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rocksdb/tools/trace_analyzer_tool.h
Josh Kang 4b983da055 Spell out special member functions (rule of five) (#15387)
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/15387

## Summary

RocksDB's `.clang-tidy` enables `cppcoreguidelines-special-member-functions`,
`cppcoreguidelines-virtual-class-destructor` and the noexcept-move checks,
and clang warns `-Wdeprecated-copy-with-user-provided-dtor`. A full scan
reports 476 findings. In most of them, a class declares a destructor (or
copy operations) but leaves the rest of copy/move implicit. That has two
costs. Readers can't tell whether a class may be copied or moved. And
resource-owning classes keep an implicit copy that would double-free if
anyone ever used it. This diff resolves 453 of the 476.

Approach, picked per class from least to most invasive:
1. An empty user-provided destructor becomes `= default`. This covers most
   interface classes, such as `virtual ~X() {}` -> `= default`. If the
   class is still copied, that would only rename the deprecated-copy
   warning, so the destructor is removed instead when nothing needs it
   (`Customizable`, `TableFactory` and `InternalKeyComparator` inherit a
   virtual one; `IteratorWrapperBase` isn't polymorphic), and
   `MemTableRep::KeyComparator` gets defaulted copy and move.
2. Classes whose copy is already deleted get explicitly deleted move
   operations too. Move was already unavailable, so this only documents
   it.
3. Resource-owning classes that are never copied get deleted copy and move
   operations. Examples: the C API wrapper structs, which run a
   `destructor_` callback (edited in `tools/c_api_gen/c_base.cc` and
   regenerated into `db/c.cc`); `ShardedCache`, which frees its shards;
   iterator wrappers; and RAII handles.
4. Value types that are copied or moved get the missing operations as
   `= default`, which keeps their current behavior.
5. Exception specifications of existing functions are unchanged, except
   for `WriteBatch`'s move assignment (below): no other `noexcept` is
   added or removed. Only the move operations this diff
   newly declares (`Comparator`, `FileSampledStats` and the thread-local
   `Entry`) are `noexcept`; they copy only scalars or atomics.

`WriteBatch`'s copy and move assignment destroyed `*this` and
placement-new'ed a new `WriteBatch` over it. That is undefined behavior
when `*this` is a subclass, and if the copy constructor threw, `*this`
was left destroyed and was later destroyed again. Move assignment now
assigns member-wise and ends in the same state as the move constructor,
which leaves `has_key_with_ts_`, the timestamp-size tracking and the
other fields it doesn't copy at their defaults. `rep_` is swapped through
a temporary, because a plain string move-assignment can keep the old
buffer (e.g. a large batch reset with `batch = WriteBatch()` would keep
its memory). Nothing in it can throw, so it is now `noexcept`. Copy
assignment copies into a temporary and moves it in, so a throwing copy
leaves `*this` unchanged.

Bugs this exposed and fixed:
- `RestoreAfterCopyOrCreateWorkItem` (backup engine): the hand-written
  move constructor and assignment moved only some fields, so `from_file`
  and `to_file` were empty after `push_back(std::move(...))`. A restore
  that hit a checksum mismatch then reported "While restoring  -> : ..."
  without file names. It now uses the compiler-generated moves, which
  are still `noexcept`.
- `ExternalSstFileIngestionJob` lived in a `std::vector`, and its
  destructor frees raw-owned pointers, so the implicit copy used on
  vector reallocation would double-free. Its file batches also point into
  its own inline file storage, so neither a copy nor a move is safe after
  `Prepare()`. Copy and move are now deleted, and `DBImpl` holds jobs
  through `std::unique_ptr`.

Compatibility: no public class loses an operation users can call. Public
interfaces mostly only get `virtual ~X() = default;`.
`WriteBatch`'s move assignment becomes `noexcept`, which is not part of
the mangled name, so the ABI doesn't change.
`SubcompactionJobInfo` and `CompactionJobInfo` intentionally stay C++20
aggregates, so users' aggregate and designated initializers keep
compiling. `Configurable`, `CompareInterface`, `WriteBatchBase`,
`ObjectLibrary::Entry` and `MemTableRep::KeyComparator` declare defaulted
copy and move, and `Customizable` no longer declares a destructor. As a
result, `Configurable` and `Customizable` subclasses that declare no
destructor or copy operations of their own now move their
registered-options list instead of copying it. In-tree, these are the
mutable-options adapters, the table factories, the memory allocators and
test classes; all are held through smart pointers or used in place, and
`Clone()` copies, so none is moved by value.

