From 54b533d7cbad60089348cfdb2ac37c988f1828f4 Mon Sep 17 00:00:00 2001
From: alexfisher <1823748191@qq.com>
Date: Sat, 30 Nov 2024 22:51:33 +0800
Subject: [PATCH] version 2 roughly complete with GC

---
 db/builder.cc      |  9 +++++++++
 db/db_impl.cc      | 29 ++++++++++++++++++++++++-----
 db/repair.cc       |  2 +-
 db/version_edit.cc |  4 ++++
 db/version_edit.h  |  5 ++++-
 db/version_set.cc  |  2 +-
 test/test.cpp      |  6 ++++--
 7 files changed, 47 insertions(+), 10 deletions(-)

diff --git a/db/builder.cc b/db/builder.cc
index e6329e0..7cf13f8 100644
--- a/db/builder.cc
+++ b/db/builder.cc
@@ -28,6 +28,15 @@ Status BuildTable(const std::string& dbname, Env* env, const Options& options,
       return s;
     }
 
+    {
+      auto tmp_value=iter->value();
+      if(tmp_value.data()[0]==(char)(0x01)){
+        tmp_value.remove_prefix(1);
+        assert(GetVarint64(&tmp_value,&meta->valuelog_id));
+      }
+      else meta->valuelog_id=0;
+    }
+
     TableBuilder* builder = new TableBuilder(options, file);
     meta->smallest.DecodeFrom(iter->key());
     Slice key;
diff --git a/db/db_impl.cc b/db/db_impl.cc
index f09caf1..94a45b2 100644
--- a/db/db_impl.cc
+++ b/db/db_impl.cc
@@ -57,6 +57,7 @@ struct DBImpl::CompactionState {
   struct Output {
     uint64_t number;
     uint64_t file_size;
+    uint64_t valuelog_id;
     InternalKey smallest, largest;
   };
 
@@ -541,7 +542,7 @@ 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.valuelog_id);
   }
 
   CompactionStats stats;
@@ -745,7 +746,7 @@ 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->valuelog_id);
     status = versions_->LogAndApply(c->edit(), &mutex_);
     if (!status.ok()) {
       RecordBackgroundError(status);
@@ -819,8 +820,11 @@ Status DBImpl::OpenCompactionOutputFile(CompactionState* compact) {
     out.number = file_number;
     out.smallest.Clear();
     out.largest.Clear();
-    compact->outputs.push_back(out);
     compact->valuelog_file_id=versions_->NewFileNumber();
+    out.valuelog_id=compact->valuelog_file_id;
+    
+    compact->outputs.push_back(out);
+    
     mutex_.Unlock();
   }
 
@@ -913,7 +917,7 @@ 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.valuelog_id);
   }
   return versions_->LogAndApply(compact->compaction->edit(), &mutex_);
 }
@@ -947,6 +951,12 @@ Status DBImpl::DoCompactionWork(CompactionState* compact) {
   std::string current_user_key;
   bool has_current_user_key = false;
   SequenceNumber last_sequence_for_key = kMaxSequenceNumber;
+  std::set<uint64_t> old_valuelog_ids;
+  for (int which = 0; which < 2; which++) {
+    for (int i = 0; i < compact->compaction->num_input_files(which); i++) {
+      if(compact->compaction->input(which, i)->valuelog_id)old_valuelog_ids.emplace(compact->compaction->input(which, i)->valuelog_id);
+    }
+  }
   while (input->Valid() && !shutting_down_.load(std::memory_order_acquire)) {
     // Prioritize immutable compaction work
     if (has_imm_.load(std::memory_order_relaxed)) {
@@ -1035,6 +1045,7 @@ Status DBImpl::DoCompactionWork(CompactionState* compact) {
         new_value=old_value;
       }
       else{
+        old_value.remove_prefix(1);
         uint64_t file_id,valuelog_offset,valuelog_len;
         bool res=GetVarint64(&old_value,&file_id);
         if(!res)assert(0);
@@ -1078,6 +1089,14 @@ Status DBImpl::DoCompactionWork(CompactionState* compact) {
   if (status.ok()) {
     status = input->status();
   }
+  //not completely correct, should be written in new function, related to removeabsol...
+  if(status.ok()){
+    for(auto id:old_valuelog_ids){
+      auto valuelog_filename=ValueLogFileName(dbname_,id);
+      Status s=env_->RemoveFile(valuelog_filename);
+      assert(s.ok());
+    }
+  }
   delete input;
   input = nullptr;
 
