rocksdb/include/leveldb/arena.h
Xing Jin 0f0a24e298 Make arena block size configurable
Summary:
Add an option for arena block size, default value 4096 bytes. Arena will allocate blocks with such size.

I am not sure about passing parameter to skiplist in the new virtualized framework, though I talked to Jim a bit. So add Jim as reviewer.

Test Plan:
new unit test, I am running db_test.

For passing paramter from configured option to Arena, I tried tests like:

  TEST(DBTest, Arena_Option) {
  std::string dbname = test::TmpDir() + "/db_arena_option_test";
  DestroyDB(dbname, Options());

  DB* db = nullptr;
  Options opts;
  opts.create_if_missing = true;
  opts.arena_block_size = 1000000; // tested 99, 999999
  Status s = DB::Open(opts, dbname, &db);
  db->Put(WriteOptions(), "a", "123");
  }

and printed some debug info. The results look good. Any suggestion for such a unit-test?

Reviewers: haobo, dhruba, emayanke, jpaton

Reviewed By: dhruba

CC: leveldb, zshao

Differential Revision: https://reviews.facebook.net/D11799
2013-07-31 12:42:23 -07:00

39 lines
1.1 KiB
C++

// 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.
//
// Arena class defines memory allocation methods. It's used by memtable and
// skiplist.
#ifndef STORAGE_LEVELDB_INCLUDE_ARENA_H_
#define STORAGE_LEVELDB_INCLUDE_ARENA_H_
namespace leveldb {
class Arena {
public:
Arena() {};
virtual ~Arena() {};
// Return a pointer to a newly allocated memory block of "bytes" bytes.
virtual char* Allocate(size_t bytes) = 0;
// Allocate memory with the normal alignment guarantees provided by malloc.
virtual char* AllocateAligned(size_t bytes) = 0;
// Returns an estimate of the total memory used by arena.
virtual const size_t ApproximateMemoryUsage() = 0;
// Returns the total number of bytes in all blocks allocated so far.
virtual const size_t MemoryAllocatedBytes() = 0;
private:
// No copying allowed
Arena(const Arena&);
void operator=(const Arena&);
};
} // namespace leveldb
#endif // STORAGE_LEVELDB_INCLUDE_ARENA_H_