Not changed (23): `IODebugContext` (custom deep copy plus a
`std::shared_mutex`), `DBWithColumnFamilies` in db_bench (stored in a
`std::vector` with non-movable members), `Snapshot`'s protected virtual
destructor (intended), `ManagedSnapshot`, the `SubcompactionJobInfo` and
`CompactionJobInfo` aggregates, and the 16 noexcept-move-constructor and
noexcept-swap findings on existing functions, including `autovector`'s
move assignment (adding `noexcept` would change their exception
specifications). Copying `ManagedSnapshot` already double-releases the
snapshot. Fixing that needs a real move implementation and is a behavior
change, so it is left for a separate diff.

Reviewed By: rban1

Differential Revision: D123186309

fbshipit-source-id: 6f8e57e233e12199a007407130bb9a1f6d52e8d1
2026-10-12 16:00:09 -07:00

336 lines
12 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#pragma once
#include <list>
#include <map>
#include <queue>
#include <set>
#include <utility>
#include <vector>
#include "rocksdb/env.h"
#include "rocksdb/trace_reader_writer.h"
#include "rocksdb/trace_record.h"
#include "rocksdb/write_batch.h"
#include "trace_replay/trace_replay.h"
namespace ROCKSDB_NAMESPACE {
// Value sizes may be used as denominators. Replacing 0 value sizes with this
// positive integer avoids division error.
extern const size_t kShadowValueSize /* = 10*/;
enum TraceOperationType : int {
kGet = 0,
kPut = 1,
kDelete = 2,
kSingleDelete = 3,
kRangeDelete = 4,
kMerge = 5,
kIteratorSeek = 6,
kIteratorSeekForPrev = 7,
kMultiGet = 8,
kPutEntity = 9,
kTaTypeNum = 10
};
struct TraceUnit {
uint64_t ts;
uint32_t type;
uint32_t cf_id;
size_t value_size;
std::string key;
};
struct TypeCorrelation {
uint64_t count;
uint64_t total_ts;
};
struct StatsUnit {
uint64_t key_id;
uint64_t access_count;
uint64_t latest_ts;
uint64_t succ_count; // current only used to count Get if key found
uint32_t cf_id;
size_t value_size;
std::vector<TypeCorrelation> v_correlation;
};
class AnalyzerOptions {
public:
std::vector<std::vector<int>> correlation_map;
std::vector<std::pair<int, int>> correlation_list;
AnalyzerOptions();
~AnalyzerOptions() = default;
void SparseCorrelationInput(const std::string& in_str);
};
// Note that, for the variable names in the trace_analyzer,
// Starting with 'a_' means the variable is used for 'accessed_keys'.
// Starting with 'w_' means it is used for 'the whole key space'.
// Ending with '_f' means a file write or reader pointer.
// For example, 'a_count' means 'accessed_keys_count',
// 'w_key_f' means 'whole_key_space_file'.
struct TraceStats {
uint32_t cf_id;
std::string cf_name;
uint64_t a_count;
uint64_t a_succ_count;
uint64_t a_key_id;
uint64_t a_key_size_sqsum;
uint64_t a_key_size_sum;
uint64_t a_key_mid;
uint64_t a_value_size_sqsum;
uint64_t a_value_size_sum;
uint64_t a_value_mid;
uint32_t a_peak_qps;
double a_ave_qps;
std::map<std::string, StatsUnit> a_key_stats;
std::map<uint64_t, uint64_t> a_count_stats;
std::map<uint64_t, uint64_t> a_key_size_stats;
std::map<uint64_t, uint64_t> a_value_size_stats;
std::map<uint32_t, uint32_t> a_qps_stats;
std::map<uint32_t, std::map<std::string, uint32_t>> a_qps_prefix_stats;
std::priority_queue<std::pair<uint64_t, std::string>,
std::vector<std::pair<uint64_t, std::string>>,
std::greater<std::pair<uint64_t, std::string>>>
top_k_queue;
std::priority_queue<std::pair<uint64_t, std::string>,
std::vector<std::pair<uint64_t, std::string>>,
std::greater<std::pair<uint64_t, std::string>>>
top_k_prefix_access;
std::priority_queue<std::pair<double, std::string>,
std::vector<std::pair<double, std::string>>,
std::greater<std::pair<double, std::string>>>
top_k_prefix_ave;
std::priority_queue<std::pair<uint32_t, uint32_t>,
std::vector<std::pair<uint32_t, uint32_t>>,
