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7c673cae | 1 | // Copyright (c) 2011-present, Facebook, Inc. All rights reserved. |
11fdf7f2 TL |
2 | // This source code is licensed under both the GPLv2 (found in the |
3 | // COPYING file in the root directory) and Apache 2.0 License | |
4 | // (found in the LICENSE.Apache file in the root directory). | |
7c673cae FG |
5 | // |
6 | // Copyright (c) 2011 The LevelDB Authors. All rights reserved. | |
7 | // Use of this source code is governed by a BSD-style license that can be | |
8 | // found in the LICENSE file. See the AUTHORS file for names of contributors. | |
9 | ||
10 | #pragma once | |
11 | #include <atomic> | |
12 | #include <deque> | |
13 | #include <functional> | |
14 | #include <memory> | |
15 | #include <string> | |
16 | #include <unordered_map> | |
17 | #include <vector> | |
18 | #include "db/dbformat.h" | |
494da23a | 19 | #include "db/range_tombstone_fragmenter.h" |
11fdf7f2 | 20 | #include "db/read_callback.h" |
7c673cae | 21 | #include "db/version_edit.h" |
f67539c2 TL |
22 | #include "memory/allocator.h" |
23 | #include "memory/concurrent_arena.h" | |
7c673cae FG |
24 | #include "monitoring/instrumented_mutex.h" |
25 | #include "options/cf_options.h" | |
26 | #include "rocksdb/db.h" | |
27 | #include "rocksdb/env.h" | |
28 | #include "rocksdb/memtablerep.h" | |
f67539c2 | 29 | #include "table/multiget_context.h" |
7c673cae FG |
30 | #include "util/dynamic_bloom.h" |
31 | #include "util/hash.h" | |
32 | ||
f67539c2 | 33 | namespace ROCKSDB_NAMESPACE { |
7c673cae | 34 | |
f67539c2 | 35 | struct FlushJobInfo; |
7c673cae FG |
36 | class Mutex; |
37 | class MemTableIterator; | |
38 | class MergeContext; | |
7c673cae | 39 | |
11fdf7f2 TL |
40 | struct ImmutableMemTableOptions { |
41 | explicit ImmutableMemTableOptions(const ImmutableCFOptions& ioptions, | |
42 | const MutableCFOptions& mutable_cf_options); | |
7c673cae FG |
43 | size_t arena_block_size; |
44 | uint32_t memtable_prefix_bloom_bits; | |
45 | size_t memtable_huge_page_size; | |
494da23a | 46 | bool memtable_whole_key_filtering; |
7c673cae FG |
47 | bool inplace_update_support; |
48 | size_t inplace_update_num_locks; | |
49 | UpdateStatus (*inplace_callback)(char* existing_value, | |
50 | uint32_t* existing_value_size, | |
51 | Slice delta_value, | |
52 | std::string* merged_value); | |
53 | size_t max_successive_merges; | |
54 | Statistics* statistics; | |
55 | MergeOperator* merge_operator; | |
56 | Logger* info_log; | |
57 | }; | |
58 | ||
59 | // Batched counters to updated when inserting keys in one write batch. | |
60 | // In post process of the write batch, these can be updated together. | |
61 | // Only used in concurrent memtable insert case. | |
62 | struct MemTablePostProcessInfo { | |
63 | uint64_t data_size = 0; | |
64 | uint64_t num_entries = 0; | |
65 | uint64_t num_deletes = 0; | |
66 | }; | |
67 | ||
f67539c2 | 68 | using MultiGetRange = MultiGetContext::Range; |
7c673cae | 69 | // Note: Many of the methods in this class have comments indicating that |
11fdf7f2 | 70 | // external synchronization is required as these methods are not thread-safe. |
7c673cae FG |
71 | // It is up to higher layers of code to decide how to prevent concurrent |
72 | // invokation of these methods. This is usually done by acquiring either | |
73 | // the db mutex or the single writer thread. | |
74 | // | |
75 | // Some of these methods are documented to only require external | |
76 | // synchronization if this memtable is immutable. Calling MarkImmutable() is | |
77 | // not sufficient to guarantee immutability. It is up to higher layers of | |
