Revision 346d1069c3031468cf5cb06299f018a873c9fb33 authored by Daniel Black on 26 June 2018, 05:42:35 UTC, committed by Facebook Github Bot on 26 June 2018, 05:58:19 UTC
Summary: Pinned the alignment of StatisticsData to the cacheline size rather than just extending its size (which could go over two cache lines)if unaligned in allocation. Avoid compile errors in the process as per individual commit messages. strengthen static_assert to CACHELINE rather than the highest common multiple. Closes https://github.com/facebook/rocksdb/pull/4036 Differential Revision: D8582844 Pulled By: yiwu-arbug fbshipit-source-id: 363c37029f28e6093e06c60b987bca9aa204bc71
1 parent 6d454d7
version_edit.h
// 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).
//
// 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.
#pragma once
#include <algorithm>
#include <set>
#include <utility>
#include <vector>
#include <string>
#include "rocksdb/cache.h"
#include "db/dbformat.h"
#include "util/arena.h"
#include "util/autovector.h"
namespace rocksdb {
class VersionSet;
const uint64_t kFileNumberMask = 0x3FFFFFFFFFFFFFFF;
extern uint64_t PackFileNumberAndPathId(uint64_t number, uint64_t path_id);
// A copyable structure contains information needed to read data from an SST
// file. It can contains a pointer to a table reader opened for the file, or
// file number and size, which can be used to create a new table reader for it.
// The behavior is undefined when a copied of the structure is used when the
// file is not in any live version any more.
struct FileDescriptor {
// Table reader in table_reader_handle
TableReader* table_reader;
uint64_t packed_number_and_path_id;
uint64_t file_size; // File size in bytes
FileDescriptor() : FileDescriptor(0, 0, 0) {}
FileDescriptor(uint64_t number, uint32_t path_id, uint64_t _file_size)
: table_reader(nullptr),
packed_number_and_path_id(PackFileNumberAndPathId(number, path_id)),
file_size(_file_size) {}
FileDescriptor& operator=(const FileDescriptor& fd) {
table_reader = fd.table_reader;
packed_number_and_path_id = fd.packed_number_and_path_id;
file_size = fd.file_size;
return *this;
}
uint64_t GetNumber() const {
return packed_number_and_path_id & kFileNumberMask;
}
uint32_t GetPathId() const {
return static_cast<uint32_t>(
packed_number_and_path_id / (kFileNumberMask + 1));
}
uint64_t GetFileSize() const { return file_size; }
};
struct FileSampledStats {
FileSampledStats() : num_reads_sampled(0) {}
FileSampledStats(const FileSampledStats& other) { *this = other; }
FileSampledStats& operator=(const FileSampledStats& other) {
num_reads_sampled = other.num_reads_sampled.load();
return *this;
}
// number of user reads to this file.
mutable std::atomic<uint64_t> num_reads_sampled;
};
struct FileMetaData {
FileDescriptor fd;
InternalKey smallest; // Smallest internal key served by table
InternalKey largest; // Largest internal key served by table
SequenceNumber smallest_seqno; // The smallest seqno in this file
SequenceNumber largest_seqno; // The largest seqno in this file
// Needs to be disposed when refs becomes 0.
Cache::Handle* table_reader_handle;
FileSampledStats stats;
// Stats for compensating deletion entries during compaction
// File size compensated by deletion entry.
// This is updated in Version::UpdateAccumulatedStats() first time when the
// file is created or loaded. After it is updated (!= 0), it is immutable.
uint64_t compensated_file_size;
// These values can mutate, but they can only be read or written from
// single-threaded LogAndApply thread
uint64_t num_entries; // the number of entries.
uint64_t num_deletions; // the number of deletion entries.
uint64_t raw_key_size; // total uncompressed key size.
uint64_t raw_value_size; // total uncompressed value size.
int refs; // Reference count
bool being_compacted; // Is this file undergoing compaction?
bool init_stats_from_file; // true if the data-entry stats of this file
// has initialized from file.
bool marked_for_compaction; // True if client asked us nicely to compact this
// file.
FileMetaData()
: smallest_seqno(kMaxSequenceNumber),
largest_seqno(0),
table_reader_handle(nullptr),
compensated_file_size(0),
num_entries(0),
num_deletions(0),
raw_key_size(0),
raw_value_size(0),
refs(0),
being_compacted(false),
init_stats_from_file(false),
marked_for_compaction(false) {}
// REQUIRED: Keys must be given to the function in sorted order (it expects
// the last key to be the largest).
void UpdateBoundaries(const Slice& key, SequenceNumber seqno) {
if (smallest.size() == 0) {
smallest.DecodeFrom(key);
}
largest.DecodeFrom(key);
smallest_seqno = std::min(smallest_seqno, seqno);
largest_seqno = std::max(largest_seqno, seqno);
}
};
// A compressed copy of file meta data that just contain minimum data needed
// to server read operations, while still keeping the pointer to full metadata
// of the file in case it is needed.
