From 9fe305c7d28e993e55c55427f377ae7e3251ea4f Mon Sep 17 00:00:00 2001
From: "Douglas B. Rumbaugh" <dbr4@psu.edu>
Date: Fri, 6 Dec 2024 13:13:51 -0500
Subject: Interface update (#5)

* Query Interface Adjustments/Refactoring

Began the process of adjusting the query interface (and also the shard
interface, to a lesser degree) to better accommodate the user. In
particular the following changes have been made,

    1. The number of necessary template arguments for the query type
       has been drastically reduced, while also removing the void pointers
       and manual delete functions from the interface.

       This was accomplished by requiring many of the sub-types associated
       with a query (parameters, etc.) to be nested inside the main query
       class, and by forcing the SHARD type to expose its associated
       record type.

    2. User-defined query return types are now supported.

       Queries no longer are required to return strictly sets of records.
       Instead, the query now has LocalResultType and ResultType
       template parameters (which can be defaulted using a typedef in
       the Query type itself), allowing much more flexibility.

       Note that, at least for the short term, the LocalResultType must
       still expose the same is_deleted/is_tombstone interface as a
       Wrapped<R> used to, as this is currently needed for delete
       filtering. A better approach to this is, hopefully, forthcoming.

    3. Updated the ISAMTree.h shard and rangequery.h query to use the
       new interfaces, and adjusted the associated unit tests as well.

    4. Dropped the unnecessary "get_data()" function from the ShardInterface
       concept.

    5. Dropped the need to specify a record type in the ShardInterface
       concept. This is now handled using a required Shard::RECORD
       member of the Shard class itself, which should expose the name
       of the record type.

* Updates to framework to support new Query/Shard interfaces

Pretty extensive adjustments to the framework, particularly to the
templates themselves, along with some type-renaming work, to support
the new query and shard interfaces.

Adjusted the external query interface to take an rvalue reference, rather
than a pointer, to the query parameters.

* Removed framework-level delete filtering

This was causing some issues with the new query interface, and should
probably be reworked anyway, so I'm temporarily (TM) removing the
feature.

* Updated benchmarks + remaining code for new interface
---
 include/query/knn.h | 224 ++++++++++++++++++++++++++--------------------------
 1 file changed, 112 insertions(+), 112 deletions(-)

(limited to 'include/query/knn.h')

diff --git a/include/query/knn.h b/include/query/knn.h
index a227293..87ea10a 100644
--- a/include/query/knn.h
+++ b/include/query/knn.h
@@ -6,7 +6,7 @@
  * Distributed under the Modified BSD License.
  *
  * A query class for k-NN queries, designed for use with the VPTree
- * shard. 
+ * shard.
  *
  * FIXME: no support for tombstone deletes just yet. This would require a
  * query resumption mechanism, most likely.
@@ -16,147 +16,147 @@
 #include "framework/QueryRequirements.h"
 #include "psu-ds/PriorityQueue.h"
 
-namespace de { namespace knn {
+namespace de {
+namespace knn {
 
 using psudb::PriorityQueue;
 
-template <NDRecordInterface R>
-struct Parms {
+template <ShardInterface S> class Query {
+  typedef typename S::RECORD R;
+
+public:
+  struct Parameters {
     R point;
     size_t k;
-};
+  };
 
-template <NDRecordInterface R>
-struct State {
-    size_t k;
-};
+  struct LocalQuery {
+    Parameters global_parms;
+  };
 
-template <NDRecordInterface R>
-struct BufferState {
+  struct LocalQueryBuffer {
     BufferView<R> *buffer;
+    Parameters global_parms;
+  };
 
-    BufferState(BufferView<R> *buffer) 
-        : buffer(buffer) {}
-};
+  typedef Wrapped<R> LocalResultType;
+  typedef R ResultType;
+  constexpr static bool EARLY_ABORT = false;
+  constexpr static bool SKIP_DELETE_FILTER = true;
 
-template <NDRecordInterface R, ShardInterface<R> S>
-class Query {
-public:
-    constexpr static bool EARLY_ABORT=false;
-    constexpr static bool SKIP_DELETE_FILTER=true;
+  static LocalQuery *local_preproc(S *shard, Parameters *parms) {
+    auto query = new LocalQuery();
+    query->global_parms = *parms;
 
-    static void *get_query_state(S *shard, void *parms) {
-        return nullptr;
-    }
+    return query;
+  }
 
-    static void* get_buffer_query_state(BufferView<R> *buffer, void *parms) {
-        return new BufferState<R>(buffer);
-    }
+  static LocalQueryBuffer *local_preproc_buffer(BufferView<R> *buffer,
+                                                Parameters *parms) {
+    auto query = new LocalQueryBuffer();
+    query->global_parms = *parms;
+    query->buffer = buffer;
 
-    static void process_query_states(void *query_parms, std::vector<void*> &shard_states, void* buffer_state) {
-        return;
-    }
+    return query;
+  }
 
-    static std::vector<Wrapped<R>> query(S *shard, void *q_state, void *parms) {
-        std::vector<Wrapped<R>> results;
-        Parms<R> *p = (Parms<R> *) parms;
-        Wrapped<R> wrec;
-        wrec.rec = p->point;
-        wrec.header = 0;
+  static void distribute_query(Parameters *parms,
+                               std::vector<LocalQuery *> const &local_queries,
+                               LocalQueryBuffer *buffer_query) {
+    return;
+  }
 
-        PriorityQueue<Wrapped<R>, DistCmpMax<Wrapped<R>>> pq(p->k, &wrec);
+  static std::vector<LocalResultType> local_query(S *shard, LocalQuery *query) {
+    std::vector<LocalResultType> results;
 
