rocksdb/utilities/write_batch_with_index/write_batch_with_index.cc

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// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
// This source code is also licensed under the GPLv2 license found in the
// COPYING file in the root directory of this source tree.
#ifndef ROCKSDB_LITE
#include "rocksdb/utilities/write_batch_with_index.h"
#include <limits>
#include <memory>
#include "db/column_family.h"
#include "db/db_impl.h"
#include "db/merge_context.h"
#include "db/merge_helper.h"
#include "memtable/skiplist.h"
#include "options/db_options.h"
#include "rocksdb/comparator.h"
#include "rocksdb/iterator.h"
#include "util/arena.h"
#include "utilities/write_batch_with_index/write_batch_with_index_internal.h"
namespace rocksdb {
2014-10-07 18:47:16 +02:00
// when direction == forward
// * current_at_base_ <=> base_iterator > delta_iterator
// when direction == backwards
// * current_at_base_ <=> base_iterator < delta_iterator
// always:
// * equal_keys_ <=> base_iterator == delta_iterator
class BaseDeltaIterator : public Iterator {
public:
BaseDeltaIterator(Iterator* base_iterator, WBWIIterator* delta_iterator,
const Comparator* comparator)
: forward_(true),
current_at_base_(true),
equal_keys_(false),
status_(Status::OK()),
base_iterator_(base_iterator),
delta_iterator_(delta_iterator),
comparator_(comparator) {}
virtual ~BaseDeltaIterator() {}
bool Valid() const override {
return current_at_base_ ? BaseValid() : DeltaValid();
}
void SeekToFirst() override {
forward_ = true;
base_iterator_->SeekToFirst();
delta_iterator_->SeekToFirst();
UpdateCurrent();
}
void SeekToLast() override {
forward_ = false;
base_iterator_->SeekToLast();
delta_iterator_->SeekToLast();
UpdateCurrent();
}
void Seek(const Slice& k) override {
forward_ = true;
base_iterator_->Seek(k);
delta_iterator_->Seek(k);
UpdateCurrent();
}
void SeekForPrev(const Slice& k) override {
forward_ = false;
base_iterator_->SeekForPrev(k);
delta_iterator_->SeekForPrev(k);
UpdateCurrent();
}
void Next() override {
if (!Valid()) {
status_ = Status::NotSupported("Next() on invalid iterator");
}
if (!forward_) {
// Need to change direction
// if our direction was backward and we're not equal, we have two states:
// * both iterators are valid: we're already in a good state (current
// shows to smaller)
// * only one iterator is valid: we need to advance that iterator
forward_ = true;
equal_keys_ = false;
if (!BaseValid()) {
assert(DeltaValid());
base_iterator_->SeekToFirst();
} else if (!DeltaValid()) {
delta_iterator_->SeekToFirst();
} else if (current_at_base_) {
// Change delta from larger than base to smaller
AdvanceDelta();
} else {
// Change base from larger than delta to smaller
AdvanceBase();
}
if (DeltaValid() && BaseValid()) {
if (comparator_->Equal(delta_iterator_->Entry().key,
base_iterator_->key())) {
equal_keys_ = true;
}
}
}
Advance();
}
void Prev() override {
if (!Valid()) {
status_ = Status::NotSupported("Prev() on invalid iterator");
}
if (forward_) {
// Need to change direction
// if our direction was backward and we're not equal, we have two states:
// * both iterators are valid: we're already in a good state (current
// shows to smaller)
// * only one iterator is valid: we need to advance that iterator
forward_ = false;