78 | // code to determine if this MemTable can still be modified by other threads. | |
79 | // Eg: The Superversion stores a pointer to the current MemTable (that can | |
80 | // be modified) and a separate list of the MemTables that can no longer be | |
81 | // written to (aka the 'immutable memtables'). | |
82 | class MemTable { | |
83 | public: | |
84 | struct KeyComparator : public MemTableRep::KeyComparator { | |
85 | const InternalKeyComparator comparator; | |
86 | explicit KeyComparator(const InternalKeyComparator& c) : comparator(c) { } | |
87 | virtual int operator()(const char* prefix_len_key1, | |
88 | const char* prefix_len_key2) const override; | |
89 | virtual int operator()(const char* prefix_len_key, | |
11fdf7f2 | 90 | const DecodedType& key) const override; |
7c673cae FG |
91 | }; |
92 | ||
93 | // MemTables are reference counted. The initial reference count | |
94 | // is zero and the caller must call Ref() at least once. | |
95 | // | |
96 | // earliest_seq should be the current SequenceNumber in the db such that any | |
97 | // key inserted into this memtable will have an equal or larger seq number. | |
98 | // (When a db is first created, the earliest sequence number will be 0). | |
99 | // If the earliest sequence number is not known, kMaxSequenceNumber may be | |
100 | // used, but this may prevent some transactions from succeeding until the | |
101 | // first key is inserted into the memtable. | |
102 | explicit MemTable(const InternalKeyComparator& comparator, | |
103 | const ImmutableCFOptions& ioptions, | |
104 | const MutableCFOptions& mutable_cf_options, | |
105 | WriteBufferManager* write_buffer_manager, | |
11fdf7f2 | 106 | SequenceNumber earliest_seq, uint32_t column_family_id); |
f67539c2 TL |
107 | // No copying allowed |
108 | MemTable(const MemTable&) = delete; | |
109 | MemTable& operator=(const MemTable&) = delete; | |
7c673cae FG |
110 | |
111 | // Do not delete this MemTable unless Unref() indicates it not in use. | |
112 | ~MemTable(); | |
113 | ||
114 | // Increase reference count. | |
115 | // REQUIRES: external synchronization to prevent simultaneous | |
116 | // operations on the same MemTable. | |
117 | void Ref() { ++refs_; } | |
118 | ||
119 | // Drop reference count. | |
120 | // If the refcount goes to zero return this memtable, otherwise return null. | |
121 | // REQUIRES: external synchronization to prevent simultaneous | |
122 | // operations on the same MemTable. | |
123 | MemTable* Unref() { | |
124 | --refs_; | |
125 | assert(refs_ >= 0); | |
126 | if (refs_ <= 0) { | |
127 | return this; | |
128 | } | |
129 | return nullptr; | |
130 | } | |
131 | ||
132 | // Returns an estimate of the number of bytes of data in use by this | |
133 | // data structure. | |
134 | // | |
135 | // REQUIRES: external synchronization to prevent simultaneous | |
136 | // operations on the same MemTable (unless this Memtable is immutable). | |
137 | size_t ApproximateMemoryUsage(); | |
138 | ||
f67539c2 TL |
139 | // As a cheap version of `ApproximateMemoryUsage()`, this function doens't |
140 | // require external synchronization. The value may be less accurate though | |
141 | size_t ApproximateMemoryUsageFast() const { | |
142 | return approximate_memory_usage_.load(std::memory_order_relaxed); | |
143 | } | |
144 | ||
7c673cae FG |
145 | // This method heuristically determines if the memtable should continue to |
146 | // host more data. | |
147 | bool ShouldScheduleFlush() const { | |
148 | return flush_state_.load(std::memory_order_relaxed) == FLUSH_REQUESTED; | |
149 | } | |
150 | ||
151 | // Returns true if a flush should be scheduled and the caller should | |
152 | // be the one to schedule it | |
