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

1 files changed, 146 insertions, 137 deletions

diff --git a/include/query/rangequery.h b/include/query/rangequery.h
index e0690e6..e7be39c 100644
--- a/include/query/rangequery.h
+++ b/include/query/rangequery.h
@@ -1,177 +1,186 @@
 /*
  * include/query/rangequery.h
  *
- * Copyright (C) 2023 Douglas B. Rumbaugh <drumbaugh@psu.edu>
+ * Copyright (C) 2023-2024 Douglas B. Rumbaugh <drumbaugh@psu.edu>
  *
  * Distributed under the Modified BSD License.
  *
- * A query class for single dimensional range queries. This query requires 
+ * A query class for single dimensional range queries. This query requires
  * that the shard support get_lower_bound(key) and get_record_at(index).
  */
 #pragma once
 
 #include "framework/QueryRequirements.h"
+#include "framework/interface/Record.h"
 #include "psu-ds/PriorityQueue.h"
 #include "util/Cursor.h"
 
-namespace de { namespace rq {
+namespace de {
+namespace rq {
 
-template <RecordInterface R>
-struct Parms {
+template <ShardInterface S> class Query {
+  typedef typename S::RECORD R;
+
+public:
+  struct Parameters {
     decltype(R::key) lower_bound;
     decltype(R::key) upper_bound;
-};
+  };
 
-template <RecordInterface R>
-struct State {
+  struct LocalQuery {
     size_t start_idx;
     size_t stop_idx;
-};
+    Parameters global_parms;
+  };
 
-template <RecordInterface R>
-struct BufferState {
+  struct LocalQueryBuffer {
     BufferView<R> *buffer;
-
-    BufferState(BufferView<R> *buffer) 
-        : buffer(buffer) {}
-};
-
-template <RecordInterface R, ShardInterface<R> S>
-class Query {
-public:
-    constexpr static bool EARLY_ABORT=false;
-    constexpr static bool SKIP_DELETE_FILTER=true;
-
-    static void *get_query_state(S *shard, void *parms) {
-        auto res = new State<R>();
-        auto p = (Parms<R> *) parms;
-
-        res->start_idx = shard->get_lower_bound(p->lower_bound);
-        res->stop_idx = shard->get_record_count();
-
-        return res;
+    Parameters global_parms;
+  };
+
+  typedef Wrapped<R> LocalResultType;
+  typedef R ResultType;
+
+  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->start_idx = shard->get_lower_bound(parms->lower_bound);
+    query->stop_idx = shard->get_record_count();
+    query->global_parms = *parms;
+
+    return query;
+  }
+
+  static LocalQueryBuffer *local_preproc_buffer(BufferView<R> *buffer,
+                                                Parameters *parms) {
+    auto query = new LocalQueryBuffer();
+    query->buffer = buffer;
+    query->global_parms = *parms;
+
+    return query;
+  }
+
+  static void distribute_query(Parameters *parms,
+                               std::vector<LocalQuery *> const &local_queries,
+                               LocalQueryBuffer *buffer_query) {
+    return;
+  }
+
+  static std::vector<LocalResultType> local_query(S *shard, LocalQuery *query) {
+    std::vector<LocalResultType> result;
+
+    /*
+     * if the returned index is one past the end of the
+     * records for the PGM, then there are not records
+     * in the index falling into the specified range.
+     */
+    if (query->start_idx == shard->get_record_count()) {
+      return result;
     }
 
-    static void* get_buffer_query_state(BufferView<R> *buffer, void *parms) {
-        auto res = new BufferState<R>(buffer);
+    auto ptr = shard->get_record_at(query->start_idx);
 
-        return res;
+    /*
+     * roll the pointer forward to the first record that is
+     * greater than or equal to the lower bound.
+     */
+    while (ptr < shard->get_data() + query->stop_idx &&
+           ptr->rec.key < query->global_parms.lower_bound) {
+      ptr++;
     }
 
-    static void process_query_states(void *query_parms, std::vector<void*> &shard_states, void* buffer_state) {
-        return;
+    while (ptr < shard->get_data() + query->stop_idx &&
+           ptr->rec.key <= query->global_parms.upper_bound) {
+      result.emplace_back(*ptr);
+      ptr++;
     }
 
-    static std::vector<Wrapped<R>> query(S *shard, void *q_state, void *parms) {
-        std::vector<Wrapped<R>> records;
-        auto p = (Parms<R> *) parms;
-        auto s = (State<R> *) q_state;
-
-        /* 
-         * if the returned index is one past the end of the
-         * records for the PGM, then there are not records
-         * in the index falling into the specified range.
-         */
-        if (s->start_idx == shard->get_record_count()) {
-            return records;
-        }
-
-        auto ptr = shard->get_record_at(s->start_idx);
-        
-        /*
-         * roll the pointer forward to the first record that is
-         * greater than or equal to the lower bound.
-         */
-        while(ptr < shard->get_data() + s->stop_idx && ptr->rec.key < p->lower_bound) {
-            ptr++;
-        }
-
-        while (ptr < shard->get_data() + s->stop_idx && ptr->rec.key <= p->upper_bound) {
-            records.emplace_back(*ptr);
-            ptr++;
-        }
-
-        return records;
-    }
+    return result;
+  }
 