equal_keys_ = false;
if (!BaseValid()) {
assert(DeltaValid());
base_iterator_->SeekToLast();
} else if (!DeltaValid()) {
delta_iterator_->SeekToLast();
} else if (current_at_base_) {
// Change delta from less advanced than base to more advanced
AdvanceDelta();
} else {
// Change base from less advanced than delta to more advanced
AdvanceBase();
}
if (DeltaValid() && BaseValid()) {
if (comparator_->Equal(delta_iterator_->Entry().key,
base_iterator_->key())) {
equal_keys_ = true;
}
}
}
Advance();
}
Slice key() const override {
return current_at_base_ ? base_iterator_->key()
: delta_iterator_->Entry().key;
}
Slice value() const override {
return current_at_base_ ? base_iterator_->value()
: delta_iterator_->Entry().value;
}
Status status() const override {
if (!status_.ok()) {
return status_;
}
if (!base_iterator_->status().ok()) {
return base_iterator_->status();
}
return delta_iterator_->status();
}
private:
void AssertInvariants() {
#ifndef NDEBUG
if (!Valid()) {
return;
}
if (!BaseValid()) {
assert(!current_at_base_ && delta_iterator_->Valid());
return;
}
if (!DeltaValid()) {
assert(current_at_base_ && base_iterator_->Valid());
return;
}
// we don't support those yet
assert(delta_iterator_->Entry().type != kMergeRecord &&
delta_iterator_->Entry().type != kLogDataRecord);
int compare = comparator_->Compare(delta_iterator_->Entry().key,
base_iterator_->key());
if (forward_) {
// current_at_base -> compare < 0
assert(!current_at_base_ || compare < 0);
// !current_at_base -> compare <= 0
assert(current_at_base_ && compare >= 0);
} else {
// current_at_base -> compare > 0
assert(!current_at_base_ || compare > 0);
// !current_at_base -> compare <= 0
assert(current_at_base_ && compare <= 0);
}
// equal_keys_ <=> compare == 0
assert((equal_keys_ || compare != 0) && (!equal_keys_ || compare == 0));
#endif
}
void Advance() {
if (equal_keys_) {
assert(BaseValid() && DeltaValid());
AdvanceBase();
AdvanceDelta();
} else {
if (current_at_base_) {
assert(BaseValid());
AdvanceBase();
} else {
assert(DeltaValid());
AdvanceDelta();
}
}
UpdateCurrent();
}
void AdvanceDelta() {
if (forward_) {
delta_iterator_->Next();
} else {
delta_iterator_->Prev();
}
}
void AdvanceBase() {
if (forward_) {
base_iterator_->Next();
} else {
base_iterator_->Prev();
}
}
bool BaseValid() const { return base_iterator_->Valid(); }
bool DeltaValid() const { return delta_iterator_->Valid(); }
void UpdateCurrent() {
// Suppress false positive clang analyzer warnings.
#ifndef __clang_analyzer__
while (true) {
WriteEntry delta_entry;
if (DeltaValid()) {
delta_entry = delta_iterator_->Entry();
}
equal_keys_ = false;
if (!BaseValid()) {
// Base has finished.
if (!DeltaValid()) {
// Finished
return;
}
if (delta_entry.type == kDeleteRecord ||
delta_entry.type == kSingleDeleteRecord) {
AdvanceDelta();
} else {
current_at_base_ = false;
return;
}
} else if (!DeltaValid()) {
// Delta has finished.
current_at_base_ = true;
return;
} else {
int compare =
(forward_ ? 1 : -1) *
comparator_->Compare(delta_entry.key, base_iterator_->key());
if (compare <= 0) { // delta bigger or equal
if (compare == 0) {
equal_keys_ = true;
}
if (delta_entry.type != kDeleteRecord &&
delta_entry.type != kSingleDeleteRecord) {
current_at_base_ = false;
return;
}
// Delta is less advanced and is delete.