153 | bool MarkFlushScheduled() { | |
154 | auto before = FLUSH_REQUESTED; | |
155 | return flush_state_.compare_exchange_strong(before, FLUSH_SCHEDULED, | |
156 | std::memory_order_relaxed, | |
157 | std::memory_order_relaxed); | |
158 | } | |
159 | ||
160 | // Return an iterator that yields the contents of the memtable. | |
161 | // | |
162 | // The caller must ensure that the underlying MemTable remains live | |
163 | // while the returned iterator is live. The keys returned by this | |
164 | // iterator are internal keys encoded by AppendInternalKey in the | |
165 | // db/dbformat.{h,cc} module. | |
166 | // | |
167 | // By default, it returns an iterator for prefix seek if prefix_extractor | |
168 | // is configured in Options. | |
169 | // arena: If not null, the arena needs to be used to allocate the Iterator. | |
170 | // Calling ~Iterator of the iterator will destroy all the states but | |
171 | // those allocated in arena. | |
172 | InternalIterator* NewIterator(const ReadOptions& read_options, Arena* arena); | |
173 | ||
494da23a TL |
174 | FragmentedRangeTombstoneIterator* NewRangeTombstoneIterator( |
175 | const ReadOptions& read_options, SequenceNumber read_seq); | |
7c673cae FG |
176 | |
177 | // Add an entry into memtable that maps key to value at the | |
178 | // specified sequence number and with the specified type. | |
179 | // Typically value will be empty if type==kTypeDeletion. | |
180 | // | |
181 | // REQUIRES: if allow_concurrent = false, external synchronization to prevent | |
182 | // simultaneous operations on the same MemTable. | |
11fdf7f2 TL |
183 | // |
184 | // Returns false if MemTableRepFactory::CanHandleDuplicatedKey() is true and | |
185 | // the <key, seq> already exists. | |
186 | bool Add(SequenceNumber seq, ValueType type, const Slice& key, | |
7c673cae | 187 | const Slice& value, bool allow_concurrent = false, |
f67539c2 TL |
188 | MemTablePostProcessInfo* post_process_info = nullptr, |
189 | void** hint = nullptr); | |
7c673cae | 190 | |
f67539c2 TL |
191 | // Used to Get value associated with key or Get Merge Operands associated |
192 | // with key. | |
193 | // If do_merge = true the default behavior which is Get value for key is | |
194 | // executed. Expected behavior is described right below. | |
7c673cae FG |
195 | // If memtable contains a value for key, store it in *value and return true. |
196 | // If memtable contains a deletion for key, store a NotFound() error | |
197 | // in *status and return true. | |
198 | // If memtable contains Merge operation as the most recent entry for a key, | |
199 | // and the merge process does not stop (not reaching a value or delete), | |
200 | // prepend the current merge operand to *operands. | |
201 | // store MergeInProgress in s, and return false. | |
202 | // Else, return false. | |
203 | // If any operation was found, its most recent sequence number | |
204 | // will be stored in *seq on success (regardless of whether true/false is | |
205 | // returned). Otherwise, *seq will be set to kMaxSequenceNumber. | |
206 | // On success, *s may be set to OK, NotFound, or MergeInProgress. Any other | |
207 | // status returned indicates a corruption or other unexpected error. | |
f67539c2 TL |
208 | // If do_merge = false then any Merge Operands encountered for key are simply |
209 | // stored in merge_context.operands_list and never actually merged to get a | |
210 | // final value. The raw Merge Operands are eventually returned to the user. | |
7c673cae | 211 | bool Get(const LookupKey& key, std::string* value, Status* s, |
494da23a TL |
212 | MergeContext* merge_context, |
