Expose base db object from ttl wrapper

Summary: rocksdb replicaiton will need this when writing value+TS from master to slave 'as is'

Test Plan: make

Reviewers: dhruba, vamsi, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11919

db/merge_test.cc

@@ -20,6 +20,7 @@ auto mergeOperator = MergeOperators::CreateUInt64AddOperator();
 
 std::shared_ptr<DB> OpenDb(const string& dbname, const bool ttl = false) {
   DB* db;
+  StackableDB* sdb;
   Options options;
   options.create_if_missing = true;
   options.merge_operator = mergeOperator.get();
@@ -27,7 +28,8 @@ std::shared_ptr<DB> OpenDb(const string& dbname, const bool ttl = false) {
   DestroyDB(dbname, Options());
   if (ttl) {
     cout << "Opening database with TTL\n";
-    s = UtilityDB::OpenTtlDB(options, test::TmpDir() + "/merge_testdbttl", &db);
+    s = UtilityDB::OpenTtlDB(options, test::TmpDir() + "/merge_testdbttl",&sdb);
+    db = sdb;
   } else {
     s = DB::Open(options, test::TmpDir() + "/merge_testdb", &db);
   }

include/utilities/stackable_db.h

@@ -0,0 +1,154 @@
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+#ifndef LEVELDB_INCLUDE_UTILITIES_STACKABLE_DB_H_
+#define LEVELDB_INCLUDE_UTILITIES_STACKABLE_DB_H_
+
+#include "leveldb/db.h"
+
+namespace leveldb {
+
+// This class contains APIs to stack rocksdb wrappers.Eg. Stack TTL over base d
+class StackableDB : public DB {
+ public:
+  explicit StackableDB(StackableDB* sdb) : sdb_(sdb) {}
+
+  // Returns the DB object that is the lowermost component in the stack of DBs
+  virtual DB* GetRawDB() {
+    return sdb_->GetRawDB();
+  }
+
+  // convert a DB to StackableDB
+  static StackableDB* DBToStackableDB(DB* db) {
+    class NewStackableDB : public StackableDB {
+     public:
+      NewStackableDB(DB* db)
+        : StackableDB(nullptr),
+          db_(db) {}
+
+      DB* GetRawDB() {
+        return db_;
+      }
+
+     private:
+      DB* db_;
+    };
+    return new NewStackableDB(db);
+  }
+
+  virtual Status Put(const WriteOptions& options,
+                     const Slice& key,
+                     const Slice& val) override {
+    return sdb_->Put(options, key, val);
+  }
+
+  virtual Status Get(const ReadOptions& options,
+                     const Slice& key,
+                     std::string* value) override {
+    return sdb_->Get(options, key, value);
+  }
+
+  virtual std::vector<Status> MultiGet(const ReadOptions& options,
+                                       const std::vector<Slice>& keys,
+                                       std::vector<std::string>* values)
+    override {
+      return sdb_->MultiGet(options, keys, values);
+  }
+
+  virtual bool KeyMayExist(const ReadOptions& options,
+                           const Slice& key,
+                           std::string* value,
+                           bool* value_found = nullptr) override {
+    return KeyMayExist(options, key, value, value_found);
+  }
+
+  virtual Status Delete(const WriteOptions& wopts, const Slice& key) override {
+    return sdb_->Delete(wopts, key);
+  }
+
+  virtual Status Merge(const WriteOptions& options,
+                       const Slice& key,
+                       const Slice& value) override {
+    return sdb_->Merge(options, key, value);
+  }
+
+
+  virtual Status Write(const WriteOptions& opts, WriteBatch* updates)
+    override {
+      return sdb_->Write(opts, updates);
+  }
+
+  virtual Iterator* NewIterator(const ReadOptions& opts) override {
+    return sdb_->NewIterator(opts);
+  }
+
+  virtual const Snapshot* GetSnapshot() override {
+    return sdb_->GetSnapshot();
+  }
+
+  virtual void ReleaseSnapshot(const Snapshot* snapshot) override {
+    return sdb_->ReleaseSnapshot(snapshot);
+  }
+
+  virtual bool GetProperty(const Slice& property, std::string* value)
+    override {
+      return sdb_->GetProperty(property, value);
+  }
+
+  virtual void GetApproximateSizes(const Range* r, int n, uint64_t* sizes)
+    override {
+      return sdb_->GetApproximateSizes(r, n, sizes);
+  }
+
+  virtual void CompactRange(const Slice* begin, const Slice* end,
+                            bool reduce_level = false) override {
+    return sdb_->CompactRange(begin, end, reduce_level);
+  }
+
+  virtual int NumberLevels() override {
+    return sdb_->NumberLevels();
+  }
+
+  virtual int MaxMemCompactionLevel() override {
+    return sdb_->MaxMemCompactionLevel();
+  }
+
+  virtual int Level0StopWriteTrigger() override {
+    return sdb_->Level0StopWriteTrigger();
+  }
+
+  virtual Status Flush(const FlushOptions& fopts) override {
+    return sdb_->Flush(fopts);
+  }
+
+  virtual Status DisableFileDeletions() override {
+    return sdb_->DisableFileDeletions();
+  }
+
+  virtual Status EnableFileDeletions() override {
+    return sdb_->EnableFileDeletions();
+  }
+
+  virtual Status GetLiveFiles(std::vector<std::string>& vec, uint64_t* mfs)
+    override {
+      return sdb_->GetLiveFiles(vec, mfs);
+  }
+
+  virtual SequenceNumber GetLatestSequenceNumber() override {
+    return sdb_->GetLatestSequenceNumber();
+  }
+
+  virtual Status GetUpdatesSince(SequenceNumber seq_number,
+                                 unique_ptr<TransactionLogIterator>* iter)
+    override {
+      return sdb_->GetUpdatesSince(seq_number, iter);
+  }
+
+ protected:
+  StackableDB* sdb_;
+};
+
+} //  namespace leveldb
+
+#endif  //  LEVELDB_INCLUDE_UTILITIES_STACKABLE_DB_H_

