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Introduce FullMergeV2 (eliminate memcpy from merge operators)

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Summary:
This diff update the code to pin the merge operator operands while the merge operation is done, so that we can eliminate the memcpy cost, to do that we need a new public API for FullMerge that replace the std::deque<std::string> with std::vector<Slice>

This diff is stacked on top of D56493 and D56511

In this diff we
- Update FullMergeV2 arguments to be encapsulated in MergeOperationInput and MergeOperationOutput which will make it easier to add new arguments in the future
- Replace std::deque<std::string> with std::vector<Slice> to pass operands
- Replace MergeContext std::deque with std::vector (based on a simple benchmark I ran https://gist.github.com/IslamAbdelRahman/78fc86c9ab9f52b1df791e58943fb187)
- Allow FullMergeV2 output to be an existing operand

```
[Everything in Memtable | 10K operands | 10 KB each | 1 operand per key]

DEBUG_LEVEL=0 make db_bench -j64 && ./db_bench --benchmarks="mergerandom,readseq,readseq,readseq,readseq,readseq" --merge_operator="max" --merge_keys=10000 --num=10000 --disable_auto_compactions --value_size=10240 --write_buffer_size=1000000000

[FullMergeV2]
readseq      :       0.607 micros/op 1648235 ops/sec; 16121.2 MB/s
readseq      :       0.478 micros/op 2091546 ops/sec; 20457.2 MB/s
readseq      :       0.252 micros/op 3972081 ops/sec; 38850.5 MB/s
readseq      :       0.237 micros/op 4218328 ops/sec; 41259.0 MB/s
readseq      :       0.247 micros/op 4043927 ops/sec; 39553.2 MB/s

[master]
readseq      :       3.935 micros/op 254140 ops/sec; 2485.7 MB/s
readseq      :       3.722 micros/op 268657 ops/sec; 2627.7 MB/s
readseq      :       3.149 micros/op 317605 ops/sec; 3106.5 MB/s
readseq      :       3.125 micros/op 320024 ops/sec; 3130.1 MB/s
readseq      :       4.075 micros/op 245374 ops/sec; 2400.0 MB/s
```

```
[Everything in Memtable | 10K operands | 10 KB each | 10 operand per key]

DEBUG_LEVEL=0 make db_bench -j64 && ./db_bench --benchmarks="mergerandom,readseq,readseq,readseq,readseq,readseq" --merge_operator="max" --merge_keys=1000 --num=10000 --disable_auto_compactions --value_size=10240 --write_buffer_size=1000000000

[FullMergeV2]
readseq      :       3.472 micros/op 288018 ops/sec; 2817.1 MB/s
readseq      :       2.304 micros/op 434027 ops/sec; 4245.2 MB/s
readseq      :       1.163 micros/op 859845 ops/sec; 8410.0 MB/s
readseq      :       1.192 micros/op 838926 ops/sec; 8205.4 MB/s
readseq      :       1.250 micros/op 800000 ops/sec; 7824.7 MB/s

[master]
readseq      :      24.025 micros/op 41623 ops/sec;  407.1 MB/s
readseq      :      18.489 micros/op 54086 ops/sec;  529.0 MB/s
readseq      :      18.693 micros/op 53495 ops/sec;  523.2 MB/s
readseq      :      23.621 micros/op 42335 ops/sec;  414.1 MB/s
readseq      :      18.775 micros/op 53262 ops/sec;  521.0 MB/s

```

```
[Everything in Block cache | 10K operands | 10 KB each | 1 operand per key]

[FullMergeV2]
$ DEBUG_LEVEL=0 make db_bench -j64 && ./db_bench --benchmarks="readseq,readseq,readseq,readseq,readseq" --merge_operator="max" --num=100000 --db="/dev/shm/merge-random-10K-10KB" --cache_size=1000000000 --use_existing_db --disable_auto_compactions
readseq      :      14.741 micros/op 67837 ops/sec;  663.5 MB/s
readseq      :       1.029 micros/op 971446 ops/sec; 9501.6 MB/s
readseq      :       0.974 micros/op 1026229 ops/sec; 10037.4 MB/s
readseq      :       0.965 micros/op 1036080 ops/sec; 10133.8 MB/s
readseq      :       0.943 micros/op 1060657 ops/sec; 10374.2 MB/s

[master]
readseq      :      16.735 micros/op 59755 ops/sec;  584.5 MB/s
readseq      :       3.029 micros/op 330151 ops/sec; 3229.2 MB/s
readseq      :       3.136 micros/op 318883 ops/sec; 3119.0 MB/s
readseq      :       3.065 micros/op 326245 ops/sec; 3191.0 MB/s
readseq      :       3.014 micros/op 331813 ops/sec; 3245.4 MB/s
```

```
[Everything in Block cache | 10K operands | 10 KB each | 10 operand per key]

DEBUG_LEVEL=0 make db_bench -j64 && ./db_bench --benchmarks="readseq,readseq,readseq,readseq,readseq" --merge_operator="max" --num=100000 --db="/dev/shm/merge-random-10-operands-10K-10KB" --cache_size=1000000000 --use_existing_db --disable_auto_compactions

[FullMergeV2]
readseq      :      24.325 micros/op 41109 ops/sec;  402.1 MB/s
readseq      :       1.470 micros/op 680272 ops/sec; 6653.7 MB/s
readseq      :       1.231 micros/op 812347 ops/sec; 7945.5 MB/s
readseq      :       1.091 micros/op 916590 ops/sec; 8965.1 MB/s
readseq      :       1.109 micros/op 901713 ops/sec; 8819.6 MB/s

[master]
readseq      :      27.257 micros/op 36687 ops/sec;  358.8 MB/s
readseq      :       4.443 micros/op 225073 ops/sec; 2201.4 MB/s
readseq      :       5.830 micros/op 171526 ops/sec; 1677.7 MB/s
readseq      :       4.173 micros/op 239635 ops/sec; 2343.8 MB/s
readseq      :       4.150 micros/op 240963 ops/sec; 2356.8 MB/s
```

Test Plan: COMPILE_WITH_ASAN=1 make check -j64

Reviewers: yhchiang, andrewkr, sdong

Reviewed By: sdong

Subscribers: lovro, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D57075
This commit is contained in:
Islam AbdelRahman 2016-07-20 09:49:03 -07:00
parent e70ba4e40e
commit 68a8e6b8fa
38 changed files with 814 additions and 237 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
db/c.cc
View File

@ -269,33 +269,31 @@ struct rocksdb_mergeoperator_t : public MergeOperator {
virtual const char* Name() const override { return (*name_)(state_); } virtual const char* Name() const override { return (*name_)(state_); }
virtual bool FullMerge(const Slice& key, const Slice* existing_value, virtual bool FullMergeV2(const MergeOperationInput& merge_in,
const std::deque<std::string>& operand_list, MergeOperationOutput* merge_out) const override {
std::string* new_value, size_t n = merge_in.operand_list.size();
Logger* logger) const override {
size_t n = operand_list.size();
std::vector<const char*> operand_pointers(n); std::vector<const char*> operand_pointers(n);
std::vector<size_t> operand_sizes(n); std::vector<size_t> operand_sizes(n);
for (size_t i = 0; i < n; i++) { for (size_t i = 0; i < n; i++) {
Slice operand(operand_list[i]); Slice operand(merge_in.operand_list[i]);
operand_pointers[i] = operand.data(); operand_pointers[i] = operand.data();
operand_sizes[i] = operand.size(); operand_sizes[i] = operand.size();
} }
const char* existing_value_data = nullptr; const char* existing_value_data = nullptr;
size_t existing_value_len = 0; size_t existing_value_len = 0;
if (existing_value != nullptr) { if (merge_in.existing_value != nullptr) {
existing_value_data = existing_value->data(); existing_value_data = merge_in.existing_value->data();
existing_value_len = existing_value->size(); existing_value_len = merge_in.existing_value->size();
} }
unsigned char success; unsigned char success;
size_t new_value_len; size_t new_value_len;
char* tmp_new_value = (*full_merge_)( char* tmp_new_value = (*full_merge_)(
state_, key.data(), key.size(), existing_value_data, existing_value_len, state_, merge_in.key.data(), merge_in.key.size(), existing_value_data,
&operand_pointers[0], &operand_sizes[0], static_cast<int>(n), &success, existing_value_len, &operand_pointers[0], &operand_sizes[0],
&new_value_len); static_cast<int>(n), &success, &new_value_len);
new_value->assign(tmp_new_value, new_value_len); merge_out->new_value.assign(tmp_new_value, new_value_len);
if (delete_value_ != nullptr) { if (delete_value_ != nullptr) {
(*delete_value_)(state_, tmp_new_value, new_value_len); (*delete_value_)(state_, tmp_new_value, new_value_len);

10
db/compaction_iterator.cc
View File

@ -49,6 +49,12 @@ CompactionIterator::CompactionIterator(
} else { } else {
ignore_snapshots_ = false; ignore_snapshots_ = false;
} }
input_->SetPinnedItersMgr(&pinned_iters_mgr_);
}
CompactionIterator::~CompactionIterator() {
// input_ Iteartor lifetime is longer than pinned_iters_mgr_ lifetime
input_->SetPinnedItersMgr(nullptr);
} }
void CompactionIterator::ResetRecordCounts() { void CompactionIterator::ResetRecordCounts() {
@ -83,6 +89,8 @@ void CompactionIterator::Next() {
ikey_.user_key = current_key_.GetUserKey(); ikey_.user_key = current_key_.GetUserKey();
valid_ = true; valid_ = true;
} else { } else {
// We consumed all pinned merge operands, release pinned iterators
pinned_iters_mgr_.ReleasePinnedIterators();
// MergeHelper moves the iterator to the first record after the merged // MergeHelper moves the iterator to the first record after the merged
// records, so even though we reached the end of the merge output, we do // records, so even though we reached the end of the merge output, we do
// not want to advance the iterator. // not want to advance the iterator.
@ -368,6 +376,7 @@ void CompactionIterator::NextFromInput() {
return; return;
} }
pinned_iters_mgr_.StartPinning();
// We know the merge type entry is not hidden, otherwise we would // We know the merge type entry is not hidden, otherwise we would
// have hit (A) // have hit (A)
// We encapsulate the merge related state machine in a different // We encapsulate the merge related state machine in a different
@ -395,6 +404,7 @@ void CompactionIterator::NextFromInput() {
// batch consumed by the merge operator should not shadow any keys // batch consumed by the merge operator should not shadow any keys
// coming after the merges // coming after the merges
has_current_user_key_ = false; has_current_user_key_ = false;
pinned_iters_mgr_.ReleasePinnedIterators();
} }
} else { } else {
valid_ = true; valid_ = true;

6
db/compaction_iterator.h
View File

@ -13,6 +13,7 @@
#include "db/compaction.h" #include "db/compaction.h"
#include "db/merge_helper.h" #include "db/merge_helper.h"
#include "db/pinned_iterators_manager.h"
#include "rocksdb/compaction_filter.h" #include "rocksdb/compaction_filter.h"
#include "util/log_buffer.h" #include "util/log_buffer.h"
@ -46,6 +47,8 @@ class CompactionIterator {
const CompactionFilter* compaction_filter = nullptr, const CompactionFilter* compaction_filter = nullptr,
LogBuffer* log_buffer = nullptr); LogBuffer* log_buffer = nullptr);
~CompactionIterator();
void ResetRecordCounts(); void ResetRecordCounts();
// Seek to the beginning of the compaction iterator output. // Seek to the beginning of the compaction iterator output.
@ -136,6 +139,9 @@ class CompactionIterator {
bool clear_and_output_next_key_ = false; bool clear_and_output_next_key_ = false;
MergeOutputIterator merge_out_iter_; MergeOutputIterator merge_out_iter_;
// PinnedIteratorsManager used to pin input_ Iterator blocks while reading
// merge operands and then releasing them after consuming them.
PinnedIteratorsManager pinned_iters_mgr_;
std::string compaction_filter_value_; std::string compaction_filter_value_;
// "level_ptrs" holds indices that remember which file of an associated // "level_ptrs" holds indices that remember which file of an associated
// level we were last checking during the last call to compaction-> // level we were last checking during the last call to compaction->

