From 99c5e80fbe814c77ce536bbf0e0c17ef02222cbc Mon Sep 17 00:00:00 2001
From: lihongjian <lihongjian@stoneatom.com>
Date: Wed, 12 Apr 2023 00:34:41 +0800
Subject: [PATCH] fix(tianmu):Remove excess log printing and add some code
 comments(#1545)

---
 storage/tianmu/executor/combined_iterator.cpp |  7 ++-----
 storage/tianmu/handler/ha_tianmu.cpp          | 17 +++++++++++++++--
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/storage/tianmu/executor/combined_iterator.cpp b/storage/tianmu/executor/combined_iterator.cpp
index 309de24b8..e5227f4b7 100644
--- a/storage/tianmu/executor/combined_iterator.cpp
+++ b/storage/tianmu/executor/combined_iterator.cpp
@@ -51,9 +51,6 @@ void CombinedIterator::Next() {
     }
   } else {
     base_iter_->Next();
-    if (base_iter_->Valid()) {
-      TIANMU_LOG(LogCtl_Level::ERROR, "base pos: %d", base_iter_->Position());
-    }
   }
 }
 
@@ -85,8 +82,8 @@ bool CombinedIterator::Valid() const { return Position() != -1; }
 bool CombinedIterator::IsBase() const { return is_base_; }
 
 bool CombinedIterator::BaseCurrentRowIsInvalid() const {
-  if (base_iter_->CurrentRowIsDeleted() || InDeltaDeletedRow.find(base_iter_->Position()) != InDeltaDeletedRow.end() ||
-      InDeltaUpdateRow.find(base_iter_->Position()) != InDeltaUpdateRow.end()) {
+  if (InDeltaDeletedRow.find(base_iter_->Position()) != InDeltaDeletedRow.end() ||
+      InDeltaUpdateRow.find(base_iter_->Position()) != InDeltaUpdateRow.end() || base_iter_->CurrentRowIsDeleted()) {
     return true;
   }
   return false;
diff --git a/storage/tianmu/handler/ha_tianmu.cpp b/storage/tianmu/handler/ha_tianmu.cpp
index 0bc83465d..342071d89 100644
--- a/storage/tianmu/handler/ha_tianmu.cpp
+++ b/storage/tianmu/handler/ha_tianmu.cpp
@@ -1259,8 +1259,10 @@ int ha_tianmu::fill_row(uchar *buf) {
     std::memcpy(buffer.get(), table->record[0], table->s->reclength);
   }
   if (iterator_->IsBase()) {
-    // judge whether this line has been deleted.
-    // if this line has been deleted, data will not be copied.
+    /*
+      Determine whether the current row is invalid in the base layer,
+      If it is invalid, directly return to the SQL layer that the current row has been deleted
+    */
     if (iterator_->BaseCurrentRowIsInvalid()) {
       current_position_ = iterator_->Position();
       iterator_->Next();
@@ -1275,6 +1277,7 @@ int ha_tianmu::fill_row(uchar *buf) {
     if (!delta_record.empty()) {
       switch (core::DeltaRecordHead::GetRecordType(delta_record.data())) {
         case core::RecordType::kInsert:
+          // If the function change fails, it will be considered that the row change has been deleted.
           if (!core::Engine::DecodeInsertRecordToField(delta_record.data(), table->field)) {
             current_position_ = iterator_->Position();
             iterator_->Next();
@@ -1283,6 +1286,11 @@ int ha_tianmu::fill_row(uchar *buf) {
           }
           break;
         case core::RecordType::kUpdate:
+          /*
+            Merge data from the base layer and delta layer.
+            At the same time, record the status of switching to the delta layer
+            When iterating the base layer data, it is judged as invalid for changing rows
+          */
           current_txn_->GetTableByPath(table_name_)->FillRowByRowid(table, iterator_->Position());
           core::Engine::DecodeUpdateRecordToField(delta_record.data(), table->field);
           iterator_->InDeltaUpdateRow.insert(
@@ -1290,6 +1298,11 @@ int ha_tianmu::fill_row(uchar *buf) {
           break;
         case core::RecordType::kDelete:
           current_position_ = iterator_->Position();
+          /*
+            If there is deleted data with a new row in the delta layer,
+            Just record it down,
+            When iterating the base layer data, it is judged as invalid for changing rows
+          */
           iterator_->InDeltaDeletedRow.insert(std::unordered_map<int64_t, bool>::value_type(current_position_, true));
           iterator_->Next();
           dbug_tmp_restore_column_map(table->write_set, org_bitmap);