rocksdb/db/write_batch.cc
Maysam Yabandeh f383641a1d Unordered Writes (#5218)
Summary:
Performing unordered writes in rocksdb when unordered_write option is set to true. When enabled the writes to memtable are done without joining any write thread. This offers much higher write throughput since the upcoming writes would not have to wait for the slowest memtable write to finish. The tradeoff is that the writes visible to a snapshot might change over time. If the application cannot tolerate that, it should implement its own mechanisms to work around that. Using TransactionDB with WRITE_PREPARED write policy is one way to achieve that. Doing so increases the max throughput by 2.2x without however compromising the snapshot guarantees.
The patch is prepared based on an original by siying
Existing unit tests are extended to include unordered_write option.

Benchmark Results:
```
TEST_TMPDIR=/dev/shm/ ./db_bench_unordered --benchmarks=fillrandom --threads=32 --num=10000000 -max_write_buffer_number=16 --max_background_jobs=64 --batch_size=8 --writes=3000000 -level0_file_num_compaction_trigger=99999 --level0_slowdown_writes_trigger=99999 --level0_stop_writes_trigger=99999 -enable_pipelined_write=false -disable_auto_compactions  --unordered_write=1
```
With WAL
- Vanilla RocksDB: 78.6 MB/s
- WRITER_PREPARED with unordered_write: 177.8 MB/s (2.2x)
- unordered_write: 368.9 MB/s (4.7x with relaxed snapshot guarantees)

Without WAL
- Vanilla RocksDB: 111.3 MB/s
- WRITER_PREPARED with unordered_write: 259.3 MB/s MB/s (2.3x)
- unordered_write: 645.6 MB/s (5.8x with relaxed snapshot guarantees)

- WRITER_PREPARED with unordered_write disable concurrency control: 185.3 MB/s MB/s (2.35x)

Limitations:
- The feature is not yet extended to `max_successive_merges` > 0. The feature is also incompatible with `enable_pipelined_write` = true as well as with `allow_concurrent_memtable_write` = false.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5218

Differential Revision: D15219029

Pulled By: maysamyabandeh

fbshipit-source-id: 38f2abc4af8780148c6128acdba2b3227bc81759
2019-05-13 17:47:21 -07:00

1882 lines
67 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.
//
// WriteBatch::rep_ :=
// sequence: fixed64
// count: fixed32
// data: record[count]
// record :=
// kTypeValue varstring varstring
// kTypeDeletion varstring
// kTypeSingleDeletion varstring
// kTypeRangeDeletion varstring varstring
// kTypeMerge varstring varstring
// kTypeColumnFamilyValue varint32 varstring varstring
// kTypeColumnFamilyDeletion varint32 varstring
// kTypeColumnFamilySingleDeletion varint32 varstring
// kTypeColumnFamilyRangeDeletion varint32 varstring varstring
// kTypeColumnFamilyMerge varint32 varstring varstring
// kTypeBeginPrepareXID varstring
// kTypeEndPrepareXID
// kTypeCommitXID varstring
// kTypeRollbackXID varstring
// kTypeBeginPersistedPrepareXID varstring
// kTypeBeginUnprepareXID varstring
// kTypeNoop
// varstring :=
// len: varint32
// data: uint8[len]
#include "rocksdb/write_batch.h"
#include <map>
#include <stack>
#include <stdexcept>
#include <type_traits>
#include <vector>
#include "db/column_family.h"
#include "db/db_impl.h"
#include "db/dbformat.h"
#include "db/flush_scheduler.h"
#include "db/memtable.h"
#include "db/merge_context.h"
#include "db/snapshot_impl.h"
#include "db/write_batch_internal.h"
#include "monitoring/perf_context_imp.h"
#include "monitoring/statistics.h"
#include "rocksdb/merge_operator.h"
#include "util/autovector.h"
#include "util/coding.h"
#include "util/duplicate_detector.h"
#include "util/string_util.h"
#include "util/util.h"
namespace rocksdb {
// anon namespace for file-local types
namespace {
enum ContentFlags : uint32_t {
DEFERRED = 1 << 0,
HAS_PUT = 1 << 1,
HAS_DELETE = 1 << 2,
HAS_SINGLE_DELETE = 1 << 3,
HAS_MERGE = 1 << 4,
HAS_BEGIN_PREPARE = 1 << 5,
HAS_END_PREPARE = 1 << 6,
HAS_COMMIT = 1 << 7,
HAS_ROLLBACK = 1 << 8,
HAS_DELETE_RANGE = 1 << 9,
HAS_BLOB_INDEX = 1 << 10,
HAS_BEGIN_UNPREPARE = 1 << 11,
};
struct BatchContentClassifier : public WriteBatch::Handler {
uint32_t content_flags = 0;
Status PutCF(uint32_t, const Slice&, const Slice&) override {
content_flags |= ContentFlags::HAS_PUT;
return Status::OK();
}
Status DeleteCF(uint32_t, const Slice&) override {
content_flags |= ContentFlags::HAS_DELETE;
return Status::OK();
}
Status SingleDeleteCF(uint32_t, const Slice&) override {
content_flags |= ContentFlags::HAS_SINGLE_DELETE;
return Status::OK();
}
Status DeleteRangeCF(uint32_t, const Slice&, const Slice&) override {
content_flags |= ContentFlags::HAS_DELETE_RANGE;
return Status::OK();
}
Status MergeCF(uint32_t, const Slice&, const Slice&) override {
content_flags |= ContentFlags::HAS_MERGE;
return Status::OK();
}
Status PutBlobIndexCF(uint32_t, const Slice&, const Slice&) override {
content_flags |= ContentFlags::HAS_BLOB_INDEX;
return Status::OK();
}
Status MarkBeginPrepare(bool unprepare) override {
content_flags |= ContentFlags::HAS_BEGIN_PREPARE;
if (unprepare) {
content_flags |= ContentFlags::HAS_BEGIN_UNPREPARE;
}
return Status::OK();
}
Status MarkEndPrepare(const Slice&) override {
content_flags |= ContentFlags::HAS_END_PREPARE;
return Status::OK();
}
Status MarkCommit(const Slice&) override {
content_flags |= ContentFlags::HAS_COMMIT;
return Status::OK();
}
Status MarkRollback(const Slice&) override {
content_flags |= ContentFlags::HAS_ROLLBACK;
return Status::OK();
}
};
} // anon namespace
struct SavePoints {
std::stack<SavePoint, autovector<SavePoint>> stack;
};
WriteBatch::WriteBatch(size_t reserved_bytes, size_t max_bytes)
: content_flags_(0), max_bytes_(max_bytes), rep_() {
rep_.reserve((reserved_bytes > WriteBatchInternal::kHeader) ?
reserved_bytes : WriteBatchInternal::kHeader);
rep_.resize(WriteBatchInternal::kHeader);
}
WriteBatch::WriteBatch(const std::string& rep)
: content_flags_(ContentFlags::DEFERRED),
max_bytes_(0),
rep_(rep) {}
WriteBatch::WriteBatch(std::string&& rep)
: content_flags_(ContentFlags::DEFERRED),
max_bytes_(0),
rep_(std::move(rep)) {}
WriteBatch::WriteBatch(const WriteBatch& src)
: wal_term_point_(src.wal_term_point_),
content_flags_(src.content_flags_.load(std::memory_order_relaxed)),
max_bytes_(src.max_bytes_),
rep_(src.rep_) {
if (src.save_points_ != nullptr) {
save_points_.reset(new SavePoints());
save_points_->stack = src.save_points_->stack;
}
}
WriteBatch::WriteBatch(WriteBatch&& src) noexcept
: save_points_(std::move(src.save_points_)),
wal_term_point_(std::move(src.wal_term_point_)),
content_flags_(src.content_flags_.load(std::memory_order_relaxed)),
max_bytes_(src.max_bytes_),
rep_(std::move(src.rep_)) {}
WriteBatch& WriteBatch::operator=(const WriteBatch& src) {
if (&src != this) {
this->~WriteBatch();
new (this) WriteBatch(src);
}
return *this;
}
WriteBatch& WriteBatch::operator=(WriteBatch&& src) {
if (&src != this) {
this->~WriteBatch();
new (this) WriteBatch(std::move(src));
}
return *this;
}
WriteBatch::~WriteBatch() { }
WriteBatch::Handler::~Handler() { }
void WriteBatch::Handler::LogData(const Slice& /*blob*/) {
// If the user has not specified something to do with blobs, then we ignore
// them.
