blockstorage.h
1 // Copyright (c) 2011-present The Bitcoin Core developers 2 // Distributed under the MIT software license, see the accompanying 3 // file COPYING or http://www.opensource.org/licenses/mit-license.php. 4 5 #ifndef BITCOIN_NODE_BLOCKSTORAGE_H 6 #define BITCOIN_NODE_BLOCKSTORAGE_H 7 8 #include <attributes.h> 9 #include <chain.h> 10 #include <dbwrapper.h> 11 #include <flatfile.h> 12 #include <kernel/blockmanager_opts.h> 13 #include <kernel/chainparams.h> 14 #include <kernel/cs_main.h> 15 #include <kernel/messagestartchars.h> 16 #include <primitives/block.h> 17 #include <serialize.h> 18 #include <streams.h> 19 #include <sync.h> 20 #include <uint256.h> 21 #include <util/expected.h> 22 #include <util/fs.h> 23 #include <util/hasher.h> 24 #include <util/obfuscation.h> 25 26 #include <algorithm> 27 #include <array> 28 #include <atomic> 29 #include <cstddef> 30 #include <cstdint> 31 #include <functional> 32 #include <iosfwd> 33 #include <limits> 34 #include <map> 35 #include <memory> 36 #include <optional> 37 #include <set> 38 #include <span> 39 #include <string> 40 #include <unordered_map> 41 #include <utility> 42 #include <vector> 43 44 class BlockValidationState; 45 class CBlockUndo; 46 class Chainstate; 47 class ChainstateManager; 48 namespace Consensus { 49 struct Params; 50 } 51 namespace util { 52 class SignalInterrupt; 53 } // namespace util 54 55 namespace kernel { 56 class CBlockFileInfo 57 { 58 public: 59 uint32_t nBlocks{}; //!< number of blocks stored in file 60 uint32_t nSize{}; //!< number of used bytes of block file 61 uint32_t nUndoSize{}; //!< number of used bytes in the undo file 62 uint32_t nHeightFirst{}; //!< lowest height of block in file 63 uint32_t nHeightLast{}; //!< highest height of block in file 64 uint64_t nTimeFirst{}; //!< earliest time of block in file 65 uint64_t nTimeLast{}; //!< latest time of block in file 66 67 SERIALIZE_METHODS(CBlockFileInfo, obj) 68 { 69 READWRITE(VARINT(obj.nBlocks)); 70 READWRITE(VARINT(obj.nSize)); 71 READWRITE(VARINT(obj.nUndoSize)); 72 READWRITE(VARINT(obj.nHeightFirst)); 73 READWRITE(VARINT(obj.nHeightLast)); 74 READWRITE(VARINT(obj.nTimeFirst)); 75 READWRITE(VARINT(obj.nTimeLast)); 76 } 77 78 CBlockFileInfo() = default; 79 80 std::string ToString() const; 81 82 /** update statistics (does not update nSize) */ 83 void AddBlock(unsigned int nHeightIn, uint64_t nTimeIn) 84 { 85 if (nBlocks == 0 || nHeightFirst > nHeightIn) 86 nHeightFirst = nHeightIn; 87 if (nBlocks == 0 || nTimeFirst > nTimeIn) 88 nTimeFirst = nTimeIn; 89 nBlocks++; 90 if (nHeightIn > nHeightLast) 91 nHeightLast = nHeightIn; 92 if (nTimeIn > nTimeLast) 93 nTimeLast = nTimeIn; 94 } 95 }; 96 97 /** Access to the block database (blocks/index/) */ 98 class BlockTreeDB : public CDBWrapper 99 { 100 public: 101 using CDBWrapper::CDBWrapper; 102 void WriteBatchSync(const std::vector<std::pair<int, const CBlockFileInfo*>>& fileInfo, int nLastFile, const std::vector<const CBlockIndex*>& blockinfo); 103 bool ReadBlockFileInfo(int nFile, CBlockFileInfo& info); 104 bool ReadLastBlockFile(int& nFile); 105 void WriteReindexing(bool fReindexing); 106 void ReadReindexing(bool& fReindexing); 107 void WriteFlag(const std::string& name, bool fValue); 108 bool ReadFlag(const std::string& name, bool& fValue); 109 bool LoadBlockIndexGuts(const Consensus::Params& consensusParams, std::function<CBlockIndex*(const uint256&)> insertBlockIndex, const util::SignalInterrupt& interrupt) 110 EXCLUSIVE_LOCKS_REQUIRED(::cs_main); 111 }; 112 } // namespace kernel 113 114 namespace node { 115 using kernel::CBlockFileInfo; 116 using kernel::BlockTreeDB; 117 118 /** The pre-allocation chunk size for blk?????.dat files (since 0.8) */ 119 static const unsigned int BLOCKFILE_CHUNK_SIZE = 0x1000000; // 16 MiB 120 /** The pre-allocation chunk size for rev?????.dat files (since 0.8) */ 121 static const unsigned int UNDOFILE_CHUNK_SIZE = 0x100000; // 1 MiB 122 /** The maximum size of a blk?????.dat file (since 0.8) */ 123 static const unsigned int MAX_BLOCKFILE_SIZE = 0x8000000; // 128 MiB 124 125 /** Size of header written by WriteBlock before a serialized CBlock (8 bytes) */ 126 static constexpr uint32_t