std::greater<std::pair<uint32_t, uint32_t>>>
top_k_qps_sec;
std::list<TraceUnit> time_series;
std::vector<std::pair<uint64_t, uint64_t>> correlation_output;
std::map<uint32_t, uint64_t> uni_key_num;
std::unique_ptr<ROCKSDB_NAMESPACE::WritableFile> time_series_f;
std::unique_ptr<ROCKSDB_NAMESPACE::WritableFile> a_key_f;
std::unique_ptr<ROCKSDB_NAMESPACE::WritableFile> a_count_dist_f;
std::unique_ptr<ROCKSDB_NAMESPACE::WritableFile> a_prefix_cut_f;
std::unique_ptr<ROCKSDB_NAMESPACE::WritableFile> a_value_size_f;
std::unique_ptr<ROCKSDB_NAMESPACE::WritableFile> a_key_size_f;
std::unique_ptr<ROCKSDB_NAMESPACE::WritableFile> a_key_num_f;
std::unique_ptr<ROCKSDB_NAMESPACE::WritableFile> a_qps_f;
std::unique_ptr<ROCKSDB_NAMESPACE::WritableFile> a_top_qps_prefix_f;
std::unique_ptr<ROCKSDB_NAMESPACE::WritableFile> w_key_f;
std::unique_ptr<ROCKSDB_NAMESPACE::WritableFile> w_prefix_cut_f;
TraceStats();
~TraceStats();
TraceStats(const TraceStats&) = delete;
TraceStats& operator=(const TraceStats&) = delete;
TraceStats(TraceStats&&) = default;
TraceStats& operator=(TraceStats&&) = default;
};
struct TypeUnit {
std::string type_name;
bool enabled;
uint64_t total_keys;
uint64_t total_access;
uint64_t total_succ_access;
uint32_t sample_count;
std::map<uint32_t, TraceStats> stats;
TypeUnit() = default;
~TypeUnit() = default;
TypeUnit(const TypeUnit&) = delete;
TypeUnit& operator=(const TypeUnit&) = delete;
TypeUnit(TypeUnit&&) = default;
TypeUnit& operator=(TypeUnit&&) = default;
};
struct CfUnit {
uint32_t cf_id;
uint64_t w_count; // total keys in this cf if we use the whole key space
uint64_t a_count; // the total keys in this cf that are accessed
std::map<uint64_t, uint64_t> w_key_size_stats; // whole key space key size
// statistic this cf
std::map<uint32_t, uint32_t> cf_qps;
};
class TraceAnalyzer : private TraceRecord::Handler,
private WriteBatch::Handler {
public:
TraceAnalyzer(std::string& trace_path, std::string& output_path,
AnalyzerOptions _analyzer_opts);
~TraceAnalyzer() override;
Status PrepareProcessing();
Status StartProcessing();
Status MakeStatistics();
Status ReProcessing();
Status EndProcessing();
Status WriteTraceUnit(TraceUnit& unit);
std::vector<TypeUnit>& GetTaVector() { return ta_; }
private:
using TraceRecord::Handler::Handle;
Status Handle(const WriteQueryTraceRecord& record,
std::unique_ptr<TraceRecordResult>* result) override;
Status Handle(const GetQueryTraceRecord& record,
std::unique_ptr<TraceRecordResult>* result) override;
Status Handle(const IteratorSeekQueryTraceRecord& record,
std::unique_ptr<TraceRecordResult>* result) override;
Status Handle(const MultiGetQueryTraceRecord& record,
std::unique_ptr<TraceRecordResult>* result) override;
using WriteBatch::Handler::PutCF;
Status PutCF(uint32_t column_family_id, const Slice& key,
const Slice& value) override;
using WriteBatch::Handler::TimedPutCF;
Status TimedPutCF(uint32_t column_family_id, const Slice& key,
const Slice& value, uint64_t write_unix_time) override;
using WriteBatch::Handler::PutEntityCF;
Status PutEntityCF(uint32_t column_family_id, const Slice& key,
const Slice& value) override;
using WriteBatch::Handler::DeleteCF;
Status DeleteCF(uint32_t column_family_id, const Slice& key) override;
using WriteBatch::Handler::SingleDeleteCF;
Status SingleDeleteCF(uint32_t column_family_id, const Slice& key) override;
using WriteBatch::Handler::DeleteRangeCF;
Status DeleteRangeCF(uint32_t column_family_id, const Slice& begin_key,
const Slice& end_key) override;
using WriteBatch::Handler::MergeCF;
Status MergeCF(uint32_t column_family_id, const Slice& key,
const Slice& value) override;
// The following hanlders are not implemented, return Status::OK() to avoid
// the running time assertion and other irrelevant falures.
using WriteBatch::Handler::PutBlobIndexCF;