50
db/db_iter.cc
View File

@ -155,7 +155,9 @@ class DBIter: public Iterator {
virtual Slice value() const override { virtual Slice value() const override {
assert(valid_); assert(valid_);
if (current_entry_is_merged_) { if (current_entry_is_merged_) {
return saved_value_; // If pinned_value_ is set then the result of merge operator is one of
// the merge operands and we should return it.
return pinned_value_.data() ? pinned_value_ : saved_value_;
} else if (direction_ == kReverse) { } else if (direction_ == kReverse) {
return pinned_value_; return pinned_value_;
} else { } else {
@ -286,9 +288,9 @@ inline bool DBIter::ParseKey(ParsedInternalKey* ikey) {
void DBIter::Next() { void DBIter::Next() {
assert(valid_); assert(valid_);
// Release temporarily pinned blocks from last operation
ReleaseTempPinnedData();
if (direction_ == kReverse) { if (direction_ == kReverse) {
// We only pin blocks when doing kReverse
ReleaseTempPinnedData();
FindNextUserKey(); FindNextUserKey();
direction_ = kForward; direction_ = kForward;
if (!iter_->Valid()) { if (!iter_->Valid()) {
@ -433,9 +435,12 @@ void DBIter::MergeValuesNewToOld() {
return; return;
} }
// Temporarily pin the blocks that hold merge operands
TempPinData();
merge_context_.Clear(); merge_context_.Clear();
// Start the merge process by pushing the first operand // Start the merge process by pushing the first operand
merge_context_.PushOperand(iter_->value()); merge_context_.PushOperand(iter_->value(),
iter_->IsValuePinned() /* operand_pinned */);
ParsedInternalKey ikey; ParsedInternalKey ikey;
for (iter_->Next(); iter_->Valid(); iter_->Next()) { for (iter_->Next(); iter_->Valid(); iter_->Next()) {
@ -459,15 +464,15 @@ void DBIter::MergeValuesNewToOld() {
const Slice val = iter_->value(); const Slice val = iter_->value();
MergeHelper::TimedFullMerge(merge_operator_, ikey.user_key, &val, MergeHelper::TimedFullMerge(merge_operator_, ikey.user_key, &val,
merge_context_.GetOperands(), &saved_value_, merge_context_.GetOperands(), &saved_value_,
logger_, statistics_, env_); logger_, statistics_, env_, &pinned_value_);
// iter_ is positioned after put // iter_ is positioned after put
iter_->Next(); iter_->Next();
return; return;
} else if (kTypeMerge == ikey.type) { } else if (kTypeMerge == ikey.type) {
// hit a merge, add the value as an operand and run associative merge. // hit a merge, add the value as an operand and run associative merge.
// when complete, add result to operands and continue. // when complete, add result to operands and continue.
const Slice& val = iter_->value(); merge_context_.PushOperand(iter_->value(),
merge_context_.PushOperand(val); iter_->IsValuePinned() /* operand_pinned */);
} else { } else {
assert(false); assert(false);
} }
@ -479,15 +484,15 @@ void DBIter::MergeValuesNewToOld() {
// client can differentiate this scenario and do things accordingly. // client can differentiate this scenario and do things accordingly.
MergeHelper::TimedFullMerge(merge_operator_, saved_key_.GetKey(), nullptr, MergeHelper::TimedFullMerge(merge_operator_, saved_key_.GetKey(), nullptr,
merge_context_.GetOperands(), &saved_value_, merge_context_.GetOperands(), &saved_value_,
logger_, statistics_, env_); logger_, statistics_, env_, &pinned_value_);
} }
void DBIter::Prev() { void DBIter::Prev() {
assert(valid_); assert(valid_);
ReleaseTempPinnedData();
if (direction_ == kForward) { if (direction_ == kForward) {
ReverseToBackward(); ReverseToBackward();
} }
ReleaseTempPinnedData();
PrevInternal(); PrevInternal();
if (statistics_ != nullptr) { if (statistics_ != nullptr) {
local_stats_.prev_count_++; local_stats_.prev_count_++;
@ -580,6 +585,9 @@ bool DBIter::FindValueForCurrentKey() {
ParsedInternalKey ikey; ParsedInternalKey ikey;
FindParseableKey(&ikey, kReverse); FindParseableKey(&ikey, kReverse);
// Temporarily pin blocks that hold (merge operands / the value)
ReleaseTempPinnedData();
TempPinData();
size_t num_skipped = 0; size_t num_skipped = 0;
while (iter_->Valid() && ikey.sequence <= sequence_ && while (iter_->Valid() && ikey.sequence <= sequence_ &&
user_comparator_->Equal(ikey.user_key, saved_key_.GetKey())) { user_comparator_->Equal(ikey.user_key, saved_key_.GetKey())) {
@ -592,8 +600,7 @@ bool DBIter::FindValueForCurrentKey() {
switch (last_key_entry_type) { switch (last_key_entry_type) {
case kTypeValue: case kTypeValue:
merge_context_.Clear(); merge_context_.Clear();
ReleaseTempPinnedData(); assert(iter_->IsValuePinned());
TempPinData();
pinned_value_ = iter_->value(); pinned_value_ = iter_->value();
last_not_merge_type = kTypeValue; last_not_merge_type = kTypeValue;
break; break;
@ -605,7 +612,8 @@ bool DBIter::FindValueForCurrentKey() {
break; break;
case kTypeMerge: case kTypeMerge:
assert(merge_operator_ != nullptr); assert(merge_operator_ != nullptr);
merge_context_.PushOperandBack(iter_->value()); merge_context_.PushOperandBack(
iter_->value(), iter_->IsValuePinned() /* operand_pinned */);
break; break;
default: default:
assert(false); assert(false);
@ -628,13 +636,14 @@ bool DBIter::FindValueForCurrentKey() {
if (last_not_merge_type == kTypeDeletion) { if (last_not_merge_type == kTypeDeletion) {
MergeHelper::TimedFullMerge(merge_operator_, saved_key_.GetKey(), MergeHelper::TimedFullMerge(merge_operator_, saved_key_.GetKey(),
nullptr, merge_context_.GetOperands(), nullptr, merge_context_.GetOperands(),
&saved_value_, logger_, statistics_, env_); &saved_value_, logger_, statistics_, env_,
&pinned_value_);
} else { } else {
assert(last_not_merge_type == kTypeValue); assert(last_not_merge_type == kTypeValue);
MergeHelper::TimedFullMerge(merge_operator_, saved_key_.GetKey(), MergeHelper::TimedFullMerge(merge_operator_, saved_key_.GetKey(),
&pinned_value_, &pinned_value_,
merge_context_.GetOperands(), &saved_value_, merge_context_.GetOperands(), &saved_value_,
logger_, statistics_, env_); logger_, statistics_, env_, &pinned_value_);
} }
break; break;
case kTypeValue: case kTypeValue:
@ -651,6 +660,9 @@ bool DBIter::FindValueForCurrentKey() {
// This function is used in FindValueForCurrentKey. // This function is used in FindValueForCurrentKey.
// We use Seek() function instead of Prev() to find necessary value // We use Seek() function instead of Prev() to find necessary value
bool DBIter::FindValueForCurrentKeyUsingSeek() { bool DBIter::FindValueForCurrentKeyUsingSeek() {
// FindValueForCurrentKey will enable pinning before calling
// FindValueForCurrentKeyUsingSeek()
assert(pinned_iters_mgr_.PinningEnabled());
std::string last_key; std::string last_key;
AppendInternalKey(&last_key, ParsedInternalKey(saved_key_.GetKey(), sequence_, AppendInternalKey(&last_key, ParsedInternalKey(saved_key_.GetKey(), sequence_,
kValueTypeForSeek)); kValueTypeForSeek));
@ -664,8 +676,7 @@ bool DBIter::FindValueForCurrentKeyUsingSeek() {
if (ikey.type == kTypeValue || ikey.type == kTypeDeletion || if (ikey.type == kTypeValue || ikey.type == kTypeDeletion ||
ikey.type == kTypeSingleDeletion) { ikey.type == kTypeSingleDeletion) {
if (ikey.type == kTypeValue) { if (ikey.type == kTypeValue) {
ReleaseTempPinnedData(); assert(iter_->IsValuePinned());
TempPinData();
pinned_value_ = iter_->value(); pinned_value_ = iter_->value();
valid_ = true; valid_ = true;
return true; return true;
@ -681,7 +692,8 @@ bool DBIter::FindValueForCurrentKeyUsingSeek() {
while (iter_->Valid() && while (iter_->Valid() &&
user_comparator_->Equal(ikey.user_key, saved_key_.GetKey()) && user_comparator_->Equal(ikey.user_key, saved_key_.GetKey()) &&
ikey.type == kTypeMerge) { ikey.type == kTypeMerge) {
merge_context_.PushOperand(iter_->value()); merge_context_.PushOperand(iter_->value(),
iter_->IsValuePinned() /* operand_pinned */);
iter_->Next(); iter_->Next();
FindParseableKey(&ikey, kForward); FindParseableKey(&ikey, kForward);
} }
@ -691,7 +703,7 @@ bool DBIter::FindValueForCurrentKeyUsingSeek() {
ikey.type == kTypeDeletion || ikey.type == kTypeSingleDeletion) { ikey.type == kTypeDeletion || ikey.type == kTypeSingleDeletion) {
MergeHelper::TimedFullMerge(merge_operator_, saved_key_.GetKey(), nullptr, MergeHelper::TimedFullMerge(merge_operator_, saved_key_.GetKey(), nullptr,
merge_context_.GetOperands(), &saved_value_, merge_context_.GetOperands(), &saved_value_,
logger_, statistics_, env_); logger_, statistics_, env_, &pinned_value_);
// Make iter_ valid and point to saved_key_ // Make iter_ valid and point to saved_key_
if (!iter_->Valid() || if (!iter_->Valid() ||
!user_comparator_->Equal(ikey.user_key, saved_key_.GetKey())) { !user_comparator_->Equal(ikey.user_key, saved_key_.GetKey())) {
@ -705,7 +717,7 @@ bool DBIter::FindValueForCurrentKeyUsingSeek() {
const Slice& val = iter_->value(); const Slice& val = iter_->value();
MergeHelper::TimedFullMerge(merge_operator_, saved_key_.GetKey(), &val, MergeHelper::TimedFullMerge(merge_operator_, saved_key_.GetKey(), &val,
merge_context_.GetOperands(), &saved_value_, merge_context_.GetOperands(), &saved_value_,
logger_, statistics_, env_); logger_, statistics_, env_, &pinned_value_);
valid_ = true; valid_ = true;
return true; return true;
} }

3
db/db_iter_test.cc
View File

@ -150,6 +150,9 @@ class TestIterator : public InternalIterator {
return Status::OK(); return Status::OK();
} }
virtual bool IsKeyPinned() const override { return true; }
virtual bool IsValuePinned() const override { return true; }
private: private:
bool initialized_; bool initialized_;
bool valid_; bool valid_;

9
db/db_test.cc
View File

@ -4848,12 +4848,11 @@ class DelayedMergeOperator : public MergeOperator {
public: public:
explicit DelayedMergeOperator(DBTest* d) : db_test_(d) {} explicit DelayedMergeOperator(DBTest* d) : db_test_(d) {}
virtual bool FullMerge(const Slice& key, const Slice* existing_value,
const std::deque<std::string>& operand_list, virtual bool FullMergeV2(const MergeOperationInput& merge_in,
std::string* new_value, MergeOperationOutput* merge_out) const override {
Logger* logger) const override {
db_test_->env_->addon_time_.fetch_add(1000); db_test_->env_->addon_time_.fetch_add(1000);
*new_value = ""; merge_out->new_value = "";
return true; return true;
} }

