From 2927716e49a37d8dbe117c18e09c1283b099b725 Mon Sep 17 00:00:00 2001
From: Yechi Ma <2662511702@qq.com>
Date: Wed, 6 Nov 2024 18:12:33 +0800
Subject: [PATCH] TestTTL.ReadTTL passed

---
 db/db_impl.cc        | 31 +++++++++++++++++++++++++++++++
 db/db_impl.h         |  3 +++
 include/leveldb/db.h |  8 ++++----
 test/ttl_test.cc     | 10 +++++-----
 4 files changed, 43 insertions(+), 9 deletions(-)

diff --git a/db/db_impl.cc b/db/db_impl.cc
index f96d245..2497871 100644
--- a/db/db_impl.cc
+++ b/db/db_impl.cc
@@ -1161,6 +1161,24 @@ Status DBImpl::Get(const ReadOptions& options, const Slice& key,
   mem->Unref();
   if (imm != nullptr) imm->Unref();
   current->Unref();
+  /** parse ttl from value **/
+  size_t pos = value->find_last_of('_');
+  if (pos != std::string::npos) {
+    std::string substring = value->substr(pos + 1);
+    auto ttl = static_cast<uint64_t>(std::stoll(substring));
+    auto now = std::chrono::system_clock::now();
+    auto timestamp = std::chrono::duration_cast<std::chrono::microseconds>(now.time_since_epoch()).count();
+    auto microsecondsTimestamp = static_cast<uint64_t>(timestamp);
+    if (ttl <= microsecondsTimestamp) {
+      value->clear();
+      Slice msg1("value not found!");
+      Slice msg2("value has expired!");
+      s = leveldb::Status::NotFound(msg1, msg2);
+    } else {
+      value->resize(pos);
+    }
+  }
+  /** parse ttl from value **/
   return s;
 }
 
@@ -1198,6 +1216,19 @@ Status DBImpl::Put(const WriteOptions& o, const Slice& key, const Slice& val) {
   return DB::Put(o, key, val);
 }
 
+Status DBImpl::Put(const WriteOptions& opt, const Slice& key,
+                   const Slice& value, uint64_t ttl) {
+  WriteBatch batch;
+  auto now = std::chrono::system_clock::now();
+  auto timestamp = std::chrono::duration_cast<std::chrono::microseconds>(now.time_since_epoch()).count();
+  auto microsecondsTimestamp = static_cast<uint64_t>(timestamp) + ttl*1000000;
+  std::string value_ttl = value.ToString();
+  value_ttl += "_" + std::to_string(microsecondsTimestamp);
+  Slice new_value(value_ttl.c_str(), value_ttl.size());
+  batch.Put(key, new_value);
+  return Write(opt, &batch);
+}
+
 Status DBImpl::Delete(const WriteOptions& options, const Slice& key) {
   return DB::Delete(options, key);
 }
diff --git a/db/db_impl.h b/db/db_impl.h
index c7b0172..f36fdd7 100644
--- a/db/db_impl.h
+++ b/db/db_impl.h
@@ -38,6 +38,9 @@ class DBImpl : public DB {
   // Implementations of the DB interface
   Status Put(const WriteOptions&, const Slice& key,
              const Slice& value) override;
+  // For TTL           
+  Status Put(const WriteOptions& opt, const Slice& key,
+             const Slice& value, uint64_t ttl) override;
   Status Delete(const WriteOptions&, const Slice& key) override;
   Status Write(const WriteOptions& options, WriteBatch* updates) override;
   Status Get(const ReadOptions& options, const Slice& key,
diff --git a/include/leveldb/db.h b/include/leveldb/db.h
index 0618d48..60cf9db 100644
--- a/include/leveldb/db.h
+++ b/include/leveldb/db.h
@@ -146,10 +146,10 @@ class LEVELDB_EXPORT DB {
   //    db->CompactRange(nullptr, nullptr);
   virtual void CompactRange(const Slice* begin, const Slice* end) = 0;
 
-  // // ----------------------------For TTL-----------------------------
-  // // 为当前key设置ttl，过期后自动失效
-  // virtual Status Put(const WriteOptions& options, const Slice& key,
-  //                    const Slice& value, uint64_t ttl) = 0;
+  /// ----------------------------For TTL-----------------------------
+  /// 为当前key设置ttl，过期后自动失效
+  virtual Status Put(const WriteOptions& options, const Slice& key,
+                     const Slice& value, uint64_t ttl) = 0;
 };
 
 // Destroy the contents of the specified database.
diff --git a/test/ttl_test.cc b/test/ttl_test.cc
index 4bb524a..7402893 100644
--- a/test/ttl_test.cc
+++ b/test/ttl_test.cc
@@ -99,11 +99,11 @@ TEST(TestTTL, CompactionTTL) {
 
     db->CompactRange(nullptr, nullptr);
 
-    leveldb::Range ranges[1];
-    ranges[0] = leveldb::Range("-", "A");
-    uint64_t sizes[1];
-    db->GetApproximateSizes(ranges, 1, sizes);
-    ASSERT_EQ(sizes[0], 0);
+    leveldb::Range ranges_[1];
+    ranges_[0] = leveldb::Range("-", "A");
+    uint64_t sizes_[1];
+    db->GetApproximateSizes(ranges_, 1, sizes_);
+    ASSERT_EQ(sizes_[0], 0);
 }