STORAGE_HEADER_BYTES{std::tuple_size_v<MessageStartChars> + sizeof(unsigned int)}; 127 128 /** Total overhead when writing undo data: header (8 bytes) plus checksum (32 bytes) */ 129 static constexpr uint32_t UNDO_DATA_DISK_OVERHEAD{STORAGE_HEADER_BYTES + uint256::size()}; 130 131 // Because validation code takes pointers to the map's CBlockIndex objects, if 132 // we ever switch to another associative container, we need to either use a 133 // container that has stable addressing (true of all std associative 134 // containers), or make the key a `std::unique_ptr<CBlockIndex>` 135 using BlockMap = std::unordered_map<uint256, CBlockIndex, BlockHasher>; 136 137 struct CBlockIndexWorkComparator { 138 bool operator()(const CBlockIndex* pa, const CBlockIndex* pb) const; 139 using is_transparent = void; 140 }; 141 142 struct CBlockIndexHeightOnlyComparator { 143 /* Only compares the height of two block indices, doesn't try to tie-break */ 144 bool operator()(const CBlockIndex* pa, const CBlockIndex* pb) const; 145 }; 146 147 struct PruneLockInfo { 148 int height_first{std::numeric_limits<int>::max()}; //! Height of earliest block that should be kept and not pruned 149 }; 150 151 enum BlockfileType { 152 // Values used as array indexes - do not change carelessly. 153 NORMAL = 0, 154 ASSUMED = 1, 155 NUM_TYPES = 2, 156 }; 157 158 std::ostream& operator<<(std::ostream& os, const BlockfileType& type); 159 160 struct BlockfileCursor { 161 // The latest blockfile number. 162 int file_num{0}; 163 164 // Track the height of the highest block in file_num whose undo 165 // data has been written. Block data is written to block files in download 166 // order, but is written to undo files in validation order, which is 167 // usually in order by height. To avoid wasting disk space, undo files will 168 // be trimmed whenever the corresponding block file is finalized and 169 // the height of the highest block written to the block file equals the 170 // height of the highest block written to the undo file. This is a 171 // heuristic and can sometimes preemptively trim undo files that will write 172 // more data later, and sometimes fail to trim undo files that can't have 173 // more data written later. 174 int undo_height{0}; 175 }; 176 177 std::ostream& operator<<(std::ostream& os, const BlockfileCursor& cursor); 178 179 enum class ReadRawError { 180 IO, 181 BadPartRange, 182 }; 183 184 /** 185 * Maintains a tree of blocks (stored in `m_block_index`) which is consulted 186 * to determine where the most-work tip is. 187 * 188 * This data is used mostly in `Chainstate` - information about, e.g., 189 * candidate tips is not maintained here. 190 */ 191 class BlockManager 192 { 193 friend Chainstate; 194 friend ChainstateManager; 195 196 private: 197 const CChainParams& GetParams() const { return m_opts.chainparams; } 198 const Consensus::Params& GetConsensus() const { return m_opts.chainparams.GetConsensus(); } 199 /** 200 * Load the blocktree off disk and into memory. Populate certain metadata 201 * per index entry (nStatus, nChainWork, nTimeMax, etc.) as well as peripheral 202 * collections like m_dirty_blockindex. 203 */ 204 bool LoadBlockIndex(const std::optional<uint256>& snapshot_blockhash) 205 EXCLUSIVE_LOCKS_REQUIRED(cs_main); 206 207 /** Return false if block file or undo file flushing fails. */ 208 [[nodiscard]] bool FlushBlockFile(int blockfile_num, bool fFinalize, bool finalize_undo); 209 210 /** Return false if undo file flushing fails. */ 211 [[nodiscard]] bool FlushUndoFile(int block_file, bool finalize = false); 212 213 /** 214 * Helper function performing various preparations before a block can be saved to disk: 215 * Returns the correct position for the block to be saved, which may be in the current or a new 216 * block file depending on nAddSize. May flush the previous blockfile to disk if full, updates 217 * blockfile info, and checks if there is enough disk space to save the block. 218 * 219 * The nAddSize argument passed to this function should include not just the size of the serialized CBlock, but also the size of 220 * separator fields (STORAGE_HEADER_BYTES). 