213 | SequenceNumber* max_covering_tombstone_seq, SequenceNumber* seq, | |
214 | const ReadOptions& read_opts, ReadCallback* callback = nullptr, | |
f67539c2 | 215 | bool* is_blob_index = nullptr, bool do_merge = true); |
7c673cae FG |
216 | |
217 | bool Get(const LookupKey& key, std::string* value, Status* s, | |
494da23a TL |
218 | MergeContext* merge_context, |
219 | SequenceNumber* max_covering_tombstone_seq, | |
11fdf7f2 | 220 | const ReadOptions& read_opts, ReadCallback* callback = nullptr, |
f67539c2 | 221 | bool* is_blob_index = nullptr, bool do_merge = true) { |
7c673cae | 222 | SequenceNumber seq; |
494da23a | 223 | return Get(key, value, s, merge_context, max_covering_tombstone_seq, &seq, |
f67539c2 | 224 | read_opts, callback, is_blob_index, do_merge); |
7c673cae FG |
225 | } |
226 | ||
f67539c2 TL |
227 | void MultiGet(const ReadOptions& read_options, MultiGetRange* range, |
228 | ReadCallback* callback, bool* is_blob); | |
229 | ||
7c673cae FG |
230 | // Attempts to update the new_value inplace, else does normal Add |
231 | // Pseudocode | |
232 | // if key exists in current memtable && prev_value is of type kTypeValue | |
233 | // if new sizeof(new_value) <= sizeof(prev_value) | |
234 | // update inplace | |
235 | // else add(key, new_value) | |
236 | // else add(key, new_value) | |
237 | // | |
238 | // REQUIRES: external synchronization to prevent simultaneous | |
239 | // operations on the same MemTable. | |
240 | void Update(SequenceNumber seq, | |
241 | const Slice& key, | |
242 | const Slice& value); | |
243 | ||
244 | // If prev_value for key exists, attempts to update it inplace. | |
245 | // else returns false | |
246 | // Pseudocode | |
247 | // if key exists in current memtable && prev_value is of type kTypeValue | |
248 | // new_value = delta(prev_value) | |
249 | // if sizeof(new_value) <= sizeof(prev_value) | |
250 | // update inplace | |
251 | // else add(key, new_value) | |
252 | // else return false | |
253 | // | |
254 | // REQUIRES: external synchronization to prevent simultaneous | |
255 | // operations on the same MemTable. | |
256 | bool UpdateCallback(SequenceNumber seq, | |
257 | const Slice& key, | |
258 | const Slice& delta); | |
259 | ||
260 | // Returns the number of successive merge entries starting from the newest | |
261 | // entry for the key up to the last non-merge entry or last entry for the | |
262 | // key in the memtable. | |
263 | size_t CountSuccessiveMergeEntries(const LookupKey& key); | |
264 | ||
265 | // Update counters and flush status after inserting a whole write batch | |
266 | // Used in concurrent memtable inserts. | |
267 | void BatchPostProcess(const MemTablePostProcessInfo& update_counters) { | |
268 | num_entries_.fetch_add(update_counters.num_entries, | |
269 | std::memory_order_relaxed); | |
270 | data_size_.fetch_add(update_counters.data_size, std::memory_order_relaxed); | |
271 | if (update_counters.num_deletes != 0) { | |
272 | num_deletes_.fetch_add(update_counters.num_deletes, | |
273 | std::memory_order_relaxed); | |
274 | } | |
275 | UpdateFlushState(); | |
276 | } | |
277 | ||
278 | // Get total number of entries in the mem table. | |
279 | // REQUIRES: external synchronization to prevent simultaneous | |
280 | // operations on the same MemTable (unless this Memtable is immutable). | |
281 | uint64_t num_entries() const { | |
282 | return num_entries_.load(std::memory_order_relaxed); | |
283 | } | |
284 | ||
285 | // Get total number of deletes in the mem table. | |
286 | // REQUIRES: external synchronization to prevent simultaneous | |
287 | // operations on the same MemTable (unless this Memtable is immutable). | |
288 | uint64_t num_deletes() const { | |
