rocksdb/db/compaction.cc
PeifengSi 43defe9872 Correct the code comment in Compaction::KeyNotExistsBeyondOutputLevel (#4902)
Summary:
Even one key falls in a file's range, we can not infer it definitely exists in this file.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4902

Differential Revision: D13795018

Pulled By: siying

fbshipit-source-id: 590956f727e9440fcdee55ad9541ace934c64914
2019-01-23 18:00:56 -08:00

565 lines
19 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).
//
// 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.
#include "db/compaction.h"
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
#include <vector>
#include "db/column_family.h"
#include "rocksdb/compaction_filter.h"
#include "util/string_util.h"
#include "util/sync_point.h"
namespace rocksdb {
const uint64_t kRangeTombstoneSentinel =
PackSequenceAndType(kMaxSequenceNumber, kTypeRangeDeletion);
int sstableKeyCompare(const Comparator* user_cmp, const InternalKey& a,
const InternalKey& b) {
auto c = user_cmp->Compare(a.user_key(), b.user_key());
if (c != 0) {
return c;
}
auto a_footer = ExtractInternalKeyFooter(a.Encode());
auto b_footer = ExtractInternalKeyFooter(b.Encode());
if (a_footer == kRangeTombstoneSentinel) {
if (b_footer != kRangeTombstoneSentinel) {
return -1;
}
} else if (b_footer == kRangeTombstoneSentinel) {
return 1;
}
return 0;
}
int sstableKeyCompare(const Comparator* user_cmp, const InternalKey* a,
const InternalKey& b) {
if (a == nullptr) {
return -1;
}
return sstableKeyCompare(user_cmp, *a, b);
}
int sstableKeyCompare(const Comparator* user_cmp, const InternalKey& a,
const InternalKey* b) {
if (b == nullptr) {
return -1;
}
return sstableKeyCompare(user_cmp, a, *b);
}
uint64_t TotalFileSize(const std::vector<FileMetaData*>& files) {
uint64_t sum = 0;
for (size_t i = 0; i < files.size() && files[i]; i++) {
sum += files[i]->fd.GetFileSize();
}
return sum;
}
void Compaction::SetInputVersion(Version* _input_version) {
input_version_ = _input_version;
cfd_ = input_version_->cfd();
cfd_->Ref();
input_version_->Ref();
edit_.SetColumnFamily(cfd_->GetID());
}
void Compaction::GetBoundaryKeys(
VersionStorageInfo* vstorage,
const std::vector<CompactionInputFiles>& inputs, Slice* smallest_user_key,
Slice* largest_user_key) {
bool initialized = false;
const Comparator* ucmp = vstorage->InternalComparator()->user_comparator();
for (size_t i = 0; i < inputs.size(); ++i) {
if (inputs[i].files.empty()) {
continue;
}
if (inputs[i].level == 0) {
// we need to consider all files on level 0
for (const auto* f : inputs[i].files) {
const Slice& start_user_key = f->smallest.user_key();
if (!initialized ||
ucmp->Compare(start_user_key, *smallest_user_key) < 0) {
*smallest_user_key = start_user_key;
}
const Slice& end_user_key = f->largest.user_key();
if (!initialized ||
ucmp->Compare(end_user_key, *largest_user_key) > 0) {
*largest_user_key = end_user_key;
}
initialized = true;
}
} else {
// we only need to consider the first and last file
const Slice& start_user_key = inputs[i].files[0]->smallest.user_key();
if (!initialized ||
ucmp->Compare(start_user_key, *smallest_user_key) < 0) {
*smallest_user_key = start_user_key;
}
const Slice& end_user_key = inputs[i].files.back()->largest.user_key();
if (!initialized || ucmp->Compare(end_user_key, *largest_user_key) > 0) {
*largest_user_key = end_user_key;
}
initialized = true;
}
}
}
std::vector<CompactionInputFiles> Compaction::PopulateWithAtomicBoundaries(
VersionStorageInfo* vstorage, std::vector<CompactionInputFiles> inputs) {
const Comparator* ucmp = vstorage->InternalComparator()->user_comparator();
for (size_t i = 0; i < inputs.size(); i++) {
if (inputs[i].level == 0 || inputs[i].files.empty()) {
continue;
}
inputs[i].atomic_compaction_unit_boundaries.reserve(inputs[i].files.size());
AtomicCompactionUnitBoundary cur_boundary;
size_t first_atomic_idx = 0;
auto add_unit_boundary = [&](size_t to) {
if (first_atomic_idx == to) return;
for (size_t k = first_atomic_idx; k < to; k++) {
inputs[i].atomic_compaction_unit_boundaries.push_back(cur_boundary);
}
first_atomic_idx = to;
};
for (size_t j = 0; j < inputs[i].files.size(); j++) {
const auto* f = inputs[i].files[j];
if (j == 0) {
// First file in a level.