261
db/db_test2.cc
View File

@ -1487,6 +1487,267 @@ TEST_F(DBTest2, SyncPointMarker) {
rocksdb::SyncPoint::GetInstance()->DisableProcessing(); rocksdb::SyncPoint::GetInstance()->DisableProcessing();
} }
#endif #endif
class MergeOperatorPinningTest : public DBTest2,
public testing::WithParamInterface<bool> {
public:
MergeOperatorPinningTest() { disable_block_cache_ = GetParam(); }
bool disable_block_cache_;
};
INSTANTIATE_TEST_CASE_P(MergeOperatorPinningTest, MergeOperatorPinningTest,
::testing::Bool());
#ifndef ROCKSDB_LITE
TEST_P(MergeOperatorPinningTest, OperandsMultiBlocks) {
Options options = CurrentOptions();
BlockBasedTableOptions table_options;
table_options.block_size = 1; // every block will contain one entry
table_options.no_block_cache = disable_block_cache_;
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
options.merge_operator = MergeOperators::CreateStringAppendTESTOperator();
options.level0_slowdown_writes_trigger = (1 << 30);
options.level0_stop_writes_trigger = (1 << 30);
options.disable_auto_compactions = true;
DestroyAndReopen(options);
const int kKeysPerFile = 10;
const int kOperandsPerKeyPerFile = 7;
const int kOperandSize = 100;
// Filse to write in L0 before compacting to lower level
const int kFilesPerLevel = 3;
Random rnd(301);
std::map<std::string, std::string> true_data;
int batch_num = 1;
int lvl_to_fill = 4;
int key_id = 0;
while (true) {
for (int j = 0; j < kKeysPerFile; j++) {
std::string key = Key(key_id % 35);
key_id++;
for (int k = 0; k < kOperandsPerKeyPerFile; k++) {
std::string val = RandomString(&rnd, kOperandSize);
ASSERT_OK(db_->Merge(WriteOptions(), key, val));
if (true_data[key].size() == 0) {
true_data[key] = val;
} else {
true_data[key] += "," + val;
}
}
}
if (lvl_to_fill == -1) {
// Keep last batch in memtable and stop
break;
}
ASSERT_OK(Flush());
if (batch_num % kFilesPerLevel == 0) {
if (lvl_to_fill != 0) {
MoveFilesToLevel(lvl_to_fill);
}
lvl_to_fill--;
}
batch_num++;
}
// 3 L0 files
// 1 L1 file
// 3 L2 files
// 1 L3 file
// 3 L4 Files
ASSERT_EQ(FilesPerLevel(), "3,1,3,1,3");
// Verify Get()
for (auto kv : true_data) {
ASSERT_EQ(Get(kv.first), kv.second);
}
Iterator* iter = db_->NewIterator(ReadOptions());
// Verify Iterator::Next()
auto data_iter = true_data.begin();
for (iter->SeekToFirst(); iter->Valid(); iter->Next(), data_iter++) {
ASSERT_EQ(iter->key().ToString(), data_iter->first);
ASSERT_EQ(iter->value().ToString(), data_iter->second);
}
ASSERT_EQ(data_iter, true_data.end());
// Verify Iterator::Prev()
auto data_rev = true_data.rbegin();
for (iter->SeekToLast(); iter->Valid(); iter->Prev(), data_rev++) {
ASSERT_EQ(iter->key().ToString(), data_rev->first);
ASSERT_EQ(iter->value().ToString(), data_rev->second);
}
ASSERT_EQ(data_rev, true_data.rend());
// Verify Iterator::Seek()
for (auto kv : true_data) {
iter->Seek(kv.first);
ASSERT_EQ(kv.first, iter->key().ToString());
ASSERT_EQ(kv.second, iter->value().ToString());
}
delete iter;
}
TEST_P(MergeOperatorPinningTest, Randomized) {
do {
Options options = CurrentOptions();
options.merge_operator = MergeOperators::CreateMaxOperator();
BlockBasedTableOptions table_options;
table_options.no_block_cache = disable_block_cache_;
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
DestroyAndReopen(options);
Random rnd(301);
std::map<std::string, std::string> true_data;
const int kTotalMerges = 10000;
// Every key gets ~10 operands
const int kKeyRange = kTotalMerges / 10;
const int kOperandSize = 20;
const int kNumPutBefore = kKeyRange / 10; // 10% value
const int kNumPutAfter = kKeyRange / 10; // 10% overwrite
const int kNumDelete = kKeyRange / 10; // 10% delete
// kNumPutBefore keys will have base values
for (int i = 0; i < kNumPutBefore; i++) {
std::string key = Key(rnd.Next() % kKeyRange);
std::string value = RandomString(&rnd, kOperandSize);
ASSERT_OK(db_->Put(WriteOptions(), key, value));
true_data[key] = value;
}
// Do kTotalMerges merges
for (int i = 0; i < kTotalMerges; i++) {
std::string key = Key(rnd.Next() % kKeyRange);
std::string value = RandomString(&rnd, kOperandSize);
ASSERT_OK(db_->Merge(WriteOptions(), key, value));
if (true_data[key] < value) {
true_data[key] = value;
}
}
// Overwrite random kNumPutAfter keys
for (int i = 0; i < kNumPutAfter; i++) {
std::string key = Key(rnd.Next() % kKeyRange);
std::string value = RandomString(&rnd, kOperandSize);
ASSERT_OK(db_->Put(WriteOptions(), key, value));
true_data[key] = value;
}
// Delete random kNumDelete keys
for (int i = 0; i < kNumDelete; i++) {
std::string key = Key(rnd.Next() % kKeyRange);
ASSERT_OK(db_->Delete(WriteOptions(), key));
true_data.erase(key);
}
VerifyDBFromMap(true_data);
// Skip HashCuckoo since it does not support merge operators
} while (ChangeOptions(kSkipMergePut | kSkipHashCuckoo));
}
class MergeOperatorHook : public MergeOperator {
public:
explicit MergeOperatorHook(std::shared_ptr<MergeOperator> _merge_op)
: merge_op_(_merge_op) {}
virtual bool FullMergeV2(const MergeOperationInput& merge_in,
MergeOperationOutput* merge_out) const override {
before_merge_();
bool res = merge_op_->FullMergeV2(merge_in, merge_out);
after_merge_();
return res;
}
virtual const char* Name() const override { return merge_op_->Name(); }
std::shared_ptr<MergeOperator> merge_op_;
std::function<void()> before_merge_ = []() {};
std::function<void()> after_merge_ = []() {};
};
TEST_P(MergeOperatorPinningTest, EvictCacheBeforeMerge) {
Options options = CurrentOptions();
auto merge_hook =
std::make_shared<MergeOperatorHook>(MergeOperators::CreateMaxOperator());
options.merge_operator = merge_hook;
options.disable_auto_compactions = true;
options.level0_slowdown_writes_trigger = (1 << 30);
options.level0_stop_writes_trigger = (1 << 30);
options.max_open_files = 20;
BlockBasedTableOptions bbto;
bbto.no_block_cache = disable_block_cache_;
if (bbto.no_block_cache == false) {
bbto.block_cache = NewLRUCache(64 * 1024 * 1024);
} else {
bbto.block_cache = nullptr;
}
options.table_factory.reset(NewBlockBasedTableFactory(bbto));
DestroyAndReopen(options);
const int kNumOperands = 30;
const int kNumKeys = 1000;
const int kOperandSize = 100;
Random rnd(301);
// 1000 keys every key have 30 operands, every operand is in a different file
std::map<std::string, std::string> true_data;
for (int i = 0; i < kNumOperands; i++) {
for (int j = 0; j < kNumKeys; j++) {
std::string k = Key(j);
std::string v = RandomString(&rnd, kOperandSize);
ASSERT_OK(db_->Merge(WriteOptions(), k, v));
true_data[k] = std::max(true_data[k], v);
}
ASSERT_OK(Flush());
}
std::vector<uint64_t> file_numbers = ListTableFiles(env_, dbname_);
ASSERT_EQ(file_numbers.size(), kNumOperands);
int merge_cnt = 0;
// Code executed before merge operation
merge_hook->before_merge_ = [&]() {
// Evict all tables from cache before every merge operation
for (uint64_t num : file_numbers) {
TableCache::Evict(dbfull()->TEST_table_cache(), num);
}
// Decrease cache capacity to force all unrefed blocks to be evicted
if (bbto.block_cache) {
bbto.block_cache->SetCapacity(1);
}
merge_cnt++;
};
// Code executed after merge operation
merge_hook->after_merge_ = [&]() {
// Increase capacity again after doing the merge
if (bbto.block_cache) {
bbto.block_cache->SetCapacity(64 * 1024 * 1024);
}
};
VerifyDBFromMap(true_data);
ASSERT_EQ(merge_cnt, kNumKeys * 4 /* get + next + prev + seek */);
db_->CompactRange(CompactRangeOptions(), nullptr, nullptr);
VerifyDBFromMap(true_data);
}
#endif // ROCKSDB_LITE
} // namespace rocksdb } // namespace rocksdb
int main(int argc, char** argv) { int main(int argc, char** argv) {

34
db/db_test_util.cc
View File

@ -1074,6 +1074,40 @@ std::vector<std::uint64_t> DBTestBase::ListTableFiles(Env* env,
return file_numbers; return file_numbers;
} }
void DBTestBase::VerifyDBFromMap(std::map<std::string, std::string> true_data) {
for (auto& kv : true_data) {
ASSERT_EQ(Get(kv.first), kv.second);
}
ReadOptions ro;
ro.total_order_seek = true;
Iterator* iter = db_->NewIterator(ro);
// Verify Iterator::Next()
auto data_iter = true_data.begin();
for (iter->SeekToFirst(); iter->Valid(); iter->Next(), data_iter++) {
ASSERT_EQ(iter->key().ToString(), data_iter->first);
ASSERT_EQ(iter->value().ToString(), data_iter->second);
}
ASSERT_EQ(data_iter, true_data.end());
// Verify Iterator::Prev()
auto data_rev = true_data.rbegin();
for (iter->SeekToLast(); iter->Valid(); iter->Prev(), data_rev++) {
ASSERT_EQ(iter->key().ToString(), data_rev->first);
ASSERT_EQ(iter->value().ToString(), data_rev->second);
}
ASSERT_EQ(data_rev, true_data.rend());
// Verify Iterator::Seek()
for (auto kv : true_data) {
iter->Seek(kv.first);
ASSERT_EQ(kv.first, iter->key().ToString());
ASSERT_EQ(kv.second, iter->value().ToString());
}
delete iter;
}
#ifndef ROCKSDB_LITE #ifndef ROCKSDB_LITE
Status DBTestBase::GenerateAndAddExternalFile(const Options options, Status DBTestBase::GenerateAndAddExternalFile(const Options options,

2
db/db_test_util.h
View File

@ -797,6 +797,8 @@ class DBTestBase : public testing::Test {
std::vector<std::uint64_t> ListTableFiles(Env* env, const std::string& path); std::vector<std::uint64_t> ListTableFiles(Env* env, const std::string& path);
void VerifyDBFromMap(std::map<std::string, std::string> true_data);
#ifndef ROCKSDB_LITE #ifndef ROCKSDB_LITE
Status GenerateAndAddExternalFile(const Options options, Status GenerateAndAddExternalFile(const Options options,
std::vector<int> keys, size_t file_id); std::vector<int> keys, size_t file_id);

17
db/memtable.cc
View File

@ -218,12 +218,13 @@ const char* EncodeKey(std::string* scratch, const Slice& target) {
class MemTableIterator : public InternalIterator { class MemTableIterator : public InternalIterator {
public: public:
MemTableIterator( MemTableIterator(const MemTable& mem, const ReadOptions& read_options,
const MemTable& mem, const ReadOptions& read_options, Arena* arena) Arena* arena)
: bloom_(nullptr), : bloom_(nullptr),
prefix_extractor_(mem.prefix_extractor_), prefix_extractor_(mem.prefix_extractor_),
valid_(false), valid_(false),
arena_mode_(arena != nullptr) { arena_mode_(arena != nullptr),
value_pinned_(!mem.GetMemTableOptions()->inplace_update_support) {
if (prefix_extractor_ != nullptr && !read_options.total_order_seek) { if (prefix_extractor_ != nullptr && !read_options.total_order_seek) {
bloom_ = mem.prefix_bloom_.get(); bloom_ = mem.prefix_bloom_.get();
iter_ = mem.table_->GetDynamicPrefixIterator(arena); iter_ = mem.table_->GetDynamicPrefixIterator(arena);
@ -306,12 +307,18 @@ class MemTableIterator : public InternalIterator {
return true; return true;
} }
virtual bool IsValuePinned() const override {
// memtable value is always pinned, except if we allow inplace update.
return value_pinned_;
}
private: private:
DynamicBloom* bloom_; DynamicBloom* bloom_;
const SliceTransform* const prefix_extractor_; const SliceTransform* const prefix_extractor_;
MemTableRep::Iterator* iter_; MemTableRep::Iterator* iter_;
bool valid_; bool valid_;
bool arena_mode_; bool arena_mode_;
bool value_pinned_;
// No copying allowed // No copying allowed
MemTableIterator(const MemTableIterator&); MemTableIterator(const MemTableIterator&);
@ -508,7 +515,6 @@ static bool SaveValue(void* arg, const char* entry) {
case kTypeDeletion: case kTypeDeletion:
case kTypeSingleDeletion: { case kTypeSingleDeletion: {
if (*(s->merge_in_progress)) { if (*(s->merge_in_progress)) {
*(s->status) = Status::OK();
*(s->status) = MergeHelper::TimedFullMerge( *(s->status) = MergeHelper::TimedFullMerge(
merge_operator, s->key->user_key(), nullptr, merge_operator, s->key->user_key(), nullptr,
merge_context->GetOperands(), s->value, s->logger, s->statistics, merge_context->GetOperands(), s->value, s->logger, s->statistics,
@ -532,7 +538,8 @@ static bool SaveValue(void* arg, const char* entry) {
} }
Slice v = GetLengthPrefixedSlice(key_ptr + key_length); Slice v = GetLengthPrefixedSlice(key_ptr + key_length);
*(s->merge_in_progress) = true; *(s->merge_in_progress) = true;
merge_context->PushOperand(v); merge_context->PushOperand(
v, s->inplace_update_support == false /* operand_pinned */);
return true; return true;
} }
default: default:

101
db/merge_context.h
View File

@ -4,70 +4,113 @@
// of patent rights can be found in the PATENTS file in the same directory. // of patent rights can be found in the PATENTS file in the same directory.
// //
#pragma once #pragma once
#include <string>
#include <vector>
#include "db/dbformat.h" #include "db/dbformat.h"
#include "rocksdb/slice.h" #include "rocksdb/slice.h"
#include <string>
#include <deque>
namespace rocksdb { namespace rocksdb {
const std::deque<std::string> empty_operand_list; const std::vector<Slice> empty_operand_list;
// The merge context for merging a user key. // The merge context for merging a user key.
// When doing a Get(), DB will create such a class and pass it when // When doing a Get(), DB will create such a class and pass it when
// issuing Get() operation to memtables and version_set. The operands // issuing Get() operation to memtables and version_set. The operands
// will be fetched from the context when issuing partial of full merge. // will be fetched from the context when issuing partial of full merge.
class MergeContext { class MergeContext {
public: public:
// Clear all the operands // Clear all the operands
void Clear() { void Clear() {
if (operand_list) { if (operand_list_) {
operand_list->clear(); operand_list_->clear();
copied_operands_->clear();
} }
} }
// Replace all operands with merge_result, which are expected to be the
// merge result of them.
void PushPartialMergeResult(std::string& merge_result) {
assert (operand_list);
operand_list->clear();
operand_list->push_front(std::move(merge_result));
}
// Push a merge operand // Push a merge operand
void PushOperand(const Slice& operand_slice) { void PushOperand(const Slice& operand_slice, bool operand_pinned = false) {
Initialize(); Initialize();
operand_list->push_front(operand_slice.ToString()); SetDirectionBackward();
if (operand_pinned) {
operand_list_->push_back(operand_slice);
} else {
// We need to have our own copy of the operand since it's not pinned
copied_operands_->emplace_back(operand_slice.data(),
operand_slice.size());
operand_list_->push_back(copied_operands_->back());
}
} }
// Push back a merge operand // Push back a merge operand
void PushOperandBack(const Slice& operand_slice) { void PushOperandBack(const Slice& operand_slice,
bool operand_pinned = false) {
Initialize(); Initialize();
operand_list->push_back(operand_slice.ToString()); SetDirectionForward();
if (operand_pinned) {
operand_list_->push_back(operand_slice);
} else {
// We need to have our own copy of the operand since it's not pinned
copied_operands_->emplace_back(operand_slice.data(),
operand_slice.size());
operand_list_->push_back(copied_operands_->back());
}
} }
// return total number of operands in the list // return total number of operands in the list
size_t GetNumOperands() const { size_t GetNumOperands() const {
if (!operand_list) { if (!operand_list_) {
return 0; return 0;
} }
return operand_list->size(); return operand_list_->size();
} }
// Get the operand at the index. // Get the operand at the index.
Slice GetOperand(int index) const { Slice GetOperand(int index) {
assert (operand_list); assert(operand_list_);
return (*operand_list)[index];
SetDirectionForward();
return (*operand_list_)[index];
} }
// Return all the operands. // Return all the operands.
const std::deque<std::string>& GetOperands() const { const std::vector<Slice>& GetOperands() {
if (!operand_list) { if (!operand_list_) {
return empty_operand_list; return empty_operand_list;
} }
return *operand_list;
SetDirectionForward();
return *operand_list_;
} }
private:
private:
void Initialize() { void Initialize() {
if (!operand_list) { if (!operand_list_) {
operand_list.reset(new std::deque<std::string>()); operand_list_.reset(new std::vector<Slice>());
copied_operands_.reset(new std::vector<std::string>());
} }
} }
std::unique_ptr<std::deque<std::string>> operand_list;
void SetDirectionForward() {
if (operands_reversed_ == true) {
std::reverse(operand_list_->begin(), operand_list_->end());
operands_reversed_ = false;
}
}
void SetDirectionBackward() {
if (operands_reversed_ == false) {
std::reverse(operand_list_->begin(), operand_list_->end());
operands_reversed_ = true;
}
}
// List of operands
std::unique_ptr<std::vector<Slice>> operand_list_;
// Copy of operands that are not pinned.
std::unique_ptr<std::vector<std::string>> copied_operands_;
bool operands_reversed_ = true;
}; };
} // namespace rocksdb } // namespace rocksdb

60
db/merge_helper.cc
View File

@ -20,9 +20,10 @@ namespace rocksdb {
Status MergeHelper::TimedFullMerge(const MergeOperator* merge_operator, Status MergeHelper::TimedFullMerge(const MergeOperator* merge_operator,
const Slice& key, const Slice* value, const Slice& key, const Slice* value,
const std::deque<std::string>& operands, const std::vector<Slice>& operands,
std::string* result, Logger* logger, std::string* result, Logger* logger,
Statistics* statistics, Env* env) { Statistics* statistics, Env* env,
Slice* result_operand) {
assert(merge_operator != nullptr); assert(merge_operator != nullptr);
if (operands.size() == 0) { if (operands.size() == 0) {
@ -32,13 +33,28 @@ Status MergeHelper::TimedFullMerge(const MergeOperator* merge_operator,
} }
bool success; bool success;
Slice tmp_result_operand(nullptr, 0);
const MergeOperator::MergeOperationInput merge_in(key, value, operands,
logger);
MergeOperator::MergeOperationOutput merge_out(*result, tmp_result_operand);
{ {
// Setup to time the merge // Setup to time the merge
StopWatchNano timer(env, statistics != nullptr); StopWatchNano timer(env, statistics != nullptr);
PERF_TIMER_GUARD(merge_operator_time_nanos); PERF_TIMER_GUARD(merge_operator_time_nanos);
// Do the merge // Do the merge
success = merge_operator->FullMerge(key, value, operands, result, logger); success = merge_operator->FullMergeV2(merge_in, &merge_out);
if (tmp_result_operand.data()) {
// FullMergeV2 result is an existing operand
if (result_operand != nullptr) {
*result_operand = tmp_result_operand;
} else {
result->assign(tmp_result_operand.data(), tmp_result_operand.size());
}
} else if (result_operand) {
*result_operand = Slice(nullptr, 0);
}
RecordTick(statistics, MERGE_OPERATION_TOTAL_TIME, RecordTick(statistics, MERGE_OPERATION_TOTAL_TIME,
statistics ? timer.ElapsedNanos() : 0); statistics ? timer.ElapsedNanos() : 0);
@ -65,7 +81,7 @@ Status MergeHelper::MergeUntil(InternalIterator* iter,
// Also maintain the list of merge operands seen. // Also maintain the list of merge operands seen.
assert(HasOperator()); assert(HasOperator());
keys_.clear(); keys_.clear();
operands_.clear(); merge_context_.Clear();
assert(user_merge_operator_); assert(user_merge_operator_);
bool first_key = true; bool first_key = true;
@ -87,7 +103,7 @@ Status MergeHelper::MergeUntil(InternalIterator* iter,
bool hit_the_next_user_key = false; bool hit_the_next_user_key = false;
for (; iter->Valid(); iter->Next(), original_key_is_iter = false) { for (; iter->Valid(); iter->Next(), original_key_is_iter = false) {
ParsedInternalKey ikey; ParsedInternalKey ikey;
assert(keys_.size() == operands_.size()); assert(keys_.size() == merge_context_.GetNumOperands());
if (!ParseInternalKey(iter->key(), &ikey)) { if (!ParseInternalKey(iter->key(), &ikey)) {
// stop at corrupted key // stop at corrupted key
@ -142,7 +158,8 @@ Status MergeHelper::MergeUntil(InternalIterator* iter,
const Slice* val_ptr = (kTypeValue == ikey.type) ? &val : nullptr; const Slice* val_ptr = (kTypeValue == ikey.type) ? &val : nullptr;
std::string merge_result; std::string merge_result;
s = TimedFullMerge(user_merge_operator_, ikey.user_key, val_ptr, s = TimedFullMerge(user_merge_operator_, ikey.user_key, val_ptr,
operands_, &merge_result, logger_, stats_, env_); merge_context_.GetOperands(), &merge_result, logger_,
stats_, env_);
// We store the result in keys_.back() and operands_.back() // We store the result in keys_.back() and operands_.back()
// if nothing went wrong (i.e.: no operand corruption on disk) // if nothing went wrong (i.e.: no operand corruption on disk)
@ -152,9 +169,9 @@ Status MergeHelper::MergeUntil(InternalIterator* iter,
orig_ikey.type = kTypeValue; orig_ikey.type = kTypeValue;
UpdateInternalKey(&original_key, orig_ikey.sequence, orig_ikey.type); UpdateInternalKey(&original_key, orig_ikey.sequence, orig_ikey.type);
keys_.clear(); keys_.clear();
operands_.clear(); merge_context_.Clear();
keys_.emplace_front(std::move(original_key)); keys_.emplace_front(std::move(original_key));
operands_.emplace_front(std::move(merge_result)); merge_context_.PushOperand(merge_result);
} }
// move iter to the next entry // move iter to the next entry
@ -188,12 +205,13 @@ Status MergeHelper::MergeUntil(InternalIterator* iter,
// original_key before // original_key before
ParseInternalKey(keys_.back(), &orig_ikey); ParseInternalKey(keys_.back(), &orig_ikey);
} }
operands_.push_front(value_slice.ToString()); merge_context_.PushOperand(value_slice,
iter->IsValuePinned() /* operand_pinned */);
} }
} }
} }
if (operands_.size() == 0) { if (merge_context_.GetNumOperands() == 0) {
// we filtered out all the merge operands // we filtered out all the merge operands
return Status::OK(); return Status::OK();
} }
@ -218,11 +236,12 @@ Status MergeHelper::MergeUntil(InternalIterator* iter,
// do a final merge with nullptr as the existing value and say // do a final merge with nullptr as the existing value and say
// bye to the merge type (it's now converted to a Put) // bye to the merge type (it's now converted to a Put)
assert(kTypeMerge == orig_ikey.type); assert(kTypeMerge == orig_ikey.type);
assert(operands_.size() >= 1); assert(merge_context_.GetNumOperands() >= 1);
assert(operands_.size() == keys_.size()); assert(merge_context_.GetNumOperands() == keys_.size());
std::string merge_result; std::string merge_result;
s = TimedFullMerge(user_merge_operator_, orig_ikey.user_key, nullptr, s = TimedFullMerge(user_merge_operator_, orig_ikey.user_key, nullptr,
operands_, &merge_result, logger_, stats_, env_); merge_context_.GetOperands(), &merge_result, logger_,
stats_, env_);
if (s.ok()) { if (s.ok()) {
// The original key encountered // The original key encountered
// We are certain that keys_ is not empty here (see assertions couple of // We are certain that keys_ is not empty here (see assertions couple of
@ -231,9 +250,9 @@ Status MergeHelper::MergeUntil(InternalIterator* iter,
orig_ikey.type = kTypeValue; orig_ikey.type = kTypeValue;
UpdateInternalKey(&original_key, orig_ikey.sequence, orig_ikey.type); UpdateInternalKey(&original_key, orig_ikey.sequence, orig_ikey.type);
keys_.clear(); keys_.clear();
operands_.clear(); merge_context_.Clear();
keys_.emplace_front(std::move(original_key)); keys_.emplace_front(std::move(original_key));
operands_.emplace_front(std::move(merge_result)); merge_context_.PushOperand(merge_result);
} }
} else { } else {
// We haven't seen the beginning of the key nor a Put/Delete. // We haven't seen the beginning of the key nor a Put/Delete.
@ -244,8 +263,8 @@ Status MergeHelper::MergeUntil(InternalIterator* iter,
// partial merge returns Status::OK(). Should we change the status code // partial merge returns Status::OK(). Should we change the status code
// after a successful partial merge? // after a successful partial merge?
s = Status::MergeInProgress(); s = Status::MergeInProgress();
if (operands_.size() >= 2 && if (merge_context_.GetNumOperands() >= 2 &&
operands_.size() >= min_partial_merge_operands_) { merge_context_.GetNumOperands() >= min_partial_merge_operands_) {
bool merge_success = false; bool merge_success = false;
std::string merge_result; std::string merge_result;
{ {
@ -253,7 +272,8 @@ Status MergeHelper::MergeUntil(InternalIterator* iter,
PERF_TIMER_GUARD(merge_operator_time_nanos); PERF_TIMER_GUARD(merge_operator_time_nanos);
merge_success = user_merge_operator_->PartialMergeMulti( merge_success = user_merge_operator_->PartialMergeMulti(
orig_ikey.user_key, orig_ikey.user_key,
std::deque<Slice>(operands_.begin(), operands_.end()), std::deque<Slice>(merge_context_.GetOperands().begin(),
merge_context_.GetOperands().end()),
&merge_result, logger_); &merge_result, logger_);
RecordTick(stats_, MERGE_OPERATION_TOTAL_TIME, RecordTick(stats_, MERGE_OPERATION_TOTAL_TIME,
stats_ ? timer.ElapsedNanosSafe() : 0); stats_ ? timer.ElapsedNanosSafe() : 0);
@ -261,8 +281,8 @@ Status MergeHelper::MergeUntil(InternalIterator* iter,
if (merge_success) { if (merge_success) {
// Merging of operands (associative merge) was successful. // Merging of operands (associative merge) was successful.
// Replace operands with the merge result // Replace operands with the merge result
operands_.clear(); merge_context_.Clear();
operands_.emplace_front(std::move(merge_result)); merge_context_.PushOperand(merge_result);
keys_.erase(keys_.begin(), keys_.end() - 1); keys_.erase(keys_.begin(), keys_.end() - 1);
} }
} }

