TestTTL.ReadTTL passed

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);
 }

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,

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.

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);
 }