cur_boundary.smallest = &f->smallest;
cur_boundary.largest = &f->largest;
} else if (sstableKeyCompare(ucmp, *cur_boundary.largest, f->smallest) ==
0) {
// SSTs overlap but the end key of the previous file was not
// artificially extended by a range tombstone. Extend the current
// boundary.
cur_boundary.largest = &f->largest;
} else {
// Atomic compaction unit has ended.
add_unit_boundary(j);
cur_boundary.smallest = &f->smallest;
cur_boundary.largest = &f->largest;
}
}
add_unit_boundary(inputs[i].files.size());
assert(inputs[i].files.size() ==
inputs[i].atomic_compaction_unit_boundaries.size());
}
return inputs;
}
// helper function to determine if compaction is creating files at the
// bottommost level
bool Compaction::IsBottommostLevel(
int output_level, VersionStorageInfo* vstorage,
const std::vector<CompactionInputFiles>& inputs) {
int output_l0_idx;
if (output_level == 0) {
output_l0_idx = 0;
for (const auto* file : vstorage->LevelFiles(0)) {
if (inputs[0].files.back() == file) {
break;
}
++output_l0_idx;
}
assert(static_cast<size_t>(output_l0_idx) < vstorage->LevelFiles(0).size());
} else {
output_l0_idx = -1;
}
Slice smallest_key, largest_key;
GetBoundaryKeys(vstorage, inputs, &smallest_key, &largest_key);
return !vstorage->RangeMightExistAfterSortedRun(smallest_key, largest_key,
output_level, output_l0_idx);
}
// test function to validate the functionality of IsBottommostLevel()
// function -- determines if compaction with inputs and storage is bottommost
bool Compaction::TEST_IsBottommostLevel(
int output_level, VersionStorageInfo* vstorage,
const std::vector<CompactionInputFiles>& inputs) {
return IsBottommostLevel(output_level, vstorage, inputs);
}
bool Compaction::IsFullCompaction(
VersionStorageInfo* vstorage,
const std::vector<CompactionInputFiles>& inputs) {
size_t num_files_in_compaction = 0;
size_t total_num_files = 0;
for (int l = 0; l < vstorage->num_levels(); l++) {
total_num_files += vstorage->NumLevelFiles(l);
}
for (size_t i = 0; i < inputs.size(); i++) {
num_files_in_compaction += inputs[i].size();
}
return num_files_in_compaction == total_num_files;
}
Compaction::Compaction(VersionStorageInfo* vstorage,
const ImmutableCFOptions& _immutable_cf_options,
const MutableCFOptions& _mutable_cf_options,
std::vector<CompactionInputFiles> _inputs,
int _output_level, uint64_t _target_file_size,
uint64_t _max_compaction_bytes, uint32_t _output_path_id,
CompressionType _compression,
CompressionOptions _compression_opts,
uint32_t _max_subcompactions,
std::vector<FileMetaData*> _grandparents,
bool _manual_compaction, double _score,