}
bool WriteBatch::Handler::Continue() {
return true;
}
void WriteBatch::Clear() {
rep_.clear();
rep_.resize(WriteBatchInternal::kHeader);
content_flags_.store(0, std::memory_order_relaxed);
if (save_points_ != nullptr) {
while (!save_points_->stack.empty()) {
save_points_->stack.pop();
}
}
wal_term_point_.clear();
}
int WriteBatch::Count() const {
return WriteBatchInternal::Count(this);
}
uint32_t WriteBatch::ComputeContentFlags() const {
auto rv = content_flags_.load(std::memory_order_relaxed);
if ((rv & ContentFlags::DEFERRED) != 0) {
BatchContentClassifier classifier;
Iterate(&classifier);
rv = classifier.content_flags;
// this method is conceptually const, because it is performing a lazy
// computation that doesn't affect the abstract state of the batch.
// content_flags_ is marked mutable so that we can perform the
// following assignment
content_flags_.store(rv, std::memory_order_relaxed);
}
return rv;
}
void WriteBatch::MarkWalTerminationPoint() {
wal_term_point_.size = GetDataSize();
wal_term_point_.count = Count();
wal_term_point_.content_flags = content_flags_;
}
bool WriteBatch::HasPut() const {
return (ComputeContentFlags() & ContentFlags::HAS_PUT) != 0;
}
bool WriteBatch::HasDelete() const {
return (ComputeContentFlags() & ContentFlags::HAS_DELETE) != 0;
}
bool WriteBatch::HasSingleDelete() const {
return (ComputeContentFlags() & ContentFlags::HAS_SINGLE_DELETE) != 0;
}
bool WriteBatch::HasDeleteRange() const {
return (ComputeContentFlags() & ContentFlags::HAS_DELETE_RANGE) != 0;
}
bool WriteBatch::HasMerge() const {
return (ComputeContentFlags() & ContentFlags::HAS_MERGE) != 0;
}
bool ReadKeyFromWriteBatchEntry(Slice* input, Slice* key, bool cf_record) {
assert(input != nullptr && key != nullptr);
// Skip tag byte
input->remove_prefix(1);
if (cf_record) {
// Skip column_family bytes
uint32_t cf;
if (!GetVarint32(input, &cf)) {
return false;
}
}
// Extract key
return GetLengthPrefixedSlice(input, key);
}
bool WriteBatch::HasBeginPrepare() const {
return (ComputeContentFlags() & ContentFlags::HAS_BEGIN_PREPARE) != 0;
}
bool WriteBatch::HasEndPrepare() const {
return (ComputeContentFlags() & ContentFlags::HAS_END_PREPARE) != 0;
}
bool WriteBatch::HasCommit() const {
return (ComputeContentFlags() & ContentFlags::HAS_COMMIT) != 0;
}
bool WriteBatch::HasRollback() const {
return (ComputeContentFlags() & ContentFlags::HAS_ROLLBACK) != 0;
}
Status ReadRecordFromWriteBatch(Slice* input, char* tag,
uint32_t* column_family, Slice* key,
Slice* value, Slice* blob, Slice* xid) {
assert(key != nullptr && value != nullptr);
*tag = (*input)[0];
input->remove_prefix(1);
*column_family = 0; // default
switch (*tag) {
case kTypeColumnFamilyValue:
if (!GetVarint32(input, column_family)) {
return Status::Corruption("bad WriteBatch Put");
}
FALLTHROUGH_INTENDED;
case kTypeValue:
if (!GetLengthPrefixedSlice(input, key) ||
!GetLengthPrefixedSlice(input, value)) {
return Status::Corruption("bad WriteBatch Put");
}
break;
case kTypeColumnFamilyDeletion:
case kTypeColumnFamilySingleDeletion:
if (!GetVarint32(input, column_family)) {
return Status::Corruption("bad WriteBatch Delete");
}
FALLTHROUGH_INTENDED;
case kTypeDeletion:
case kTypeSingleDeletion:
if (!GetLengthPrefixedSlice(input, key)) {
return Status::Corruption("bad WriteBatch Delete");
}
break;
case kTypeColumnFamilyRangeDeletion:
if (!GetVarint32(input, column_family)) {
return Status::Corruption("bad WriteBatch DeleteRange");
}
FALLTHROUGH_INTENDED;
case kTypeRangeDeletion:
// for range delete, "key" is begin_key, "value" is end_key
if (!GetLengthPrefixedSlice(input, key) ||
!GetLengthPrefixedSlice(input, value)) {
return Status::Corruption("bad WriteBatch DeleteRange");
}
break;
case kTypeColumnFamilyMerge:
if (!GetVarint32(input, column_family)) {
return Status::Corruption("bad WriteBatch Merge");
}
FALLTHROUGH_INTENDED;
case kTypeMerge:
if (!GetLengthPrefixedSlice(input, key) ||
!GetLengthPrefixedSlice(input, value)) {
return Status::Corruption("bad WriteBatch Merge");
}
break;
case kTypeColumnFamilyBlobIndex:
if (!GetVarint32(input, column_family)) {
return Status::Corruption("bad WriteBatch BlobIndex");
}
FALLTHROUGH_INTENDED;
case kTypeBlobIndex:
if (!GetLengthPrefixedSlice(input, key) ||
!GetLengthPrefixedSlice(input, value)) {
return Status::Corruption("bad WriteBatch BlobIndex");
}
break;
case kTypeLogData:
assert(blob != nullptr);
if (!GetLengthPrefixedSlice(input, blob)) {
return Status::Corruption("bad WriteBatch Blob");
}
break;
case kTypeNoop:
case kTypeBeginPrepareXID:
// This indicates that the prepared batch is also persisted in the db.
// This is used in WritePreparedTxn
case kTypeBeginPersistedPrepareXID:
// This is used in WriteUnpreparedTxn
case kTypeBeginUnprepareXID:
break;
case kTypeEndPrepareXID:
if (!GetLengthPrefixedSlice(input, xid)) {
return Status::Corruption("bad EndPrepare XID");
}
break;
case kTypeCommitXID:
if (!GetLengthPrefixedSlice(input, xid)) {
return Status::Corruption("bad Commit XID");
}
break;
case kTypeRollbackXID:
if (!GetLengthPrefixedSlice(input, xid)) {
return Status::Corruption("bad Rollback XID");
}
break;
default:
return Status::Corruption("unknown WriteBatch tag");
}
return Status::OK();
}
Status WriteBatch::Iterate(Handler* handler) const {
Slice input(rep_);
if (input.size() < WriteBatchInternal::kHeader) {
return Status::Corruption("malformed WriteBatch (too small)");
}
input.remove_prefix(WriteBatchInternal::kHeader);
Slice key, value, blob, xid;
// Sometimes a sub-batch starts with a Noop. We want to exclude such Noops as
// the batch boundary symbols otherwise we would mis-count the number of
// batches. We do that by checking whether the accumulated batch is empty
// before seeing the next Noop.
bool empty_batch = true;
int found = 0;
Status s;
char tag = 0;
uint32_t column_family = 0; // default
bool last_was_try_again = false;
bool handler_continue = true;
while (((s.ok() && !input.empty()) || UNLIKELY(s.IsTryAgain()))) {
handler_continue = handler->Continue();
if (!handler_continue) {
break;
}
if (LIKELY(!s.IsTryAgain())) {
last_was_try_again = false;
tag = 0;
column_family = 0; // default
s = ReadRecordFromWriteBatch(&input, &tag, &column_family, &key, &value,
&blob, &xid);
if (!s.ok()) {
return s;
}
} else {
assert(s.IsTryAgain());
assert(!last_was_try_again); // to detect infinite loop bugs
if (UNLIKELY(last_was_try_again)) {
return Status::Corruption(
"two consecutive TryAgain in WriteBatch handler; this is either a "
"software bug or data corruption.");
}
last_was_try_again = true;
s = Status::OK();
}
switch (tag) {
case kTypeColumnFamilyValue:
case kTypeValue:
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_PUT));
s = handler->PutCF(column_family, key, value);
if (LIKELY(s.ok())) {
empty_batch = false;
found++;
}
break;
case kTypeColumnFamilyDeletion:
case kTypeDeletion:
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_DELETE));
s = handler->DeleteCF(column_family, key);
if (LIKELY(s.ok())) {
empty_batch = false;
found++;
}
break;
case kTypeColumnFamilySingleDeletion:
case kTypeSingleDeletion:
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_SINGLE_DELETE));
s = handler->SingleDeleteCF(column_family, key);
if (LIKELY(s.ok())) {
empty_batch = false;
found++;
}
break;
case kTypeColumnFamilyRangeDeletion:
case kTypeRangeDeletion:
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_DELETE_RANGE));
s = handler->DeleteRangeCF(column_family, key, value);
if (LIKELY(s.ok())) {
empty_batch = false;
found++;
}
break;
case kTypeColumnFamilyMerge:
case kTypeMerge:
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_MERGE));
s = handler->MergeCF(column_family, key, value);
if (LIKELY(s.ok())) {
empty_batch = false;
found++;
}
break;
case kTypeColumnFamilyBlobIndex:
case kTypeBlobIndex:
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_BLOB_INDEX));
s = handler->PutBlobIndexCF(column_family, key, value);
if (LIKELY(s.ok())) {
found++;
}
break;
case kTypeLogData:
handler->LogData(blob);
// A batch might have nothing but LogData. It is still a batch.