289 | return num_deletes_.load(std::memory_order_relaxed); | |
290 | } | |
291 | ||
494da23a TL |
292 | uint64_t get_data_size() const { |
293 | return data_size_.load(std::memory_order_relaxed); | |
294 | } | |
295 | ||
11fdf7f2 TL |
296 | // Dynamically change the memtable's capacity. If set below the current usage, |
297 | // the next key added will trigger a flush. Can only increase size when | |
298 | // memtable prefix bloom is disabled, since we can't easily allocate more | |
299 | // space. | |
300 | void UpdateWriteBufferSize(size_t new_write_buffer_size) { | |
494da23a | 301 | if (bloom_filter_ == nullptr || |
11fdf7f2 TL |
302 | new_write_buffer_size < write_buffer_size_) { |
303 | write_buffer_size_.store(new_write_buffer_size, | |
304 | std::memory_order_relaxed); | |
305 | } | |
306 | } | |
307 | ||
7c673cae FG |
308 | // Returns the edits area that is needed for flushing the memtable |
309 | VersionEdit* GetEdits() { return &edit_; } | |
310 | ||
311 | // Returns if there is no entry inserted to the mem table. | |
312 | // REQUIRES: external synchronization to prevent simultaneous | |
313 | // operations on the same MemTable (unless this Memtable is immutable). | |
314 | bool IsEmpty() const { return first_seqno_ == 0; } | |
315 | ||
316 | // Returns the sequence number of the first element that was inserted | |
317 | // into the memtable. | |
318 | // REQUIRES: external synchronization to prevent simultaneous | |
319 | // operations on the same MemTable (unless this Memtable is immutable). | |
320 | SequenceNumber GetFirstSequenceNumber() { | |
321 | return first_seqno_.load(std::memory_order_relaxed); | |
322 | } | |
323 | ||
324 | // Returns the sequence number that is guaranteed to be smaller than or equal | |
325 | // to the sequence number of any key that could be inserted into this | |
326 | // memtable. It can then be assumed that any write with a larger(or equal) | |
327 | // sequence number will be present in this memtable or a later memtable. | |
328 | // | |
329 | // If the earliest sequence number could not be determined, | |
330 | // kMaxSequenceNumber will be returned. | |
331 | SequenceNumber GetEarliestSequenceNumber() { | |
332 | return earliest_seqno_.load(std::memory_order_relaxed); | |
333 | } | |
334 | ||
335 | // DB's latest sequence ID when the memtable is created. This number | |
336 | // may be updated to a more recent one before any key is inserted. | |
337 | SequenceNumber GetCreationSeq() const { return creation_seq_; } | |
338 | ||
339 | void SetCreationSeq(SequenceNumber sn) { creation_seq_ = sn; } | |
340 | ||
341 | // Returns the next active logfile number when this memtable is about to | |
342 | // be flushed to storage | |
343 | // REQUIRES: external synchronization to prevent simultaneous | |
344 | // operations on the same MemTable. | |
345 | uint64_t GetNextLogNumber() { return mem_next_logfile_number_; } | |
346 | ||
347 | // Sets the next active logfile number when this memtable is about to | |
348 | // be flushed to storage | |
349 | // REQUIRES: external synchronization to prevent simultaneous | |
350 | // operations on the same MemTable. | |
351 | void SetNextLogNumber(uint64_t num) { mem_next_logfile_number_ = num; } | |
352 | ||
353 | // if this memtable contains data from a committed | |
354 | // two phase transaction we must take note of the | |
355 | // log which contains that data so we can know | |
356 | // when to relese that log | |
357 | void RefLogContainingPrepSection(uint64_t log); | |
358 | uint64_t GetMinLogContainingPrepSection(); | |
359 | ||
360 | // Notify the underlying storage that no more items will be added. | |
