rocksdb/db/memtablelist.h
Abhishek Kona d29f181923 Fix all the lint errors.
Summary:
Scripted and removed all trailing spaces and converted all tabs to
spaces.

Also fixed other lint errors.
All lint errors from this point of time should be taken seriously.

Test Plan: make all check

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7059
2012-11-28 17:18:41 -08:00

97 lines
2.7 KiB
C++

// Copyright (c) 2012 Facebook.
#ifndef STORAGE_LEVELDB_DB_MEMTABLELIST_H_
#define STORAGE_LEVELDB_DB_MEMTABLELIST_H_
#include <string>
#include <list>
#include "leveldb/db.h"
#include "db/dbformat.h"
#include "db/skiplist.h"
#include "util/arena.h"
#include "memtable.h"
namespace leveldb {
class InternalKeyComparator;
class Mutex;
class MemTableListIterator;
//
// This class stores refeernces to all the immutable memtables.
// The memtables are flushed to L0 as soon as possible and in
// any order. If there are more than one immutable memtable, their
// flushes can occur concurrently. However, they are 'committed'
// to the manifest in FIFO order to maintain correctness and
// recoverability from a crash.
//
class MemTableList {
public:
// A list of memtables.
MemTableList() : size_(0), num_flush_not_started_(0),
commit_in_progress_(false) {
imm_flush_needed.Release_Store(NULL);
}
~MemTableList() {};
// so that backgrund threads can detect non-NULL pointer to
// determine whether this is anything more to start flushing.
port::AtomicPointer imm_flush_needed;
// Increase reference count on all underling memtables
void RefAll();
// Drop reference count on all underling memtables
void UnrefAll();
// Returns the total number of memtables in the list
int size();
// Returns true if there is at least one memtable on which flush has
// not yet started.
bool IsFlushPending();
// Returns the earliest memtable that needs to be flushed.
// Returns null, if no such memtable exist.
MemTable* PickMemtableToFlush();
// Commit a successful flush in the manifest file
Status InstallMemtableFlushResults(MemTable* m,
VersionSet* vset, Status flushStatus,
port::Mutex* mu, Logger* info_log,
uint64_t file_number,
std::set<uint64_t>& pending_outputs);
// New memtables are inserted at the front of the list.
void Add(MemTable* m);
// Returns an estimate of the number of bytes of data in use.
size_t ApproximateMemoryUsage();
// Search all the memtables starting from the most recent one.
// Return the most recent value found, if any.
bool Get(const LookupKey& key, std::string* value, Status* s);
// Returns the list of underlying memtables.
void GetMemTables(std::vector<MemTable*>* list);
// Copying allowed
// MemTableList(const MemTableList&);
// void operator=(const MemTableList&);
private:
std::list<MemTable*> memlist_;
int size_;
// the number of elements that still need flushing
int num_flush_not_started_;
// committing in progress
bool commit_in_progress_;
};
} // namespace leveldb
#endif // STORAGE_LEVELDB_DB_MEMTABLELIST_H_