empty_batch = false;
break;
case kTypeBeginPrepareXID:
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_BEGIN_PREPARE));
handler->MarkBeginPrepare();
empty_batch = false;
if (!handler->WriteAfterCommit()) {
s = Status::NotSupported(
"WriteCommitted txn tag when write_after_commit_ is disabled (in "
"WritePrepared/WriteUnprepared mode). If it is not due to "
"corruption, the WAL must be emptied before changing the "
"WritePolicy.");
}
if (handler->WriteBeforePrepare()) {
s = Status::NotSupported(
"WriteCommitted txn tag when write_before_prepare_ is enabled "
"(in WriteUnprepared mode). If it is not due to corruption, the "
"WAL must be emptied before changing the WritePolicy.");
}
break;
case kTypeBeginPersistedPrepareXID:
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_BEGIN_PREPARE));
handler->MarkBeginPrepare();
empty_batch = false;
if (handler->WriteAfterCommit()) {
s = Status::NotSupported(
"WritePrepared/WriteUnprepared txn tag when write_after_commit_ "
"is enabled (in default WriteCommitted mode). If it is not due "
"to corruption, the WAL must be emptied before changing the "
"WritePolicy.");
}
break;
case kTypeBeginUnprepareXID:
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_BEGIN_UNPREPARE));
handler->MarkBeginPrepare(true /* unprepared */);
empty_batch = false;
if (handler->WriteAfterCommit()) {
s = Status::NotSupported(
"WriteUnprepared txn tag when write_after_commit_ is enabled (in "
"default WriteCommitted mode). If it is not due to corruption, "
"the WAL must be emptied before changing the WritePolicy.");
}
if (!handler->WriteBeforePrepare()) {
s = Status::NotSupported(
"WriteUnprepared txn tag when write_before_prepare_ is disabled "
"(in WriteCommitted/WritePrepared mode). If it is not due to "
"corruption, the WAL must be emptied before changing the "
"WritePolicy.");
}
break;
case kTypeEndPrepareXID:
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_END_PREPARE));
handler->MarkEndPrepare(xid);
empty_batch = true;
break;
case kTypeCommitXID:
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_COMMIT));
handler->MarkCommit(xid);
empty_batch = true;
break;
case kTypeRollbackXID:
assert(content_flags_.load(std::memory_order_relaxed) &
(ContentFlags::DEFERRED | ContentFlags::HAS_ROLLBACK));
handler->MarkRollback(xid);
empty_batch = true;
break;
case kTypeNoop:
handler->MarkNoop(empty_batch);
empty_batch = true;
break;
default:
return Status::Corruption("unknown WriteBatch tag");
}
}
if (!s.ok()) {
return s;
}
if (handler_continue && found != WriteBatchInternal::Count(this)) {
return Status::Corruption("WriteBatch has wrong count");
} else {
return Status::OK();
}
}
bool WriteBatchInternal::IsLatestPersistentState(const WriteBatch* b) {
return b->is_latest_persistent_state_;
}
void WriteBatchInternal::SetAsLastestPersistentState(WriteBatch* b) {
b->is_latest_persistent_state_ = true;
}
int WriteBatchInternal::Count(const WriteBatch* b) {
return DecodeFixed32(b->rep_.data() + 8);
}
void WriteBatchInternal::SetCount(WriteBatch* b, int n) {
EncodeFixed32(&b->rep_[8], n);
}
SequenceNumber WriteBatchInternal::Sequence(const WriteBatch* b) {
return SequenceNumber(DecodeFixed64(b->rep_.data()));
}
void WriteBatchInternal::SetSequence(WriteBatch* b, SequenceNumber seq) {
EncodeFixed64(&b->rep_[0], seq);
}
size_t WriteBatchInternal::GetFirstOffset(WriteBatch* /*b*/) {
return WriteBatchInternal::kHeader;
}
Status WriteBatchInternal::Put(WriteBatch* b, uint32_t column_family_id,
const Slice& key, const Slice& value) {
if (key.size() > size_t{port::kMaxUint32}) {
return Status::InvalidArgument("key is too large");
}
if (value.size() > size_t{port::kMaxUint32}) {
return Status::InvalidArgument("value is too large");
}
LocalSavePoint save(b);
WriteBatchInternal::SetCount(b, WriteBatchInternal::Count(b) + 1);
if (column_family_id == 0) {
b->rep_.push_back(static_cast<char>(kTypeValue));
} else {
b->rep_.push_back(static_cast<char>(kTypeColumnFamilyValue));
PutVarint32(&b->rep_, column_family_id);
}
PutLengthPrefixedSlice(&b->rep_, key);
PutLengthPrefixedSlice(&b->rep_, value);
b->content_flags_.store(
b->content_flags_.load(std::memory_order_relaxed) | ContentFlags::HAS_PUT,
std::memory_order_relaxed);
return save.commit();
}
Status WriteBatch::Put(ColumnFamilyHandle* column_family, const Slice& key,
const Slice& value) {
return WriteBatchInternal::Put(this, GetColumnFamilyID(column_family), key,
value);
}
Status WriteBatchInternal::CheckSlicePartsLength(const SliceParts& key,
const SliceParts& value) {
size_t total_key_bytes = 0;
for (int i = 0; i < key.num_parts; ++i) {
total_key_bytes += key.parts[i].size();
}
if (total_key_bytes >= size_t{port::kMaxUint32}) {
return Status::InvalidArgument("key is too large");
}
size_t total_value_bytes = 0;
for (int i = 0; i < value.num_parts; ++i) {
total_value_bytes += value.parts[i].size();
}
if (total_value_bytes >= size_t{port::kMaxUint32}) {
return Status::InvalidArgument("value is too large");
}
return Status::OK();
}
Status WriteBatchInternal::Put(WriteBatch* b, uint32_t column_family_id,
const SliceParts& key, const SliceParts& value) {
Status s = CheckSlicePartsLength(key, value);
if (!s.ok()) {
return s;
}
LocalSavePoint save(b);
WriteBatchInternal::SetCount(b, WriteBatchInternal::Count(b) + 1);
if (column_family_id == 0) {
b->rep_.push_back(static_cast<char>(kTypeValue));
} else {
b->rep_.push_back(static_cast<char>(kTypeColumnFamilyValue));
PutVarint32(&b->rep_, column_family_id);
}
PutLengthPrefixedSliceParts(&b->rep_, key);
PutLengthPrefixedSliceParts(&b->rep_, value);
b->content_flags_.store(
b->content_flags_.load(std::memory_order_relaxed) | ContentFlags::HAS_PUT,
std::memory_order_relaxed);
return save.commit();
}
Status WriteBatch::Put(ColumnFamilyHandle* column_family, const SliceParts& key,
const SliceParts& value) {
return WriteBatchInternal::Put(this, GetColumnFamilyID(column_family), key,
value);
}
Status WriteBatchInternal::InsertNoop(WriteBatch* b) {
b->rep_.push_back(static_cast<char>(kTypeNoop));
return Status::OK();
}
Status WriteBatchInternal::MarkEndPrepare(WriteBatch* b, const Slice& xid,
bool write_after_commit,
bool unprepared_batch) {
// a manually constructed batch can only contain one prepare section
assert(b->rep_[12] == static_cast<char>(kTypeNoop));
// all savepoints up to this point are cleared
if (b->save_points_ != nullptr) {
while (!b->save_points_->stack.empty()) {
b->save_points_->stack.pop();
}
}
// rewrite noop as begin marker
b->rep_[12] = static_cast<char>(
write_after_commit ? kTypeBeginPrepareXID
: (unprepared_batch ? kTypeBeginUnprepareXID
: kTypeBeginPersistedPrepareXID));
b->rep_.push_back(static_cast<char>(kTypeEndPrepareXID));
PutLengthPrefixedSlice(&b->rep_, xid);
b->content_flags_.store(b->content_flags_.load(std::memory_order_relaxed) |
ContentFlags::HAS_END_PREPARE |
ContentFlags::HAS_BEGIN_PREPARE,
std::memory_order_relaxed);
if (unprepared_batch) {
b->content_flags_.store(b->content_flags_.load(std::memory_order_relaxed) |
ContentFlags::HAS_BEGIN_UNPREPARE,
std::memory_order_relaxed);
}
return Status::OK();
}
Status WriteBatchInternal::MarkCommit(WriteBatch* b, const Slice& xid) {
b->rep_.push_back(static_cast<char>(kTypeCommitXID));
PutLengthPrefixedSlice(&b->rep_, xid);
b->content_flags_.store(b->content_flags_.load(std::memory_order_relaxed) |
ContentFlags::HAS_COMMIT,
std::memory_order_relaxed);
return Status::OK();
}
Status WriteBatchInternal::MarkRollback(WriteBatch* b, const Slice& xid) {
b->rep_.push_back(static_cast<char>(kTypeRollbackXID));
PutLengthPrefixedSlice(&b->rep_, xid);
b->content_flags_.store(b->content_flags_.load(std::memory_order_relaxed) |
ContentFlags::HAS_ROLLBACK,
std::memory_order_relaxed);
return Status::OK();
}
Status WriteBatchInternal::Delete(WriteBatch* b, uint32_t column_family_id,