-        shard->search(p->point, p->k, pq);
+    Wrapped<R> wrec;
+    wrec.rec = query->global_parms.point;
+    wrec.header = 0;
 
-        while (pq.size() > 0) {
-            results.emplace_back(*pq.peek().data);
-            pq.pop();
-        }
+    PriorityQueue<Wrapped<R>, DistCmpMax<Wrapped<R>>> pq(query->global_parms.k,
+                                                         &wrec);
 
-        return results;
+    shard->search(query->global_parms.point, query->global_parms.k, pq);
+
+    while (pq.size() > 0) {
+      results.emplace_back(*pq.peek().data);
+      pq.pop();
     }
 
-    static std::vector<Wrapped<R>> buffer_query(void *state, void *parms) {
-        Parms<R> *p = (Parms<R> *) parms;
-        BufferState<R> *s = (BufferState<R> *) state;
-        Wrapped<R> wrec;
-        wrec.rec = p->point;
-        wrec.header = 0;
-
-        size_t k = p->k;
-
-        PriorityQueue<Wrapped<R>, DistCmpMax<Wrapped<R>>> pq(k, &wrec);
-        for (size_t i=0; i<s->buffer->get_record_count(); i++) {
-            // Skip over deleted records (under tagging)
-            if (s->buffer->get(i)->is_deleted()) {
-                continue;
-            }
-
-            if (pq.size() < k) {
-                pq.push(s->buffer->get(i));
-            } else {
-                double head_dist = pq.peek().data->rec.calc_distance(wrec.rec);
-                double cur_dist = (s->buffer->get(i))->rec.calc_distance(wrec.rec);
-
-                if (cur_dist < head_dist) {
-                    pq.pop();
-                    pq.push(s->buffer->get(i));
-                }
-            }
-        }
+    return results;
+  }
 
-        std::vector<Wrapped<R>> results;
-        while (pq.size() > 0) {
-            results.emplace_back(*(pq.peek().data));
-            pq.pop();
-        }
+  static std::vector<LocalResultType>
+  local_query_buffer(LocalQueryBuffer *query) {
 
-        return std::move(results);
-    }
+    std::vector<LocalResultType> results;
 
-    static std::vector<R> merge(std::vector<std::vector<Wrapped<R>>> &results, void *parms, std::vector<R> &output) {
-        Parms<R> *p = (Parms<R> *) parms;
-        R rec = p->point;
-        size_t k = p->k;
-
-        PriorityQueue<R, DistCmpMax<R>> pq(k, &rec);
-        for (size_t i=0; i<results.size(); i++) {
-            for (size_t j=0; j<results[i].size(); j++) {
-                if (pq.size() < k) {
-                    pq.push(&results[i][j].rec);
-                } else {
-                    double head_dist = pq.peek().data->calc_distance(rec);
-                    double cur_dist = results[i][j].rec.calc_distance(rec);
-
-                    if (cur_dist < head_dist) {
-                        pq.pop();
-                        pq.push(&results[i][j].rec);
-                    }
-                }
-            }
-        }
+    Wrapped<R> wrec;
+    wrec.rec = query->global_parms.point;
+    wrec.header = 0;
 
-        while (pq.size() > 0) {
-            output.emplace_back(*pq.peek().data);
-            pq.pop();
-        }
+    PriorityQueue<Wrapped<R>, DistCmpMax<Wrapped<R>>> pq(query->global_parms.k,
+                                                         &wrec);
+
+    for (size_t i = 0; i < query->buffer->get_record_count(); i++) {
+      // Skip over deleted records (under tagging)
+      if (query->buffer->get(i)->is_deleted()) {
+        continue;
+      }
 
-        return std::move(output);
+      if (pq.size() < query->global_parms.k) {
+        pq.push(query->buffer->get(i));
+      } else {
+        double head_dist = pq.peek().data->rec.calc_distance(wrec.rec);
+        double cur_dist = (query->buffer->get(i))->rec.calc_distance(wrec.rec);
+
+        if (cur_dist < head_dist) {
+          pq.pop();
+          pq.push(query->buffer->get(i));
+        }
+      }
     }
 
-    static void delete_query_state(void *state) {
-        auto s = (State<R> *) state;
-        delete s;
+    while (pq.size() > 0) {
+      results.emplace_back(*(pq.peek().data));
+      pq.pop();
     }
 
-    static void delete_buffer_query_state(void *state) {
-        auto s = (BufferState<R> *) state;
-        delete s;
+    return std::move(results);
+  }
+
+  static void
+  combine(std::vector<std::vector<LocalResultType>> const &local_results,
+          Parameters *parms, std::vector<ResultType> &output) {
+
+    PriorityQueue<R, DistCmpMax<R>> pq(parms->k, &(parms->point));
+    for (size_t i = 0; i < local_results.size(); i++) {
+      for (size_t j = 0; j < local_results[i].size(); j++) {
+        if (pq.size() < parms->k) {
+          pq.push(&local_results[i][j].rec);
+        } else {
+          double head_dist = pq.peek().data->calc_distance(parms->point);
+          double cur_dist = local_results[i][j].rec.calc_distance(parms->point);
+
+          if (cur_dist < head_dist) {
+            pq.pop();
+            pq.push(&local_results[i][j].rec);
+          }
+        }
+      }
     }
 
-    static bool repeat(void *parms, std::vector<R> &results, std::vector<void*> states, void* buffer_state) {
-        return false;
+    while (pq.size() > 0) {
+      output.emplace_back(*pq.peek().data);
+      pq.pop();
     }
-};
+  }
 
-}}
+  static bool repeat(Parameters *parms, std::vector<ResultType> &output,
+                     std::vector<LocalQuery *> const &local_queries,
+                     LocalQueryBuffer *buffer_query) {
+    return false;
+  }
+};
+} // namespace knn
+} // namespace de
-- 
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