diff --git a/db/db_impl.cc b/db/db_impl.cc
index 06752aa..ffb1889 100644
--- a/db/db_impl.cc
+++ b/db/db_impl.cc
@@ -42,7 +42,7 @@ const int kNumNonTableCacheFiles = 10;
 //TTL ToDo : add func for TTL Put
 
 void AppendExpirationTime(std::string* value, uint64_t expiration_time) {
-  // 将过期时间戳（64位整数）附加到值的前面
+  // 直接将小端序的过期时间戳（64位整数）附加到值的前面
   value->append(reinterpret_cast<const char*>(&expiration_time), sizeof(expiration_time));
 }
 
@@ -53,11 +53,11 @@ uint64_t GetCurrentTime() {
 
 // 解析过期时间戳
 uint64_t ParseExpirationTime(const std::string& value) {
-  // 假设过期时间戳在值的前 8 字节，以大端序存储
+  // 假设过期时间戳在值的前 8 字节
   assert(value.size() >= sizeof(uint64_t));
   uint64_t expiration_time;
   memcpy(&expiration_time, value.data(), sizeof(uint64_t));
-  return expiration_time;
+  return expiration_time;  // 直接返回小端序的值
 }
 
 // 解析出实际的值（去掉前面的过期时间戳部分）
@@ -1207,14 +1207,14 @@ Status DBImpl::Get(const ReadOptions& options, const Slice& key,
 
     // 如果当前时间已经超过过期时间，则认为数据过期，返回 NotFound
     if (current_time > expiration_time) {
-      s = Status::NotFound("Key expired");
+      s = Status::NotFound(Slice());
     } else {
       // 数据未过期，解析出实际的值
       *value = ParseActualValue(*value);
     }
   }
 
-  //finish modify
+  // //finish modify
 
   if (have_stat_update && current->UpdateStats(stats)) {
     MaybeScheduleCompaction();
diff --git a/db/db_test.cc b/db/db_test.cc
index f0af181..e04ead4 100644
--- a/db/db_test.cc
+++ b/db/db_test.cc
@@ -348,6 +348,7 @@ class DBTest : public testing::Test {
   Status Put(const std::string& k, const std::string& v) {
     return db_->Put(WriteOptions(), k, v);
   }
+  
 
   Status Delete(const std::string& k) { return db_->Delete(WriteOptions(), k); }
 
diff --git a/db/memtable.cc b/db/memtable.cc
index 4f09340..d7c4078 100644
--- a/db/memtable.cc
+++ b/db/memtable.cc
@@ -73,6 +73,8 @@ class MemTableIterator : public Iterator {
 
 Iterator* MemTable::NewIterator() { return new MemTableIterator(&table_); }
 
+
+
 void MemTable::Add(SequenceNumber s, ValueType type, const Slice& key,
                    const Slice& value) {
   // Format of an entry is concatenation of:
@@ -124,6 +126,23 @@ bool MemTable::Get(const LookupKey& key, std::string* value, Status* s) {
         case kTypeValue: {
           Slice v = GetLengthPrefixedSlice(key_ptr + key_length);
           value->assign(v.data(), v.size());
+
+          // TTL ToDo :检查：从 value 中解析出过期时间戳并与当前时间比较
+          assert(value->size() >= sizeof(uint64_t));
+          uint64_t expiration_time;
+          memcpy(&expiration_time, value->data(), sizeof(uint64_t)); // 解析出过期时间戳
+          uint64_t current_time = static_cast<uint64_t>(time(nullptr));  // 获取当前时间
+
+          // 如果当前时间已超过过期时间，设置状态为 NotFound 表示数据过期
+          if (current_time > expiration_time) {
+            *s = Status::NotFound(Slice());
+            return true;
+          } else {
+            // 数据未过期，解析出实际的值部分，去掉过期时间戳
+            *value = value->substr(sizeof(uint64_t));
+          }
+
+          //finish modify
           return true;
         }
         case kTypeDeletion:
diff --git a/test/ttl_test.cc b/test/ttl_test.cc
index a8d611e..3712b25 100644
--- a/test/ttl_test.cc
+++ b/test/ttl_test.cc
@@ -4,7 +4,7 @@
 
 #include "leveldb/env.h"
 #include "leveldb/db.h"
-
+#include <unordered_set>
 
 using namespace leveldb;
 
@@ -20,14 +20,28 @@ Status OpenDB(std::string dbName, DB **db) {
 void InsertData(DB *db, uint64_t ttl/* second */) {
   WriteOptions writeOptions;
   int key_num = data_size / value_size;
-  srand(static_cast<unsigned int>(time(0)));
+  srand(42);
+
+  // 用于存储成功写入的唯一键
+  std::unordered_set<std::string> unique_keys;
 
   for (int i = 0; i < key_num; i++) {
     int key_ = rand() % key_num+1;
     std::string key = std::to_string(key_);
     std::string value(value_size, 'a');
-    db->Put(writeOptions, key, value, ttl);
+    Status status = db->Put(writeOptions, key, value, ttl);
+    if (!status.ok()) {
+        // 输出失败的状态信息并退出循环
+        std::cerr << "Failed to write key: " << key 
+                  << ", Status: " << status.ToString() << std::endl;
+    }else{
+        std::cerr << "Success to write key: " << key << std::endl;
+        unique_keys.insert(key);  // 插入集合中，如果已经存在则不会重复插入
+    }
   }
+
+  // 打印成功写入的唯一键的数量
+    std::cout << "Total unique keys successfully written: " << unique_keys.size() << std::endl;
 }
 
 void GetData(DB *db, int size = (1 << 30)) {
@@ -35,7 +49,7 @@ void GetData(DB *db, int size = (1 << 30)) {
   int key_num = data_size / value_size;
   
   // 点查
-  srand(static_cast<unsigned int>(time(0)));
+  srand(42);
   for (int i = 0; i < 100; i++) {
     int key_ = rand() % key_num+1;
     std::string key = std::to_string(key_);
@@ -58,12 +72,18 @@ TEST(TestTTL, ReadTTL) {
     ReadOptions readOptions;
     Status status;
     int key_num = data_size / value_size;
-    srand(static_cast<unsigned int>(time(0)));
+    srand(42);
     for (int i = 0; i < 100; i++) {
         int key_ = rand() % key_num+1;
         std::string key = std::to_string(key_);
         std::string value;
         status = db->Get(readOptions, key, &value);
+
+        // 检查 status 并打印出失败的状态信息
+        if (!status.ok()) {
+            std::cerr << "Key: " << key << ", Status: " << status.ToString() << std::endl;
+        }
+        
         ASSERT_TRUE(status.ok());
     }
 
@@ -74,6 +94,12 @@ TEST(TestTTL, ReadTTL) {
         std::string key = std::to_string(key_);
         std::string value;
         status = db->Get(readOptions, key, &value);
+
+        // 检查 status 并打印出失败的状态信息
+        if (status.ok()) {
+            std::cerr << "Key: " << key << ", Status: " << status.ToString() << std::endl;
+        }
+
         ASSERT_FALSE(status.ok());
     }
 }
@@ -106,6 +132,7 @@ TEST(TestTTL, CompactionTTL) {
 
 
 int main(int argc, char** argv) {
+  srand(42);
   // All tests currently run with the same read-only file limits.
   testing::InitGoogleTest(&argc, argv);
   return RUN_ALL_TESTS();