23
db/merge_helper.h
View File

@ -8,8 +8,10 @@
#include <deque> #include <deque>
#include <string> #include <string>
#include <vector>
#include "db/dbformat.h" #include "db/dbformat.h"
#include "db/merge_context.h"
#include "rocksdb/compaction_filter.h" #include "rocksdb/compaction_filter.h"
#include "rocksdb/env.h" #include "rocksdb/env.h"
#include "rocksdb/slice.h" #include "rocksdb/slice.h"
@ -42,14 +44,13 @@ class MergeHelper {
latest_snapshot_(latest_snapshot), latest_snapshot_(latest_snapshot),
level_(level), level_(level),
keys_(), keys_(),
operands_(),
filter_timer_(env_), filter_timer_(env_),
total_filter_time_(0U), total_filter_time_(0U),
stats_(stats) { stats_(stats) {
assert(user_comparator_ != nullptr); assert(user_comparator_ != nullptr);
} }
// Wrapper around MergeOperator::FullMerge() that records perf statistics. // Wrapper around MergeOperator::FullMergeV2() that records perf statistics.
// Result of merge will be written to result if status returned is OK. // Result of merge will be written to result if status returned is OK.
// If operands is empty, the value will simply be copied to result. // If operands is empty, the value will simply be copied to result.
// Returns one of the following statuses: // Returns one of the following statuses:
@ -57,9 +58,10 @@ class MergeHelper {
// - Corruption: Merge operator reported unsuccessful merge. // - Corruption: Merge operator reported unsuccessful merge.
static Status TimedFullMerge(const MergeOperator* merge_operator, static Status TimedFullMerge(const MergeOperator* merge_operator,
const Slice& key, const Slice* value, const Slice& key, const Slice* value,
const std::deque<std::string>& operands, const std::vector<Slice>& operands,
std::string* result, Logger* logger, std::string* result, Logger* logger,
Statistics* statistics, Env* env); Statistics* statistics, Env* env,
Slice* result_operand = nullptr);
// Merge entries until we hit // Merge entries until we hit
// - a corrupted key // - a corrupted key
@ -116,7 +118,9 @@ class MergeHelper {
// So keys().back() was the first key seen by iterator. // So keys().back() was the first key seen by iterator.
// TODO: Re-style this comment to be like the first one // TODO: Re-style this comment to be like the first one
const std::deque<std::string>& keys() const { return keys_; } const std::deque<std::string>& keys() const { return keys_; }
const std::deque<std::string>& values() const { return operands_; } const std::vector<Slice>& values() const {
return merge_context_.GetOperands();
}
uint64_t TotalFilterTime() const { return total_filter_time_; } uint64_t TotalFilterTime() const { return total_filter_time_; }
bool HasOperator() const { return user_merge_operator_ != nullptr; } bool HasOperator() const { return user_merge_operator_ != nullptr; }
@ -133,8 +137,11 @@ class MergeHelper {
// the scratch area that holds the result of MergeUntil // the scratch area that holds the result of MergeUntil
// valid up to the next MergeUntil call // valid up to the next MergeUntil call
std::deque<std::string> keys_; // Keeps track of the sequence of keys seen
std::deque<std::string> operands_; // Parallel with keys_; stores the values // Keeps track of the sequence of keys seen
std::deque<std::string> keys_;
// Parallel with keys_; stores the operands
mutable MergeContext merge_context_;
StopWatchNano filter_timer_; StopWatchNano filter_timer_;
uint64_t total_filter_time_; uint64_t total_filter_time_;
@ -159,7 +166,7 @@ class MergeOutputIterator {
private: private:
const MergeHelper* merge_helper_; const MergeHelper* merge_helper_;
std::deque<std::string>::const_reverse_iterator it_keys_; std::deque<std::string>::const_reverse_iterator it_keys_;
std::deque<std::string>::const_reverse_iterator it_values_; std::vector<Slice>::const_reverse_iterator it_values_;
}; };
} // namespace rocksdb } // namespace rocksdb

33
db/merge_operator.cc
View File

@ -11,6 +11,18 @@
namespace rocksdb { namespace rocksdb {
bool MergeOperator::FullMergeV2(const MergeOperationInput& merge_in,
MergeOperationOutput* merge_out) const {
// If FullMergeV2 is not implemented, we convert the operand_list to
// std::deque<std::string> and pass it to FullMerge
std::deque<std::string> operand_list_str;
for (auto& op : merge_in.operand_list) {
operand_list_str.emplace_back(op.data(), op.size());
}
return FullMerge(merge_in.key, merge_in.existing_value, operand_list_str,
&merge_out->new_value, merge_in.logger);
}
// The default implementation of PartialMergeMulti, which invokes // The default implementation of PartialMergeMulti, which invokes
// PartialMerge multiple times internally and merges two operands at // PartialMerge multiple times internally and merges two operands at
// a time. // a time.
@ -39,23 +51,20 @@ bool MergeOperator::PartialMergeMulti(const Slice& key,
// Given a "real" merge from the library, call the user's // Given a "real" merge from the library, call the user's
// associative merge function one-by-one on each of the operands. // associative merge function one-by-one on each of the operands.
// NOTE: It is assumed that the client's merge-operator will handle any errors. // NOTE: It is assumed that the client's merge-operator will handle any errors.
bool AssociativeMergeOperator::FullMerge( bool AssociativeMergeOperator::FullMergeV2(
const Slice& key, const MergeOperationInput& merge_in,
const Slice* existing_value, MergeOperationOutput* merge_out) const {
const std::deque<std::string>& operand_list,
std::string* new_value,
Logger* logger) const {
// Simply loop through the operands // Simply loop through the operands
Slice temp_existing; Slice temp_existing;
for (const auto& operand : operand_list) { const Slice* existing_value = merge_in.existing_value;
Slice value(operand); for (const auto& operand : merge_in.operand_list) {
std::string temp_value; std::string temp_value;
if (!Merge(key, existing_value, value, &temp_value, logger)) { if (!Merge(merge_in.key, existing_value, operand, &temp_value,
merge_in.logger)) {
return false; return false;
} }
swap(temp_value, *new_value); swap(temp_value, merge_out->new_value);
temp_existing = Slice(*new_value); temp_existing = Slice(merge_out->new_value);
existing_value = &temp_existing; existing_value = &temp_existing;
} }

4
db/pinned_iterators_manager.h
View File

@ -18,7 +18,7 @@ namespace rocksdb {
class PinnedIteratorsManager { class PinnedIteratorsManager {
public: public:
PinnedIteratorsManager() : pinning_enabled(false), pinned_iters_(nullptr) {} PinnedIteratorsManager() : pinning_enabled(false), pinned_iters_(nullptr) {}
~PinnedIteratorsManager() { assert(!pinning_enabled); } ~PinnedIteratorsManager() { ReleasePinnedIterators(); }
// Enable Iterators pinning // Enable Iterators pinning
void StartPinning() { void StartPinning() {
@ -43,7 +43,7 @@ class PinnedIteratorsManager {
} }
// Release pinned Iterators // Release pinned Iterators
void ReleasePinnedIterators() { inline void ReleasePinnedIterators() {
if (pinning_enabled) { if (pinning_enabled) {
pinning_enabled = false; pinning_enabled = false;

10
db/version_set.cc
View File

@ -31,6 +31,7 @@
#include "db/memtable.h" #include "db/memtable.h"
#include "db/merge_context.h" #include "db/merge_context.h"
#include "db/merge_helper.h" #include "db/merge_helper.h"
#include "db/pinned_iterators_manager.h"
#include "db/table_cache.h" #include "db/table_cache.h"
#include "db/version_builder.h" #include "db/version_builder.h"
#include "rocksdb/env.h" #include "rocksdb/env.h"
@ -917,10 +918,17 @@ void Version::Get(const ReadOptions& read_options, const LookupKey& k,
*key_exists = true; *key_exists = true;
} }
PinnedIteratorsManager pinned_iters_mgr;
GetContext get_context( GetContext get_context(
user_comparator(), merge_operator_, info_log_, db_statistics_, user_comparator(), merge_operator_, info_log_, db_statistics_,
status->ok() ? GetContext::kNotFound : GetContext::kMerge, user_key, status->ok() ? GetContext::kNotFound : GetContext::kMerge, user_key,
value, value_found, merge_context, this->env_, seq); value, value_found, merge_context, this->env_, seq,
merge_operator_ ? &pinned_iters_mgr : nullptr);
// Pin blocks that we read to hold merge operands
if (merge_operator_) {
pinned_iters_mgr.StartPinning();
}
FilePicker fp( FilePicker fp(
storage_info_.files_, user_key, ikey, &storage_info_.level_files_brief_, storage_info_.files_, user_key, ikey, &storage_info_.level_files_brief_,

4
db/write_batch.cc
View File

@ -922,12 +922,10 @@ class MemTableInserter : public WriteBatch::Handler {
auto merge_operator = moptions->merge_operator; auto merge_operator = moptions->merge_operator;
assert(merge_operator); assert(merge_operator);
std::deque<std::string> operands;
operands.push_front(value.ToString());
std::string new_value; std::string new_value;
Status merge_status = MergeHelper::TimedFullMerge( Status merge_status = MergeHelper::TimedFullMerge(
merge_operator, key, &get_value_slice, operands, &new_value, merge_operator, key, &get_value_slice, {value}, &new_value,
moptions->info_log, moptions->statistics, Env::Default()); moptions->info_log, moptions->statistics, Env::Default());
if (!merge_status.ok()) { if (!merge_status.ok()) {

23
examples/compaction_filter_example.cc
View File

@ -10,19 +10,18 @@
class MyMerge : public rocksdb::MergeOperator { class MyMerge : public rocksdb::MergeOperator {
public: public:
bool FullMerge(const rocksdb::Slice& key, virtual bool FullMergeV2(const MergeOperationInput& merge_in,
const rocksdb::Slice* existing_value, MergeOperationOutput* merge_out) const override {
const std::deque<std::string>& operand_list, merge_out->new_value.clear();
std::string* new_value, if (merge_in.existing_value != nullptr) {
rocksdb::Logger* logger) const override { merge_out->new_value.assign(merge_in.existing_value->data(),
new_value->clear(); merge_in.existing_value->size());
if (existing_value != nullptr) {
new_value->assign(existing_value->data(), existing_value->size());
} }
for (const std::string& m : operand_list) { for (const rocksdb::Slice& m : merge_in.operand_list) {
fprintf(stderr, "Merge(%s)\n", m.c_str()); fprintf(stderr, "Merge(%s)\n", m.ToString().c_str());
assert(m != "bad"); // the compaction filter filters out bad values // the compaction filter filters out bad values
new_value->assign(m); assert(m.ToString() != "bad");
merge_out->new_value.assign(m.data(), m.size());
} }
return true; return true;
} }