-    static std::vector<Wrapped<R>> buffer_query(void *state, void *parms) {
-        auto p = (Parms<R> *) parms;
-        auto s = (BufferState<R> *) state;
+  static std::vector<LocalResultType>
+  local_query_buffer(LocalQueryBuffer *query) {
 
-        std::vector<Wrapped<R>> records;
-        for (size_t i=0; i<s->buffer->get_record_count(); i++) {
-            auto rec = s->buffer->get(i);
-            if (rec->rec.key >= p->lower_bound && rec->rec.key <= p->upper_bound) {
-                records.emplace_back(*rec);
-            }
-        }
-
-        return records;
+    std::vector<LocalResultType> result;
+    for (size_t i = 0; i < query->buffer->get_record_count(); i++) {
+      auto rec = query->buffer->get(i);
+      if (rec->rec.key >= query->global_parms.lower_bound &&
+          rec->rec.key <= query->global_parms.upper_bound) {
+        result.emplace_back(*rec);
+      }
     }
 
-    static std::vector<R> merge(std::vector<std::vector<Wrapped<R>>> &results, void *parms, std::vector<R> &output) {
-        std::vector<Cursor<Wrapped<R>>> cursors;
-        cursors.reserve(results.size());
-
-        psudb::PriorityQueue<Wrapped<R>> pq(results.size());
-        size_t total = 0;
-		size_t tmp_n = results.size();
-        
-
-        for (size_t i = 0; i < tmp_n; ++i)
-			if (results[i].size() > 0){
-	            auto base = results[i].data();
-		        cursors.emplace_back(Cursor<Wrapped<R>>{base, base + results[i].size(), 0, results[i].size()});
-				assert(i == cursors.size() - 1);
-			    total += results[i].size();
-				pq.push(cursors[i].ptr, tmp_n - i - 1);
-			} else {
-				cursors.emplace_back(Cursor<Wrapped<R>>{nullptr, nullptr, 0, 0});
-			}
-
-        if (total == 0) {
-            return std::vector<R>();
-        }
-
-        output.reserve(total);
-
-        while (pq.size()) {
-            auto now = pq.peek();
-            auto next = pq.size() > 1 ? pq.peek(1) : psudb::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[tmp_n - now.version - 1];
-                auto& cursor2 = cursors[tmp_n - next.version - 1];
-                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[tmp_n - now.version - 1];
-                if (!now.data->is_tombstone()) output.push_back(cursor.ptr->rec);
-
-                pq.pop();
-                
-                if (advance_cursor<Wrapped<R>>(cursor)) pq.push(cursor.ptr, now.version);
-            }
-        }
-
-        return output;
+    return result;
+  }
+
+  static void
+  combine(std::vector<std::vector<LocalResultType>> const &local_results,
+          Parameters *parms, std::vector<ResultType> &output) {
+    std::vector<Cursor<LocalResultType>> cursors;
+    cursors.reserve(local_results.size());
+
+    psudb::PriorityQueue<LocalResultType> pq(local_results.size());
+    size_t total = 0;
+    size_t tmp_n = local_results.size();
+
+    for (size_t i = 0; i < tmp_n; ++i)
+      if (local_results[i].size() > 0) {
+        auto base = local_results[i].data();
+        cursors.emplace_back(Cursor<LocalResultType>{
+            base, base + local_results[i].size(), 0, local_results[i].size()});
+        assert(i == cursors.size() - 1);
+        total += local_results[i].size();
+        pq.push(cursors[i].ptr, tmp_n - i - 1);
+      } else {
+        cursors.emplace_back(Cursor<LocalResultType>{nullptr, nullptr, 0, 0});
+      }
+
+    if (total == 0) {
+      return;
     }
 
-    static void delete_query_state(void *state) {
-        auto s = (State<R> *) state;
-        delete s;
+    output.reserve(total);
+
+    while (pq.size()) {
+      auto now = pq.peek();
+      auto next = pq.size() > 1
+                      ? pq.peek(1)
+                      : psudb::queue_record<LocalResultType>{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[tmp_n - now.version - 1];
+        auto &cursor2 = cursors[tmp_n - next.version - 1];
+        if (advance_cursor<LocalResultType>(cursor1))
+          pq.push(cursor1.ptr, now.version);
+        if (advance_cursor<LocalResultType>(cursor2))
+          pq.push(cursor2.ptr, next.version);
+      } else {
+        auto &cursor = cursors[tmp_n - now.version - 1];
+        if (!now.data->is_tombstone())
+          output.push_back(cursor.ptr->rec);
+
+        pq.pop();
+
+        if (advance_cursor<LocalResultType>(cursor))
+          pq.push(cursor.ptr, now.version);
+      }
     }
 
-    static void delete_buffer_query_state(void *state) {
-        auto s = (BufferState<R> *) state;
-        delete s;
-    }
+    return;
+  }
 
-    static bool repeat(void *parms, std::vector<R> &results, std::vector<void*> states, void* buffer_state) {
-        return false;
-    }
+  static bool repeat(Parameters *parms, std::vector<ResultType> &output,
+                     std::vector<LocalQuery *> const &local_queries,
+                     LocalQueryBuffer *buffer_query) {
+    return false;
+  }
 };
 
-}}
+} // namespace rq
+} // namespace de