include/utilities/utility_db.h

@@ -5,7 +5,7 @@
 #ifndef LEVELDB_INCLUDE_UTILITIES_UTILITY_DB_H_
 #define LEVELDB_INCLUDE_UTILITIES_UTILITY_DB_H_
 
-#include "leveldb/db.h"
+#include "stackable_db.h"
 
 namespace leveldb {
 
@@ -44,7 +44,7 @@ class UtilityDB {
     //  whole database may be deleted in a small amount of time
     static Status OpenTtlDB(const Options& options,
                             const std::string& name,
-                            DB** dbptr,
+                            StackableDB** dbptr,
                             int32_t ttl = 0,
                             bool read_only = false);
 };

tools/db_stress.cc

@@ -972,7 +972,8 @@ class StressTest {
     if (FLAGS_ttl == -1) {
       s = DB::Open(options, FLAGS_db, &db_);
     } else {
-      s = UtilityDB::OpenTtlDB(options, FLAGS_db, &db_, FLAGS_ttl);
+      s = UtilityDB::OpenTtlDB(options, FLAGS_db, &sdb_, FLAGS_ttl);
+      db_ = sdb_;
     }
     if (!s.ok()) {
       fprintf(stderr, "open error: %s\n", s.ToString().c_str());
@@ -1008,6 +1009,7 @@ class StressTest {
   shared_ptr<Cache> cache_;
   const FilterPolicy* filter_policy_;
   DB* db_;
+  StackableDB* sdb_;
   int num_times_reopened_;
 };
 