bool _deletion_compaction,
CompactionReason _compaction_reason)
: input_vstorage_(vstorage),
start_level_(_inputs[0].level),
output_level_(_output_level),
max_output_file_size_(_target_file_size),
max_compaction_bytes_(_max_compaction_bytes),
max_subcompactions_(_max_subcompactions),
immutable_cf_options_(_immutable_cf_options),
mutable_cf_options_(_mutable_cf_options),
input_version_(nullptr),
number_levels_(vstorage->num_levels()),
cfd_(nullptr),
output_path_id_(_output_path_id),
output_compression_(_compression),
output_compression_opts_(_compression_opts),
deletion_compaction_(_deletion_compaction),
inputs_(PopulateWithAtomicBoundaries(vstorage, std::move(_inputs))),
grandparents_(std::move(_grandparents)),
score_(_score),
bottommost_level_(IsBottommostLevel(output_level_, vstorage, inputs_)),
is_full_compaction_(IsFullCompaction(vstorage, inputs_)),
is_manual_compaction_(_manual_compaction),
is_trivial_move_(false),
compaction_reason_(_compaction_reason) {
MarkFilesBeingCompacted(true);
if (is_manual_compaction_) {
compaction_reason_ = CompactionReason::kManualCompaction;
}
if (max_subcompactions_ == 0) {
max_subcompactions_ = immutable_cf_options_.max_subcompactions;
}
#ifndef NDEBUG
for (size_t i = 1; i < inputs_.size(); ++i) {
assert(inputs_[i].level > inputs_[i - 1].level);
}
#endif
// setup input_levels_
{
input_levels_.resize(num_input_levels());
for (size_t which = 0; which < num_input_levels(); which++) {
DoGenerateLevelFilesBrief(&input_levels_[which], inputs_[which].files,
&arena_);
}
}
GetBoundaryKeys(vstorage, inputs_, &smallest_user_key_, &largest_user_key_);
}
Compaction::~Compaction() {
if (input_version_ != nullptr) {
input_version_->Unref();
}
if (cfd_ != nullptr) {
if (cfd_->Unref()) {
delete cfd_;
}
}
}
bool Compaction::InputCompressionMatchesOutput() const {
int base_level = input_vstorage_->base_level();
bool matches = (GetCompressionType(immutable_cf_options_, input_vstorage_,
mutable_cf_options_, start_level_,
base_level) == output_compression_);
if (matches) {
TEST_SYNC_POINT("Compaction::InputCompressionMatchesOutput:Matches");
return true;
}
TEST_SYNC_POINT("Compaction::InputCompressionMatchesOutput:DidntMatch");
return matches;
}
bool Compaction::IsTrivialMove() const {
// Avoid a move if there is lots of overlapping grandparent data.
// Otherwise, the move could create a parent file that will require
// a very expensive merge later on.
// If start_level_== output_level_, the purpose is to force compaction
// filter to be applied to that level, and thus cannot be a trivial move.
