rocksdb/db/flush_scheduler.cc
Igor Canadi 3d9e6f7759 Push model for flushing memtables
Summary:
When memtable is full it calls the registered callback. That callback then registers column family as needing the flush. Every write checks if there are some column families that need to be flushed. This completely eliminates the need for MakeRoomForWrite() function and simplifies our Write code-path.

There is some complexity with the concurrency when the column family is dropped. I made it a bit less complex by dropping the column family from the write thread in https://reviews.facebook.net/D22965. Let me know if you want to discuss this.

Test Plan: make check works. I'll also run db_stress with creating and dropping column families for a while.

Reviewers: yhchiang, sdong, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23067
2014-09-10 18:46:09 -07:00

63 lines
1.6 KiB
C++

// Copyright (c) 2013, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
#include "db/flush_scheduler.h"
#include <cassert>
#include "db/column_family.h"
namespace rocksdb {
void FlushScheduler::ScheduleFlush(ColumnFamilyData* cfd) {
#ifndef NDEBUG
assert(column_families_set_.find(cfd) == column_families_set_.end());
column_families_set_.insert(cfd);
#endif // NDEBUG
cfd->Ref();
column_families_.push_back(cfd);
}
ColumnFamilyData* FlushScheduler::GetNextColumnFamily() {
ColumnFamilyData* cfd = nullptr;
while (column_families_.size() > 0) {
cfd = column_families_.front();
column_families_.pop_front();
if (cfd->IsDropped()) {
if (cfd->Unref()) {
delete cfd;
}
} else {
break;
}
}
#ifndef NDEBUG
if (cfd != nullptr) {
auto itr = column_families_set_.find(cfd);
assert(itr != column_families_set_.end());
column_families_set_.erase(itr);
}
#endif // NDEBUG
return cfd;
}
bool FlushScheduler::Empty() { return column_families_.empty(); }
void FlushScheduler::Clear() {
for (auto cfd : column_families_) {
#ifndef NDEBUG
auto itr = column_families_set_.find(cfd);
assert(itr != column_families_set_.end());
column_families_set_.erase(itr);
#endif // NDEBUG
if (cfd->Unref()) {
delete cfd;
}
}
column_families_.clear();
}
} // namespace rocksdb