56
include/rocksdb/merge_operator.h
View File

@ -9,6 +9,7 @@
#include <deque> #include <deque>
#include <memory> #include <memory>
#include <string> #include <string>
#include <vector>
#include "rocksdb/slice.h" #include "rocksdb/slice.h"
@ -32,7 +33,7 @@ class Logger;
// into rocksdb); numeric addition and string concatenation are examples; // into rocksdb); numeric addition and string concatenation are examples;
// //
// b) MergeOperator - the generic class for all the more abstract / complex // b) MergeOperator - the generic class for all the more abstract / complex
// operations; one method (FullMerge) to merge a Put/Delete value with a // operations; one method (FullMergeV2) to merge a Put/Delete value with a
// merge operand; and another method (PartialMerge) that merges multiple // merge operand; and another method (PartialMerge) that merges multiple
// operands together. this is especially useful if your key values have // operands together. this is especially useful if your key values have
// complex structures but you would still like to support client-specific // complex structures but you would still like to support client-specific
@ -69,7 +70,49 @@ class MergeOperator {
const Slice* existing_value, const Slice* existing_value,
const std::deque<std::string>& operand_list, const std::deque<std::string>& operand_list,
std::string* new_value, std::string* new_value,
Logger* logger) const = 0; Logger* logger) const {
// deprecated, please use FullMergeV2()
assert(false);
return false;
}
struct MergeOperationInput {
explicit MergeOperationInput(const Slice& _key,
const Slice* _existing_value,
const std::vector<Slice>& _operand_list,
Logger* _logger)
: key(_key),
existing_value(_existing_value),
operand_list(_operand_list),
logger(_logger) {}
// The key associated with the merge operation.
const Slice& key;
// The existing value of the current key, nullptr means that the
// value dont exist.
const Slice* existing_value;
// A list of operands to apply.
const std::vector<Slice>& operand_list;
// Logger could be used by client to log any errors that happen during
// the merge operation.
Logger* logger;
};
struct MergeOperationOutput {
explicit MergeOperationOutput(std::string& _new_value,
Slice& _existing_operand)
: new_value(_new_value), existing_operand(_existing_operand) {}
// Client is responsible for filling the merge result here.
std::string& new_value;
// If the merge result is one of the existing operands (or existing_value),
// client can set this field to the operand (or existing_value) instead of
// using new_value.
Slice& existing_operand;
};
virtual bool FullMergeV2(const MergeOperationInput& merge_in,
MergeOperationOutput* merge_out) const;
// This function performs merge(left_op, right_op) // This function performs merge(left_op, right_op)
// when both the operands are themselves merge operation types // when both the operands are themselves merge operation types
@ -99,7 +142,7 @@ class MergeOperator {
// TODO: Presently there is no way to differentiate between error/corruption // TODO: Presently there is no way to differentiate between error/corruption
// and simply "return false". For now, the client should simply return // and simply "return false". For now, the client should simply return
// false in any case it cannot perform partial-merge, regardless of reason. // false in any case it cannot perform partial-merge, regardless of reason.
// If there is corruption in the data, handle it in the FullMerge() function, // If there is corruption in the data, handle it in the FullMergeV2() function
// and return false there. The default implementation of PartialMerge will // and return false there. The default implementation of PartialMerge will
// always return false. // always return false.
virtual bool PartialMerge(const Slice& key, const Slice& left_operand, virtual bool PartialMerge(const Slice& key, const Slice& left_operand,
@ -171,11 +214,8 @@ class AssociativeMergeOperator : public MergeOperator {
private: private:
// Default implementations of the MergeOperator functions // Default implementations of the MergeOperator functions
virtual bool FullMerge(const Slice& key, virtual bool FullMergeV2(const MergeOperationInput& merge_in,
const Slice* existing_value, MergeOperationOutput* merge_out) const override;
const std::deque<std::string>& operand_list,
std::string* new_value,
Logger* logger) const override;
virtual bool PartialMerge(const Slice& key, virtual bool PartialMerge(const Slice& key,
const Slice& left_operand, const Slice& left_operand,

2
table/block.h
View File

@ -162,6 +162,8 @@ class BlockIter : public InternalIterator {
virtual bool IsKeyPinned() const override { return key_pinned_; } virtual bool IsKeyPinned() const override { return key_pinned_; }
virtual bool IsValuePinned() const override { return true; }
private: private:
const Comparator* comparator_; const Comparator* comparator_;
const char* data_; // underlying block contents const char* data_; // underlying block contents

46
table/block_based_table_reader.cc
View File

@ -12,6 +12,7 @@
#include <utility> #include <utility>
#include "db/dbformat.h" #include "db/dbformat.h"
#include "db/pinned_iterators_manager.h"
#include "rocksdb/cache.h" #include "rocksdb/cache.h"
#include "rocksdb/comparator.h" #include "rocksdb/comparator.h"
@ -1381,6 +1382,10 @@ Status BlockBasedTable::Get(const ReadOptions& read_options, const Slice& key,
BlockIter iiter; BlockIter iiter;
NewIndexIterator(read_options, &iiter); NewIndexIterator(read_options, &iiter);
PinnedIteratorsManager* pinned_iters_mgr = get_context->pinned_iters_mgr();
bool pin_blocks = pinned_iters_mgr && pinned_iters_mgr->PinningEnabled();
BlockIter* biter = nullptr;
bool done = false; bool done = false;
for (iiter.Seek(key); iiter.Valid() && !done; iiter.Next()) { for (iiter.Seek(key); iiter.Valid() && !done; iiter.Next()) {
Slice handle_value = iiter.value(); Slice handle_value = iiter.value();
@ -1398,37 +1403,60 @@ Status BlockBasedTable::Get(const ReadOptions& read_options, const Slice& key,
RecordTick(rep_->ioptions.statistics, BLOOM_FILTER_USEFUL); RecordTick(rep_->ioptions.statistics, BLOOM_FILTER_USEFUL);
break; break;
} else { } else {
BlockIter biter; BlockIter stack_biter;
NewDataBlockIterator(rep_, read_options, iiter.value(), &biter); if (pin_blocks) {
// We need to create the BlockIter on heap because we may need to
// pin it if we encounterd merge operands
biter = static_cast<BlockIter*>(
NewDataBlockIterator(rep_, read_options, iiter.value()));
} else {
biter = &stack_biter;
NewDataBlockIterator(rep_, read_options, iiter.value(), biter);
}
if (read_options.read_tier == kBlockCacheTier && if (read_options.read_tier == kBlockCacheTier &&
biter.status().IsIncomplete()) { biter->status().IsIncomplete()) {
// couldn't get block from block_cache // couldn't get block from block_cache
// Update Saver.state to Found because we are only looking for whether // Update Saver.state to Found because we are only looking for whether
// we can guarantee the key is not there when "no_io" is set // we can guarantee the key is not there when "no_io" is set
get_context->MarkKeyMayExist(); get_context->MarkKeyMayExist();
break; break;
} }
if (!biter.status().ok()) { if (!biter->status().ok()) {
s = biter.status(); s = biter->status();
break; break;
} }
// Call the *saver function on each entry/block until it returns false // Call the *saver function on each entry/block until it returns false
for (biter.Seek(key); biter.Valid(); biter.Next()) { for (biter->Seek(key); biter->Valid(); biter->Next()) {
ParsedInternalKey parsed_key; ParsedInternalKey parsed_key;
if (!ParseInternalKey(biter.key(), &parsed_key)) { if (!ParseInternalKey(biter->key(), &parsed_key)) {
s = Status::Corruption(Slice()); s = Status::Corruption(Slice());
} }
if (!get_context->SaveValue(parsed_key, biter.value())) { if (!get_context->SaveValue(parsed_key, biter->value(), pin_blocks)) {
done = true; done = true;
break; break;
} }
} }
s = biter.status(); s = biter->status();
if (pin_blocks) {
if (get_context->State() == GetContext::kMerge) {
// Pin blocks as long as we are merging
pinned_iters_mgr->PinIteratorIfNeeded(biter);
} else {
delete biter;
}
biter = nullptr;
} else {
// biter is on stack, Nothing to clean
}
} }
} }
if (pin_blocks && biter != nullptr) {
delete biter;
}
if (s.ok()) { if (s.ok()) {
s = iiter.status(); s = iiter.status();
} }

13
table/get_context.cc
View File

@ -5,6 +5,7 @@
#include "table/get_context.h" #include "table/get_context.h"
#include "db/merge_helper.h" #include "db/merge_helper.h"
#include "db/pinned_iterators_manager.h"
#include "rocksdb/env.h" #include "rocksdb/env.h"
#include "rocksdb/merge_operator.h" #include "rocksdb/merge_operator.h"
#include "rocksdb/statistics.h" #include "rocksdb/statistics.h"
@ -36,7 +37,8 @@ GetContext::GetContext(const Comparator* ucmp,
Statistics* statistics, GetState init_state, Statistics* statistics, GetState init_state,
const Slice& user_key, std::string* ret_value, const Slice& user_key, std::string* ret_value,
bool* value_found, MergeContext* merge_context, Env* env, bool* value_found, MergeContext* merge_context, Env* env,
SequenceNumber* seq) SequenceNumber* seq,
PinnedIteratorsManager* _pinned_iters_mgr)
: ucmp_(ucmp), : ucmp_(ucmp),
merge_operator_(merge_operator), merge_operator_(merge_operator),
logger_(logger), logger_(logger),
@ -48,7 +50,8 @@ GetContext::GetContext(const Comparator* ucmp,
merge_context_(merge_context), merge_context_(merge_context),
env_(env), env_(env),
seq_(seq), seq_(seq),
replay_log_(nullptr) { replay_log_(nullptr),
pinned_iters_mgr_(_pinned_iters_mgr) {
if (seq_) { if (seq_) {
*seq_ = kMaxSequenceNumber; *seq_ = kMaxSequenceNumber;
} }
@ -77,7 +80,7 @@ void GetContext::SaveValue(const Slice& value, SequenceNumber seq) {
} }
bool GetContext::SaveValue(const ParsedInternalKey& parsed_key, bool GetContext::SaveValue(const ParsedInternalKey& parsed_key,
const Slice& value) { const Slice& value, bool value_pinned) {
assert((state_ != kMerge && parsed_key.type != kTypeMerge) || assert((state_ != kMerge && parsed_key.type != kTypeMerge) ||
merge_context_ != nullptr); merge_context_ != nullptr);
if (ucmp_->Equal(parsed_key.user_key, user_key_)) { if (ucmp_->Equal(parsed_key.user_key, user_key_)) {
@ -139,7 +142,7 @@ bool GetContext::SaveValue(const ParsedInternalKey& parsed_key,
case kTypeMerge: case kTypeMerge:
assert(state_ == kNotFound || state_ == kMerge); assert(state_ == kNotFound || state_ == kMerge);
state_ = kMerge; state_ = kMerge;
merge_context_->PushOperand(value); merge_context_->PushOperand(value, value_pinned);
return true; return true;
default: default:
@ -167,7 +170,7 @@ void replayGetContextLog(const Slice& replay_log, const Slice& user_key,
// Since SequenceNumber is not stored and unknown, we will use // Since SequenceNumber is not stored and unknown, we will use
// kMaxSequenceNumber. // kMaxSequenceNumber.
get_context->SaveValue( get_context->SaveValue(
ParsedInternalKey(user_key, kMaxSequenceNumber, type), value); ParsedInternalKey(user_key, kMaxSequenceNumber, type), value, true);
} }
#else // ROCKSDB_LITE #else // ROCKSDB_LITE
assert(false); assert(false);