361 | // REQUIRES: external synchronization to prevent simultaneous | |
362 | // operations on the same MemTable. | |
363 | // After MarkImmutable() is called, you should not attempt to | |
364 | // write anything to this MemTable(). (Ie. do not call Add() or Update()). | |
365 | void MarkImmutable() { | |
366 | table_->MarkReadOnly(); | |
11fdf7f2 TL |
367 | mem_tracker_.DoneAllocating(); |
368 | } | |
369 | ||
370 | // Notify the underlying storage that all data it contained has been | |
371 | // persisted. | |
372 | // REQUIRES: external synchronization to prevent simultaneous | |
373 | // operations on the same MemTable. | |
374 | void MarkFlushed() { | |
375 | table_->MarkFlushed(); | |
7c673cae FG |
376 | } |
377 | ||
378 | // return true if the current MemTableRep supports merge operator. | |
379 | bool IsMergeOperatorSupported() const { | |
380 | return table_->IsMergeOperatorSupported(); | |
381 | } | |
382 | ||
383 | // return true if the current MemTableRep supports snapshots. | |
384 | // inplace update prevents snapshots, | |
385 | bool IsSnapshotSupported() const { | |
386 | return table_->IsSnapshotSupported() && !moptions_.inplace_update_support; | |
387 | } | |
388 | ||
389 | struct MemTableStats { | |
390 | uint64_t size; | |
391 | uint64_t count; | |
392 | }; | |
393 | ||
394 | MemTableStats ApproximateStats(const Slice& start_ikey, | |
395 | const Slice& end_ikey); | |
396 | ||
397 | // Get the lock associated for the key | |
398 | port::RWMutex* GetLock(const Slice& key); | |
399 | ||
400 | const InternalKeyComparator& GetInternalKeyComparator() const { | |
401 | return comparator_.comparator; | |
402 | } | |
403 | ||
11fdf7f2 TL |
404 | const ImmutableMemTableOptions* GetImmutableMemTableOptions() const { |
405 | return &moptions_; | |
406 | } | |
407 | ||
408 | uint64_t ApproximateOldestKeyTime() const { | |
409 | return oldest_key_time_.load(std::memory_order_relaxed); | |
410 | } | |
411 | ||
412 | // REQUIRES: db_mutex held. | |
413 | void SetID(uint64_t id) { id_ = id; } | |
414 | ||
415 | uint64_t GetID() const { return id_; } | |
7c673cae | 416 | |
494da23a TL |
417 | void SetFlushCompleted(bool completed) { flush_completed_ = completed; } |
418 | ||
419 | uint64_t GetFileNumber() const { return file_number_; } | |
420 | ||
421 | void SetFileNumber(uint64_t file_num) { file_number_ = file_num; } | |
422 | ||
423 | void SetFlushInProgress(bool in_progress) { | |
424 | flush_in_progress_ = in_progress; | |
425 | } | |
426 | ||
f67539c2 TL |
427 | #ifndef ROCKSDB_LITE |
428 | void SetFlushJobInfo(std::unique_ptr<FlushJobInfo>&& info) { | |
429 | flush_job_info_ = std::move(info); | |
430 | } | |
431 | ||
432 | std::unique_ptr<FlushJobInfo> ReleaseFlushJobInfo() { | |
433 | return std::move(flush_job_info_); | |
434 | } | |
435 | #endif // !ROCKSDB_LITE | |
436 | ||
7c673cae FG |
437 | private: |
438 | enum FlushStateEnum { FLUSH_NOT_REQUESTED, FLUSH_REQUESTED, FLUSH_SCHEDULED }; | |
439 | ||
440 | friend class MemTableIterator; | |
441 | friend class MemTableBackwardIterator; | |
442 | friend class MemTableList; | |
443 | ||
444 | KeyComparator comparator_; | |
11fdf7f2 | 445 | const ImmutableMemTableOptions moptions_; |
7c673cae FG |
446 | int refs_; |
447 | const size_t kArenaBlockSize; | |
11fdf7f2 | 448 | AllocTracker mem_tracker_; |
7c673cae | 449 | ConcurrentArena arena_; |
494da23a TL |
450 | std::unique_ptr<MemTableRep> table_; |
451 | std::unique_ptr<MemTableRep> range_del_table_; | |
452 | std::atomic_bool is_range_del_table_empty_; | |
7c673cae FG |
453 | |
454 | // Total data size of all data inserted | |
455 | std::atomic<uint64_t> data_size_; | |