util/ldb_cmd.cc

@@ -821,7 +821,8 @@ void DBDumperCommand::DoCommand() {
     if (max_keys == 0)
       break;
     if (is_db_ttl_) {
-      TtlIterator* it_ttl = (TtlIterator*)iter;
+      TtlIterator* it_ttl = dynamic_cast<TtlIterator*>(iter);
+      assert(it_ttl);
       rawtime = it_ttl->timestamp();
       if (rawtime < ttl_start || rawtime >= ttl_end) {
         continue;
@@ -1342,7 +1343,8 @@ void ScanCommand::DoCommand() {
         it->Next()) {
     string key = it->key().ToString();
     if (is_db_ttl_) {
-      TtlIterator* it_ttl = (TtlIterator*)it;
+      TtlIterator* it_ttl = dynamic_cast<TtlIterator*>(it);
+      assert(it_ttl);
       int rawtime = it_ttl->timestamp();
       if (rawtime < ttl_start || rawtime >= ttl_end) {
         continue;

util/ldb_cmd.h

@@ -150,6 +150,7 @@ protected:
   LDBCommandExecuteResult exec_state_;
   string db_path_;
   DB* db_;
+  StackableDB* sdb_;
 
   /**
    * true implies that this command can work if the db is opened in read-only
@@ -217,10 +218,11 @@ protected:
     Status st;
     if (is_db_ttl_) {
       if (is_read_only_) {
-        st = UtilityDB::OpenTtlDB(opt, db_path_, &db_, 0, true);
+        st = UtilityDB::OpenTtlDB(opt, db_path_, &sdb_, 0, true);
       } else {
-        st = UtilityDB::OpenTtlDB(opt, db_path_, &db_);
+        st = UtilityDB::OpenTtlDB(opt, db_path_, &sdb_);
       }
+      db_ = sdb_;
     } else if (is_read_only_) {
       st = DB::OpenForReadOnly(opt, db_path_, &db_);
     } else {

utilities/ttl/db_ttl.cc

@@ -3,7 +3,6 @@
 // found in the LICENSE file. See the AUTHORS file for names of contributors.
 
 #include "utilities/ttl/db_ttl.h"
-#include "include/utilities/utility_db.h"
 #include "db/filename.h"
 #include "util/coding.h"
 #include "include/leveldb/env.h"
@@ -17,7 +16,8 @@ DBWithTTL::DBWithTTL(const int32_t ttl,
                      const std::string& dbname,
                      Status& st,
                      bool read_only)
-    : ttl_(ttl) {
+    : StackableDB(nullptr),
+      ttl_(ttl) {
   Options options_to_open = options;
 
   ttl_comp_filter_.reset(new TtlCompactionFilter(ttl,
@@ -43,7 +43,7 @@ DBWithTTL::~DBWithTTL() {
 Status UtilityDB::OpenTtlDB(
     const Options& options,
     const std::string& dbname,
-    DB** dbptr,
+    StackableDB** dbptr,
     int32_t ttl,
     bool read_only) {
   Status st;

utilities/ttl/db_ttl.h

@@ -9,11 +9,12 @@
 #include "leveldb/env.h"
 #include "leveldb/compaction_filter.h"
 #include "leveldb/merge_operator.h"
+#include "utilities/utility_db.h"
 #include "db/db_impl.h"
 
 namespace leveldb {
 
-class DBWithTTL : public DB {
+class DBWithTTL : public StackableDB {
  public:
   DBWithTTL(const int32_t ttl,
             const Options& options,
@@ -84,6 +85,10 @@ class DBWithTTL : public DB {
   // Simulate a db crash, no elegant closing of database.
   void TEST_Destroy_DBWithTtl();
 
+  virtual DB* GetRawDB() {
+    return db_;
+  }
+
   static bool IsStale(const Slice& value, int32_t ttl);
 
   static Status AppendTS(const Slice& val, std::string& val_with_ts);

utilities/ttl/ttl_test.cc

@@ -257,7 +257,7 @@ class TtlTest {
 
  private:
   std::string dbname_;
-  DB* db_ttl_;
+  StackableDB* db_ttl_;
   Options options_;
   KVMap kvmap_;
   KVMap::iterator kv_it_;