k - cnt].first;
p_id[k] = list[k - cnt].second;
}
cnt += topk;
}
return std::make_tuple(cnt, p_id, p_dist);
return std::make_tuple(p_id, p_dist);
}
milvus::DatasetPtr
@ -93,10 +87,8 @@ CheckRangeSearchSortResult(int64_t* p_id,
auto id = milvus::GetDatasetIDs(dataset);
auto dist = milvus::GetDatasetDistance(dataset);
for (int i = 0; i < n; i++) {
AssertInfo(id[i] == p_id[i],
"id of range search result are not the same");
AssertInfo(dist[i] == p_dist[i],
"distance of range search result are not the same");
AssertInfo(id[i] == p_id[i], "id of range search result not same");
AssertInfo(dist[i] == p_dist[i], "distance of range search result not same");
}
}
@ -173,10 +165,9 @@ INSTANTIATE_TEST_CASE_P(RangeSearchSortParameters,
knowhere::metric::HAMMING));
TEST_P(RangeSearchSortTest, CheckRangeSearchSort) {
auto res = milvus::SortRangeSearchResult(dataset, TOPK, N, metric_type);
auto [real_num, p_id, p_dist] =
RangeSearchSortResultBF(dataset, TOPK, N, metric_type);
CheckRangeSearchSortResult(p_id, p_dist, res, real_num);
auto res = milvus::ReGenRangeSearchResult(dataset, TOPK, N, metric_type);
auto [p_id, p_dist] = RangeSearchSortResultBF(dataset, TOPK, N, metric_type);
CheckRangeSearchSortResult(p_id, p_dist, res, N * TOPK);
delete[] p_id;
delete[] p_dist;
}