11
table/get_context.h
View File

@ -11,6 +11,7 @@
namespace rocksdb { namespace rocksdb {
class MergeContext; class MergeContext;
class PinnedIteratorsManager;
class GetContext { class GetContext {
public: public:
@ -26,7 +27,8 @@ class GetContext {
Logger* logger, Statistics* statistics, GetState init_state, Logger* logger, Statistics* statistics, GetState init_state,
const Slice& user_key, std::string* ret_value, bool* value_found, const Slice& user_key, std::string* ret_value, bool* value_found,
MergeContext* merge_context, Env* env, MergeContext* merge_context, Env* env,
SequenceNumber* seq = nullptr); SequenceNumber* seq = nullptr,
PinnedIteratorsManager* _pinned_iters_mgr = nullptr);
void MarkKeyMayExist(); void MarkKeyMayExist();
@ -35,7 +37,8 @@ class GetContext {
// //
// Returns True if more keys need to be read (due to merges) or // Returns True if more keys need to be read (due to merges) or
// False if the complete value has been found. // False if the complete value has been found.
bool SaveValue(const ParsedInternalKey& parsed_key, const Slice& value); bool SaveValue(const ParsedInternalKey& parsed_key, const Slice& value,
bool value_pinned = false);
// Simplified version of the previous function. Should only be used when we // Simplified version of the previous function. Should only be used when we
// know that the operation is a Put. // know that the operation is a Put.
@ -43,6 +46,8 @@ class GetContext {
GetState State() const { return state_; } GetState State() const { return state_; }
PinnedIteratorsManager* pinned_iters_mgr() { return pinned_iters_mgr_; }
// If a non-null string is passed, all the SaveValue calls will be // If a non-null string is passed, all the SaveValue calls will be
// logged into the string. The operations can then be replayed on // logged into the string. The operations can then be replayed on
// another GetContext with replayGetContextLog. // another GetContext with replayGetContextLog.
@ -68,6 +73,8 @@ class GetContext {
// write to the key or kMaxSequenceNumber if unknown // write to the key or kMaxSequenceNumber if unknown
SequenceNumber* seq_; SequenceNumber* seq_;
std::string* replay_log_; std::string* replay_log_;
// Used to temporarily pin blocks when state_ == GetContext::kMerge
PinnedIteratorsManager* pinned_iters_mgr_;
}; };
void replayGetContextLog(const Slice& replay_log, const Slice& user_key, void replayGetContextLog(const Slice& replay_log, const Slice& user_key,

5
table/internal_iterator.h
View File

@ -80,6 +80,11 @@ class InternalIterator : public Cleanable {
// set to false. // set to false.
virtual bool IsKeyPinned() const { return false; } virtual bool IsKeyPinned() const { return false; }
// If true, this means that the Slice returned by value() is valid as long as
// PinnedIteratorsManager::ReleasePinnedIterators is not called and the
// Iterator is not deleted.
virtual bool IsValuePinned() const { return false; }
virtual Status GetProperty(std::string prop_name, std::string* prop) { virtual Status GetProperty(std::string prop_name, std::string* prop) {
return Status::NotSupported(""); return Status::NotSupported("");
} }

15
table/iterator_wrapper.h
View File

@ -16,7 +16,7 @@
namespace rocksdb { namespace rocksdb {
// A internal wrapper class with an interface similar to Iterator that caches // A internal wrapper class with an interface similar to Iterator that caches
// the valid(), key() and IsKeyPinned() results for an underlying iterator. // the valid() and key() results for an underlying iterator.
// This can help avoid virtual function calls and also gives better // This can help avoid virtual function calls and also gives better
// cache locality. // cache locality.
class IteratorWrapper { class IteratorWrapper {
@ -55,7 +55,6 @@ class IteratorWrapper {
// Iterator interface methods // Iterator interface methods
bool Valid() const { return valid_; } bool Valid() const { return valid_; }
Slice key() const { assert(Valid()); return key_; } Slice key() const { assert(Valid()); return key_; }
bool IsKeyPinned() const { assert(Valid()); return is_key_pinned_; }
Slice value() const { assert(Valid()); return iter_->value(); } Slice value() const { assert(Valid()); return iter_->value(); }
// Methods below require iter() != nullptr // Methods below require iter() != nullptr
Status status() const { assert(iter_); return iter_->status(); } Status status() const { assert(iter_); return iter_->status(); }
@ -64,10 +63,18 @@ class IteratorWrapper {
void Seek(const Slice& k) { assert(iter_); iter_->Seek(k); Update(); } void Seek(const Slice& k) { assert(iter_); iter_->Seek(k); Update(); }
void SeekToFirst() { assert(iter_); iter_->SeekToFirst(); Update(); } void SeekToFirst() { assert(iter_); iter_->SeekToFirst(); Update(); }
void SeekToLast() { assert(iter_); iter_->SeekToLast(); Update(); } void SeekToLast() { assert(iter_); iter_->SeekToLast(); Update(); }
void SetPinnedItersMgr(PinnedIteratorsManager* pinned_iters_mgr) { void SetPinnedItersMgr(PinnedIteratorsManager* pinned_iters_mgr) {
assert(iter_); assert(iter_);
iter_->SetPinnedItersMgr(pinned_iters_mgr); iter_->SetPinnedItersMgr(pinned_iters_mgr);
Update(); }
bool IsKeyPinned() const {
assert(Valid());
return iter_->IsKeyPinned();
}
bool IsValuePinned() const {
assert(Valid());
return iter_->IsValuePinned();
} }
private: private:
@ -75,14 +82,12 @@ class IteratorWrapper {
valid_ = iter_->Valid(); valid_ = iter_->Valid();
if (valid_) { if (valid_) {
key_ = iter_->key(); key_ = iter_->key();
is_key_pinned_ = iter_->IsKeyPinned();
} }
} }
InternalIterator* iter_; InternalIterator* iter_;
bool valid_; bool valid_;
Slice key_; Slice key_;
bool is_key_pinned_;
}; };
class Arena; class Arena;

6
table/merger.cc
View File

@ -257,6 +257,12 @@ class MergingIterator : public InternalIterator {
current_->IsKeyPinned(); current_->IsKeyPinned();
} }
virtual bool IsValuePinned() const override {
assert(Valid());
return pinned_iters_mgr_ && pinned_iters_mgr_->PinningEnabled() &&
current_->IsValuePinned();
}
private: private:
// Clears heaps for both directions, used when changing direction or seeking // Clears heaps for both directions, used when changing direction or seeking
void ClearHeaps(); void ClearHeaps();

4
table/two_level_iterator.cc
View File

@ -78,6 +78,10 @@ class TwoLevelIterator : public InternalIterator {
return pinned_iters_mgr_ && pinned_iters_mgr_->PinningEnabled() && return pinned_iters_mgr_ && pinned_iters_mgr_->PinningEnabled() &&
second_level_iter_.iter() && second_level_iter_.IsKeyPinned(); second_level_iter_.iter() && second_level_iter_.IsKeyPinned();
} }
virtual bool IsValuePinned() const override {
return pinned_iters_mgr_ && pinned_iters_mgr_->PinningEnabled() &&
second_level_iter_.iter() && second_level_iter_.IsValuePinned();
}
private: private:
void SaveError(const Status& s) { void SaveError(const Status& s) {

2
tools/db_crashtest.py
View File

@ -45,6 +45,8 @@ default_params = {
"write_buffer_size": 4 * 1024 * 1024, "write_buffer_size": 4 * 1024 * 1024,
"writepercent": 35, "writepercent": 35,
"subcompactions": lambda: random.randint(1, 4), "subcompactions": lambda: random.randint(1, 4),
"use_merge": lambda: random.randint(0, 1),
"use_full_merge_v1": lambda: random.randint(0, 1),
} }

9
tools/db_stress.cc
View File

@ -453,6 +453,9 @@ static const bool FLAGS_prefix_size_dummy __attribute__((unused)) =
DEFINE_bool(use_merge, false, "On true, replaces all writes with a Merge " DEFINE_bool(use_merge, false, "On true, replaces all writes with a Merge "
"that behaves like a Put"); "that behaves like a Put");
DEFINE_bool(use_full_merge_v1, false,
"On true, use a merge operator that implement the deprecated "
"version of FullMerge");
namespace rocksdb { namespace rocksdb {
@ -2106,7 +2109,11 @@ class StressTest {
} }
if (FLAGS_use_merge) { if (FLAGS_use_merge) {
options_.merge_operator = MergeOperators::CreatePutOperator(); if (FLAGS_use_full_merge_v1) {
options_.merge_operator = MergeOperators::CreateDeprecatedPutOperator();
} else {
options_.merge_operator = MergeOperators::CreatePutOperator();
}
} }
// set universal style compaction configurations, if applicable // set universal style compaction configurations, if applicable

6
util/testutil.h
View File

@ -614,10 +614,8 @@ class ChanglingMergeOperator : public MergeOperator {
void SetName(const std::string& name) { name_ = name; } void SetName(const std::string& name) { name_ = name; }
virtual bool FullMerge(const Slice& key, const Slice* existing_value, virtual bool FullMergeV2(const MergeOperationInput& merge_in,
const std::deque<std::string>& operand_list, MergeOperationOutput* merge_out) const override {
std::string* new_value,
Logger* logger) const override {
return false; return false;
} }
virtual bool PartialMergeMulti(const Slice& key, virtual bool PartialMergeMulti(const Slice& key,

3
utilities/merge_operators.h
View File

@ -16,6 +16,7 @@ namespace rocksdb {
class MergeOperators { class MergeOperators {
public: public:
static std::shared_ptr<MergeOperator> CreatePutOperator(); static std::shared_ptr<MergeOperator> CreatePutOperator();
static std::shared_ptr<MergeOperator> CreateDeprecatedPutOperator();
static std::shared_ptr<MergeOperator> CreateUInt64AddOperator(); static std::shared_ptr<MergeOperator> CreateUInt64AddOperator();
static std::shared_ptr<MergeOperator> CreateStringAppendOperator(); static std::shared_ptr<MergeOperator> CreateStringAppendOperator();
static std::shared_ptr<MergeOperator> CreateStringAppendTESTOperator(); static std::shared_ptr<MergeOperator> CreateStringAppendTESTOperator();
@ -27,6 +28,8 @@ class MergeOperators {
const std::string& name) { const std::string& name) {
if (name == "put") { if (name == "put") {
return CreatePutOperator(); return CreatePutOperator();
} else if (name == "put_v1") {
return CreateDeprecatedPutOperator();
} else if ( name == "uint64add") { } else if ( name == "uint64add") {
return CreateUInt64AddOperator(); return CreateUInt64AddOperator();
} else if (name == "stringappend") { } else if (name == "stringappend") {

18
utilities/merge_operators/max.cc
View File

@ -19,22 +19,20 @@ namespace { // anonymous namespace
// Slice::compare // Slice::compare
class MaxOperator : public MergeOperator { class MaxOperator : public MergeOperator {
public: public:
virtual bool FullMerge(const Slice& key, const Slice* existing_value, virtual bool FullMergeV2(const MergeOperationInput& merge_in,
const std::deque<std::string>& operand_list, MergeOperationOutput* merge_out) const override {
std::string* new_value, Slice& max = merge_out->existing_operand;
Logger* logger) const override { if (merge_in.existing_value) {
Slice max; max = Slice(merge_in.existing_value->data(),
if (existing_value) { merge_in.existing_value->size());
max = Slice(existing_value->data(), existing_value->size());
} }
for (const auto& op : operand_list) { for (const auto& op : merge_in.operand_list) {
if (max.compare(op) < 0) { if (max.compare(op) < 0) {
max = Slice(op.data(), op.size()); max = op;
} }
} }
new_value->assign(max.data(), max.size());
return true; return true;
} }

23
utilities/merge_operators/put.cc
View File

@ -57,12 +57,33 @@ class PutOperator : public MergeOperator {
} }
}; };
class PutOperatorV2 : public PutOperator {
virtual bool FullMerge(const Slice& key, const Slice* existing_value,
const std::deque<std::string>& operand_sequence,
std::string* new_value,
Logger* logger) const override {
assert(false);
return false;
}
virtual bool FullMergeV2(const MergeOperationInput& merge_in,
MergeOperationOutput* merge_out) const override {
// Put basically only looks at the current/latest value
assert(!merge_in.operand_list.empty());
merge_out->existing_operand = merge_in.operand_list.back();
return true;
}
};
} // end of anonymous namespace } // end of anonymous namespace
namespace rocksdb { namespace rocksdb {
std::shared_ptr<MergeOperator> MergeOperators::CreatePutOperator() { std::shared_ptr<MergeOperator> MergeOperators::CreateDeprecatedPutOperator() {
return std::make_shared<PutOperator>(); return std::make_shared<PutOperator>();
} }
std::shared_ptr<MergeOperator> MergeOperators::CreatePutOperator() {
return std::make_shared<PutOperatorV2>();
}
} }

