// 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). #include "table/get_context.h" #include "db/blob//blob_fetcher.h" #include "db/merge_helper.h" #include "db/pinned_iterators_manager.h" #include "db/read_callback.h" #include "db/wide/wide_column_serialization.h" #include "monitoring/file_read_sample.h" #include "monitoring/perf_context_imp.h" #include "monitoring/statistics.h" #include "rocksdb/merge_operator.h" #include "rocksdb/statistics.h" #include "rocksdb/system_clock.h" namespace ROCKSDB_NAMESPACE { namespace { void appendToReplayLog(std::string* replay_log, ValueType type, Slice value) { if (replay_log) { if (replay_log->empty()) { // Optimization: in the common case of only one operation in the // log, we allocate the exact amount of space needed. replay_log->reserve(1 + VarintLength(value.size()) + value.size()); } replay_log->push_back(type); PutLengthPrefixedSlice(replay_log, value); } } } // namespace GetContext::GetContext( const Comparator* ucmp, const MergeOperator* merge_operator, Logger* logger, Statistics* statistics, GetState init_state, const Slice& user_key, PinnableSlice* pinnable_val, PinnableWideColumns* columns, std::string* timestamp, bool* value_found, MergeContext* merge_context, bool do_merge, SequenceNumber* _max_covering_tombstone_seq, SystemClock* clock, SequenceNumber* seq, PinnedIteratorsManager* _pinned_iters_mgr, ReadCallback* callback, bool* is_blob_index, uint64_t tracing_get_id, BlobFetcher* blob_fetcher) : ucmp_(ucmp), merge_operator_(merge_operator), logger_(logger), statistics_(statistics), state_(init_state), user_key_(user_key), pinnable_val_(pinnable_val), columns_(columns), timestamp_(timestamp), value_found_(value_found), merge_context_(merge_context), max_covering_tombstone_seq_(_max_covering_tombstone_seq), clock_(clock), seq_(seq), replay_log_(nullptr), pinned_iters_mgr_(_pinned_iters_mgr), callback_(callback), do_merge_(do_merge), is_blob_index_(is_blob_index), tracing_get_id_(tracing_get_id), blob_fetcher_(blob_fetcher) { if (seq_) { *seq_ = kMaxSequenceNumber; } sample_ = should_sample_file_read(); } GetContext::GetContext(const Comparator* ucmp, const MergeOperator* merge_operator, Logger* logger, Statistics* statistics, GetState init_state, const Slice& user_key, PinnableSlice* pinnable_val, PinnableWideColumns* columns, bool* value_found, MergeContext* merge_context, bool do_merge, SequenceNumber* _max_covering_tombstone_seq, SystemClock* clock, SequenceNumber* seq, PinnedIteratorsManager* _pinned_iters_mgr, ReadCallback* callback, bool* is_blob_index, uint64_t tracing_get_id, BlobFetcher* blob_fetcher) : GetContext(ucmp, merge_operator, logger, statistics, init_state, user_key, pinnable_val, columns, /*timestamp=*/nullptr, value_found, merge_context, do_merge, _max_covering_tombstone_seq, clock, seq, _pinned_iters_mgr, callback, is_blob_index, tracing_get_id, blob_fetcher) {} // Called from TableCache::Get and Table::Get when file/block in which // key may exist are not there in TableCache/BlockCache respectively. In this // case we can't guarantee that key does not exist and are not permitted to do // IO to be certain.Set the status=kFound and value_found=false to let the // caller know that key may exist but is not there in memory void GetContext::MarkKeyMayExist() { state_ = kFound; if (value_found_ != nullptr) { *value_found_ = false; } } void GetContext::SaveValue(const Slice& value, SequenceNumber /*seq*/) { assert(state_ == kNotFound); appendToReplayLog(replay_log_, kTypeValue, value); state_ = kFound; if (LIKELY(pinnable_val_ != nullptr)) { pinnable_val_->PinSelf(value); } } void