AdvanceDelta();
if (equal_keys_) {
AdvanceBase();
}
} else {
current_at_base_ = true;
return;
}
}
}
AssertInvariants();
#endif // __clang_analyzer__
}
bool forward_;
bool current_at_base_;
bool equal_keys_;
Status status_;
std::unique_ptr<Iterator> base_iterator_;
std::unique_ptr<WBWIIterator> delta_iterator_;
const Comparator* comparator_; // not owned
};
typedef SkipList<WriteBatchIndexEntry*, const WriteBatchEntryComparator&>
WriteBatchEntrySkipList;
class WBWIIteratorImpl : public WBWIIterator {
public:
WBWIIteratorImpl(uint32_t column_family_id,
WriteBatchEntrySkipList* skip_list,
const ReadableWriteBatch* write_batch)
: column_family_id_(column_family_id),
skip_list_iter_(skip_list),
write_batch_(write_batch) {}
virtual ~WBWIIteratorImpl() {}
virtual bool Valid() const override {
if (!skip_list_iter_.Valid()) {
return false;
}
const WriteBatchIndexEntry* iter_entry = skip_list_iter_.key();
return (iter_entry != nullptr &&
iter_entry->column_family == column_family_id_);
}
virtual void SeekToFirst() override {
WriteBatchIndexEntry search_entry(WriteBatchIndexEntry::kFlagMin,
column_family_id_, 0, 0);
skip_list_iter_.Seek(&search_entry);
}
virtual void SeekToLast() override {
WriteBatchIndexEntry search_entry(WriteBatchIndexEntry::kFlagMin,
column_family_id_ + 1, 0, 0);
skip_list_iter_.Seek(&search_entry);
if (!skip_list_iter_.Valid()) {
skip_list_iter_.SeekToLast();
} else {
skip_list_iter_.Prev();
}
}
virtual void Seek(const Slice& key) override {
WriteBatchIndexEntry search_entry(&key, column_family_id_);
skip_list_iter_.Seek(&search_entry);
}
virtual void SeekForPrev(const Slice& key) override {
WriteBatchIndexEntry search_entry(&key, column_family_id_);
skip_list_iter_.SeekForPrev(&search_entry);
}
virtual void Next() override { skip_list_iter_.Next(); }
virtual void Prev() override { skip_list_iter_.Prev(); }
virtual WriteEntry Entry() const override {
WriteEntry ret;
Slice blob, xid;
const WriteBatchIndexEntry* iter_entry = skip_list_iter_.key();
// this is guaranteed with Valid()
assert(iter_entry != nullptr &&
iter_entry->column_family == column_family_id_);
auto s = write_batch_->GetEntryFromDataOffset(
iter_entry->offset, &ret.type, &ret.key, &ret.value, &blob, &xid);
assert(s.ok());
assert(ret.type == kPutRecord || ret.type == kDeleteRecord ||
ret.type == kSingleDeleteRecord || ret.type == kDeleteRangeRecord ||
ret.type == kMergeRecord);
return ret;
}
virtual Status status() const override {
// this is in-memory data structure, so the only way status can be non-ok is
// through memory corruption
return Status::OK();
}
const WriteBatchIndexEntry* GetRawEntry() const {
return skip_list_iter_.key();
}
private:
uint32_t column_family_id_;
WriteBatchEntrySkipList::Iterator skip_list_iter_;
const ReadableWriteBatch* write_batch_;
};
struct WriteBatchWithIndex::Rep {
Rep(const Comparator* index_comparator, size_t reserved_bytes = 0,
size_t max_bytes = 0, bool _overwrite_key = false)
: write_batch(reserved_bytes, max_bytes),
comparator(index_comparator, &write_batch),
skip_list(comparator, &arena),
overwrite_key(_overwrite_key),
last_entry_offset(0) {}
ReadableWriteBatch write_batch;
WriteBatchEntryComparator comparator;
Arena arena;
WriteBatchEntrySkipList skip_list;
bool overwrite_key;
size_t last_entry_offset;
// Remember current offset of internal write batch, which is used as
// the starting offset of the next record.
void SetLastEntryOffset() { last_entry_offset = write_batch.GetDataSize(); }
// In overwrite mode, find the existing entry for the same key and update it
// to point to the current entry.
// Return true if the key is found and updated.
bool UpdateExistingEntry(ColumnFamilyHandle* column_family, const Slice& key);
bool UpdateExistingEntryWithCfId(uint32_t column_family_id, const Slice& key);
// Add the recent entry to the update.
