c7ee9c3ab7
Summary: This breaks mongo+rocks build https://mci.10gen.com/task_log_raw/rocksdb_ubuntu1404_rocksdb_c6e8e3d868660dc66b3bbd438cdc135df6356c5a_14_11_10_21_36_10_compile_ubuntu1404_rocksdb/0?type=T Test Plan: m check + -Wnon-virtual-dtor Reviewers: sdong Reviewed By: sdong Subscribers: dhruba, leveldb Differential Revision: https://reviews.facebook.net/D28653
67 lines
2.7 KiB
C++
67 lines
2.7 KiB
C++
// Copyright (c) 2014 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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#pragma once
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#ifndef ROCKSDB_LITE
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#include <string>
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#include "rocksdb/status.h"
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namespace rocksdb {
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class DB;
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class Status;
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// EventListener class contains a set of call-back functions that will
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// be called when specific RocksDB event happens such as flush. It can
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// be used as a building block for developing custom features such as
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// stats-collector or external compaction algorithm.
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//
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// Note that call-back functions should not run for an extended period of
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// time before the function returns, otherwise RocksDB may be blocked.
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// For example, it is not suggested to do DB::CompactFiles() (as it may
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// run for a long while) or issue many of DB::Put() (as Put may be blocked
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// in certain cases) in the same thread in the EventListener callback.
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// However, doing DB::CompactFiles() and DB::Put() in another thread is
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// considered safe.
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//
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// [Threading] All EventListener callback will be called using the
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// actual thread that involves in that specific event. For example, it
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// is the RocksDB background flush thread that does the actual flush to
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// call EventListener::OnFlushCompleted().
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class EventListener {
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public:
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// A call-back function to RocksDB which will be called whenever a
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// registered RocksDB flushes a file. The default implementation is
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// no-op.
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//
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// Note that the this function must be implemented in a way such that
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// it should not run for an extended period of time before the function
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// returns. Otherwise, RocksDB may be blocked.
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//
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// @param db a pointer to the rocksdb instance which just flushed
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// a memtable to disk.
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// @param column_family_id the id of the flushed column family.
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// @param file_path the path to the newly created file.
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// @param triggered_writes_slowdown true when rocksdb is currently
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// slowing-down all writes to prevent creating too many Level 0
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// files as compaction seems not able to catch up the write request
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// speed. This indicates that there're too many files in Level 0.
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// @param triggered_writes_stop true when rocksdb is currently blocking
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// any writes to prevent creating more L0 files. This indicates that
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// there're too many files in level 0. Compactions should try to
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// compact L0 files down to lower levels as soon as possible.
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virtual void OnFlushCompleted(
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DB* db, const std::string& column_family_name,
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const std::string& file_path,
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bool triggered_writes_slowdown,
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bool triggered_writes_stop) {}
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virtual ~EventListener() {}
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};
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} // namespace rocksdb
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#endif // ROCKSDB_LITE
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