GetContext::ReportCounters() { if (get_context_stats_.num_cache_hit > 0) { RecordTick(statistics_, BLOCK_CACHE_HIT, get_context_stats_.num_cache_hit); } if (get_context_stats_.num_cache_index_hit > 0) { RecordTick(statistics_, BLOCK_CACHE_INDEX_HIT, get_context_stats_.num_cache_index_hit); } if (get_context_stats_.num_cache_data_hit > 0) { RecordTick(statistics_, BLOCK_CACHE_DATA_HIT, get_context_stats_.num_cache_data_hit); } if (get_context_stats_.num_cache_filter_hit > 0) { RecordTick(statistics_, BLOCK_CACHE_FILTER_HIT, get_context_stats_.num_cache_filter_hit); } if (get_context_stats_.num_cache_compression_dict_hit > 0) { RecordTick(statistics_, BLOCK_CACHE_COMPRESSION_DICT_HIT, get_context_stats_.num_cache_compression_dict_hit); } if (get_context_stats_.num_cache_index_miss > 0) { RecordTick(statistics_, BLOCK_CACHE_INDEX_MISS, get_context_stats_.num_cache_index_miss); } if (get_context_stats_.num_cache_filter_miss > 0) { RecordTick(statistics_, BLOCK_CACHE_FILTER_MISS, get_context_stats_.num_cache_filter_miss); } if (get_context_stats_.num_cache_data_miss > 0) { RecordTick(statistics_, BLOCK_CACHE_DATA_MISS, get_context_stats_.num_cache_data_miss); } if (get_context_stats_.num_cache_compression_dict_miss > 0) { RecordTick(statistics_, BLOCK_CACHE_COMPRESSION_DICT_MISS, get_context_stats_.num_cache_compression_dict_miss); } if (get_context_stats_.num_cache_bytes_read > 0) { RecordTick(statistics_, BLOCK_CACHE_BYTES_READ, get_context_stats_.num_cache_bytes_read); } if (get_context_stats_.num_cache_miss > 0) { RecordTick(statistics_, BLOCK_CACHE_MISS, get_context_stats_.num_cache_miss); } if (get_context_stats_.num_cache_add > 0) { RecordTick(statistics_, BLOCK_CACHE_ADD, get_context_stats_.num_cache_add); } if (get_context_stats_.num_cache_add_redundant > 0) { RecordTick(statistics_, BLOCK_CACHE_ADD_REDUNDANT, get_context_stats_.num_cache_add_redundant); } if (get_context_stats_.num_cache_bytes_write > 0) { RecordTick(statistics_, BLOCK_CACHE_BYTES_WRITE, get_context_stats_.num_cache_bytes_write); } if (get_context_stats_.num_cache_index_add > 0) { RecordTick(statistics_, BLOCK_CACHE_INDEX_ADD, get_context_stats_.num_cache_index_add); } if (get_context_stats_.num_cache_index_add_redundant > 0) { RecordTick(statistics_, BLOCK_CACHE_INDEX_ADD_REDUNDANT, get_context_stats_.num_cache_index_add_redundant); } if (get_context_stats_.num_cache_index_bytes_insert > 0) { RecordTick(statistics_, BLOCK_CACHE_INDEX_BYTES_INSERT, get_context_stats_.num_cache_index_bytes_insert); } if (get_context_stats_.num_cache_data_add > 0) { RecordTick(statistics_, BLOCK_CACHE_DATA_ADD, get_context_stats_.num_cache_data_add); } if (get_context_stats_.num_cache_data_add_redundant > 0) { RecordTick(statistics_, BLOCK_CACHE_DATA_ADD_REDUNDANT, get_context_stats_.num_cache_data_add_redundant); } if (get_context_stats_.num_cache_data_bytes_insert > 0) { RecordTick(statistics_, BLOCK_CACHE_DATA_BYTES_INSERT, get_context_stats_.num_cache_data_bytes_insert); } if (get_context_stats_.num_cache_filter_add > 0) { RecordTick(statistics_, BLOCK_CACHE_FILTER_ADD, get_context_stats_.num_cache_filter_add); } if (get_context_stats_.num_cache_filter_add_redundant > 0) { RecordTick(statistics_, BLOCK_CACHE_FILTER_ADD_REDUNDANT, get_context_stats_.num_cache_filter_add_redundant); } if (get_context_stats_.num_cache_filter_bytes_insert > 0) { RecordTick(statistics_, BLOCK_CACHE_FILTER_BYTES_INSERT, get_context_stats_.num_cache_filter_bytes_insert); } if (get_context_stats_.num_cache_compression_dict_add > 0) { RecordTick(statistics_, BLOCK_CACHE_COMPRESSION_DICT_ADD, get_context_stats_.num_cache_compression_dict_add); } if (get_context_stats_.num_cache_compression_dict_add_redundant > 0) { RecordTick(statistics_, BLOCK_CACHE_COMPRESSION_DICT_ADD_REDUNDANT, get_context_stats_.num_cache_compression_dict_add_redundant); } if (get_context_stats_.num_cache_compression_dict_bytes_insert > 0) { RecordTick(statistics_, BLOCK_CACHE_COMPRESSION_DICT_BYTES_INSERT, get_context_stats_.num_cache_compression_dict_bytes_insert); } } bool GetContext::SaveValue(const ParsedInternalKey& parsed_key, const Slice& value, bool* matched, Cleanable* value_pinner) { assert(matched); assert((state_ != kMerge && parsed_key.type != kTypeMerge) || merge_context_ != nullptr); if (ucmp_->EqualWithoutTimestamp(parsed_key.user_key, user_key_)) { *matched = true; // If the value is not in the snapshot, skip it if (!CheckCallback(parsed_key.sequence)) { return true; // to continue to the next seq } appendToReplayLog(replay_log_, parsed_key.type, value); if (seq_ != nullptr) { // Set the sequence number if it is uninitialized if (*seq_ == kMaxSequenceNumber) { *seq_ = parsed_key.sequence; } if (max_covering_tombstone_seq_) { *seq_ = std::max(*seq_, *max_covering_tombstone_seq_); } } size_t ts_sz = ucmp_->timestamp_size(); if (ts_sz > 0 && timestamp_ != nullptr) { if (!timestamp_->empty()) { assert(ts_sz == timestamp_->size()); // `timestamp` can be set before `SaveValue` is ever called // when max_covering_tombstone_seq_ was set. // If this key has a higher sequence number than range tombstone, // then timestamp should be updated. `ts_from_rangetombstone_` is // set to false afterwards so that only the key with highest seqno // updates the timestamp. if (ts_from_rangetombstone_) { assert(max_covering_tombstone_seq_); if (parsed_key.sequence > *max_covering_tombstone_seq_) { Slice ts = ExtractTimestampFromUserKey(parsed_key.user_key, ts_sz); timestamp_->assign(ts.data(), ts.size()); ts_from_rangetombstone_ = false; } } } // TODO optimize for small size ts const std::string kMaxTs(ts_sz, '\xff'); if (timestamp_->empty() || ucmp_->CompareTimestamp(*timestamp_, kMaxTs) == 0) { Slice ts = ExtractTimestampFromUserKey(parsed_key.user_key, ts_sz); timestamp_->assign(ts.data(), ts.size()); } } auto type = parsed_key.type; // Key matches. Process it if ((type == kTypeValue || type == kTypeMerge || type == kTypeBlobIndex || type == kTypeWideColumnEntity || type == kTypeDeletion || type == kTypeDeletionWithTimestamp || type == kTypeSingleDeletion) && max_covering_tombstone_seq_ != nullptr && *max_covering_tombstone_seq_ > parsed_key.sequence) { // Note that deletion types are also considered, this is for the case // when we need to return timestamp to user. If a range tombstone has a // higher seqno than point tombstone, its timestamp should be returned. type = kTypeRangeDeletion; } switch (type) { case kTypeValue: case kTypeBlobIndex: case kTypeWideColumnEntity: assert(state_ == kNotFound || state_ == kMerge); if (type == kTypeBlobIndex) { if (is_blob_index_ == nullptr) { // Blob value not supported. Stop. state_ = kUnexpectedBlobIndex; return false; } } if (is_blob_index_ != nullptr) { *is_blob_index_ = (type == kTypeBlobIndex); } if (kNotFound == state_) { state_ = kFound; if (do_merge_) { if (type == kTypeBlobIndex && ucmp_->timestamp_size() != 0) { ukey_with_ts_found_.PinSelf(parsed_key.user_key); } if (LIKELY(pinnable_val_ != nullptr)) { Slice value_to_use = value; if (type == kTypeWideColumnEntity) { Slice value_copy = value; if (!WideColumnSerialization::GetValueOfDefaultColumn( value_copy, value_to_use) .ok()) { state_ = kCorrupt; return false; } } if (LIKELY(value_pinner != nullptr)) { // If the backing resources for the value