Status PutBlobIndexCF(uint32_t /*column_family_id*/, const Slice& /*key*/,
const Slice& /*value*/) override {
return Status::OK();
}
// The default implementation of LogData does nothing.
using WriteBatch::Handler::LogData;
void LogData(const Slice& /*blob*/) override {}
using WriteBatch::Handler::MarkBeginPrepare;
Status MarkBeginPrepare(bool = false) override { return Status::OK(); }
using WriteBatch::Handler::MarkEndPrepare;
Status MarkEndPrepare(const Slice& /*xid*/) override { return Status::OK(); }
using WriteBatch::Handler::MarkNoop;
Status MarkNoop(bool /*empty_batch*/) override { return Status::OK(); }
using WriteBatch::Handler::MarkRollback;
Status MarkRollback(const Slice& /*xid*/) override { return Status::OK(); }
using WriteBatch::Handler::MarkCommit;
Status MarkCommit(const Slice& /*xid*/) override { return Status::OK(); }
using WriteBatch::Handler::MarkCommitWithTimestamp;
Status MarkCommitWithTimestamp(const Slice& /*xid*/,
const Slice& /*commit_ts*/) override {
return Status::OK();
}
// Process each trace operation and output the analysis result to
// stdout/files.
Status OutputAnalysisResult(TraceOperationType op_type, uint64_t timestamp,
std::vector<uint32_t> cf_ids,
std::vector<Slice> keys,
std::vector<size_t> value_sizes);
Status OutputAnalysisResult(TraceOperationType op_type, uint64_t timestamp,
uint32_t cf_id, const Slice& key,
size_t value_size);
ROCKSDB_NAMESPACE::Env* env_;
EnvOptions env_options_;
std::unique_ptr<TraceReader> trace_reader_;
size_t offset_;
char buffer_[1024];
// Timestamp of a WriteBatch, used in its iteration.
uint64_t write_batch_ts_;
std::string trace_name_;
std::string output_path_;
AnalyzerOptions analyzer_opts_;
uint64_t total_requests_;
uint64_t total_access_keys_;
uint64_t total_gets_;
uint64_t total_writes_;
uint64_t total_seeks_;
uint64_t total_seek_prevs_;
uint64_t total_multigets_;
uint64_t trace_create_time_;
uint64_t begin_time_;
uint64_t end_time_;
uint64_t time_series_start_;
uint32_t sample_max_;
uint32_t cur_time_sec_;
std::unique_ptr<ROCKSDB_NAMESPACE::WritableFile>
trace_sequence_f_; // readable trace
std::unique_ptr<ROCKSDB_NAMESPACE::WritableFile> qps_f_; // overall qps
std::unique_ptr<ROCKSDB_NAMESPACE::WritableFile>
cf_qps_f_; // The qps of each CF>
std::vector<TypeUnit> ta_; // The main statistic collecting data structure
std::map<uint32_t, CfUnit> cfs_; // All the cf_id appears in this trace;
std::vector<uint32_t> qps_peak_;
std::vector<double> qps_ave_;
Status ReadTraceHeader(Trace* header);
Status ReadTraceFooter(Trace* footer);
Status ReadTraceRecord(Trace* trace);
Status KeyStatsInsertion(const uint32_t& type, const uint32_t& cf_id,
const std::string& key, const size_t value_size,
const uint64_t ts);
Status StatsUnitCorrelationUpdate(StatsUnit& unit, const uint32_t& type,
const uint64_t& ts, const std::string& key);
Status OpenStatsOutputFiles(const std::string& type, TraceStats& new_stats);
Status CreateOutputFile(
const std::string& type, const std::string& cf_name,
const std::string& ending,
std::unique_ptr<ROCKSDB_NAMESPACE::WritableFile>* f_ptr);
Status CloseOutputFiles();
void PrintStatistics();
Status TraceUnitWriter(
std::unique_ptr<ROCKSDB_NAMESPACE::WritableFile>& f_ptr, TraceUnit& unit);
Status WriteTraceSequence(const uint32_t& type, const uint32_t& cf_id,
const Slice& key, const size_t value_size,
const uint64_t ts);
Status WriteRangeDeleteTraceSequence(const uint32_t& cf_id,
const Slice& begin_key,
const Slice& end_key, const uint64_t ts);
Status MakeStatisticKeyStatsOrPrefix(TraceStats& stats);
Status MakeStatisticCorrelation(TraceStats& stats, StatsUnit& unit);
Status MakeStatisticQPS();
int db_version_;
};
int trace_analyzer_tool(int argc, char** argv);
} // namespace ROCKSDB_NAMESPACE