// Check if start level have files with overlapping ranges
if (start_level_ == 0 && input_vstorage_->level0_non_overlapping() == false) {
// We cannot move files from L0 to L1 if the files are overlapping
return false;
}
if (is_manual_compaction_ &&
(immutable_cf_options_.compaction_filter != nullptr ||
immutable_cf_options_.compaction_filter_factory != nullptr)) {
// This is a manual compaction and we have a compaction filter that should
// be executed, we cannot do a trivial move
return false;
}
// Used in universal compaction, where trivial move can be done if the
// input files are non overlapping
if ((mutable_cf_options_.compaction_options_universal.allow_trivial_move) &&
(output_level_ != 0)) {
return is_trivial_move_;
}
if (!(start_level_ != output_level_ && num_input_levels() == 1 &&
input(0, 0)->fd.GetPathId() == output_path_id() &&
InputCompressionMatchesOutput())) {
return false;
}
// assert inputs_.size() == 1
for (const auto& file : inputs_.front().files) {
std::vector<FileMetaData*> file_grand_parents;
if (output_level_ + 1 >= number_levels_) {
continue;
}
input_vstorage_->GetOverlappingInputs(output_level_ + 1, &file->smallest,
&file->largest, &file_grand_parents);
const auto compaction_size =
file->fd.GetFileSize() + TotalFileSize(file_grand_parents);
if (compaction_size > max_compaction_bytes_) {
return false;
}
}
return true;
}
void Compaction::AddInputDeletions(VersionEdit* out_edit) {
for (size_t which = 0; which < num_input_levels(); which++) {
for (size_t i = 0; i < inputs_[which].size(); i++) {
out_edit->DeleteFile(level(which), inputs_[which][i]->fd.GetNumber());
}
}
}
bool Compaction::KeyNotExistsBeyondOutputLevel(
const Slice& user_key, std::vector<size_t>* level_ptrs) const {
assert(input_version_ != nullptr);
assert(level_ptrs != nullptr);
assert(level_ptrs->size() == static_cast<size_t>(number_levels_));
if (bottommost_level_) {
return true;
} else if (output_level_ != 0 &&
cfd_->ioptions()->compaction_style == kCompactionStyleLevel) {
// Maybe use binary search to find right entry instead of linear search?
const Comparator* user_cmp = cfd_->user_comparator();
for (int lvl = output_level_ + 1; lvl < number_levels_; lvl++) {
const std::vector<FileMetaData*>& files =
input_vstorage_->LevelFiles(lvl);
for (; level_ptrs->at(lvl) < files.size(); level_ptrs->at(lvl)++) {
auto* f = files[level_ptrs->at(lvl)];
if (user_cmp->Compare(user_key, f->largest.user_key()) <= 0) {
// We've advanced far enough
if (user_cmp->Compare(user_key, f->smallest.user_key()) >= 0) {
// Key falls in this file's range, so it may
// exist beyond output level
return false;
}
break;
}
}
}
return true;
}
return false;
}
// Mark (or clear) each file that is being compacted
void Compaction::MarkFilesBeingCompacted(bool mark_as_compacted) {
for (size_t i = 0; i < num_input_levels(); i++) {
for (size_t j = 0; j < inputs_[i].size(); j++) {
assert(mark_as_compacted ? !inputs_[i][j]->being_compacted
: inputs_[i][j]->being_compacted);
inputs_[i][j]->being_compacted = mark_as_compacted;
}
}
}
// Sample output:
// If compacting 3 L0 files, 2 L3 files and 1 L4 file, and outputting to L5,
// print: "3@0 + 2@3 + 1@4 files to L5"
const char* Compaction::InputLevelSummary(
InputLevelSummaryBuffer* scratch) const {
int len = 0;
bool is_first = true;
for (auto& input_level : inputs_) {
if (input_level.empty()) {
continue;
}
if (!is_first) {
len +=
snprintf(scratch->buffer + len, sizeof(scratch->buffer) - len, " + ");
len = std::min(len, static_cast<int>(sizeof(scratch->buffer)));
} else {
is_first = false;
}
len += snprintf(scratch->buffer + len, sizeof(scratch->buffer) - len,
"%" ROCKSDB_PRIszt "@%d", input_level.size(),
input_level.level);
len = std::min(len, static_cast<int>(sizeof(scratch->buffer)));
}
snprintf(scratch->buffer + len, sizeof(scratch->buffer) - len,