39
utilities/merge_operators/string_append/stringappend2.cc
View File

@ -21,20 +21,22 @@ StringAppendTESTOperator::StringAppendTESTOperator(char delim_char)
} }
// Implementation for the merge operation (concatenates two strings) // Implementation for the merge operation (concatenates two strings)
bool StringAppendTESTOperator::FullMerge( bool StringAppendTESTOperator::FullMergeV2(
const Slice& key, const MergeOperationInput& merge_in,
const Slice* existing_value, MergeOperationOutput* merge_out) const {
const std::deque<std::string>& operands,
std::string* new_value,
Logger* logger) const {
// Clear the *new_value for writing. // Clear the *new_value for writing.
assert(new_value); merge_out->new_value.clear();
new_value->clear();
if (merge_in.existing_value == nullptr && merge_in.operand_list.size() == 1) {
// Only one operand
merge_out->existing_operand = merge_in.operand_list.back();
return true;
}
// Compute the space needed for the final result. // Compute the space needed for the final result.
size_t numBytes = 0; size_t numBytes = 0;
for(auto it = operands.begin(); it != operands.end(); ++it) { for (auto it = merge_in.operand_list.begin();
it != merge_in.operand_list.end(); ++it) {
numBytes += it->size() + 1; // Plus 1 for the delimiter numBytes += it->size() + 1; // Plus 1 for the delimiter
} }
@ -42,20 +44,23 @@ bool StringAppendTESTOperator::FullMerge(
bool printDelim = false; bool printDelim = false;
// Prepend the *existing_value if one exists. // Prepend the *existing_value if one exists.
if (existing_value) { if (merge_in.existing_value) {
new_value->reserve(numBytes + existing_value->size()); merge_out->new_value.reserve(numBytes + merge_in.existing_value->size());
new_value->append(existing_value->data(), existing_value->size()); merge_out->new_value.append(merge_in.existing_value->data(),
merge_in.existing_value->size());
printDelim = true; printDelim = true;
} else if (numBytes) { } else if (numBytes) {
new_value->reserve(numBytes-1); // Minus 1 since we have one less delimiter merge_out->new_value.reserve(
numBytes - 1); // Minus 1 since we have one less delimiter
} }
// Concatenate the sequence of strings (and add a delimiter between each) // Concatenate the sequence of strings (and add a delimiter between each)
for(auto it = operands.begin(); it != operands.end(); ++it) { for (auto it = merge_in.operand_list.begin();
it != merge_in.operand_list.end(); ++it) {
if (printDelim) { if (printDelim) {
new_value->append(1,delim_); merge_out->new_value.append(1, delim_);
} }
new_value->append(*it); merge_out->new_value.append(it->data(), it->size());
printDelim = true; printDelim = true;
} }

7
utilities/merge_operators/string_append/stringappend2.h
View File

@ -24,11 +24,8 @@ class StringAppendTESTOperator : public MergeOperator {
// Constructor with delimiter // Constructor with delimiter
explicit StringAppendTESTOperator(char delim_char); explicit StringAppendTESTOperator(char delim_char);
virtual bool FullMerge(const Slice& key, virtual bool FullMergeV2(const MergeOperationInput& merge_in,
const Slice* existing_value, MergeOperationOutput* merge_out) const override;
const std::deque<std::string>& operand_sequence,
std::string* new_value,
Logger* logger) const override;
virtual bool PartialMergeMulti(const Slice& key, virtual bool PartialMergeMulti(const Slice& key,
const std::deque<Slice>& operand_list, const std::deque<Slice>& operand_list,

10
utilities/options/options_util_test.cc
View File

@ -128,19 +128,19 @@ class DummyMergeOperator : public MergeOperator {
DummyMergeOperator() {} DummyMergeOperator() {}
virtual ~DummyMergeOperator() {} virtual ~DummyMergeOperator() {}
virtual bool FullMerge(const Slice& key, const Slice* existing_value, virtual bool FullMergeV2(const MergeOperationInput& merge_in,
const std::deque<std::string>& operand_list, MergeOperationOutput* merge_out) const override {
std::string* new_value, Logger* logger) const {
return false; return false;
} }
virtual bool PartialMergeMulti(const Slice& key, virtual bool PartialMergeMulti(const Slice& key,
const std::deque<Slice>& operand_list, const std::deque<Slice>& operand_list,
std::string* new_value, Logger* logger) const { std::string* new_value,
Logger* logger) const override {
return false; return false;
} }
virtual const char* Name() const { return "DummyMergeOperator"; } virtual const char* Name() const override { return "DummyMergeOperator"; }
}; };
class DummySliceTransform : public SliceTransform { class DummySliceTransform : public SliceTransform {

49
utilities/ttl/db_ttl_impl.h
View File

@ -225,38 +225,43 @@ class TtlMergeOperator : public MergeOperator {
assert(env); assert(env);
} }
virtual bool FullMerge(const Slice& key, const Slice* existing_value, virtual bool FullMergeV2(const MergeOperationInput& merge_in,
const std::deque<std::string>& operands, MergeOperationOutput* merge_out) const override {
std::string* new_value, Logger* logger) const
override {
const uint32_t ts_len = DBWithTTLImpl::kTSLength; const uint32_t ts_len = DBWithTTLImpl::kTSLength;
if (existing_value && existing_value->size() < ts_len) { if (merge_in.existing_value && merge_in.existing_value->size() < ts_len) {
Log(InfoLogLevel::ERROR_LEVEL, logger, Log(InfoLogLevel::ERROR_LEVEL, merge_in.logger,
"Error: Could not remove timestamp from existing value."); "Error: Could not remove timestamp from existing value.");
return false; return false;
} }
// Extract time-stamp from each operand to be passed to user_merge_op_ // Extract time-stamp from each operand to be passed to user_merge_op_
std::deque<std::string> operands_without_ts; std::vector<Slice> operands_without_ts;
for (const auto& operand : operands) { for (const auto& operand : merge_in.operand_list) {
if (operand.size() < ts_len) { if (operand.size() < ts_len) {
Log(InfoLogLevel::ERROR_LEVEL, logger, Log(InfoLogLevel::ERROR_LEVEL, merge_in.logger,
"Error: Could not remove timestamp from operand value."); "Error: Could not remove timestamp from operand value.");
return false; return false;
} }
operands_without_ts.push_back(operand.substr(0, operand.size() - ts_len)); operands_without_ts.push_back(operand);
operands_without_ts.back().remove_suffix(ts_len);
} }
// Apply the user merge operator (store result in *new_value) // Apply the user merge operator (store result in *new_value)
bool good = true; bool good = true;
if (existing_value) { MergeOperationOutput user_merge_out(merge_out->new_value,
Slice existing_value_without_ts(existing_value->data(), merge_out->existing_operand);
existing_value->size() - ts_len); if (merge_in.existing_value) {
good = user_merge_op_->FullMerge(key, &existing_value_without_ts, Slice existing_value_without_ts(merge_in.existing_value->data(),
operands_without_ts, new_value, logger); merge_in.existing_value->size() - ts_len);
good = user_merge_op_->FullMergeV2(
MergeOperationInput(merge_in.key, &existing_value_without_ts,
operands_without_ts, merge_in.logger),
&user_merge_out);
} else { } else {
good = user_merge_op_->FullMerge(key, nullptr, operands_without_ts, good = user_merge_op_->FullMergeV2(
new_value, logger); MergeOperationInput(merge_in.key, nullptr, operands_without_ts,
merge_in.logger),
&user_merge_out);
} }
// Return false if the user merge operator returned false // Return false if the user merge operator returned false
@ -264,17 +269,23 @@ class TtlMergeOperator : public MergeOperator {
return false; return false;
} }
if (merge_out->existing_operand.data()) {
merge_out->new_value.assign(merge_out->existing_operand.data(),
merge_out->existing_operand.size());
merge_out->existing_operand = Slice(nullptr, 0);
}
// Augment the *new_value with the ttl time-stamp // Augment the *new_value with the ttl time-stamp
int64_t curtime; int64_t curtime;
if (!env_->GetCurrentTime(&curtime).ok()) { if (!env_->GetCurrentTime(&curtime).ok()) {
Log(InfoLogLevel::ERROR_LEVEL, logger, Log(InfoLogLevel::ERROR_LEVEL, merge_in.logger,
"Error: Could not get current time to be attached internally " "Error: Could not get current time to be attached internally "
"to the new value."); "to the new value.");
return false; return false;
} else { } else {
char ts_string[ts_len]; char ts_string[ts_len];
EncodeFixed32(ts_string, (int32_t)curtime); EncodeFixed32(ts_string, (int32_t)curtime);
new_value->append(ts_string, ts_len); merge_out->new_value.append(ts_string, ts_len);
return true; return true;
} }
} }

53
utilities/util_merge_operators_test.cc
View File

@ -13,22 +13,41 @@ class UtilMergeOperatorTest : public testing::Test {
public: public:
UtilMergeOperatorTest() {} UtilMergeOperatorTest() {}
std::string FullMerge(std::string existing_value, std::string FullMergeV2(std::string existing_value,
std::deque<std::string> operands, std::vector<std::string> operands,
std::string key = "") { std::string key = "") {
Slice existing_value_slice(existing_value);
std::string result; std::string result;
Slice result_operand(nullptr, 0);
merge_operator_->FullMerge(key, &existing_value_slice, operands, &result, Slice existing_value_slice(existing_value);
nullptr); std::vector<Slice> operands_slice(operands.begin(), operands.end());
const MergeOperator::MergeOperationInput merge_in(
key, &existing_value_slice, operands_slice, nullptr);
MergeOperator::MergeOperationOutput merge_out(result, result_operand);
merge_operator_->FullMergeV2(merge_in, &merge_out);
if (result_operand.data()) {
result.assign(result_operand.data(), result_operand.size());
}
return result; return result;
} }
std::string FullMerge(std::deque<std::string> operands, std::string FullMergeV2(std::vector<std::string> operands,
std::string key = "") { std::string key = "") {
std::string result; std::string result;
Slice result_operand(nullptr, 0);
merge_operator_->FullMerge(key, nullptr, operands, &result, nullptr); std::vector<Slice> operands_slice(operands.begin(), operands.end());
const MergeOperator::MergeOperationInput merge_in(key, nullptr,
operands_slice, nullptr);
MergeOperator::MergeOperationOutput merge_out(result, result_operand);
merge_operator_->FullMergeV2(merge_in, &merge_out);
if (result_operand.data()) {
result.assign(result_operand.data(), result_operand.size());
}
return result; return result;
} }
@ -56,14 +75,14 @@ class UtilMergeOperatorTest : public testing::Test {
TEST_F(UtilMergeOperatorTest, MaxMergeOperator) { TEST_F(UtilMergeOperatorTest, MaxMergeOperator) {
merge_operator_ = MergeOperators::CreateMaxOperator(); merge_operator_ = MergeOperators::CreateMaxOperator();
EXPECT_EQ("B", FullMerge("B", {"A"})); EXPECT_EQ("B", FullMergeV2("B", {"A"}));
EXPECT_EQ("B", FullMerge("A", {"B"})); EXPECT_EQ("B", FullMergeV2("A", {"B"}));
EXPECT_EQ("", FullMerge({"", "", ""})); EXPECT_EQ("", FullMergeV2({"", "", ""}));
EXPECT_EQ("A", FullMerge({"A"})); EXPECT_EQ("A", FullMergeV2({"A"}));
EXPECT_EQ("ABC", FullMerge({"ABC"})); EXPECT_EQ("ABC", FullMergeV2({"ABC"}));
EXPECT_EQ("Z", FullMerge({"ABC", "Z", "C", "AXX"})); EXPECT_EQ("Z", FullMergeV2({"ABC", "Z", "C", "AXX"}));
EXPECT_EQ("ZZZ", FullMerge({"ABC", "CC", "Z", "ZZZ"})); EXPECT_EQ("ZZZ", FullMergeV2({"ABC", "CC", "Z", "ZZZ"}));
EXPECT_EQ("a", FullMerge("a", {"ABC", "CC", "Z", "ZZZ"})); EXPECT_EQ("a", FullMergeV2("a", {"ABC", "CC", "Z", "ZZZ"}));
EXPECT_EQ("z", PartialMergeMulti({"a", "z", "efqfqwgwew", "aaz", "hhhhh"})); EXPECT_EQ("z", PartialMergeMulti({"a", "z", "efqfqwgwew", "aaz", "hhhhh"}));