Bugfixes for tiering

Fixed a few issues that manifested during the tiering tests,

    1) When a version is copied, it now contains copies of the levels,
       not just pointers (the levels themselves still hold pointers to
       the shards, though).
    2) Ensure that tasks are scheduled with the correct timestamp, they
       were originally being scheduled backwards. The get_merge_tasks()
       method already returns them in the correct order, so reversing
       them again put it in the wrong order.

3 files changed, 9 insertions, 4 deletions

diff --git a/include/framework/ExtensionStructure.h b/include/framework/ExtensionStructure.h
index 2fb9cf0..892e63b 100644
--- a/include/framework/ExtensionStructure.h
+++ b/include/framework/ExtensionStructure.h
@@ -312,6 +312,7 @@ public:
             m_levels[base_level] = InternalLevel<R, Shard, Q>::merge_levels(m_levels[base_level].get(), m_levels[incoming_level].get());
         } else {
             m_levels[base_level]->append_merged_shards(m_levels[incoming_level].get());
+            m_levels[base_level]->finalize();
         }
 
         m_levels[incoming_level] = std::shared_ptr<InternalLevel<R, Shard, Q>>(new InternalLevel<R, Shard, Q>(incoming_level, (L == LayoutPolicy::LEVELING) ? 1 : m_scale_factor));
diff --git a/include/framework/InternalLevel.h b/include/framework/InternalLevel.h
index e67ae45..6cdac4e 100644
--- a/include/framework/InternalLevel.h
+++ b/include/framework/InternalLevel.h
@@ -106,6 +106,7 @@ public:
             for (size_t i=0; i<m_shards.size(); i++) {
                 if (m_owns[i]) {
                     delete m_shards[i];
+                    m_shards[i] = nullptr;
                     m_owns[i] = false;
                 }
             }
@@ -113,6 +114,7 @@ public:
             m_shards[0] = m_pending_shard;
             m_owns[0] = true;
             m_pending_shard = nullptr;
+            m_shard_cnt = 1;
         }
     }
 
@@ -241,13 +243,15 @@ private:
 
     std::vector<bool> m_owns;
 
-    InternalLevel *clone() {
-        auto new_level = new InternalLevel(m_level_no, m_shards.size());
+    std::shared_ptr<InternalLevel> clone() {
+        auto new_level = std::make_shared<InternalLevel>(m_level_no, m_shards.size());
         for (size_t i=0; i<m_shard_cnt; i++) {
             new_level->m_shards[i] = m_shards[i];
             new_level->m_owns[i] = true;
             m_owns[i] = false;
         }
+
+        return new_level;
     }
 };
 
diff --git a/include/framework/Scheduler.h b/include/framework/Scheduler.h
index 534ce25..6055bef 100644
--- a/include/framework/Scheduler.h
+++ b/include/framework/Scheduler.h
@@ -68,7 +68,7 @@ public:
          * Schedule the merge tasks (FIXME: currently this just 
          * executes them sequentially in a blocking fashion)
          */
-        for (ssize_t i=merges.size()-1; i>=0; i--) {
+        for (ssize_t i=0; i<merges.size(); i++) {
             merges[i].m_timestamp = m_timestamp.fetch_add(1);
             m_merge_queue_lock.lock();
             m_merge_queue.push(merges[i]);
@@ -120,6 +120,7 @@ private:
 
     void run_merge(MergeTask task, Structure *version) {
         version->merge_levels(task.m_target_level, task.m_source_level); 
+
         if (!version->validate_tombstone_proportion(task.m_target_level)) {
             auto tasks = version->get_merge_tasks(task.m_target_level);    
             /*
@@ -188,7 +189,6 @@ private:
     std::thread m_sched_thrd;
 
     bool m_shutdown;
-
 };
 
 }