456 | std::atomic<uint64_t> num_entries_; | |
457 | std::atomic<uint64_t> num_deletes_; | |
458 | ||
11fdf7f2 TL |
459 | // Dynamically changeable memtable option |
460 | std::atomic<size_t> write_buffer_size_; | |
461 | ||
7c673cae FG |
462 | // These are used to manage memtable flushes to storage |
463 | bool flush_in_progress_; // started the flush | |
464 | bool flush_completed_; // finished the flush | |
465 | uint64_t file_number_; // filled up after flush is complete | |
466 | ||
467 | // The updates to be applied to the transaction log when this | |
468 | // memtable is flushed to storage. | |
469 | VersionEdit edit_; | |
470 | ||
471 | // The sequence number of the kv that was inserted first | |
472 | std::atomic<SequenceNumber> first_seqno_; | |
473 | ||
474 | // The db sequence number at the time of creation or kMaxSequenceNumber | |
475 | // if not set. | |
476 | std::atomic<SequenceNumber> earliest_seqno_; | |
477 | ||
478 | SequenceNumber creation_seq_; | |
479 | ||
480 | // The log files earlier than this number can be deleted. | |
481 | uint64_t mem_next_logfile_number_; | |
482 | ||
483 | // the earliest log containing a prepared section | |
484 | // which has been inserted into this memtable. | |
485 | std::atomic<uint64_t> min_prep_log_referenced_; | |
486 | ||
487 | // rw locks for inplace updates | |
488 | std::vector<port::RWMutex> locks_; | |
489 | ||
490 | const SliceTransform* const prefix_extractor_; | |
494da23a | 491 | std::unique_ptr<DynamicBloom> bloom_filter_; |
7c673cae FG |
492 | |
493 | std::atomic<FlushStateEnum> flush_state_; | |
494 | ||
495 | Env* env_; | |
496 | ||
497 | // Extract sequential insert prefixes. | |
498 | const SliceTransform* insert_with_hint_prefix_extractor_; | |
499 | ||
500 | // Insert hints for each prefix. | |
501 | std::unordered_map<Slice, void*, SliceHasher> insert_hints_; | |
502 | ||
11fdf7f2 TL |
503 | // Timestamp of oldest key |
504 | std::atomic<uint64_t> oldest_key_time_; | |
505 | ||
506 | // Memtable id to track flush. | |
507 | uint64_t id_ = 0; | |
508 | ||
494da23a TL |
509 | // Sequence number of the atomic flush that is responsible for this memtable. |
510 | // The sequence number of atomic flush is a seq, such that no writes with | |
511 | // sequence numbers greater than or equal to seq are flushed, while all | |
512 | // writes with sequence number smaller than seq are flushed. | |
513 | SequenceNumber atomic_flush_seqno_; | |
514 | ||
f67539c2 TL |
515 | // keep track of memory usage in table_, arena_, and range_del_table_. |
516 | // Gets refrshed inside `ApproximateMemoryUsage()` or `ShouldFlushNow` | |
517 | std::atomic<uint64_t> approximate_memory_usage_; | |
518 | ||
519 | #ifndef ROCKSDB_LITE | |
520 | // Flush job info of the current memtable. | |
521 | std::unique_ptr<FlushJobInfo> flush_job_info_; | |
522 | #endif // !ROCKSDB_LITE | |
523 | ||
7c673cae | 524 | // Returns a heuristic flush decision |
f67539c2 | 525 | bool ShouldFlushNow(); |
7c673cae FG |
526 | |
527 | // Updates flush_state_ using ShouldFlushNow() | |
528 | void UpdateFlushState(); | |
529 | ||
11fdf7f2 TL |
530 | void UpdateOldestKeyTime(); |
531 | ||
f67539c2 TL |
532 | void GetFromTable(const LookupKey& key, |
533 | SequenceNumber max_covering_tombstone_seq, bool do_merge, | |
534 | ReadCallback* callback, bool* is_blob_index, | |
535 | std::string* value, Status* s, MergeContext* merge_context, | |
536 | SequenceNumber* seq, bool* found_final_value, | |
537 | bool* merge_in_progress); | |
7c673cae FG |
538 | }; |
539 | ||
540 | extern const char* EncodeKey(std::string* scratch, const Slice& target); | |
541 | ||
f67539c2 | 542 | } // namespace ROCKSDB_NAMESPACE |