diff --git a/db/builder.cc b/db/builder.cc
index e6329e0..5a0e07f 100644
--- a/db/builder.cc
+++ b/db/builder.cc
@@ -31,9 +31,18 @@ Status BuildTable(const std::string& dbname, Env* env, const Options& options,
     TableBuilder* builder = new TableBuilder(options, file);
     meta->smallest.DecodeFrom(iter->key());
     Slice key;
+    ParsedInternalKey parsed;
+    meta->smallest_deadtime = UINT64_MAX;
+    meta->largest_deadtime = 0;
     for (; iter->Valid(); iter->Next()) {
       key = iter->key();
       builder->Add(key, iter->value());
+      //在构建sstable文件的时候，记录当前文件的生存期最大和最小值,
+      //这里要注意internalkey和metadata中对于没有生存期的表示的转换
+      ParseInternalKey(key,&parsed);
+      if(parsed.deadTime == 0) parsed.deadTime = UINT64_MAX;
+      meta->smallest_deadtime = std::min(meta->smallest_deadtime,parsed.deadTime);
+      meta->largest_deadtime = std::max(meta->largest_deadtime,parsed.deadTime);
     }
     if (!key.empty()) {
       meta->largest.DecodeFrom(key);
diff --git a/db/db_impl.cc b/db/db_impl.cc
index 4617e18..6513f89 100644
--- a/db/db_impl.cc
+++ b/db/db_impl.cc
@@ -52,11 +52,12 @@ struct DBImpl::Writer {
 };
 
 struct DBImpl::CompactionState {
-  // Files produced by compaction
+  // Files produced by compaction 这里的改动和filemetadata对应
   struct Output {
     uint64_t number;
     uint64_t file_size;
     InternalKey smallest, largest;
+    uint64_t smallest_deadtime,largest_deadtime;
   };
 
   Output* current_output() { return &outputs[outputs.size() - 1]; }
@@ -536,7 +537,7 @@ Status DBImpl::WriteLevel0Table(MemTable* mem, VersionEdit* edit,
       level = base->PickLevelForMemTableOutput(min_user_key, max_user_key);
     }
     edit->AddFile(level, meta.number, meta.file_size, meta.smallest,
-                  meta.largest);
+                  meta.largest,meta.smallest_deadtime,meta.largest_deadtime);
   }
 
   CompactionStats stats;
@@ -740,7 +741,7 @@ void DBImpl::BackgroundCompaction() {
     FileMetaData* f = c->input(0, 0);
     c->edit()->RemoveFile(c->level(), f->number);
     c->edit()->AddFile(c->level() + 1, f->number, f->file_size, f->smallest,
-                       f->largest);
+                       f->largest,f->smallest_deadtime,f->largest_deadtime);
     status = versions_->LogAndApply(c->edit(), &mutex_);
     if (!status.ok()) {
       RecordBackgroundError(status);
@@ -814,6 +815,8 @@ Status DBImpl::OpenCompactionOutputFile(CompactionState* compact) {
     out.number = file_number;
     out.smallest.Clear();
     out.largest.Clear();
+    out.smallest_deadtime = UINT64_MAX;
+    out.largest_deadtime = 0;
     compact->outputs.push_back(out);
     mutex_.Unlock();
   }
@@ -889,7 +892,7 @@ Status DBImpl::InstallCompactionResults(CompactionState* compact) {
   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);
+                  out.smallest, out.largest,out.smallest_deadtime,out.largest_deadtime);
   }
   return versions_->LogAndApply(compact->compaction->edit(), &mutex_);
 }
@@ -1003,6 +1006,17 @@ Status DBImpl::DoCompactionWork(CompactionState* compact) {
         compact->current_output()->smallest.DecodeFrom(key);
       }
       compact->current_output()->largest.DecodeFrom(key);
+
+      ParsedInternalKey parsed;
+      ParseInternalKey(key,&parsed);
+      uint64_t &smallest_deadtime = compact->current_output()->smallest_deadtime;
+      uint64_t &largest_deadtime = compact->current_output()->largest_deadtime;
+      if(parsed.deadTime == 0) {
+        smallest_deadtime = UINT64_MAX;
+      }
+      smallest_deadtime = std::min(smallest_deadtime,parsed.deadTime);
+      largest_deadtime = std::max(largest_deadtime,parsed.deadTime);
+      
       compact->builder->Add(key, input->value());
 