const Slice& key) {
LocalSavePoint save(b);
WriteBatchInternal::SetCount(b, WriteBatchInternal::Count(b) + 1);
if (column_family_id == 0) {
b->rep_.push_back(static_cast<char>(kTypeDeletion));
} else {
b->rep_.push_back(static_cast<char>(kTypeColumnFamilyDeletion));
PutVarint32(&b->rep_, column_family_id);
}
PutLengthPrefixedSlice(&b->rep_, key);
b->content_flags_.store(b->content_flags_.load(std::memory_order_relaxed) |
ContentFlags::HAS_DELETE,
std::memory_order_relaxed);
return save.commit();
}
Status WriteBatch::Delete(ColumnFamilyHandle* column_family, const Slice& key) {
return WriteBatchInternal::Delete(this, GetColumnFamilyID(column_family),
key);
}
Status WriteBatchInternal::Delete(WriteBatch* b, uint32_t column_family_id,
const SliceParts& key) {
LocalSavePoint save(b);
WriteBatchInternal::SetCount(b, WriteBatchInternal::Count(b) + 1);
if (column_family_id == 0) {
b->rep_.push_back(static_cast<char>(kTypeDeletion));
} else {
b->rep_.push_back(static_cast<char>(kTypeColumnFamilyDeletion));
PutVarint32(&b->rep_, column_family_id);
}
PutLengthPrefixedSliceParts(&b->rep_, key);
b->content_flags_.store(b->content_flags_.load(std::memory_order_relaxed) |
ContentFlags::HAS_DELETE,
std::memory_order_relaxed);
return save.commit();
}
Status WriteBatch::Delete(ColumnFamilyHandle* column_family,
const SliceParts& key) {
return WriteBatchInternal::Delete(this, GetColumnFamilyID(column_family),
key);
}
Status WriteBatchInternal::SingleDelete(WriteBatch* b,
uint32_t column_family_id,
const Slice& key) {
LocalSavePoint save(b);
WriteBatchInternal::SetCount(b, WriteBatchInternal::Count(b) + 1);
if (column_family_id == 0) {
b->rep_.push_back(static_cast<char>(kTypeSingleDeletion));
} else {
b->rep_.push_back(static_cast<char>(kTypeColumnFamilySingleDeletion));
PutVarint32(&b->rep_, column_family_id);
}
PutLengthPrefixedSlice(&b->rep_, key);
b->content_flags_.store(b->content_flags_.load(std::memory_order_relaxed) |
ContentFlags::HAS_SINGLE_DELETE,
std::memory_order_relaxed);
return save.commit();
}
Status WriteBatch::SingleDelete(ColumnFamilyHandle* column_family,
const Slice& key) {
return WriteBatchInternal::SingleDelete(
this, GetColumnFamilyID(column_family), key);
}
Status WriteBatchInternal::SingleDelete(WriteBatch* b,
uint32_t column_family_id,
const SliceParts& key) {
LocalSavePoint save(b);
WriteBatchInternal::SetCount(b, WriteBatchInternal::Count(b) + 1);
if (column_family_id == 0) {
b->rep_.push_back(static_cast<char>(kTypeSingleDeletion));
} else {
b->rep_.push_back(static_cast<char>(kTypeColumnFamilySingleDeletion));
PutVarint32(&b->rep_, column_family_id);
}
PutLengthPrefixedSliceParts(&b->rep_, key);
b->content_flags_.store(b->content_flags_.load(std::memory_order_relaxed) |
ContentFlags::HAS_SINGLE_DELETE,
std::memory_order_relaxed);
return save.commit();
}
Status WriteBatch::SingleDelete(ColumnFamilyHandle* column_family,
const SliceParts& key) {
return WriteBatchInternal::SingleDelete(
this, GetColumnFamilyID(column_family), key);
}
Status WriteBatchInternal::DeleteRange(WriteBatch* b, uint32_t column_family_id,
const Slice& begin_key,
const Slice& end_key) {
LocalSavePoint save(b);
WriteBatchInternal::SetCount(b, WriteBatchInternal::Count(b) + 1);
if (column_family_id == 0) {
b->rep_.push_back(static_cast<char>(kTypeRangeDeletion));
} else {
b->rep_.push_back(static_cast<char>(kTypeColumnFamilyRangeDeletion));
PutVarint32(&b->rep_, column_family_id);
}
PutLengthPrefixedSlice(&b->rep_, begin_key);
PutLengthPrefixedSlice(&b->rep_, end_key);
b->content_flags_.store(b->content_flags_.load(std::memory_order_relaxed) |
ContentFlags::HAS_DELETE_RANGE,
std::memory_order_relaxed);
return save.commit();
}
Status WriteBatch::DeleteRange(ColumnFamilyHandle* column_family,
const Slice& begin_key, const Slice& end_key) {
return WriteBatchInternal::DeleteRange(this, GetColumnFamilyID(column_family),
begin_key, end_key);
}
Status WriteBatchInternal::DeleteRange(WriteBatch* b, uint32_t column_family_id,
const SliceParts& begin_key,
const SliceParts& end_key) {
LocalSavePoint save(b);
WriteBatchInternal::SetCount(b, WriteBatchInternal::Count(b) + 1);
if (column_family_id == 0) {
b->rep_.push_back(static_cast<char>(kTypeRangeDeletion));
} else {
b->rep_.push_back(static_cast<char>(kTypeColumnFamilyRangeDeletion));
PutVarint32(&b->rep_, column_family_id);
}
PutLengthPrefixedSliceParts(&b->rep_, begin_key);
PutLengthPrefixedSliceParts(&b->rep_, end_key);
b->content_flags_.store(b->content_flags_.load(std::memory_order_relaxed) |
ContentFlags::HAS_DELETE_RANGE,
std::memory_order_relaxed);
return save.commit();
}
Status WriteBatch::DeleteRange(ColumnFamilyHandle* column_family,
const SliceParts& begin_key,
const SliceParts& end_key) {
return WriteBatchInternal::DeleteRange(this, GetColumnFamilyID(column_family),
begin_key, end_key);
}
Status WriteBatchInternal::Merge(WriteBatch* b, uint32_t column_family_id,
const Slice& key, const Slice& value) {
if (key.size() > size_t{port::kMaxUint32}) {
return Status::InvalidArgument("key is too large");
}
if (value.size() > size_t{port::kMaxUint32}) {
return Status::InvalidArgument("value is too large");
}
LocalSavePoint save(b);
WriteBatchInternal::SetCount(b, WriteBatchInternal::Count(b) + 1);
if (column_family_id == 0) {
b->rep_.push_back(static_cast<char>(kTypeMerge));
} else {
b->rep_.push_back(static_cast<char>(kTypeColumnFamilyMerge));
PutVarint32(&b->rep_, column_family_id);
}
PutLengthPrefixedSlice(&b->rep_, key);
PutLengthPrefixedSlice(&b->rep_, value);
b->content_flags_.store(b->content_flags_.load(std::memory_order_relaxed) |
ContentFlags::HAS_MERGE,
std::memory_order_relaxed);
return save.commit();
}
Status WriteBatch::Merge(ColumnFamilyHandle* column_family, const Slice& key,
const Slice& value) {
return WriteBatchInternal::Merge(this, GetColumnFamilyID(column_family), key,
value);
}
Status WriteBatchInternal::Merge(WriteBatch* b, uint32_t column_family_id,
const SliceParts& key,
const SliceParts& value) {
Status s = CheckSlicePartsLength(key, value);
if (!s.ok()) {
return s;
}
LocalSavePoint save(b);
WriteBatchInternal::SetCount(b, WriteBatchInternal::Count(b) + 1);
if (column_family_id == 0) {
b->rep_.push_back(static_cast<char>(kTypeMerge));
} else {
b->rep_.push_back(static_cast<char>(kTypeColumnFamilyMerge));
PutVarint32(&b->rep_, column_family_id);
}
PutLengthPrefixedSliceParts(&b->rep_, key);
PutLengthPrefixedSliceParts(&b->rep_, value);
b->content_flags_.store(b->content_flags_.load(std::memory_order_relaxed) |
ContentFlags::HAS_MERGE,
std::memory_order_relaxed);
return save.commit();
}
Status WriteBatch::Merge(ColumnFamilyHandle* column_family,
const SliceParts& key, const SliceParts& value) {
return WriteBatchInternal::Merge(this, GetColumnFamilyID(column_family), key,
value);
}
Status WriteBatchInternal::PutBlobIndex(WriteBatch* b,
uint32_t column_family_id,
const Slice& key, const Slice& value) {
LocalSavePoint save(b);
WriteBatchInternal::SetCount(b, WriteBatchInternal::Count(b) + 1);
if (column_family_id == 0) {
b->rep_.push_back(static_cast<char>(kTypeBlobIndex));
} else {
b->rep_.push_back(static_cast<char>(kTypeColumnFamilyBlobIndex));
PutVarint32(&b->rep_, column_family_id);
}
PutLengthPrefixedSlice(&b->rep_, key);
PutLengthPrefixedSlice(&b->rep_, value);
b->content_flags_.store(b->content_flags_.load(std::memory_order_relaxed) |
ContentFlags::HAS_BLOB_INDEX,
std::memory_order_relaxed);
return save.commit();
}
Status WriteBatch::PutLogData(const Slice& blob) {
LocalSavePoint save(this);
rep_.push_back(static_cast<char>(kTypeLogData));
PutLengthPrefixedSlice(&rep_, blob);
return save.commit();
}
void WriteBatch::SetSavePoint() {
if (save_points_ == nullptr) {
save_points_.reset(new SavePoints());
}
// Record length and count of current batch of writes.