// In overwrite mode, if key already exists in the index, update it.
void AddOrUpdateIndex(ColumnFamilyHandle* column_family, const Slice& key);
void AddOrUpdateIndex(const Slice& key);
// Allocate an index entry pointing to the last entry in the write batch and
// put it to skip list.
void AddNewEntry(uint32_t column_family_id);
// Clear all updates buffered in this batch.
void Clear();
void ClearIndex();
// Rebuild index by reading all records from the batch.
// Returns non-ok status on corruption.
Status ReBuildIndex();
};
bool WriteBatchWithIndex::Rep::UpdateExistingEntry(
ColumnFamilyHandle* column_family, const Slice& key) {
uint32_t cf_id = GetColumnFamilyID(column_family);
return UpdateExistingEntryWithCfId(cf_id, key);
}
bool WriteBatchWithIndex::Rep::UpdateExistingEntryWithCfId(
uint32_t column_family_id, const Slice& key) {
if (!overwrite_key) {
return false;
}
WBWIIteratorImpl iter(column_family_id, &skip_list, &write_batch);
iter.Seek(key);
if (!iter.Valid()) {
return false;
}
if (comparator.CompareKey(column_family_id, key, iter.Entry().key) != 0) {
return false;
}
WriteBatchIndexEntry* non_const_entry =
const_cast<WriteBatchIndexEntry*>(iter.GetRawEntry());
non_const_entry->offset = last_entry_offset;
return true;
}
void WriteBatchWithIndex::Rep::AddOrUpdateIndex(
ColumnFamilyHandle* column_family, const Slice& key) {
if (!UpdateExistingEntry(column_family, key)) {
uint32_t cf_id = GetColumnFamilyID(column_family);
const auto* cf_cmp = GetColumnFamilyUserComparator(column_family);
if (cf_cmp != nullptr) {
comparator.SetComparatorForCF(cf_id, cf_cmp);
}
AddNewEntry(cf_id);
}
}
void WriteBatchWithIndex::Rep::AddOrUpdateIndex(const Slice& key) {
if (!UpdateExistingEntryWithCfId(0, key)) {
AddNewEntry(0);
}
}
void WriteBatchWithIndex::Rep::AddNewEntry(uint32_t column_family_id) {
const std::string& wb_data = write_batch.Data();
Slice entry_ptr = Slice(wb_data.data() + last_entry_offset,
wb_data.size() - last_entry_offset);
// Extract key
Slice key;
bool success __attribute__((__unused__)) =
ReadKeyFromWriteBatchEntry(&entry_ptr, &key, column_family_id != 0);
assert(success);
auto* mem = arena.Allocate(sizeof(WriteBatchIndexEntry));
auto* index_entry =
new (mem) WriteBatchIndexEntry(last_entry_offset, column_family_id,
key.data() - wb_data.data(), key.size());
skip_list.Insert(index_entry);
}
void WriteBatchWithIndex::Rep::Clear() {
write_batch.Clear();
ClearIndex();
}
void WriteBatchWithIndex::Rep::ClearIndex() {
skip_list.~WriteBatchEntrySkipList();
arena.~Arena();
new (&arena) Arena();
new (&skip_list) WriteBatchEntrySkipList(comparator, &arena);
last_entry_offset = 0;
}
Status WriteBatchWithIndex::Rep::ReBuildIndex() {
Status s;
ClearIndex();
if (write_batch.Count() == 0) {
// Nothing to re-index
return s;
}
size_t offset = WriteBatchInternal::GetFirstOffset(&write_batch);
Slice input(write_batch.Data());
input.remove_prefix(offset);
// Loop through all entries in Rep and add each one to the index
int found = 0;
while (s.ok() && !input.empty()) {
Slice key, value, blob, xid;
uint32_t column_family_id = 0; // default
char tag = 0;
// set offset of current entry for call to AddNewEntry()
last_entry_offset = input.data() - write_batch.Data().data();
s = ReadRecordFromWriteBatch(&input, &tag, &column_family_id, &key,
&value, &blob, &xid);
if (!s.ok()) {
break;
}
switch (tag) {
case kTypeColumnFamilyValue:
case kTypeValue:
case kTypeColumnFamilyDeletion:
case kTypeDeletion:
case kTypeColumnFamilySingleDeletion:
case kTypeSingleDeletion:
case kTypeColumnFamilyMerge:
case kTypeMerge:
found++;
if (!UpdateExistingEntryWithCfId(column_family_id, key)) {
AddNewEntry(column_family_id);
}
break;
case kTypeLogData:
case kTypeBeginPrepareXID:
case kTypeEndPrepareXID:
case kTypeCommitXID:
case kTypeRollbackXID:
case kTypeNoop:
break;
default:
return Status::Corruption("unknown WriteBatch tag");
}
}
if (s.ok() && found != write_batch.Count()) {
s = Status::Corruption("WriteBatch has wrong count");
}
return s;
}
WriteBatchWithIndex::WriteBatchWithIndex(
const Comparator* default_index_comparator, size_t reserved_bytes,
bool overwrite_key, size_t max_bytes)
: rep(new Rep(default_index_comparator, reserved_bytes, max_bytes,
overwrite_key)) {}
WriteBatchWithIndex::~WriteBatchWithIndex() {}
WriteBatch* WriteBatchWithIndex::GetWriteBatch() { return &rep->write_batch; }
WBWIIterator* WriteBatchWithIndex::NewIterator() {
return new WBWIIteratorImpl(0, &(rep->skip_list), &rep->write_batch);
}
WBWIIterator* WriteBatchWithIndex::NewIterator(
ColumnFamilyHandle* column_family) {
return new WBWIIteratorImpl(GetColumnFamilyID(column_family),
&(rep->skip_list), &rep->write_batch);
}
Iterator* WriteBatchWithIndex::NewIteratorWithBase(
ColumnFamilyHandle* column_family, Iterator* base_iterator) {
if (rep->overwrite_key == false) {
assert(false);
return nullptr;
}
return new BaseDeltaIterator(base_iterator, NewIterator(column_family),
GetColumnFamilyUserComparator(column_family));
}
Iterator* WriteBatchWithIndex::NewIteratorWithBase(Iterator* base_iterator) {
if (rep->overwrite_key == false) {
assert(false);
return nullptr;
}
// default column family's comparator
return new BaseDeltaIterator(base_iterator, NewIterator(),
rep->comparator.default_comparator());
}
Status WriteBatchWithIndex::Put(ColumnFamilyHandle* column_family,
const Slice& key, const Slice& value) {
rep->SetLastEntryOffset();
auto s = rep->write_batch.Put(column_family, key, value);
if (s.ok()) {
rep->AddOrUpdateIndex(column_family, key);
}
return s;
}
Status WriteBatchWithIndex::Put(const Slice& key, const Slice& value) {
rep->SetLastEntryOffset();
auto s = rep->write_batch.Put(key, value);
if (s.ok()) {
rep->AddOrUpdateIndex(key);
}
return s;
}
Status WriteBatchWithIndex::Delete(ColumnFamilyHandle* column_family,
const Slice& key) {
rep->SetLastEntryOffset();
auto s = rep->write_batch.Delete(column_family, key);
if (s.ok()) {
rep->AddOrUpdateIndex(column_family, key);
}
return s;
}
Status WriteBatchWithIndex::Delete(const Slice& key) {
rep->SetLastEntryOffset();
auto s = rep->write_batch.Delete(key);
if (s.ok()) {
rep->AddOrUpdateIndex(key);
}
return s;
}
Status WriteBatchWithIndex::SingleDelete(ColumnFamilyHandle* column_family,
const Slice& key) {
Support for SingleDelete() Summary: This patch fixes #7460559. It introduces SingleDelete as a new database operation. This operation can be used to delete keys that were never overwritten (no put following another put of the same key). If an overwritten key is single deleted the behavior is undefined. Single deletion of a non-existent key has no effect but multiple consecutive single deletions are not allowed (see limitations). In contrast to the conventional Delete() operation, the deletion entry is removed along with the value when the two are lined up in a compaction. Note: The semantics are similar to @igor's prototype that allowed to have this behavior on the granularity of a column family ( https://reviews.facebook.net/D42093 ). This new patch, however, is more aggressive when it comes to removing tombstones: It removes the SingleDelete together with the value whenever there is no snapshot between them while the older patch only did this when the sequence number of the deletion was older than the earliest snapshot. Most of the complex additions are in the Compaction Iterator, all other changes should be relatively straightforward. The patch also includes basic support for single deletions in db_stress and db_bench. Limitations: - Not compatible with cuckoo hash tables - Single deletions cannot be used in combination with merges and normal deletions on the same key (other keys are not affected by this) - Consecutive single deletions are currently not allowed (and older version of this patch supported this so it could be resurrected if needed) Test Plan: make all check Reviewers: yhchiang, sdong, rven, anthony, yoshinorim, igor Reviewed By: igor Subscribers: maykov, dhruba, leveldb Differential Revision: https://reviews.facebook.net/D43179