struct FdWithKeyRange {
FileDescriptor fd;
FileMetaData* file_metadata; // Point to all metadata
Slice smallest_key; // slice that contain smallest key
Slice largest_key; // slice that contain largest key
FdWithKeyRange()
: fd(),
file_metadata(nullptr),
smallest_key(),
largest_key() {
}
FdWithKeyRange(FileDescriptor _fd, Slice _smallest_key, Slice _largest_key,
FileMetaData* _file_metadata)
: fd(_fd),
file_metadata(_file_metadata),
smallest_key(_smallest_key),
largest_key(_largest_key) {}
};
// Data structure to store an array of FdWithKeyRange in one level
// Actual data is guaranteed to be stored closely
struct LevelFilesBrief {
size_t num_files;
FdWithKeyRange* files;
LevelFilesBrief() {
num_files = 0;
files = nullptr;
}
};
class VersionEdit {
public:
VersionEdit() { Clear(); }
~VersionEdit() { }
void Clear();
void SetComparatorName(const Slice& name) {
has_comparator_ = true;
comparator_ = name.ToString();
}
void SetLogNumber(uint64_t num) {
has_log_number_ = true;
log_number_ = num;
}
void SetPrevLogNumber(uint64_t num) {
has_prev_log_number_ = true;
prev_log_number_ = num;
}
void SetNextFile(uint64_t num) {
has_next_file_number_ = true;
next_file_number_ = num;
}
void SetLastSequence(SequenceNumber seq) {
has_last_sequence_ = true;
last_sequence_ = seq;
}
void SetMaxColumnFamily(uint32_t max_column_family) {
has_max_column_family_ = true;
max_column_family_ = max_column_family;
}
void SetMinLogNumberToKeep(uint64_t num) {
has_min_log_number_to_keep_ = true;
min_log_number_to_keep_ = num;
}
bool has_log_number() { return has_log_number_; }
uint64_t log_number() { return log_number_; }
// Add the specified file at the specified number.
// REQUIRES: This version has not been saved (see VersionSet::SaveTo)
// REQUIRES: "smallest" and "largest" are smallest and largest keys in file
void AddFile(int level, uint64_t file, uint32_t file_path_id,
uint64_t file_size, const InternalKey& smallest,
const InternalKey& largest, const SequenceNumber& smallest_seqno,
const SequenceNumber& largest_seqno,
bool marked_for_compaction) {
assert(smallest_seqno <= largest_seqno);
FileMetaData f;
f.fd = FileDescriptor(file, file_path_id, file_size);
f.smallest = smallest;
f.largest = largest;
f.smallest_seqno = smallest_seqno;
f.largest_seqno = largest_seqno;
f.marked_for_compaction = marked_for_compaction;
new_files_.emplace_back(level, std::move(f));
}
void AddFile(int level, const FileMetaData& f) {
assert(f.smallest_seqno <= f.largest_seqno);
new_files_.emplace_back(level, f);
}
// Delete the specified "file" from the specified "level".
void DeleteFile(int level, uint64_t file) {
deleted_files_.insert({level, file});
}
// Number of edits
size_t NumEntries() { return new_files_.size() + deleted_files_.size(); }
bool IsColumnFamilyManipulation() {
return is_column_family_add_ || is_column_family_drop_;
}
void SetColumnFamily(uint32_t column_family_id) {
column_family_ = column_family_id;
}
// set column family ID by calling SetColumnFamily()
void AddColumnFamily(const std::string& name) {
assert(!is_column_family_drop_);
assert(!is_column_family_add_);
assert(NumEntries() == 0);
is_column_family_add_ = true;
column_family_name_ = name;
}
// set column family ID by calling SetColumnFamily()
void DropColumnFamily() {
assert(!is_column_family_drop_);
assert(!is_column_family_add_);
assert(NumEntries() == 0);
is_column_family_drop_ = true;
}
// return true on success.
bool EncodeTo(std::string* dst) const;
Status DecodeFrom(const Slice& src);
const char* DecodeNewFile4From(Slice* input);
typedef std::set<std::pair<int, uint64_t>> DeletedFileSet;
const DeletedFileSet& GetDeletedFiles() { return deleted_files_; }
const std::vector<std::pair<int, FileMetaData>>& GetNewFiles() {
return new_files_;
}
std::string DebugString(bool hex_key = false) const;
std::string DebugJSON(int edit_num, bool hex_key = false) const;
private:
friend class VersionSet;
friend class Version;
bool GetLevel(Slice* input, int* level, const char** msg);
int max_level_;
std::string comparator_;
uint64_t log_number_;
uint64_t prev_log_number_;
uint64_t next_file_number_;
uint32_t max_column_family_;
// The most recent WAL log number that is deleted
uint64_t min_log_number_to_keep_;
SequenceNumber last_sequence_;
bool has_comparator_;
bool has_log_number_;
bool has_prev_log_number_;
bool has_next_file_number_;
bool has_last_sequence_;
bool has_max_column_family_;
bool has_min_log_number_to_keep_;
DeletedFileSet deleted_files_;
std::vector<std::pair<int, FileMetaData>> new_files_;
// Each version edit record should have column_family_id set
// If it's not set, it is default (0)
uint32_t column_family_;
// a version edit can be either column_family add or
// column_family drop. If it's column family add,
// it also includes column family name.
bool is_column_family_drop_;
bool is_column_family_add_;
std::string column_family_name_;
};
} // namespace rocksdb
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