save_points_->stack.push(SavePoint(
GetDataSize(), Count(), content_flags_.load(std::memory_order_relaxed)));
}
Status WriteBatch::RollbackToSavePoint() {
if (save_points_ == nullptr || save_points_->stack.size() == 0) {
return Status::NotFound();
}
// Pop the most recent savepoint off the stack
SavePoint savepoint = save_points_->stack.top();
save_points_->stack.pop();
assert(savepoint.size <= rep_.size());
assert(savepoint.count <= Count());
if (savepoint.size == rep_.size()) {
// No changes to rollback
} else if (savepoint.size == 0) {
// Rollback everything
Clear();
} else {
rep_.resize(savepoint.size);
WriteBatchInternal::SetCount(this, savepoint.count);
content_flags_.store(savepoint.content_flags, std::memory_order_relaxed);
}
return Status::OK();
}
Status WriteBatch::PopSavePoint() {
if (save_points_ == nullptr || save_points_->stack.size() == 0) {
return Status::NotFound();
}
// Pop the most recent savepoint off the stack
save_points_->stack.pop();
return Status::OK();
}
class MemTableInserter : public WriteBatch::Handler {
SequenceNumber sequence_;
ColumnFamilyMemTables* const cf_mems_;
FlushScheduler* const flush_scheduler_;
const bool ignore_missing_column_families_;
const uint64_t recovering_log_number_;
// log number that all Memtables inserted into should reference
uint64_t log_number_ref_;
DBImpl* db_;
const bool concurrent_memtable_writes_;
bool post_info_created_;
bool* has_valid_writes_;
// On some (!) platforms just default creating
// a map is too expensive in the Write() path as they
// cause memory allocations though unused.
// Make creation optional but do not incur
// std::unique_ptr additional allocation
using MemPostInfoMap = std::map<MemTable*, MemTablePostProcessInfo>;
using PostMapType = std::aligned_storage<sizeof(MemPostInfoMap)>::type;
PostMapType mem_post_info_map_;
// current recovered transaction we are rebuilding (recovery)
WriteBatch* rebuilding_trx_;
SequenceNumber rebuilding_trx_seq_;
// Increase seq number once per each write batch. Otherwise increase it once
// per key.
bool seq_per_batch_;
// Whether the memtable write will be done only after the commit
bool write_after_commit_;
// Whether memtable write can be done before prepare
bool write_before_prepare_;
// Whether this batch was unprepared or not
bool unprepared_batch_;
using DupDetector = std::aligned_storage<sizeof(DuplicateDetector)>::type;
DupDetector duplicate_detector_;
bool dup_dectector_on_;
MemPostInfoMap& GetPostMap() {
assert(concurrent_memtable_writes_);
if(!post_info_created_) {
new (&mem_post_info_map_) MemPostInfoMap();
post_info_created_ = true;
}
return *reinterpret_cast<MemPostInfoMap*>(&mem_post_info_map_);
}
bool IsDuplicateKeySeq(uint32_t column_family_id, const Slice& key) {
assert(!write_after_commit_);
assert(rebuilding_trx_ != nullptr);
if (!dup_dectector_on_) {
new (&duplicate_detector_) DuplicateDetector(db_);
dup_dectector_on_ = true;
}
return reinterpret_cast<DuplicateDetector*>
(&duplicate_detector_)->IsDuplicateKeySeq(column_family_id, key, sequence_);
}
protected:
bool WriteBeforePrepare() const override { return write_before_prepare_; }
bool WriteAfterCommit() const override { return write_after_commit_; }
public:
// cf_mems should not be shared with concurrent inserters
MemTableInserter(SequenceNumber _sequence, ColumnFamilyMemTables* cf_mems,
FlushScheduler* flush_scheduler,
bool ignore_missing_column_families,
uint64_t recovering_log_number, DB* db,
bool concurrent_memtable_writes,
bool* has_valid_writes = nullptr, bool seq_per_batch = false,
bool batch_per_txn = true)
: sequence_(_sequence),
cf_mems_(cf_mems),
flush_scheduler_(flush_scheduler),
ignore_missing_column_families_(ignore_missing_column_families),
recovering_log_number_(recovering_log_number),
log_number_ref_(0),
db_(reinterpret_cast<DBImpl*>(db)),
concurrent_memtable_writes_(concurrent_memtable_writes),
post_info_created_(false),
has_valid_writes_(has_valid_writes),
rebuilding_trx_(nullptr),
rebuilding_trx_seq_(0),
seq_per_batch_(seq_per_batch),
// Write after commit currently uses one seq per key (instead of per
// batch). So seq_per_batch being false indicates write_after_commit
// approach.
write_after_commit_(!seq_per_batch),
// WriteUnprepared can write WriteBatches per transaction, so
// batch_per_txn being false indicates write_before_prepare.
write_before_prepare_(!batch_per_txn),
unprepared_batch_(false),
duplicate_detector_(),
dup_dectector_on_(false) {
assert(cf_mems_);
}
~MemTableInserter() override {
if (dup_dectector_on_) {
reinterpret_cast<DuplicateDetector*>
(&duplicate_detector_)->~DuplicateDetector();
}
if (post_info_created_) {
reinterpret_cast<MemPostInfoMap*>
(&mem_post_info_map_)->~MemPostInfoMap();
}
delete rebuilding_trx_;
}
MemTableInserter(const MemTableInserter&) = delete;
MemTableInserter& operator=(const MemTableInserter&) = delete;
// The batch seq is regularly restarted; In normal mode it is set when
// MemTableInserter is constructed in the write thread and in recovery mode it
// is set when a batch, which is tagged with seq, is read from the WAL.