221 */ 222 [[nodiscard]] FlatFilePos FindNextBlockPos(unsigned int nAddSize, unsigned int nHeight, uint64_t nTime); 223 [[nodiscard]] bool FlushChainstateBlockFile(int tip_height); 224 bool FindUndoPos(BlockValidationState& state, int nFile, FlatFilePos& pos, unsigned int nAddSize); 225 226 AutoFile OpenUndoFile(const FlatFilePos& pos, bool fReadOnly = false) const; 227 228 /* Calculate the block/rev files to delete based on height specified by user with RPC command pruneblockchain */ 229 void FindFilesToPruneManual( 230 std::set<int>& setFilesToPrune, 231 int nManualPruneHeight, 232 const Chainstate& chain); 233 234 /** 235 * Prune block and undo files (blk???.dat and rev???.dat) so that the disk space used is less than a user-defined target. 236 * The user sets the target (in MB) on the command line or in config file. This will be run on startup and whenever new 237 * space is allocated in a block or undo file, staying below the target. Changing back to unpruned requires a reindex 238 * (which in this case means the blockchain must be re-downloaded.) 239 * 240 * Pruning functions are called from FlushStateToDisk when the m_check_for_pruning flag has been set. 241 * Block and undo files are deleted in lock-step (when blk00003.dat is deleted, so is rev00003.dat.) 242 * Pruning cannot take place until the longest chain is at least a certain length (CChainParams::nPruneAfterHeight). 243 * Pruning will never delete a block within a defined distance (currently 288) from the active chain's tip. 244 * The block index is updated by unsetting HAVE_DATA and HAVE_UNDO for any blocks that were stored in the deleted files. 245 * A db flag records the fact that at least some block files have been pruned. 246 * 247 * @param[out] setFilesToPrune The set of file indices that can be unlinked will be returned 248 * @param last_prune The last height we're able to prune, according to the prune locks 249 */ 250 void FindFilesToPrune( 251 std::set<int>& setFilesToPrune, 252 int last_prune, 253 const Chainstate& chain, 254 ChainstateManager& chainman); 255 256 RecursiveMutex cs_LastBlockFile; 257 258 //! Since assumedvalid chainstates may be syncing a range of the chain that is very 259 //! far away from the normal/background validation process, we should segment blockfiles 260 //! for assumed chainstates. Otherwise, we might have wildly different height ranges 261 //! mixed into the same block files, which would impair our ability to prune 262 //! effectively. 263 //! 264 //! This data structure maintains separate blockfile number cursors for each 265 //! BlockfileType. The ASSUMED state is initialized, when necessary, in FindNextBlockPos(). 266 //! 267 //! The first element is the NORMAL cursor, second is ASSUMED. 268 std::array<std::optional<BlockfileCursor>, BlockfileType::NUM_TYPES> 269 m_blockfile_cursors GUARDED_BY(cs_LastBlockFile) = { 270 BlockfileCursor{}, 271 std::nullopt, 272 }; 273 int MaxBlockfileNum() const EXCLUSIVE_LOCKS_REQUIRED(cs_LastBlockFile) 274 { 275 static const BlockfileCursor empty_cursor; 276 const auto& normal = m_blockfile_cursors[BlockfileType::NORMAL].value_or(empty_cursor); 277 const auto& assumed = m_blockfile_cursors[BlockfileType::ASSUMED].value_or(empty_cursor); 278 return std::max(normal.file_num, assumed.file_num); 279 } 280 281 /** Global flag to indicate we should check to see if there are 282 * block/undo files that should be deleted. Set on startup 283 * or if we allocate more file space when we're in prune mode 284 */ 285 bool m_check_for_pruning = false; 286 287 const bool m_prune_mode; 288 289 const Obfuscation m_obfuscation; 290 291 /** 292 * Map from external index name to oldest block that must not be pruned. 