2015-09-17 20:42:56 +02:00
rep->SetLastEntryOffset();
auto s = rep->write_batch.SingleDelete(column_family, key);
if (s.ok()) {
rep->AddOrUpdateIndex(column_family, key);
}
return s;
}
Status WriteBatchWithIndex::SingleDelete(const Slice& key) {
rep->SetLastEntryOffset();
auto s = rep->write_batch.SingleDelete(key);
if (s.ok()) {
rep->AddOrUpdateIndex(key);
}
return s;
Support for SingleDelete() Summary: This patch fixes #7460559. It introduces SingleDelete as a new database operation. This operation can be used to delete keys that were never overwritten (no put following another put of the same key). If an overwritten key is single deleted the behavior is undefined. Single deletion of a non-existent key has no effect but multiple consecutive single deletions are not allowed (see limitations). In contrast to the conventional Delete() operation, the deletion entry is removed along with the value when the two are lined up in a compaction. Note: The semantics are similar to @igor's prototype that allowed to have this behavior on the granularity of a column family ( https://reviews.facebook.net/D42093 ). This new patch, however, is more aggressive when it comes to removing tombstones: It removes the SingleDelete together with the value whenever there is no snapshot between them while the older patch only did this when the sequence number of the deletion was older than the earliest snapshot. Most of the complex additions are in the Compaction Iterator, all other changes should be relatively straightforward. The patch also includes basic support for single deletions in db_stress and db_bench. Limitations: - Not compatible with cuckoo hash tables - Single deletions cannot be used in combination with merges and normal deletions on the same key (other keys are not affected by this) - Consecutive single deletions are currently not allowed (and older version of this patch supported this so it could be resurrected if needed) Test Plan: make all check Reviewers: yhchiang, sdong, rven, anthony, yoshinorim, igor Reviewed By: igor Subscribers: maykov, dhruba, leveldb Differential Revision: https://reviews.facebook.net/D43179
2015-09-17 20:42:56 +02:00
}
Status WriteBatchWithIndex::DeleteRange(ColumnFamilyHandle* column_family,
const Slice& begin_key,
const Slice& end_key) {
rep->SetLastEntryOffset();
auto s = rep->write_batch.DeleteRange(column_family, begin_key, end_key);
if (s.ok()) {
rep->AddOrUpdateIndex(column_family, begin_key);
}
return s;
}
Status WriteBatchWithIndex::DeleteRange(const Slice& begin_key,
const Slice& end_key) {
rep->SetLastEntryOffset();
auto s = rep->write_batch.DeleteRange(begin_key, end_key);
if (s.ok()) {
rep->AddOrUpdateIndex(begin_key);
}
return s;
}
Status WriteBatchWithIndex::Merge(ColumnFamilyHandle* column_family,
const Slice& key, const Slice& value) {