" files to L%d", output_level());
return scratch->buffer;
}
uint64_t Compaction::CalculateTotalInputSize() const {
uint64_t size = 0;
for (auto& input_level : inputs_) {
for (auto f : input_level.files) {
size += f->fd.GetFileSize();
}
}
return size;
}
void Compaction::ReleaseCompactionFiles(Status status) {
MarkFilesBeingCompacted(false);
cfd_->compaction_picker()->ReleaseCompactionFiles(this, status);
}
void Compaction::ResetNextCompactionIndex() {
assert(input_version_ != nullptr);
input_vstorage_->ResetNextCompactionIndex(start_level_);
}
namespace {
int InputSummary(const std::vector<FileMetaData*>& files, char* output,
int len) {
*output = '\0';
int write = 0;
for (size_t i = 0; i < files.size(); i++) {
int sz = len - write;
int ret;
char sztxt[16];
AppendHumanBytes(files.at(i)->fd.GetFileSize(), sztxt, 16);
ret = snprintf(output + write, sz, "%" PRIu64 "(%s) ",
files.at(i)->fd.GetNumber(), sztxt);
if (ret < 0 || ret >= sz) break;
write += ret;
}
// if files.size() is non-zero, overwrite the last space
return write - !!files.size();
}
} // namespace
void Compaction::Summary(char* output, int len) {
int write =
snprintf(output, len, "Base version %" PRIu64 " Base level %d, inputs: [",
input_version_->GetVersionNumber(), start_level_);
if (write < 0 || write >= len) {
return;
}
for (size_t level_iter = 0; level_iter < num_input_levels(); ++level_iter) {
if (level_iter > 0) {
write += snprintf(output + write, len - write, "], [");
if (write < 0 || write >= len) {
return;
}
}
write +=
InputSummary(inputs_[level_iter].files, output + write, len - write);
if (write < 0 || write >= len) {
return;
}
}
snprintf(output + write, len - write, "]");
}
uint64_t Compaction::OutputFilePreallocationSize() const {
uint64_t preallocation_size = 0;
for (const auto& level_files : inputs_) {
for (const auto& file : level_files.files) {
preallocation_size += file->fd.GetFileSize();
}
}
if (max_output_file_size_ != port::kMaxUint64 &&
(immutable_cf_options_.compaction_style == kCompactionStyleLevel ||
output_level() > 0)) {
preallocation_size = std::min(max_output_file_size_, preallocation_size);
}
// Over-estimate slightly so we don't end up just barely crossing
// the threshold
// No point to prellocate more than 1GB.
return std::min(uint64_t{1073741824},
preallocation_size + (preallocation_size / 10));
}
std::unique_ptr<CompactionFilter> Compaction::CreateCompactionFilter() const {
if (!cfd_->ioptions()->compaction_filter_factory) {
return nullptr;
}
CompactionFilter::Context context;
context.is_full_compaction = is_full_compaction_;
context.is_manual_compaction = is_manual_compaction_;
context.column_family_id = cfd_->GetID();
return cfd_->ioptions()->compaction_filter_factory->CreateCompactionFilter(
context);
}
bool Compaction::IsOutputLevelEmpty() const {
return inputs_.back().level != output_level_ || inputs_.back().empty();
}
bool Compaction::ShouldFormSubcompactions() const {
if (max_subcompactions_ <= 1 || cfd_ == nullptr) {
return false;
}
if (cfd_->ioptions()->compaction_style == kCompactionStyleLevel) {
return (start_level_ == 0 || is_manual_compaction_) && output_level_ > 0 &&
!IsOutputLevelEmpty();
} else if (cfd_->ioptions()->compaction_style == kCompactionStyleUniversal) {
return number_levels_ > 1 && output_level_ > 0;
} else {
return false;
}
}
uint64_t Compaction::MaxInputFileCreationTime() const {
uint64_t max_creation_time = 0;
for (const auto& file : inputs_[0].files) {
if (file->fd.table_reader != nullptr &&
file->fd.table_reader->GetTableProperties() != nullptr) {
uint64_t creation_time =
file->fd.table_reader->GetTableProperties()->creation_time;
max_creation_time = std::max(max_creation_time, creation_time);
}
}
return max_creation_time;
}
int Compaction::GetInputBaseLevel() const {
return input_vstorage_->base_level();
}
} // namespace rocksdb