       // Close output file if it is big enough
@@ -1206,10 +1220,10 @@ Status DBImpl::Put(const WriteOptions& o, const Slice& key,
   return DB::Put(o, key, val, ttl);
 }
 
-Status DBImpl::Put(const WriteOptions& options, const Slice& key,
-             const Slice& value, uint64_t ttl) {
-  return DB::Put(options,key,value,ttl);
-}
+// Status DBImpl::Put(const WriteOptions& options, const Slice& key,
+//              const Slice& value, uint64_t ttl) {
+//   return DB::Put(options,key,value,ttl);
+// }
 
 Status DBImpl::Delete(const WriteOptions& options, const Slice& key) {
   return DB::Delete(options, key);
@@ -1505,13 +1519,13 @@ Status DB::Put(const WriteOptions& opt, const Slice& key,
   return Write(opt, &batch);
 }
 
-//为了通过编译，忽略ttl
-Status DB::Put(const WriteOptions& options, const Slice& key,
-                                      const Slice& value, uint64_t ttl) {
-  WriteBatch batch;
-  batch.Put(key, value);
-  return Write(options, &batch);
-}
+// //为了通过编译，忽略ttl
+// Status DB::Put(const WriteOptions& options, const Slice& key,
+//                                       const Slice& value, uint64_t ttl) {
+//   WriteBatch batch;
+//   batch.Put(key, value);
+//   return Write(options, &batch);
+// }
 
 Status DB::Delete(const WriteOptions& opt, const Slice& key) {
   WriteBatch batch;
diff --git a/db/dbformat.cc b/db/dbformat.cc
index 686d04f..6f11a1d 100644
--- a/db/dbformat.cc
+++ b/db/dbformat.cc
@@ -75,11 +75,13 @@ int InternalKeyComparator::Compare(const Slice& akey, const Slice& bkey) const {
       r = -1;
       return r;
     }
-    
+    const uint64_t atime = DecodeFixed64(akey.data() + akey.size() - 16);
+    const uint64_t btime = DecodeFixed64(bkey.data() + bkey.size() - 16);
     //原本应该找到了，新加判断
     if((btag & 0b100) && (atag & 0b10)){ //一个是查询键，另一个有ttl
       const uint64_t atime = DecodeFixed64(akey.data() + akey.size() - 16);
       const uint64_t btime = DecodeFixed64(bkey.data() + bkey.size() - 16);
+    std::cout<<"atime:"<<atime<<" btime:"<<btime<<" "<<aseq<<" "<<bseq<<" "<<btag<<" "<<atag<<std::endl;
       if(atime <= btime){//过期了继续找
         r = -1;
         return r;
@@ -164,6 +166,7 @@ LookupKey::LookupKey(const Slice& user_key, SequenceNumber s, uint64_t nowTime)
   EncodeFixed64(dst, PackSequenceAndTypeAndTtlAndLookup(s, kValueTypeForSeek, 0, true));
   dst += 8;
   end_ = dst;
+  printf("lookupkey tag:%lx\n",PackSequenceAndTypeAndTtlAndLookup(s, kValueTypeForSeek, 0, true));
 }
 
 }  // namespace leveldb
diff --git a/db/memtable.cc b/db/memtable.cc
index e5c2d88..8131005 100644
--- a/db/memtable.cc
+++ b/db/memtable.cc
@@ -115,7 +115,7 @@ void MemTable::Add(SequenceNumber s, ValueType type, const Slice& key,
   std::memcpy(p, value.data(), val_size);
   assert(p + val_size == buf + encoded_len);
   table_.Insert(buf);
-  std::cout << "insert:" << key.ToString() << std::endl;
+  std::cout << "insert:" << key.ToString() <<" deadTime: " << deadTime << std::endl;
 }
 
 bool MemTable::Get(const LookupKey& key, std::string* value, Status* s) {
diff --git a/db/repair.cc b/db/repair.cc
index 97a27c6..b160ce3 100644
--- a/db/repair.cc
+++ b/db/repair.cc
@@ -90,7 +90,7 @@ class Repairer {
   }
 
  private:
-  struct TableInfo {
+  struct TableInfo { //TODO : add the recovery of smallest and largest deadtime
     FileMetaData meta;
     SequenceNumber max_sequence;
   };
diff --git a/db/version_edit.cc b/db/version_edit.cc
index 356ce88..4ee796e 100644
--- a/db/version_edit.cc
+++ b/db/version_edit.cc
@@ -81,6 +81,8 @@ void VersionEdit::EncodeTo(std::string* dst) const {
     PutVarint64(dst, f.file_size);
     PutLengthPrefixedSlice(dst, f.smallest.Encode());
     PutLengthPrefixedSlice(dst, f.largest.Encode());
+    PutVarint64(dst,f.smallest_deadtime);
+    PutVarint64(dst,f.largest_deadtime);
   }
 }
 