// Within a sequenced batch, which could be a merge of multiple batches, we
// have two policies to advance the seq: i) seq_per_key (default) and ii)
// seq_per_batch. To implement the latter we need to mark the boundary between
// the individual batches. The approach is this: 1) Use the terminating
// markers to indicate the boundary (kTypeEndPrepareXID, kTypeCommitXID,
// kTypeRollbackXID) 2) Terminate a batch with kTypeNoop in the absence of a
// natural boundary marker.
void MaybeAdvanceSeq(bool batch_boundry = false) {
if (batch_boundry == seq_per_batch_) {
sequence_++;
}
}
void set_log_number_ref(uint64_t log) { log_number_ref_ = log; }
SequenceNumber sequence() const { return sequence_; }
void PostProcess() {
assert(concurrent_memtable_writes_);
// If post info was not created there is nothing
// to process and no need to create on demand
if(post_info_created_) {
for (auto& pair : GetPostMap()) {
pair.first->BatchPostProcess(pair.second);
}
}
}
bool SeekToColumnFamily(uint32_t column_family_id, Status* s) {
// If we are in a concurrent mode, it is the caller's responsibility
// to clone the original ColumnFamilyMemTables so that each thread
// has its own instance. Otherwise, it must be guaranteed that there
// is no concurrent access
bool found = cf_mems_->Seek(column_family_id);
if (!found) {
if (ignore_missing_column_families_) {
*s = Status::OK();
} else {
*s = Status::InvalidArgument(
"Invalid column family specified in write batch");
}
return false;
}
if (recovering_log_number_ != 0 &&
recovering_log_number_ < cf_mems_->GetLogNumber()) {
// This is true only in recovery environment (recovering_log_number_ is
// always 0 in
// non-recovery, regular write code-path)
// * If recovering_log_number_ < cf_mems_->GetLogNumber(), this means that
// column
// family already contains updates from this log. We can't apply updates
// twice because of update-in-place or merge workloads -- ignore the
// update
*s = Status::OK();
return false;
}
if (has_valid_writes_ != nullptr) {
*has_valid_writes_ = true;
}
if (log_number_ref_ > 0) {
cf_mems_->GetMemTable()->RefLogContainingPrepSection(log_number_ref_);
}
return true;
}
Status PutCFImpl(uint32_t column_family_id, const Slice& key,
const Slice& value, ValueType value_type) {
// optimize for non-recovery mode
if (UNLIKELY(write_after_commit_ && rebuilding_trx_ != nullptr)) {
WriteBatchInternal::Put(rebuilding_trx_, column_family_id, key, value);
return Status::OK();
// else insert the values to the memtable right away
}
Status seek_status;
if (UNLIKELY(!SeekToColumnFamily(column_family_id, &seek_status))) {
bool batch_boundry = false;
if (rebuilding_trx_ != nullptr) {
assert(!write_after_commit_);
// The CF is probably flushed and hence no need for insert but we still
// need to keep track of the keys for upcoming rollback/commit.
WriteBatchInternal::Put(rebuilding_trx_, column_family_id, key, value);
batch_boundry = IsDuplicateKeySeq(column_family_id, key);
}
MaybeAdvanceSeq(batch_boundry);
return seek_status;
}
Status ret_status;
MemTable* mem = cf_mems_->GetMemTable();
auto* moptions = mem->GetImmutableMemTableOptions();
// inplace_update_support is inconsistent with snapshots, and therefore with
// any kind of transactions including the ones that use seq_per_batch
assert(!seq_per_batch_ || !moptions->inplace_update_support);
if (!moptions->inplace_update_support) {
bool mem_res =
mem->Add(sequence_, value_type, key, value,
concurrent_memtable_writes_, get_post_process_info(mem));
if (UNLIKELY(!mem_res)) {
assert(seq_per_batch_);
ret_status = Status::TryAgain("key+seq exists");
const bool BATCH_BOUNDRY = true;
MaybeAdvanceSeq(BATCH_BOUNDRY);
}
} else if (moptions->inplace_callback == nullptr) {
assert(!concurrent_memtable_writes_);
mem->Update(sequence_, key, value);
} else {
assert(!concurrent_memtable_writes_);
if (mem->UpdateCallback(sequence_, key, value)) {
} else {
// key not found in memtable. Do sst get, update, add
SnapshotImpl read_from_snapshot;
read_from_snapshot.number_ = sequence_;
ReadOptions ropts;
// it's going to be overwritten for sure, so no point caching data block
// containing the old version
ropts.fill_cache = false;
ropts.snapshot = &read_from_snapshot;
std::string prev_value;
std::string merged_value;
auto cf_handle = cf_mems_->GetColumnFamilyHandle();
Status s = Status::NotSupported();
if (db_ != nullptr && recovering_log_number_ == 0) {
if (cf_handle == nullptr) {
cf_handle = db_->DefaultColumnFamily();
}
s = db_->Get(ropts, cf_handle, key, &prev_value);
}
char* prev_buffer = const_cast<char*>(prev_value.c_str());
uint32_t prev_size = static_cast<uint32_t>(prev_value.size());
auto status = moptions->inplace_callback(s.ok() ? prev_buffer : nullptr,
s.ok() ? &prev_size : nullptr,
value, &merged_value);
if (status == UpdateStatus::UPDATED_INPLACE) {
// prev_value is updated in-place with final value.
bool mem_res __attribute__((__unused__));
mem_res = mem->Add(
sequence_, value_type, key, Slice(prev_buffer, prev_size));
assert(mem_res);
RecordTick(moptions->statistics, NUMBER_KEYS_WRITTEN);
} else if (status == UpdateStatus::UPDATED) {
// merged_value contains the final value.
bool mem_res __attribute__((__unused__));
mem_res =
mem->Add(sequence_, value_type, key, Slice(merged_value));
assert(mem_res);
RecordTick(moptions->statistics, NUMBER_KEYS_WRITTEN);
}
}
}
// optimize for non-recovery mode
if (UNLIKELY(!ret_status.IsTryAgain() && rebuilding_trx_ != nullptr)) {
assert(!write_after_commit_);
// If the ret_status is TryAgain then let the next try to add the ky to
// the rebuilding transaction object.
WriteBatchInternal::Put(rebuilding_trx_, column_family_id, key, value);
}
// Since all Puts are logged in transaction logs (if enabled), always bump
// sequence number. Even if the update eventually fails and does not result
// in memtable add/update.
MaybeAdvanceSeq();
CheckMemtableFull();
return ret_status;
}
Status PutCF(uint32_t column_family_id, const Slice& key,
const Slice& value) override {
return PutCFImpl(column_family_id, key, value, kTypeValue);
}
Status DeleteImpl(uint32_t /*column_family_id*/, const Slice& key,
const Slice& value, ValueType delete_type) {
Status ret_status;
MemTable* mem = cf_mems_->GetMemTable();
bool mem_res =
mem->Add(sequence_, delete_type, key, value,
concurrent_memtable_writes_, get_post_process_info(mem));
if (UNLIKELY(!mem_res)) {
assert(seq_per_batch_);
ret_status = Status::TryAgain("key+seq exists");
const bool BATCH_BOUNDRY = true;
MaybeAdvanceSeq(BATCH_BOUNDRY);
}
MaybeAdvanceSeq();
CheckMemtableFull();
return ret_status;
}
Status DeleteCF(uint32_t column_family_id, const Slice& key) override {
// optimize for non-recovery mode
if (UNLIKELY(write_after_commit_ && rebuilding_trx_ != nullptr)) {
WriteBatchInternal::Delete(rebuilding_trx_, column_family_id, key);
return Status::OK();
// else insert the values to the memtable right away
}
Status seek_status;
if (UNLIKELY(!SeekToColumnFamily(column_family_id, &seek_status))) {
bool batch_boundry = false;
if (rebuilding_trx_ != nullptr) {
assert(!write_after_commit_);
// The CF is probably flushed and hence no need for insert but we still
// need to keep track of the keys for upcoming rollback/commit.
WriteBatchInternal::Delete(rebuilding_trx_, column_family_id, key);
batch_boundry = IsDuplicateKeySeq(column_family_id, key);
}
MaybeAdvanceSeq(batch_boundry);
return seek_status;
}
auto ret_status = DeleteImpl(column_family_id, key, Slice(), kTypeDeletion);
// optimize for non-recovery mode
if (UNLIKELY(!ret_status.IsTryAgain() && rebuilding_trx_ != nullptr)) {
assert(!write_after_commit_);
// If the ret_status is TryAgain then let the next try to add the ky to
// the rebuilding transaction object.
WriteBatchInternal::Delete(rebuilding_trx_, column_family_id, key);
}
return ret_status;
}
Status SingleDeleteCF(uint32_t column_family_id, const Slice& key) override {
// optimize for non-recovery mode
if (UNLIKELY(write_after_commit_ && rebuilding_trx_ != nullptr)) {
WriteBatchInternal::SingleDelete(rebuilding_trx_, column_family_id, key);
return Status::OK();
// else insert the values to the memtable right away
}
Status seek_status;
if (UNLIKELY(!SeekToColumnFamily(column_family_id, &seek_status))) {
bool batch_boundry = false;
if (rebuilding_trx_ != nullptr) {
assert(!write_after_commit_);
// The CF is probably flushed and hence no need for insert but we still
// need to keep track of the keys for upcoming rollback/commit.