are provided, pin them pinnable_val_->PinSlice(value_to_use, value_pinner); } else { TEST_SYNC_POINT_CALLBACK("GetContext::SaveValue::PinSelf", this); // Otherwise copy the value pinnable_val_->PinSelf(value_to_use); } } else if (columns_ != nullptr) { if (type == kTypeWideColumnEntity) { if (!columns_->SetWideColumnValue(value, value_pinner).ok()) { state_ = kCorrupt; return false; } } else { columns_->SetPlainValue(value, value_pinner); } } } else { // It means this function is called as part of DB GetMergeOperands // API and the current value should be part of // merge_context_->operand_list if (type == kTypeBlobIndex) { PinnableSlice pin_val; if (GetBlobValue(parsed_key.user_key, value, &pin_val) == false) { return false; } Slice blob_value(pin_val); push_operand(blob_value, nullptr); } else if (type == kTypeWideColumnEntity) { Slice value_copy = value; Slice value_of_default; if (!WideColumnSerialization::GetValueOfDefaultColumn( value_copy, value_of_default) .ok()) { state_ = kCorrupt; return false; } push_operand(value_of_default, value_pinner); } else { assert(type == kTypeValue); push_operand(value, value_pinner); } } } else if (kMerge == state_) { assert(merge_operator_ != nullptr); if (type == kTypeBlobIndex) { PinnableSlice pin_val; if (GetBlobValue(parsed_key.user_key, value, &pin_val) == false) { return false; } Slice blob_value(pin_val); state_ = kFound; if (do_merge_) { Merge(&blob_value); } else { // It means this function is called as part of DB GetMergeOperands // API and the current value should be part of // merge_context_->operand_list push_operand(blob_value, nullptr); } } else if (type == kTypeWideColumnEntity) { state_ = kFound; if (do_merge_) { MergeWithEntity(value); } else { // It means this function is called as part of DB GetMergeOperands // API and the current value should be part of // merge_context_->operand_list Slice value_copy = value; Slice value_of_default; if (!WideColumnSerialization::GetValueOfDefaultColumn( value_copy, value_of_default) .ok()) { state_ = kCorrupt; return false; } push_operand(value_of_default, value_pinner); } } else { assert(type == kTypeValue); state_ = kFound; if (do_merge_) { Merge(&value); } else { // It means this function is called as part of DB GetMergeOperands // API and the current value should be part of // merge_context_->operand_list push_operand(value, value_pinner); } } } return false; case kTypeDeletion: case kTypeDeletionWithTimestamp: case kTypeSingleDeletion: case kTypeRangeDeletion: // TODO(noetzli): Verify correctness once merge of single-deletes // is supported assert(state_ == kNotFound || state_ == kMerge); if (kNotFound == state_) { state_ = kDeleted; } else if (kMerge == state_) { state_ = kFound; if (do_merge_) { Merge(nullptr); } // If do_merge_ = false then the current value shouldn't be part of // merge_context_->operand_list } return false; case kTypeMerge: assert(state_ == kNotFound || state_ == kMerge); state_ = kMerge; // value_pinner is not set from plain_table_reader.cc for example. push_operand(value, value_pinner); if (do_merge_ && merge_operator_ != nullptr && merge_operator_->ShouldMerge( merge_context_->GetOperandsDirectionBackward())) { state_ = kFound; Merge(nullptr); return false; } return true; default: assert(false); break; } } // state_ could be Corrupt, merge or notfound return false; } void GetContext::Merge(const Slice* value) { assert(do_merge_); assert(!pinnable_val_ || !columns_); std::string result; // `op_failure_scope` (an output parameter) is not provided (set to nullptr) // since a failure must be propagated regardless of its value. const Status s = MergeHelper::TimedFullMerge( merge_operator_, user_key_, value, merge_context_->GetOperands(), &result, logger_, statistics_, clock_, /* result_operand */ nullptr, /* update_num_ops_stats */ true, /* op_failure_scope */ nullptr); if (!s.ok()) { if (s.subcode() == Status::SubCode::kMergeOperatorFailed) { state_ = kMergeOperatorFailed; } else { state_ = kCorrupt; } return; } if (LIKELY(pinnable_val_ != nullptr)) { *(pinnable_val_->GetSelf()) = std::move(result); pinnable_val_->PinSelf(); return; } assert(columns_); columns_->SetPlainValue(result); } void GetContext::MergeWithEntity(Slice entity) { assert(do_merge_); assert(!pinnable_val_ || !columns_); if (LIKELY(pinnable_val_ != nullptr)) { Slice value_of_default; { const Status s = WideColumnSerialization::GetValueOfDefaultColumn( entity, value_of_default); if (!s.ok()) { state_ = kCorrupt; return; } } { // `op_failure_scope` (an output parameter) is not provided (set to // nullptr) since a failure must be propagated regardless of its value. const Status s = MergeHelper::TimedFullMerge( merge_operator_, user_key_, &value_of_default, merge_context_->GetOperands(), pinnable_val_->GetSelf(), logger_, statistics_, clock_, /* result_operand */ nullptr, /* update_num_ops_stats */ true, /* op_failure_scope */ nullptr); if (!s.ok()) { if (s.subcode() == Status::SubCode::kMergeOperatorFailed) { state_ = kMergeOperatorFailed; } else { state_ = kCorrupt; } return; } } pinnable_val_->PinSelf(); return; } std::string result; { // `op_failure_scope` (an output parameter) is not provided (set to nullptr) // since a failure must be propagated regardless of its value. const Status s = MergeHelper::TimedFullMergeWithEntity( merge_operator_, user_key_, entity, merge_context_->GetOperands(), &result, logger_, statistics_, clock_, /* update_num_ops_stats */ true, /* op_failure_scope */ nullptr); if (!s.ok()) { if (s.subcode() == Status::SubCode::kMergeOperatorFailed) { state_ = kMergeOperatorFailed; } else { state_ = kCorrupt; } return; } } { assert(columns_); const Status s = columns_->SetWideColumnValue(result); if (!s.ok()) { state_ = kCorrupt; return; } } } bool GetContext::GetBlobValue(const Slice& user_key, const Slice& blob_index, PinnableSlice* blob_value) { constexpr FilePrefetchBuffer* prefetch_buffer = nullptr; constexpr uint64_t* bytes_read = nullptr; Status status = blob_fetcher_->FetchBlob( user_key, blob_index, prefetch_buffer, blob_value, bytes_read); if (!status.ok()) { if (status.IsIncomplete()) { // FIXME: this code is not covered by unit tests MarkKeyMayExist(); return false; } state_ = kCorrupt; return false; } *is_blob_index_ = false; return true; } void GetContext::push_operand(const Slice& value, Cleanable* value_pinner) { // TODO(yanqin) preserve timestamps information in merge_context if (pinned_iters_mgr() && pinned_iters_mgr()->PinningEnabled() && value_pinner != nullptr) { value_pinner->DelegateCleanupsTo(pinned_iters_mgr()); merge_context_->PushOperand(value, true /*value_pinned*/); } else { merge_context_->PushOperand(value, false); } } void replayGetContextLog(const Slice& replay_log, const Slice& user_key, GetContext* get_context, Cleanable* value_pinner) { Slice s = replay_log; while (s.size()) { auto type = static_cast(*s.data()); s.remove_prefix(1); Slice value; bool ret = GetLengthPrefixedSlice(&s, &value); assert(ret); (void)ret; bool dont_care __attribute__((__unused__)); // Since SequenceNumber is not stored and unknown, we will use // kMaxSequenceNumber. get_context->SaveValue( ParsedInternalKey(user_key, kMaxSequenceNumber, type), value, &dont_care, value_pinner); } } } // namespace ROCKSDB_NAMESPACE