mirror of
https://github.com/facebook/rocksdb.git
synced 2024-11-26 07:30:54 +00:00
d29f181923
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
107 lines
3.2 KiB
C++
107 lines
3.2 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.
|
|
|
|
#ifndef STORAGE_LEVELDB_DB_MEMTABLE_H_
|
|
#define STORAGE_LEVELDB_DB_MEMTABLE_H_
|
|
|
|
#include <string>
|
|
#include "leveldb/db.h"
|
|
#include "db/dbformat.h"
|
|
#include "db/skiplist.h"
|
|
#include "db/version_set.h"
|
|
#include "util/arena.h"
|
|
|
|
namespace leveldb {
|
|
|
|
class InternalKeyComparator;
|
|
class Mutex;
|
|
class MemTableIterator;
|
|
|
|
class MemTable {
|
|
public:
|
|
// MemTables are reference counted. The initial reference count
|
|
// is zero and the caller must call Ref() at least once.
|
|
explicit MemTable(const InternalKeyComparator& comparator,
|
|
int numlevel = 7);
|
|
|
|
// Increase reference count.
|
|
void Ref() { ++refs_; }
|
|
|
|
// Drop reference count. Delete if no more references exist.
|
|
void Unref() {
|
|
--refs_;
|
|
assert(refs_ >= 0);
|
|
if (refs_ <= 0) {
|
|
delete this;
|
|
}
|
|
}
|
|
|
|
// Returns an estimate of the number of bytes of data in use by this
|
|
// data structure.
|
|
//
|
|
// REQUIRES: external synchronization to prevent simultaneous
|
|
// operations on the same MemTable.
|
|
size_t ApproximateMemoryUsage();
|
|
|
|
// Return an iterator that yields the contents of the memtable.
|
|
//
|
|
// The caller must ensure that the underlying MemTable remains live
|
|
// while the returned iterator is live. The keys returned by this
|
|
// iterator are internal keys encoded by AppendInternalKey in the
|
|
// db/format.{h,cc} module.
|
|
Iterator* NewIterator();
|
|
|
|
// Add an entry into memtable that maps key to value at the
|
|
// specified sequence number and with the specified type.
|
|
// Typically value will be empty if type==kTypeDeletion.
|
|
void Add(SequenceNumber seq, ValueType type,
|
|
const Slice& key,
|
|
const Slice& value);
|
|
|
|
// If memtable contains a value for key, store it in *value and return true.
|
|
// If memtable contains a deletion for key, store a NotFound() error
|
|
// in *status and return true.
|
|
// Else, return false.
|
|
bool Get(const LookupKey& key, std::string* value, Status* s);
|
|
|
|
// Returns the edits area that is needed for flushing the memtable
|
|
VersionEdit* GetEdits() { return &edit_; }
|
|
|
|
private:
|
|
~MemTable(); // Private since only Unref() should be used to delete it
|
|
|
|
struct KeyComparator {
|
|
const InternalKeyComparator comparator;
|
|
explicit KeyComparator(const InternalKeyComparator& c) : comparator(c) { }
|
|
int operator()(const char* a, const char* b) const;
|
|
};
|
|
friend class MemTableIterator;
|
|
friend class MemTableBackwardIterator;
|
|
friend class MemTableList;
|
|
|
|
typedef SkipList<const char*, KeyComparator> Table;
|
|
|
|
KeyComparator comparator_;
|
|
int refs_;
|
|
Arena arena_;
|
|
Table table_;
|
|
|
|
// These are used to manage memtable flushes to storage
|
|
bool flush_in_progress_; // started the flush
|
|
bool flush_completed_; // finished the flush
|
|
uint64_t file_number_; // filled up after flush is complete
|
|
|
|
// The udpates to be applied to the transaction log when this
|
|
// memtable is flushed to storage.
|
|
VersionEdit edit_;
|
|
|
|
// No copying allowed
|
|
MemTable(const MemTable&);
|
|
void operator=(const MemTable&);
|
|
};
|
|
|
|
} // namespace leveldb
|
|
|
|
#endif // STORAGE_LEVELDB_DB_MEMTABLE_H_
|