WriteBatchInternal::SingleDelete(rebuilding_trx_, column_family_id,
key);
batch_boundry = IsDuplicateKeySeq(column_family_id, key);
}
MaybeAdvanceSeq(batch_boundry);
return seek_status;
}
auto ret_status =
DeleteImpl(column_family_id, key, Slice(), kTypeSingleDeletion);
// optimize for non-recovery mode
if (UNLIKELY(!ret_status.IsTryAgain() && rebuilding_trx_ != nullptr)) {
assert(!write_after_commit_);
// If the ret_status is TryAgain then let the next try to add the ky to
// the rebuilding transaction object.
WriteBatchInternal::SingleDelete(rebuilding_trx_, column_family_id, key);
}
return ret_status;
}
Status DeleteRangeCF(uint32_t column_family_id, const Slice& begin_key,
const Slice& end_key) override {
// optimize for non-recovery mode
if (UNLIKELY(write_after_commit_ && rebuilding_trx_ != nullptr)) {
WriteBatchInternal::DeleteRange(rebuilding_trx_, column_family_id,
begin_key, end_key);
return Status::OK();
// else insert the values to the memtable right away
}
Status seek_status;
if (UNLIKELY(!SeekToColumnFamily(column_family_id, &seek_status))) {
bool batch_boundry = false;
if (rebuilding_trx_ != nullptr) {
assert(!write_after_commit_);
// The CF is probably flushed and hence no need for insert but we still
// need to keep track of the keys for upcoming rollback/commit.
WriteBatchInternal::DeleteRange(rebuilding_trx_, column_family_id,
begin_key, end_key);
// TODO(myabandeh): when transactional DeleteRange support is added,
// check if end_key must also be added.
batch_boundry = IsDuplicateKeySeq(column_family_id, begin_key);
}
MaybeAdvanceSeq(batch_boundry);
return seek_status;
}
if (db_ != nullptr) {
auto cf_handle = cf_mems_->GetColumnFamilyHandle();
if (cf_handle == nullptr) {
cf_handle = db_->DefaultColumnFamily();
}
auto* cfd = reinterpret_cast<ColumnFamilyHandleImpl*>(cf_handle)->cfd();
if (!cfd->is_delete_range_supported()) {
return Status::NotSupported(
std::string("DeleteRange not supported for table type ") +
cfd->ioptions()->table_factory->Name() + " in CF " +
cfd->GetName());
}
}
auto ret_status =
DeleteImpl(column_family_id, begin_key, end_key, kTypeRangeDeletion);
// optimize for non-recovery mode
if (UNLIKELY(!ret_status.IsTryAgain() && rebuilding_trx_ != nullptr)) {
assert(!write_after_commit_);
// If the ret_status is TryAgain then let the next try to add the ky to
// the rebuilding transaction object.
WriteBatchInternal::DeleteRange(rebuilding_trx_, column_family_id,
begin_key, end_key);
}
return ret_status;
}
Status MergeCF(uint32_t column_family_id, const Slice& key,
const Slice& value) override {
// optimize for non-recovery mode
if (UNLIKELY(write_after_commit_ && rebuilding_trx_ != nullptr)) {
WriteBatchInternal::Merge(rebuilding_trx_, column_family_id, key, value);
return Status::OK();
// else insert the values to the memtable right away
}
Status seek_status;
if (UNLIKELY(!SeekToColumnFamily(column_family_id, &seek_status))) {
bool batch_boundry = false;
if (rebuilding_trx_ != nullptr) {
assert(!write_after_commit_);
// The CF is probably flushed and hence no need for insert but we still
// need to keep track of the keys for upcoming rollback/commit.
WriteBatchInternal::Merge(rebuilding_trx_, column_family_id, key,
value);
batch_boundry = IsDuplicateKeySeq(column_family_id, key);
}
MaybeAdvanceSeq(batch_boundry);
return seek_status;
}
Status ret_status;
MemTable* mem = cf_mems_->GetMemTable();
auto* moptions = mem->GetImmutableMemTableOptions();
bool perform_merge = false;
assert(!concurrent_memtable_writes_ ||
moptions->max_successive_merges == 0);
// If we pass DB through and options.max_successive_merges is hit
// during recovery, Get() will be issued which will try to acquire
// DB mutex and cause deadlock, as DB mutex is already held.
// So we disable merge in recovery
if (moptions->max_successive_merges > 0 && db_ != nullptr &&
recovering_log_number_ == 0) {
assert(!concurrent_memtable_writes_);
LookupKey lkey(key, sequence_);
// Count the number of successive merges at the head
// of the key in the memtable
size_t num_merges = mem->CountSuccessiveMergeEntries(lkey);
if (num_merges >= moptions->max_successive_merges) {
perform_merge = true;
}
}
if (perform_merge) {
// 1) Get the existing value
std::string get_value;
// Pass in the sequence number so that we also include previous merge
// operations in the same batch.
SnapshotImpl read_from_snapshot;
read_from_snapshot.number_ = sequence_;
ReadOptions read_options;
read_options.snapshot = &read_from_snapshot;
auto cf_handle = cf_mems_->GetColumnFamilyHandle();
if (cf_handle == nullptr) {
cf_handle = db_->DefaultColumnFamily();
}
db_->Get(read_options, cf_handle, key, &get_value);
Slice get_value_slice = Slice(get_value);
// 2) Apply this merge
auto merge_operator = moptions->merge_operator;
assert(merge_operator);
std::string new_value;
Status merge_status = MergeHelper::TimedFullMerge(
merge_operator, key, &get_value_slice, {value}, &new_value,
moptions->info_log, moptions->statistics, Env::Default());
if (!merge_status.ok()) {
// Failed to merge!
// Store the delta in memtable
perform_merge = false;
} else {
// 3) Add value to memtable
assert(!concurrent_memtable_writes_);
bool mem_res = mem->Add(sequence_, kTypeValue, key, new_value);
if (UNLIKELY(!mem_res)) {
assert(seq_per_batch_);
ret_status = Status::TryAgain("key+seq exists");
const bool BATCH_BOUNDRY = true;
MaybeAdvanceSeq(BATCH_BOUNDRY);
}
}
}
if (!perform_merge) {
// Add merge operator to memtable
bool mem_res =
mem->Add(sequence_, kTypeMerge, key, value,
concurrent_memtable_writes_, get_post_process_info(mem));
if (UNLIKELY(!mem_res)) {
assert(seq_per_batch_);
ret_status = Status::TryAgain("key+seq exists");
const bool BATCH_BOUNDRY = true;
MaybeAdvanceSeq(BATCH_BOUNDRY);
}
}
// optimize for non-recovery mode
if (UNLIKELY(!ret_status.IsTryAgain() && rebuilding_trx_ != nullptr)) {
assert(!write_after_commit_);
// If the ret_status is TryAgain then let the next try to add the ky to
// the rebuilding transaction object.
WriteBatchInternal::Merge(rebuilding_trx_, column_family_id, key, value);
}
MaybeAdvanceSeq();
CheckMemtableFull();
return ret_status;
}
Status PutBlobIndexCF(uint32_t column_family_id, const Slice& key,
const Slice& value) override {
// Same as PutCF except for value type.
return PutCFImpl(column_family_id, key, value, kTypeBlobIndex);
}
void CheckMemtableFull() {
if (flush_scheduler_ != nullptr) {
auto* cfd = cf_mems_->current();
assert(cfd != nullptr);
if (cfd->mem()->ShouldScheduleFlush() &&
cfd->mem()->MarkFlushScheduled()) {
// MarkFlushScheduled only returns true if we are the one that
// should take action, so no need to dedup further
flush_scheduler_->ScheduleFlush(cfd);
}
}
}
// The write batch handler calls MarkBeginPrepare with unprepare set to true
// if it encounters the kTypeBeginUnprepareXID marker.
