From 6bdcf74ad91e0efaa8c2e4339f5085fde8a7982b Mon Sep 17 00:00:00 2001
From: Douglas Rumbaugh <dbr4@psu.edu>
Date: Sat, 5 Apr 2025 19:08:12 -0400
Subject: working commit (temporary progress, doesn't build)

---
 include/framework/reconstruction/LevelingPolicy.h | 30 ++++++++++++++++-------
 1 file changed, 21 insertions(+), 9 deletions(-)

(limited to 'include/framework/reconstruction/LevelingPolicy.h')

diff --git a/include/framework/reconstruction/LevelingPolicy.h b/include/framework/reconstruction/LevelingPolicy.h
index f0feb53..d448fee 100644
--- a/include/framework/reconstruction/LevelingPolicy.h
+++ b/include/framework/reconstruction/LevelingPolicy.h
@@ -21,8 +21,8 @@ class LevelingPolicy : public ReconstructionPolicy<ShardType, QueryType> {
       LevelVector;
 
 public:
-  LevelingPolicy(size_t scale_factor, size_t buffer_size)
-      : m_scale_factor(scale_factor), m_buffer_size(buffer_size) {}
+  LevelingPolicy(size_t scale_factor, size_t buffer_size, size_t modifier=0)
+      : m_scale_factor(scale_factor), m_buffer_size(buffer_size), m_size_modifier(modifier) {}
 
   std::vector<ReconstructionVector>
   get_reconstruction_tasks(const Version<ShardType, QueryType> *version, LockManager &lock_mngr) const override { 
@@ -34,7 +34,16 @@ public:
     ReconstructionVector reconstructions;
     auto levels = version->get_structure()->get_level_vector();
 
-    level_index target_level = find_reconstruction_target(levels);
+    /*
+     * on the very first flush, the whole structure will be empty, so
+     * there isn't anything to merge into level 1 from level 0 yet.
+     */
+    if (version->get_structure()->get_record_count() == 0) {
+      return reconstructions;
+    }
+
+    level_index target_level = find_reconstruction_target(levels, version->get_structure()->get_record_count());
+    assert(target_level != -1);
     level_index source_level = 0;
 
     if (target_level == invalid_level_idx) {
@@ -49,20 +58,22 @@ public:
           (i == 0) ? m_buffer_size + target_reccnt
                    : levels[i - 1]->get_record_count() + target_reccnt;
 
-      reconstructions.add_reconstruction(i - 1, i, total_reccnt,
-                                         ReconstructionType::Merge);
+      if (total_reccnt > 0) {
+        auto type = (i >= (level_index) levels.size()) ? ReconstructionType::Append : ReconstructionType::Merge;
+        reconstructions.add_reconstruction(i - 1, i, total_reccnt, type);
+      }
     }
 
     return reconstructions;
   }
 
 private:
-  level_index find_reconstruction_target(LevelVector &levels) const {
+  level_index find_reconstruction_target(LevelVector &levels, size_t reccnt) const {
     level_index target_level = invalid_level_idx;
     size_t incoming_records = m_buffer_size;
 
     for (level_index i = 1; i < (level_index)levels.size(); i++) {
-      if (levels[i]->get_record_count() + incoming_records < capacity(i)) {
+      if (levels[i]->get_record_count() + incoming_records < capacity(i, reccnt)) {
         target_level = i;
         break;
       }
@@ -73,11 +84,12 @@ private:
     return target_level;
   }
 
-  inline size_t capacity(level_index level) const {
-    return m_buffer_size * pow(m_scale_factor, level);
+  inline size_t capacity(level_index level, size_t reccnt) const {
+    return m_buffer_size * pow(m_scale_factor * pow(std::log(reccnt), m_size_modifier), level);
   }
 
   size_t m_scale_factor;
   size_t m_buffer_size;
+  size_t m_size_modifier;
 };
 } // namespace de
-- 
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