@@ -1607,7 +1626,7 @@ Status DBImpl::ReadValueLog(uint64_t file_id, uint64_t offset,uint64_t len,Slice
   //std::cout<<file_name_<<" "<<offset<<" "<<len<<std::endl;
   std::ifstream inFile(file_name_, std::ios::in | std::ios::binary);
   if (!inFile.is_open()) {
-      std::cerr << "Failed to open file for writing!" << std::endl;
+      std::cerr << "Failed to open file for writing!"<<file_id<<" "<<offset<<" "<<len<< std::endl;
       return Status::Corruption("Failed to open file for writing!");
   }
   inFile.seekg(offset);
diff --git a/db/repair.cc b/db/repair.cc
index 97a27c6..513327a 100644
--- a/db/repair.cc
+++ b/db/repair.cc
@@ -369,7 +369,7 @@ class Repairer {
       // TODO(opt): separate out into multiple levels
       const TableInfo& t = tables_[i];
       edit_.AddFile(0, t.meta.number, t.meta.file_size, t.meta.smallest,
-                    t.meta.largest);
+                    t.meta.largest,t.meta.valuelog_id);
     }
 
     // std::fprintf(stderr,
diff --git a/db/version_edit.cc b/db/version_edit.cc
index 356ce88..2041a3e 100644
--- a/db/version_edit.cc
+++ b/db/version_edit.cc
@@ -79,6 +79,7 @@ void VersionEdit::EncodeTo(std::string* dst) const {
     PutVarint32(dst, new_files_[i].first);  // level
     PutVarint64(dst, f.number);
     PutVarint64(dst, f.file_size);
+    PutVarint64(dst, f.valuelog_id);
     PutLengthPrefixedSlice(dst, f.smallest.Encode());
     PutLengthPrefixedSlice(dst, f.largest.Encode());
   }
@@ -178,6 +179,7 @@ Status VersionEdit::DecodeFrom(const Slice& src) {
       case kNewFile:
         if (GetLevel(&input, &level) && GetVarint64(&input, &f.number) &&
             GetVarint64(&input, &f.file_size) &&
+            GetVarint64(&input,&f.valuelog_id) &&
             GetInternalKey(&input, &f.smallest) &&
             GetInternalKey(&input, &f.largest)) {
           new_files_.push_back(std::make_pair(level, f));
@@ -247,6 +249,8 @@ std::string VersionEdit::DebugString() const {
     r.append(" ");
     AppendNumberTo(&r, f.file_size);
     r.append(" ");
+    AppendNumberTo(&r, f.valuelog_id);
+    r.append(" ");
     r.append(f.smallest.DebugString());
     r.append(" .. ");
     r.append(f.largest.DebugString());
diff --git a/db/version_edit.h b/db/version_edit.h
index 137b4b1..1ee850e 100644
--- a/db/version_edit.h
+++ b/db/version_edit.h
@@ -22,8 +22,10 @@ struct FileMetaData {
   int allowed_seeks;  // Seeks allowed until compaction
   uint64_t number;
   uint64_t file_size;    // File size in bytes
+  uint64_t valuelog_id=0;
   InternalKey smallest;  // Smallest internal key served by table
   InternalKey largest;   // Largest internal key served by table
+
 };
 
 class VersionEdit {
@@ -61,12 +63,13 @@ 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 valuelog_id=0) {
     FileMetaData f;
     f.number = file;
     f.file_size = file_size;
     f.smallest = smallest;
     f.largest = largest;
+    f.valuelog_id=valuelog_id;
     new_files_.push_back(std::make_pair(level, f));
   }
 
diff --git a/db/version_set.cc b/db/version_set.cc
index 4e37bf9..dcce922 100644
--- a/db/version_set.cc
+++ b/db/version_set.cc
@@ -1087,7 +1087,7 @@ 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->valuelog_id);
     }
   }
 
diff --git a/test/test.cpp b/test/test.cpp
index 14c2a51..ca6a5ec 100644
--- a/test/test.cpp
+++ b/test/test.cpp
@@ -10,6 +10,8 @@ using FieldArray=std::vector<std::pair<Slice, Slice>>;
 
 Status OpenDB(std::string dbName, DB **db) {
   Options options;
+  options.max_file_size=16*1024;
+  options.write_buffer_size=32*1024;
   options.create_if_missing = true;
   return DB::Open(options, dbName, db);
 }
@@ -165,7 +167,7 @@ TEST(Test, LARGE_DATA_COMPACT_TEST) {
         abort();
     }
     std::vector<std::string> values;
-    for(int i=0;i<1000;i++){
+    for(int i=0;i<100000;i++){
         std::string key=std::to_string(i);
         std::string value;
         for(int j=0;j<1000;j++){
@@ -174,7 +176,7 @@ TEST(Test, LARGE_DATA_COMPACT_TEST) {
         values.push_back(value);
         db->Put(writeOptions,key,value);
     }
-    for(int i=0;i<1000;i++){
+    for(int i=0;i<100000;i++){
         std::string key=std::to_string(i);
         std::string value;
         Status s=db->Get(readOptions,key,&value);