Status MarkBeginPrepare(bool unprepare) override {
assert(rebuilding_trx_ == nullptr);
assert(db_);
if (recovering_log_number_ != 0) {
// during recovery we rebuild a hollow transaction
// from all encountered prepare sections of the wal
if (db_->allow_2pc() == false) {
return Status::NotSupported(
"WAL contains prepared transactions. Open with "
"TransactionDB::Open().");
}
// we are now iterating through a prepared section
rebuilding_trx_ = new WriteBatch();
rebuilding_trx_seq_ = sequence_;
// We only call MarkBeginPrepare once per batch, and unprepared_batch_
// is initialized to false by default.
assert(!unprepared_batch_);
unprepared_batch_ = unprepare;
if (has_valid_writes_ != nullptr) {
*has_valid_writes_ = true;
}
}
return Status::OK();
}
Status MarkEndPrepare(const Slice& name) override {
assert(db_);
assert((rebuilding_trx_ != nullptr) == (recovering_log_number_ != 0));
if (recovering_log_number_ != 0) {
assert(db_->allow_2pc());
size_t batch_cnt =
write_after_commit_
? 0 // 0 will disable further checks
: static_cast<size_t>(sequence_ - rebuilding_trx_seq_ + 1);
db_->InsertRecoveredTransaction(recovering_log_number_, name.ToString(),
rebuilding_trx_, rebuilding_trx_seq_,
batch_cnt, unprepared_batch_);
rebuilding_trx_ = nullptr;
} else {
assert(rebuilding_trx_ == nullptr);
}
const bool batch_boundry = true;
MaybeAdvanceSeq(batch_boundry);
return Status::OK();
}
Status MarkNoop(bool empty_batch) override {
// A hack in pessimistic transaction could result into a noop at the start
// of the write batch, that should be ignored.
if (!empty_batch) {
// In the absence of Prepare markers, a kTypeNoop tag indicates the end of
// a batch. This happens when write batch commits skipping the prepare
// phase.
const bool batch_boundry = true;
MaybeAdvanceSeq(batch_boundry);
}
return Status::OK();
}
Status MarkCommit(const Slice& name) override {
assert(db_);
Status s;
if (recovering_log_number_ != 0) {
// in recovery when we encounter a commit marker
// we lookup this transaction in our set of rebuilt transactions
// and commit.
auto trx = db_->GetRecoveredTransaction(name.ToString());
// the log containing the prepared section may have
// been released in the last incarnation because the
// data was flushed to L0
if (trx != nullptr) {
// at this point individual CF lognumbers will prevent
// duplicate re-insertion of values.
assert(log_number_ref_ == 0);
if (write_after_commit_) {
// write_after_commit_ can only have one batch in trx.
assert(trx->batches_.size() == 1);
const auto& batch_info = trx->batches_.begin()->second;
// all inserts must reference this trx log number
log_number_ref_ = batch_info.log_number_;
s = batch_info.batch_->Iterate(this);
log_number_ref_ = 0;
}
// else the values are already inserted before the commit
if (s.ok()) {
db_->DeleteRecoveredTransaction(name.ToString());
}
if (has_valid_writes_ != nullptr) {
*has_valid_writes_ = true;
}
}
} else {
// When writes are not delayed until commit, there is no disconnect
// between a memtable write and the WAL that supports it. So the commit
// need not reference any log as the only log to which it depends.
assert(!write_after_commit_ || log_number_ref_ > 0);
}
const bool batch_boundry = true;
MaybeAdvanceSeq(batch_boundry);
return s;
}
Status MarkRollback(const Slice& name) override {
assert(db_);
if (recovering_log_number_ != 0) {
auto trx = db_->GetRecoveredTransaction(name.ToString());
// the log containing the transactions prep section
// may have been released in the previous incarnation
// because we knew it had been rolled back
if (trx != nullptr) {
db_->DeleteRecoveredTransaction(name.ToString());
}
} else {
// in non recovery we simply ignore this tag
}
const bool batch_boundry = true;
MaybeAdvanceSeq(batch_boundry);
return Status::OK();
}
private:
MemTablePostProcessInfo* get_post_process_info(MemTable* mem) {
if (!concurrent_memtable_writes_) {
// No need to batch counters locally if we don't use concurrent mode.
return nullptr;
}
return &GetPostMap()[mem];
}
};
// This function can only be called in these conditions:
// 1) During Recovery()
// 2) During Write(), in a single-threaded write thread
// 3) During Write(), in a concurrent context where memtables has been cloned
// The reason is that it calls memtables->Seek(), which has a stateful cache
Status WriteBatchInternal::InsertInto(
WriteThread::WriteGroup& write_group, SequenceNumber sequence,
ColumnFamilyMemTables* memtables, FlushScheduler* flush_scheduler,
bool ignore_missing_column_families, uint64_t recovery_log_number, DB* db,
bool concurrent_memtable_writes, bool seq_per_batch, bool batch_per_txn) {
MemTableInserter inserter(
sequence, memtables, flush_scheduler, ignore_missing_column_families,
recovery_log_number, db, concurrent_memtable_writes,
nullptr /*has_valid_writes*/, seq_per_batch, batch_per_txn);
for (auto w : write_group) {
if (w->CallbackFailed()) {
continue;
}
w->sequence = inserter.sequence();
if (!w->ShouldWriteToMemtable()) {
// In seq_per_batch_ mode this advances the seq by one.
inserter.MaybeAdvanceSeq(true);
continue;
}
SetSequence(w->batch, inserter.sequence());
inserter.set_log_number_ref(w->log_ref);
w->status = w->batch->Iterate(&inserter);
if (!w->status.ok()) {
return w->status;
}
assert(!seq_per_batch || w->batch_cnt != 0);
assert(!seq_per_batch || inserter.sequence() - w->sequence == w->batch_cnt);
}
return Status::OK();
}
Status WriteBatchInternal::InsertInto(
WriteThread::Writer* writer, SequenceNumber sequence,
ColumnFamilyMemTables* memtables, FlushScheduler* flush_scheduler,
bool ignore_missing_column_families, uint64_t log_number, DB* db,
bool concurrent_memtable_writes, bool seq_per_batch, size_t batch_cnt,
bool batch_per_txn) {
#ifdef NDEBUG
(void)batch_cnt;
#endif
assert(writer->ShouldWriteToMemtable());
MemTableInserter inserter(
sequence, memtables, flush_scheduler, ignore_missing_column_families,
log_number, db, concurrent_memtable_writes, nullptr /*has_valid_writes*/,
seq_per_batch, batch_per_txn);
SetSequence(writer->batch, sequence);
inserter.set_log_number_ref(writer->log_ref);
Status s = writer->batch->Iterate(&inserter);
assert(!seq_per_batch || batch_cnt != 0);
assert(!seq_per_batch || inserter.sequence() - sequence == batch_cnt);
if (concurrent_memtable_writes) {
inserter.PostProcess();
}
return s;
}
Status WriteBatchInternal::InsertInto(
const WriteBatch* batch, ColumnFamilyMemTables* memtables,
FlushScheduler* flush_scheduler, bool ignore_missing_column_families,
uint64_t log_number, DB* db, bool concurrent_memtable_writes,
SequenceNumber* next_seq, bool* has_valid_writes, bool seq_per_batch,
bool batch_per_txn) {
MemTableInserter inserter(Sequence(batch), memtables, flush_scheduler,
ignore_missing_column_families, log_number, db,
concurrent_memtable_writes, has_valid_writes,
seq_per_batch, batch_per_txn);
Status s = batch->Iterate(&inserter);
if (next_seq != nullptr) {
*next_seq = inserter.sequence();
}
if (concurrent_memtable_writes) {
inserter.PostProcess();
}
return s;
}
Status WriteBatchInternal::SetContents(WriteBatch* b, const Slice& contents) {
assert(contents.size() >= WriteBatchInternal::kHeader);
b->rep_.assign(contents.data(), contents.size());
b->content_flags_.store(ContentFlags::DEFERRED, std::memory_order_relaxed);
return Status::OK();
}
Status WriteBatchInternal::Append(WriteBatch* dst, const WriteBatch* src,
const bool wal_only) {
size_t src_len;
int src_count;
uint32_t src_flags;
const SavePoint& batch_end = src->GetWalTerminationPoint();
if (wal_only && !batch_end.is_cleared()) {
src_len = batch_end.size - WriteBatchInternal::kHeader;
src_count = batch_end.count;
src_flags = batch_end.content_flags;
} else {
src_len = src->rep_.size() - WriteBatchInternal::kHeader;
src_count = Count(src);
src_flags = src->content_flags_.load(std::memory_order_relaxed);
}
SetCount(dst, Count(dst) + src_count);
assert(src->rep_.size() >= WriteBatchInternal::kHeader);
dst->rep_.append(src->rep_.data() + WriteBatchInternal::kHeader, src_len);
dst->content_flags_.store(
dst->content_flags_.load(std::memory_order_relaxed) | src_flags,
std::memory_order_relaxed);
return Status::OK();
}
size_t WriteBatchInternal::AppendedByteSize(size_t leftByteSize,
size_t rightByteSize) {
if (leftByteSize == 0 || rightByteSize == 0) {
return leftByteSize + rightByteSize;
} else {
return leftByteSize + rightByteSize - WriteBatchInternal::kHeader;
}
}
} // namespace rocksdb