diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/shard/WSS.h | 392 |
1 files changed, 392 insertions, 0 deletions
diff --git a/include/shard/WSS.h b/include/shard/WSS.h new file mode 100644 index 0000000..929f9df --- /dev/null +++ b/include/shard/WSS.h @@ -0,0 +1,392 @@ +/* + {s.get_tombstone_count()} -> std::convertible_to<size_t>; + * include/shard/WSS.h + * + * Copyright (C) 2023 Dong Xie <dongx@psu.edu> + * + * All rights reserved. Published under the Modified BSD License. + * + */ +#pragma once + + +#include <vector> +#include <cassert> +#include <queue> +#include <memory> +#include <concepts> + +#include "ds/PriorityQueue.h" +#include "util/Cursor.h" +#include "ds/Alias.h" +#include "ds/BloomFilter.h" +#include "util/bf_config.h" +#include "framework/MutableBuffer.h" +#include "framework/RecordInterface.h" +#include "framework/ShardInterface.h" +#include "framework/QueryInterface.h" + +namespace de { + +thread_local size_t wss_cancelations = 0; + +template <WeightedRecordInterface R> +struct wss_query_parms { + size_t sample_size; + gsl_rng *rng; +}; + +template <WeightedRecordInterface R, bool Rejection> +class WSSQuery; + +template <WeightedRecordInterface R> +struct WSSState { + decltype(R::weight) tot_weight; + + WSSState() { + tot_weight = 0; + } +}; + +template <WeightedRecordInterface R> +struct WSSBufferState { + size_t cutoff; + Alias* alias; + decltype(R::weight) max_weight; + + ~WSSBufferState() { + delete alias; + } + +}; + +template <WeightedRecordInterface R> +class WSS { +private: + typedef decltype(R::key) K; + typedef decltype(R::value) V; + typedef decltype(R::weight) W; + +public: + + // FIXME: there has to be a better way to do this + friend class WSSQuery<R, true>; + friend class WSSQuery<R, false>; + + WSS(MutableBuffer<R>* buffer) + : m_reccnt(0), m_tombstone_cnt(0), m_total_weight(0) { + + size_t alloc_size = (buffer->get_record_count() * sizeof(Wrapped<R>)) + (CACHELINE_SIZE - (buffer->get_record_count() * sizeof(Wrapped<R>)) % CACHELINE_SIZE); + assert(alloc_size % CACHELINE_SIZE == 0); + m_data = (Wrapped<R>*)std::aligned_alloc(CACHELINE_SIZE, alloc_size); + + m_bf = new BloomFilter<K>(BF_FPR, buffer->get_tombstone_count(), BF_HASH_FUNCS); + + size_t offset = 0; + m_reccnt = 0; + auto base = buffer->get_data(); + auto stop = base + buffer->get_record_count(); + + std::sort(base, stop, std::less<Wrapped<R>>()); + + std::vector<W> weights; + + while (base < stop) { + if (!(base->is_tombstone()) && (base + 1) < stop) { + if (base->rec == (base + 1)->rec && (base + 1)->is_tombstone()) { + base += 2; + wss_cancelations++; + continue; + } + } else if (base->is_deleted()) { + base += 1; + continue; + } + + base->header &= 1; + m_data[m_reccnt++] = *base; + m_total_weight+= base->rec.weight; + weights.push_back(base->rec.weight); + + if (m_bf && base->is_tombstone()) { + m_tombstone_cnt++; + m_bf->insert(base->rec.key); + } + + base++; + } + + if (m_reccnt > 0) { + build_alias_structure(); + } + } + + WSS(WSS** shards, size_t len) + : m_reccnt(0), m_tombstone_cnt(0), m_total_weight(0) { + std::vector<Cursor<Wrapped<R>>> cursors; + cursors.reserve(len); + + PriorityQueue<Wrapped<R>> pq(len); + + size_t attemp_reccnt = 0; + size_t tombstone_count = 0; + + for (size_t i = 0; i < len; ++i) { + if (shards[i]) { + auto base = shards[i]->get_data(); + cursors.emplace_back(Cursor{base, base + shards[i]->get_record_count(), 0, shards[i]->get_record_count()}); + attemp_reccnt += shards[i]->get_record_count(); + tombstone_count += shards[i]->get_tombstone_count(); + pq.push(cursors[i].ptr, i); + } else { + cursors.emplace_back(Cursor<Wrapped<R>>{nullptr, nullptr, 0, 0}); + } + } + + m_bf = new BloomFilter<K>(BF_FPR, tombstone_count, BF_HASH_FUNCS); + + size_t alloc_size = (attemp_reccnt * sizeof(Wrapped<R>)) + (CACHELINE_SIZE - (attemp_reccnt * sizeof(Wrapped<R>)) % CACHELINE_SIZE); + assert(alloc_size % CACHELINE_SIZE == 0); + m_data = (Wrapped<R>*)std::aligned_alloc(CACHELINE_SIZE, alloc_size); + + std::vector<W> weights; + + while (pq.size()) { + auto now = pq.peek(); + auto next = pq.size() > 1 ? pq.peek(1) : queue_record<Wrapped<R>>{nullptr, 0}; + if (!now.data->is_tombstone() && next.data != nullptr && + now.data->rec == next.data->rec && next.data->is_tombstone()) { + + pq.pop(); pq.pop(); + auto& cursor1 = cursors[now.version]; + auto& cursor2 = cursors[next.version]; + if (advance_cursor<Wrapped<R>>(cursor1)) pq.push(cursor1.ptr, now.version); + if (advance_cursor<Wrapped<R>>(cursor2)) pq.push(cursor2.ptr, next.version); + } else { + auto& cursor = cursors[now.version]; + if (!cursor.ptr->is_deleted()) { + m_data[m_reccnt++] = *cursor.ptr; + m_total_weight += cursor.ptr->rec.weight; + weights.push_back(cursor.ptr->rec.weight); + if (m_bf && cursor.ptr->is_tombstone()) { + ++m_tombstone_cnt; + if (m_bf) m_bf->insert(cursor.ptr->rec.key); + } + } + pq.pop(); + + if (advance_cursor<Wrapped<R>>(cursor)) pq.push(cursor.ptr, now.version); + } + } + + if (m_reccnt > 0) { + build_alias_structure(weights); + } + } + + ~WSS() { + if (m_data) free(m_data); + if (m_alias) free(m_alias); + if (m_bf) delete m_bf; + + } + + Wrapped<R> *point_lookup(const R &rec, bool filter=false) { + if (filter && !m_bf->lookup(rec.key)) { + return nullptr; + } + + size_t idx = get_lower_bound(rec.key); + if (idx >= m_reccnt) { + return nullptr; + } + + while (idx < m_reccnt && m_data[idx].rec < rec) ++idx; + + if (m_data[idx].rec == rec) { + return m_data + idx; + } + + return nullptr; + } + + Wrapped<R>* get_data() const { + return m_data; + } + + size_t get_record_count() const { + return m_reccnt; + } + + size_t get_tombstone_count() const { + return m_tombstone_cnt; + } + + const Wrapped<R>* get_record_at(size_t idx) const { + if (idx >= m_reccnt) return nullptr; + return m_data + idx; + } + + + size_t get_memory_usage() { + return 0; + } + +private: + + size_t get_lower_bound(const K& key) const { + size_t min = 0; + size_t max = m_reccnt - 1; + + const char * record_key; + while (min < max) { + size_t mid = (min + max) / 2; + + if (key > m_data[mid].rec.key) { + min = mid + 1; + } else { + max = mid; + } + } + + return min; + } + + void build_alias_structure(std::vector<W> &weights) { + // normalize the weights vector + for (size_t i=0; i<weights.size(); i++) { + weights[i] = weights[i] / (double) m_total_weight; + } + + // build the alias structure + m_alias = new Alias(weights); + } + + Wrapped<R>* m_data; + Alias *m_alias; + W m_total_weight; + size_t m_reccnt; + size_t m_tombstone_cnt; + size_t m_group_size; + BloomFilter<K> *m_bf; +}; + + +template <WeightedRecordInterface R, bool Rejection=true> +class WSSQuery { +public: + static void *get_query_state(WSS<R> *wss, void *parms) { + auto res = new WSSState<R>(); + + return res; + } + + static void* get_buffer_query_state(MutableBuffer<R> *buffer, void *parms) { + WSSBufferState<R> *state = new WSSBufferState<R>(); + auto parameters = (wss_query_parms<R>*) parms; + if constexpr (Rejection) { + state->cutoff = buffer->get_record_count() - 1; + state->max_weight = buffer->get_max_weight(); + return state; + } + + std::vector<double> weights; + + state->cutoff = buffer->get_record_count() - 1; + double tot_weight = 0.0; + + for (size_t i = 0; i <= state->cutoff; i++) { + auto rec = buffer->get_data() + i; + weights.push_back(rec->rec.weight); + state->records.push_back(*rec); + tot_weight += rec->rec.weight; + } + + for (size_t i = 0; i < weights.size(); i++) { + weights[i] = weights[i] / tot_weight; + } + + state->alias = new Alias(weights); + + return state; + } + + static std::vector<Wrapped<R>> query(WSS<R> *wss, void *q_state, void *parms) { + auto sample_sz = ((wss_query_parms<R> *) parms)->sample_size; + auto rng = ((wss_query_parms<R> *) parms)->rng; + + auto state = (WSSState<R> *) q_state; + + std::vector<Wrapped<R>> result_set; + + if (sample_sz == 0) { + return result_set; + } + size_t attempts = 0; + do { + attempts++; + size_t idx = wss->m_alias->get(rng); + result_set.emplace_back(*wss->get_record_at(idx)); + } while (attempts < sample_sz); + + return result_set; + } + + static std::vector<Wrapped<R>> buffer_query(MutableBuffer<R> *buffer, void *state, void *parms) { + auto st = (WSSBufferState<R> *) state; + auto p = (wss_query_parms<R> *) parms; + + std::vector<Wrapped<R>> result; + result.reserve(p->sample_size); + + if constexpr (Rejection) { + for (size_t i=0; i<p->sample_size; i++) { + auto idx = gsl_rng_uniform_int(p->rng, st->cutoff); + auto rec = buffer->get_data() + idx; + + auto test = gsl_rng_uniform(p->rng) * st->max_weight; + + if (test <= rec->rec.weight) { + result.emplace_back(*rec); + } + } + return result; + } + + for (size_t i=0; i<p->sample_size; i++) { + auto idx = st->alias->get(p->rng); + result.emplace_back(*(buffer->get_data() + idx)); + } + + return result; + } + + static std::vector<R> merge(std::vector<std::vector<R>> &results) { + std::vector<R> output; + + for (size_t i=0; i<results.size(); i++) { + for (size_t j=0; j<results[i].size(); j++) { + output.emplace_back(results[i][j]); + } + } + + return output; + } + + static void delete_query_state(void *state) { + auto s = (WSSState<R> *) state; + delete s; + } + + static void delete_buffer_query_state(void *state) { + auto s = (WSSBufferState<R> *) state; + delete s; + } + + + //{q.get_buffer_query_state(p, p)}; + //{q.buffer_query(p, p)}; + +}; + +} |