@@ -179,7 +181,9 @@ Status VersionEdit::DecodeFrom(const Slice& src) {
         if (GetLevel(&input, &level) && GetVarint64(&input, &f.number) &&
             GetVarint64(&input, &f.file_size) &&
             GetInternalKey(&input, &f.smallest) &&
-            GetInternalKey(&input, &f.largest)) {
+            GetInternalKey(&input, &f.largest) &&
+            GetVarint64(&input,&f.smallest_deadtime) &&
+            GetVarint64(&input,&f.largest_deadtime)) {
           new_files_.push_back(std::make_pair(level, f));
         } else {
           msg = "new-file entry";
@@ -250,6 +254,10 @@ std::string VersionEdit::DebugString() const {
     r.append(f.smallest.DebugString());
     r.append(" .. ");
     r.append(f.largest.DebugString());
+    r.append(" ");
+    AppendNumberTo(&r,f.smallest_deadtime);
+    r.append(" .. ");
+    AppendNumberTo(&r,f.largest_deadtime);
   }
   r.append("\n}\n");
   return r;
diff --git a/db/version_edit.h b/db/version_edit.h
index 137b4b1..f965c3e 100644
--- a/db/version_edit.h
+++ b/db/version_edit.h
@@ -16,7 +16,8 @@ namespace leveldb {
 class VersionSet;
 
 struct FileMetaData {
-  FileMetaData() : refs(0), allowed_seeks(1 << 30), file_size(0) {}
+  FileMetaData() : refs(0), allowed_seeks(1 << 30), file_size(0),
+  smallest_deadtime(UINT64_MAX),largest_deadtime(UINT64_MAX) {}
 
   int refs;
   int allowed_seeks;  // Seeks allowed until compaction
@@ -24,6 +25,9 @@ struct FileMetaData {
   uint64_t file_size;    // File size in bytes
   InternalKey smallest;  // Smallest internal key served by table
   InternalKey largest;   // Largest internal key served by table
+  //在FileMetaData中，使用Uint64MAX作为没有生存期的标志（表示生存期无限长）
+  uint64_t smallest_deadtime;  //smallest deadtime
+  uint64_t largest_deadtime;    //largest deadtime
 };
 
 class VersionEdit {
@@ -61,12 +65,15 @@ class VersionEdit {
   // REQUIRES: This version has not been saved (see VersionSet::SaveTo)
   // REQUIRES: "smallest" and "largest" are smallest and largest keys in file
   void AddFile(int level, uint64_t file, uint64_t file_size,
-               const InternalKey& smallest, const InternalKey& largest) {
+               const InternalKey& smallest, const InternalKey& largest,
+               uint64_t smallest_deadtime = UINT64_MAX, uint64_t largest_deadtime = UINT64_MAX) {
     FileMetaData f;
     f.number = file;
     f.file_size = file_size;
     f.smallest = smallest;
     f.largest = largest;
+    f.smallest_deadtime = smallest_deadtime;
+    f.largest_deadtime = largest_deadtime;
     new_files_.push_back(std::make_pair(level, f));
   }
 
diff --git a/db/version_set.cc b/db/version_set.cc
index 4e37bf9..764a158 100644
--- a/db/version_set.cc
+++ b/db/version_set.cc
@@ -1087,7 +1087,8 @@ Status VersionSet::WriteSnapshot(log::Writer* log) {
     const std::vector<FileMetaData*>& files = current_->files_[level];
     for (size_t i = 0; i < files.size(); i++) {
       const FileMetaData* f = files[i];
-      edit.AddFile(level, f->number, f->file_size, f->smallest, f->largest);
+      edit.AddFile(level, f->number, f->file_size, f->smallest, f->largest,
+                                      f->smallest_deadtime,f->largest_deadtime);
     }
   }