From 72ffcbbb0563c0819362bbb5b9b39f8be1c7ab4c Mon Sep 17 00:00:00 2001
From: zhanglistar <zhanglinuxstar@gmail.com>
Date: Thu, 10 Feb 2022 15:43:39 +0800
Subject: [PATCH 1/3] keeper SnapshotableHashTable clean opt.

---
 src/Coordination/SnapshotableHashTable.h | 28 +++++++++++-------------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/src/Coordination/SnapshotableHashTable.h b/src/Coordination/SnapshotableHashTable.h
index b1d72578530..a837e51a9be 100644
--- a/src/Coordination/SnapshotableHashTable.h
+++ b/src/Coordination/SnapshotableHashTable.h
@@ -36,6 +36,7 @@ private:
     /// Allows to avoid additional copies in updateValue function
     size_t snapshot_up_to_size = 0;
     ArenaWithFreeLists arena;
+    std::vector<Mapped> snapshot_invalid_iters{100000};
 
     uint64_t approximate_data_size{0};
 
@@ -175,6 +176,7 @@ public:
                 list_itr->active_in_map = false;
                 auto new_list_itr = list.insert(list.end(), elem);
                 it->getMapped() = new_list_itr;
+                snapshot_invalid_iters.push_back(list_itr);
             }
             else
             {
@@ -197,6 +199,7 @@ public:
             list_itr->active_in_map = false;
             list_itr->free_key = true;
             map.erase(it->getKey());
+            snapshot_invalid_iters.push_back(list_itr);
         }
         else
         {
@@ -239,6 +242,7 @@ public:
                 auto itr = list.insert(list.end(), elem_copy);
                 it->getMapped() = itr;
                 ret = itr;
+                snapshot_invalid_iters.push_back(list_itr);
             }
             else
             {
@@ -274,23 +278,15 @@ public:
 
     void clearOutdatedNodes()
     {
-        auto start = list.begin();
-        auto end = list.end();
-        for (auto itr = start; itr != end;)
+        for (auto & itr: snapshot_invalid_iters)
         {
-            if (!itr->active_in_map)
-            {
-                updateDataSize(CLEAR_OUTDATED_NODES, itr->key.size, itr->value.sizeInBytes(), 0);
-                if (itr->free_key)
-                    arena.free(const_cast<char *>(itr->key.data), itr->key.size);
-                itr = list.erase(itr);
-            }
-            else
-            {
-                assert(!itr->free_key);
-                itr++;
-            }
+            assert(!itr->active_in_map);
+            updateDataSize(CLEAR_OUTDATED_NODES, itr->key.size, itr->value.sizeInBytes(), 0);
+            if (itr->free_key)
+                arena.free(const_cast<char *>(itr->key.data), itr->key.size);
+            list.erase(itr);
         }
+        snapshot_invalid_iters.clear();
     }
 
     void clear()
@@ -300,12 +296,14 @@ public:
             arena.free(const_cast<char *>(itr->key.data), itr->key.size);
         list.clear();
         updateDataSize(CLEAR, 0, 0, 0);
+        snapshot_invalid_iters.clear();
     }
 
     void enableSnapshotMode(size_t up_to_size)
     {
         snapshot_mode = true;
         snapshot_up_to_size = up_to_size;
+        snapshot_invalid_iters.clear();
     }
 
     void disableSnapshotMode()

From 87350f3552538bf797e42898fbf262cd1326f926 Mon Sep 17 00:00:00 2001
From: zhanglistar <zhanglinuxstar@gmail.com>
Date: Thu, 10 Feb 2022 17:33:12 +0800
Subject: [PATCH 2/3] Keeper SnapshotableHashTable fix clean bug.

---
 src/Coordination/SnapshotableHashTable.h | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/src/Coordination/SnapshotableHashTable.h b/src/Coordination/SnapshotableHashTable.h
index a837e51a9be..304183e02bb 100644
--- a/src/Coordination/SnapshotableHashTable.h
+++ b/src/Coordination/SnapshotableHashTable.h
@@ -296,19 +296,16 @@ public:
             arena.free(const_cast<char *>(itr->key.data), itr->key.size);
         list.clear();
         updateDataSize(CLEAR, 0, 0, 0);
-        snapshot_invalid_iters.clear();
     }
 
     void enableSnapshotMode(size_t up_to_size)
     {
         snapshot_mode = true;
         snapshot_up_to_size = up_to_size;
-        snapshot_invalid_iters.clear();
     }
 
     void disableSnapshotMode()
     {
-
         snapshot_mode = false;
         snapshot_up_to_size = 0;
     }

From 4d73fb7fb7a05d2677516380c43e6f146b4de05f Mon Sep 17 00:00:00 2001
From: zhanglistar <zhanglinuxstar@gmail.com>
Date: Thu, 10 Feb 2022 17:56:41 +0800
Subject: [PATCH 3/3] Fix ut in SnapshotableHashTable

---
 src/Coordination/SnapshotableHashTable.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/Coordination/SnapshotableHashTable.h b/src/Coordination/SnapshotableHashTable.h
index 304183e02bb..002f1e4e365 100644
--- a/src/Coordination/SnapshotableHashTable.h
+++ b/src/Coordination/SnapshotableHashTable.h
@@ -36,7 +36,8 @@ private:
     /// Allows to avoid additional copies in updateValue function
     size_t snapshot_up_to_size = 0;
     ArenaWithFreeLists arena;
-    std::vector<Mapped> snapshot_invalid_iters{100000};
+    /// Collect invalid iterators to avoid traversing the whole list
+    std::vector<Mapped> snapshot_invalid_iters;
 
     uint64_t approximate_data_size{0};
 
@@ -197,9 +198,9 @@ public:
         if (snapshot_mode)
         {
             list_itr->active_in_map = false;
+            snapshot_invalid_iters.push_back(list_itr);
             list_itr->free_key = true;
             map.erase(it->getKey());
-            snapshot_invalid_iters.push_back(list_itr);
         }
         else
         {
@@ -238,11 +239,11 @@ public:
             {
                 auto elem_copy = *(list_itr);
                 list_itr->active_in_map = false;
+                snapshot_invalid_iters.push_back(list_itr);
                 updater(elem_copy.value);
                 auto itr = list.insert(list.end(), elem_copy);
                 it->getMapped() = itr;
                 ret = itr;
-                snapshot_invalid_iters.push_back(list_itr);
             }
             else
             {