Support for SingleDelete() Summary: This patch fixes #7460559. It introduces SingleDelete as a new database operation. This operation can be used to delete keys that were never overwritten (no put following another put of the same key). If an overwritten key is single deleted the behavior is undefined. Single deletion of a non-existent key has no effect but multiple consecutive single deletions are not allowed (see limitations). In contrast to the conventional Delete() operation, the deletion entry is removed along with the value when the two are lined up in a compaction. Note: The semantics are similar to @igor's prototype that allowed to have this behavior on the granularity of a column family ( https://reviews.facebook.net/D42093 ). This new patch, however, is more aggressive when it comes to removing tombstones: It removes the SingleDelete together with the value whenever there is no snapshot between them while the older patch only did this when the sequence number of the deletion was older than the earliest snapshot. Most of the complex additions are in the Compaction Iterator, all other changes should be relatively straightforward. The patch also includes basic support for single deletions in db_stress and db_bench. Limitations: - Not compatible with cuckoo hash tables - Single deletions cannot be used in combination with merges and normal deletions on the same key (other keys are not affected by this) - Consecutive single deletions are currently not allowed (and older version of this patch supported this so it could be resurrected if needed) Test Plan: make all check Reviewers: yhchiang, sdong, rven, anthony, yoshinorim, igor Reviewed By: igor Subscribers: maykov, dhruba, leveldb Differential Revision: https://reviews.facebook.net/D43179
2015-09-17 20:42:56 +02:00
rep->SetLastEntryOffset();
auto s = rep->write_batch.Merge(column_family, key, value);
if (s.ok()) {
rep->AddOrUpdateIndex(column_family, key);
}
return s;
}
Status WriteBatchWithIndex::Merge(const Slice& key, const Slice& value) {
rep->SetLastEntryOffset();
auto s = rep->write_batch.Merge(key, value);
if (s.ok()) {
rep->AddOrUpdateIndex(key);
}
return s;
}
Status WriteBatchWithIndex::PutLogData(const Slice& blob) {
return rep->write_batch.PutLogData(blob);
Support for SingleDelete() Summary: This patch fixes #7460559. It introduces SingleDelete as a new database operation. This operation can be used to delete keys that were never overwritten (no put following another put of the same key). If an overwritten key is single deleted the behavior is undefined. Single deletion of a non-existent key has no effect but multiple consecutive single deletions are not allowed (see limitations). In contrast to the conventional Delete() operation, the deletion entry is removed along with the value when the two are lined up in a compaction. Note: The semantics are similar to @igor's prototype that allowed to have this behavior on the granularity of a column family ( https://reviews.facebook.net/D42093 ). This new patch, however, is more aggressive when it comes to removing tombstones: It removes the SingleDelete together with the value whenever there is no snapshot between them while the older patch only did this when the sequence number of the deletion was older than the earliest snapshot. Most of the complex additions are in the Compaction Iterator, all other changes should be relatively straightforward. The patch also includes basic support for single deletions in db_stress and db_bench. Limitations: - Not compatible with cuckoo hash tables - Single deletions cannot be used in combination with merges and normal deletions on the same key (other keys are not affected by this) - Consecutive single deletions are currently not allowed (and older version of this patch supported this so it could be resurrected if needed) Test Plan: make all check Reviewers: yhchiang, sdong, rven, anthony, yoshinorim, igor Reviewed By: igor Subscribers: maykov, dhruba, leveldb Differential Revision: https://reviews.facebook.net/D43179
2015-09-17 20:42:56 +02:00
}
void WriteBatchWithIndex::Clear() { rep->Clear(); }
Status WriteBatchWithIndex::GetFromBatch(ColumnFamilyHandle* column_family,
