From a75a5f5c4d82dbbb63a1031e0d7e62fc955252e6 Mon Sep 17 00:00:00 2001
From: ArcueidType <981354012@qq.com>
Date: Wed, 6 Nov 2024 20:15:52 +0800
Subject: [PATCH 1/3] handle last level

---
 db/db_impl.cc     | 24 +++++++++++++++---------
 db/version_set.cc |  9 ++++++---
 test/ttl_test.cc  | 40 ++++++++++++++++++++++++++++++++++++++--
 3 files changed, 59 insertions(+), 14 deletions(-)

diff --git a/db/db_impl.cc b/db/db_impl.cc
index de87e07..6d7af36 100644
--- a/db/db_impl.cc
+++ b/db/db_impl.cc
@@ -602,12 +602,7 @@ void DBImpl::CompactRange(const Slice* begin, const Slice* end) {
 void DBImpl::TEST_CompactRange(int level, const Slice* begin,
                                const Slice* end) {
   assert(level >= 0);
-  assert(level <= config::kNumLevels);
-
-  if (level == config::kNumLevels) {
-    // TTL: TODO: update files in the last level
-    return;
-  }
+  assert(level < config::kNumLevels);
 
   InternalKey begin_storage, end_storage;
 
@@ -896,8 +891,14 @@ Status DBImpl::InstallCompactionResults(CompactionState* compact) {
   const int level = compact->compaction->level();
   for (size_t i = 0; i < compact->outputs.size(); i++) {
     const CompactionState::Output& out = compact->outputs[i];
-    compact->compaction->edit()->AddFile(level + 1, out.number, out.file_size,
-                                         out.smallest, out.largest);
+    if (level < config::kNumLevels - 1) {
+      compact->compaction->edit()->AddFile(level + 1, out.number, out.file_size,
+                                           out.smallest, out.largest);
+    } else {
+      // TTL: outputs of last level compaction should be writen to last level itself
+      compact->compaction->edit()->AddFile(level, out.number, out.file_size,
+                                           out.smallest, out.largest);
+    }
   }
   return versions_->LogAndApply(compact->compaction->edit(), &mutex_);
 }
@@ -1058,7 +1059,12 @@ Status DBImpl::DoCompactionWork(CompactionState* compact) {
   }
 
   mutex_.Lock();
-  stats_[compact->compaction->level() + 1].Add(stats);
+  if (compact->compaction->level() + 1 < config::kNumLevels) {
+    stats_[compact->compaction->level() + 1].Add(stats);
+  } else {
+    // TTL: compaction for last level
+    stats_[compact->compaction->level()].Add(stats);
+  }
 
   if (status.ok()) {
     status = InstallCompactionResults(compact);
diff --git a/db/version_set.cc b/db/version_set.cc
index 4e37bf9..a9d80e2 100644
--- a/db/version_set.cc
+++ b/db/version_set.cc
@@ -1389,9 +1389,12 @@ void VersionSet::SetupOtherInputs(Compaction* c) {
   AddBoundaryInputs(icmp_, current_->files_[level], &c->inputs_[0]);
   GetRange(c->inputs_[0], &smallest, &largest);
 
-  current_->GetOverlappingInputs(level + 1, &smallest, &largest,
-                                 &c->inputs_[1]);
-  AddBoundaryInputs(icmp_, current_->files_[level + 1], &c->inputs_[1]);
+  // TTL: manual compaction for last level shouldn't have inputs[1]
+  if (level + 1 < config::kNumLevels) {
+    current_->GetOverlappingInputs(level + 1, &smallest, &largest,
+                                   &c->inputs_[1]);
+    AddBoundaryInputs(icmp_, current_->files_[level + 1], &c->inputs_[1]);
+  }
 
   // Get entire range covered by compaction
   InternalKey all_start, all_limit;
diff --git a/test/ttl_test.cc b/test/ttl_test.cc
index 06da85d..b20194d 100644
--- a/test/ttl_test.cc
+++ b/test/ttl_test.cc
@@ -92,11 +92,9 @@ TEST(TestTTL, CompactionTTL) {
     uint64_t sizes[1];
     db->GetApproximateSizes(ranges, 1, sizes);
     ASSERT_GT(sizes[0], 0);
-
     Env::Default()->SleepForMicroseconds(ttl * 1000000);
 
     db->CompactRange(nullptr, nullptr);
-
     leveldb::Range ranges1[1];
     ranges1[0] = leveldb::Range("-", "A");
     uint64_t sizes1[1];
@@ -106,6 +104,44 @@ TEST(TestTTL, CompactionTTL) {
     delete db;
 }
 
