d1cab2b64e
Summary: Add kTypeBlobIndex value type, which will be used by blob db only, to insert a (key, blob_offset) KV pair. The purpose is to 1. Make it possible to open existing rocksdb instance as blob db. Existing value will be of kTypeIndex type, while value inserted by blob db will be of kTypeBlobIndex. 2. Make rocksdb able to detect if the db contains value written by blob db, if so return error. 3. Make it possible to have blob db optionally store value in SST file (with kTypeValue type) or as a blob value (with kTypeBlobIndex type). The root db (DBImpl) basically pretended kTypeBlobIndex are normal value on write. On Get if is_blob is provided, return whether the value read is of kTypeBlobIndex type, or return Status::NotSupported() status if is_blob is not provided. On scan allow_blob flag is pass and if the flag is true, return wether the value is of kTypeBlobIndex type via iter->IsBlob(). Changes on blob db side will be in a separate patch. Closes https://github.com/facebook/rocksdb/pull/2886 Differential Revision: D5838431 Pulled By: yiwu-arbug fbshipit-source-id: 3c5306c62bc13bb11abc03422ec5cbcea1203cca
105 lines
3.4 KiB
C++
105 lines
3.4 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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#pragma once
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#include <string>
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#include "db/merge_context.h"
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#include "db/range_del_aggregator.h"
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#include "db/read_callback.h"
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#include "rocksdb/env.h"
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#include "rocksdb/types.h"
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#include "table/block.h"
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namespace rocksdb {
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class MergeContext;
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class PinnedIteratorsManager;
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class GetContext {
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public:
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enum GetState {
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kNotFound,
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kFound,
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kDeleted,
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kCorrupt,
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kMerge, // saver contains the current merge result (the operands)
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kBlobIndex,
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};
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GetContext(const Comparator* ucmp, const MergeOperator* merge_operator,
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Logger* logger, Statistics* statistics, GetState init_state,
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const Slice& user_key, PinnableSlice* value, bool* value_found,
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MergeContext* merge_context, RangeDelAggregator* range_del_agg,
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Env* env, SequenceNumber* seq = nullptr,
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PinnedIteratorsManager* _pinned_iters_mgr = nullptr,
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ReadCallback* callback = nullptr, bool* is_blob_index = nullptr);
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void MarkKeyMayExist();
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// Records this key, value, and any meta-data (such as sequence number and
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// state) into this GetContext.
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//
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// Returns True if more keys need to be read (due to merges) or
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// False if the complete value has been found.
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bool SaveValue(const ParsedInternalKey& parsed_key, const Slice& value,
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Cleanable* value_pinner = nullptr);
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// Simplified version of the previous function. Should only be used when we
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// know that the operation is a Put.
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void SaveValue(const Slice& value, SequenceNumber seq);
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GetState State() const { return state_; }
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RangeDelAggregator* range_del_agg() { return range_del_agg_; }
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PinnedIteratorsManager* pinned_iters_mgr() { return pinned_iters_mgr_; }
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// If a non-null string is passed, all the SaveValue calls will be
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// logged into the string. The operations can then be replayed on
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// another GetContext with replayGetContextLog.
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void SetReplayLog(std::string* replay_log) { replay_log_ = replay_log; }
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// Do we need to fetch the SequenceNumber for this key?
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bool NeedToReadSequence() const { return (seq_ != nullptr); }
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bool sample() const { return sample_; }
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bool CheckCallback(SequenceNumber seq) {
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if (callback_) {
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return callback_->IsCommitted(seq);
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}
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return true;
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}
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private:
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const Comparator* ucmp_;
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const MergeOperator* merge_operator_;
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// the merge operations encountered;
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Logger* logger_;
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Statistics* statistics_;
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GetState state_;
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Slice user_key_;
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PinnableSlice* pinnable_val_;
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bool* value_found_; // Is value set correctly? Used by KeyMayExist
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MergeContext* merge_context_;
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RangeDelAggregator* range_del_agg_;
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Env* env_;
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// If a key is found, seq_ will be set to the SequenceNumber of most recent
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// write to the key or kMaxSequenceNumber if unknown
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SequenceNumber* seq_;
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std::string* replay_log_;
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// Used to temporarily pin blocks when state_ == GetContext::kMerge
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PinnedIteratorsManager* pinned_iters_mgr_;
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ReadCallback* callback_;
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bool sample_;
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bool* is_blob_index_;
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};
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void replayGetContextLog(const Slice& replay_log, const Slice& user_key,
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GetContext* get_context,
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Cleanable* value_pinner = nullptr);
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} // namespace rocksdb
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