const DBOptions& options,
const Slice& key, std::string* value) {
Status s;
MergeContext merge_context;
const ImmutableDBOptions immuable_db_options(options);
WriteBatchWithIndexInternal::Result result =
WriteBatchWithIndexInternal::GetFromBatch(
immuable_db_options, this, column_family, key, &merge_context,
&rep->comparator, value, rep->overwrite_key, &s);
switch (result) {
case WriteBatchWithIndexInternal::Result::kFound:
case WriteBatchWithIndexInternal::Result::kError:
// use returned status
break;
case WriteBatchWithIndexInternal::Result::kDeleted:
case WriteBatchWithIndexInternal::Result::kNotFound:
s = Status::NotFound();
break;
case WriteBatchWithIndexInternal::Result::kMergeInProgress:
s = Status::MergeInProgress();
break;
default:
assert(false);
}
return s;
}
Status WriteBatchWithIndex::GetFromBatchAndDB(DB* db,
const ReadOptions& read_options,
const Slice& key,
std::string* value) {
return GetFromBatchAndDB(db, read_options, db->DefaultColumnFamily(), key,
value);
}
Status WriteBatchWithIndex::GetFromBatchAndDB(DB* db,
const ReadOptions& read_options,
ColumnFamilyHandle* column_family,
const Slice& key,
std::string* value) {
Status s;
MergeContext merge_context;
const ImmutableDBOptions& immuable_db_options =
reinterpret_cast<DBImpl*>(db)->immutable_db_options();
std::string batch_value;
WriteBatchWithIndexInternal::Result result =
WriteBatchWithIndexInternal::GetFromBatch(
immuable_db_options, this, column_family, key, &merge_context,
&rep->comparator, &batch_value, rep->overwrite_key, &s);
if (result == WriteBatchWithIndexInternal::Result::kFound) {
value->assign(batch_value.data(), batch_value.size());
return s;
}
if (result == WriteBatchWithIndexInternal::Result::kDeleted) {
return Status::NotFound();
}
if (result == WriteBatchWithIndexInternal::Result::kError) {
return s;
}
if (result == WriteBatchWithIndexInternal::Result::kMergeInProgress &&
rep->overwrite_key == true) {
// Since we've overwritten keys, we do not know what other operations are
// in this batch for this key, so we cannot do a Merge to compute the
// result. Instead, we will simply return MergeInProgress.
return Status::MergeInProgress();
}
assert(result == WriteBatchWithIndexInternal::Result::kMergeInProgress ||
result == WriteBatchWithIndexInternal::Result::kNotFound);
// Did not find key in batch OR could not resolve Merges. Try DB.
s = db->Get(read_options, column_family, key, value);
2015-12-10 17:54:48 +01:00
if (s.ok() || s.IsNotFound()) { // DB Get Succeeded
if (result == WriteBatchWithIndexInternal::Result::kMergeInProgress) {
// Merge result from DB with merges in Batch
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
const MergeOperator* merge_operator =
cfh->cfd()->ioptions()->merge_operator;
Statistics* statistics = immuable_db_options.statistics.get();
Env* env = immuable_db_options.env;
Logger* logger = immuable_db_options.info_log.get();
Slice db_slice(*value);
Slice* merge_data;
if (s.ok()) {
merge_data = &db_slice;
} else { // Key not present in db (s.IsNotFound())
merge_data = nullptr;
}
if (merge_operator) {
s = MergeHelper::TimedFullMerge(merge_operator, key, merge_data,
merge_context.GetOperands(), value,
logger, statistics, env);
} else {
s = Status::InvalidArgument("Options::merge_operator must be set");
}
}
}
return s;
}
void WriteBatchWithIndex::SetSavePoint() { rep->write_batch.SetSavePoint(); }
Status WriteBatchWithIndex::RollbackToSavePoint() {
Status s = rep->write_batch.RollbackToSavePoint();
if (s.ok()) {
s = rep->ReBuildIndex();
}
return s;
}
Status WriteBatchWithIndex::PopSavePoint() {
return rep->write_batch.PopSavePoint();
}
void WriteBatchWithIndex::SetMaxBytes(size_t max_bytes) {
rep->write_batch.SetMaxBytes(max_bytes);
}
} // namespace rocksdb
#endif // !ROCKSDB_LITE