+// Time-consuming when kNumLevels is 7, so run this test when kNumLevels is set to 3,
+// the codes on branch light_ver
+// In this case level 2 is the last level with files
+TEST(TestTTL, LastLevelCompaction) {
+  DB *db;
+
+  if(OpenDB("testdb", &db).ok() == false) {
+    std::cerr << "open db failed" << std::endl;
+    abort();
+  }
+
+  uint64_t ttl = 20;
+  InsertData(db, ttl);
+
+  leveldb::Range ranges[1];
+  ranges[0] = leveldb::Range("-", "A");
+  uint64_t sizes[1];
+  db->GetApproximateSizes(ranges, 1, sizes);
+  ASSERT_GT(sizes[0], 0);
+
+  std::string last_level_file_num;
+  std::string last_level = "2";
+  db->GetProperty("leveldb.num-files-at-level" + last_level, &last_level_file_num);
+  std::cout << "File nums in last level: " << last_level_file_num << std::endl;
+  ASSERT_GT(std::atoi(last_level_file_num.c_str()), 0);
+
+  Env::Default()->SleepForMicroseconds(ttl * 1000000);
+
+  db->CompactRange(nullptr, nullptr);
+  leveldb::Range ranges1[1];
+  ranges1[0] = leveldb::Range("-", "A");
+  uint64_t sizes1[1];
+  db->GetApproximateSizes(ranges1, 1, sizes1);
+  ASSERT_EQ(sizes1[0], 0);
+
+  delete db;
+}
+
 
 int main(int argc, char** argv) {
   // All tests currently run with the same read-only file limits.

From 830f61ddb789bbd0775fca115ff6926c57c1777e Mon Sep 17 00:00:00 2001
From: ArcueidType <981354012@qq.com>
Date: Wed, 6 Nov 2024 20:19:49 +0800
Subject: [PATCH 2/3] config kNumLevels for TEST LastLevelCompaction

---
 db/dbformat.h     | 2 +-
 db/version_set.cc | 8 +++-----
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/db/dbformat.h b/db/dbformat.h
index a1c30ed..6dc0ba8 100644
--- a/db/dbformat.h
+++ b/db/dbformat.h
@@ -22,7 +22,7 @@ namespace leveldb {
 // Grouping of constants.  We may want to make some of these
 // parameters set via options.
 namespace config {
-static const int kNumLevels = 7;
+static const int kNumLevels = 3;
 
 // Level-0 compaction is started when we hit this many files.
 static const int kL0_CompactionTrigger = 4;
diff --git a/db/version_set.cc b/db/version_set.cc
index a9d80e2..b147e08 100644
--- a/db/version_set.cc
+++ b/db/version_set.cc
@@ -1104,13 +1104,11 @@ int VersionSet::NumLevelFiles(int level) const {
 
 const char* VersionSet::LevelSummary(LevelSummaryStorage* scratch) const {
   // Update code if kNumLevels changes
-  static_assert(config::kNumLevels == 7, "");
+  static_assert(config::kNumLevels == 3, "");
   std::snprintf(
-      scratch->buffer, sizeof(scratch->buffer), "files[ %d %d %d %d %d %d %d ]",
+      scratch->buffer, sizeof(scratch->buffer), "files[ %d %d %d ]",
       int(current_->files_[0].size()), int(current_->files_[1].size()),
-      int(current_->files_[2].size()), int(current_->files_[3].size()),
-      int(current_->files_[4].size()), int(current_->files_[5].size()),
-      int(current_->files_[6].size()));
+      int(current_->files_[2].size()));
   return scratch->buffer;
 }
 

From 2481ca24baaf752c295ce01b86445370c4de880c Mon Sep 17 00:00:00 2001
From: ArcueidType <981354012@qq.com>
Date: Wed, 6 Nov 2024 20:20:48 +0800
Subject: [PATCH 3/3] config kNumLevels for TEST LastLevelCompaction

---
 test/ttl_test.cc | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/test/ttl_test.cc b/test/ttl_test.cc
index b20194d..ea71c06 100644
--- a/test/ttl_test.cc
+++ b/test/ttl_test.cc
@@ -104,9 +104,7 @@ TEST(TestTTL, CompactionTTL) {
     delete db;
 }
 
-// Time-consuming when kNumLevels is 7, so run this test when kNumLevels is set to 3,
-// the codes on branch light_ver
-// In this case level 2 is the last level with files
+// Test handling last level with kNumLevels = 3
 TEST(TestTTL, LastLevelCompaction) {
   DB *db;