293 * 294 * @note Internally, only blocks at height (height_first - PRUNE_LOCK_BUFFER - 1) and 295 * below will be pruned, but callers should avoid assuming any particular buffer size. 296 */ 297 std::unordered_map<std::string, PruneLockInfo> m_prune_locks GUARDED_BY(::cs_main); 298 299 BlockfileType BlockfileTypeForHeight(int height); 300 301 const kernel::BlockManagerOpts m_opts; 302 303 const FlatFileSeq m_block_file_seq; 304 const FlatFileSeq m_undo_file_seq; 305 306 protected: 307 std::vector<CBlockFileInfo> m_blockfile_info; 308 309 /** Dirty block index entries. */ 310 std::set<CBlockIndex*> m_dirty_blockindex; 311 312 /** Dirty block file entries. */ 313 std::set<int> m_dirty_fileinfo; 314 315 public: 316 using Options = kernel::BlockManagerOpts; 317 using ReadRawBlockResult = util::Expected<std::vector<std::byte>, ReadRawError>; 318 319 explicit BlockManager(const util::SignalInterrupt& interrupt, Options opts); 320 321 const util::SignalInterrupt& m_interrupt; 322 std::atomic<bool> m_importing{false}; 323 324 /** 325 * Whether all blockfiles have been added to the block tree database. 326 * Normally true, but set to false when a reindex is requested and the 327 * database is wiped. The value is persisted in the database across restarts 328 * and will be false until reindexing completes. 329 */ 330 std::atomic_bool m_blockfiles_indexed{true}; 331 332 BlockMap m_block_index GUARDED_BY(cs_main); 333 334 /** 335 * The height of the base block of an assumeutxo snapshot, if one is in use. 336 * 337 * This controls how blockfiles are segmented by chainstate type to avoid 338 * comingling different height regions of the chain when an assumedvalid chainstate 339 * is in use. If heights are drastically different in the same blockfile, pruning 340 * suffers. 341 * 342 * This is set during ActivateSnapshot() or upon LoadBlockIndex() if a snapshot 343 * had been previously loaded. After the snapshot is validated, this is unset to 344 * restore normal LoadBlockIndex behavior. 345 */ 346 std::optional<int> m_snapshot_height; 347 348 std::vector<CBlockIndex*> GetAllBlockIndices() EXCLUSIVE_LOCKS_REQUIRED(::cs_main); 349 350 /** 351 * All pairs A->B, where A (or one of its ancestors) misses transactions, but B has transactions. 352 * Pruned nodes may have entries where B is missing data. 353 */ 354 std::multimap<CBlockIndex*, CBlockIndex*> m_blocks_unlinked; 355 356 std::unique_ptr<BlockTreeDB> m_block_tree_db GUARDED_BY(::cs_main); 357 358 void WriteBlockIndexDB() EXCLUSIVE_LOCKS_REQUIRED(::cs_main); 359 bool LoadBlockIndexDB(const std::optional<uint256>& snapshot_blockhash) 360 EXCLUSIVE_LOCKS_REQUIRED(::cs_main); 361 362 /** 363 * Remove any pruned block & undo files that are still on disk. 364 * This could happen on some systems if the file was still being read while unlinked, 365 * or if we crash before unlinking. 366 */ 367 void ScanAndUnlinkAlreadyPrunedFiles() EXCLUSIVE_LOCKS_REQUIRED(::cs_main); 368 369 CBlockIndex* AddToBlockIndex(const CBlockHeader& block, CBlockIndex*& best_header) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 370 /** Create a new block index entry for a given block hash */ 371 CBlockIndex* InsertBlockIndex(const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 372 373 //! Mark one block file as pruned (modify associated database entries) 374 void PruneOneBlockFile(int fileNumber) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 375 376 CBlockIndex* LookupBlockIndex(const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main); 377 const CBlockIndex* LookupBlockIndex(const uint256& hash) const EXCLUSIVE_LOCKS_REQUIRED(cs_main); 378 379 /** Get block file info entry for one block file */ 380 CBlockFileInfo* GetBlockFileInfo(size_t n); 381 382 bool WriteBlockUndo(const CBlockUndo& blockundo, BlockValidationState& state, CBlockIndex& block) 383 EXCLUSIVE_LOCKS_REQUIRED(::cs_main); 384 385 /** Store block on disk and update block file statistics. 386 * 387 * @param[in] block the block to be stored 388 * @param[in] nHeight the height of the block 389 * 390 * @returns in case of success, the position to which the block was written to 391 * in case of an error, an empty FlatFilePos 392 */ 393 FlatFilePos WriteBlock(const CBlock& block, int nHeight); 394 395 /** Update blockfile info while processing a block during reindex. The block must be available on disk. 396 * 397 * @param[in] block the block being processed 398 * @param[in] nHeight the height of the block 399 * @param[in] pos the position of the serialized CBlock on disk 400 */ 401 void UpdateBlockInfo(const CBlock& block, unsigned int nHeight, const FlatFilePos& pos); 402 403 /** Whether running in -prune mode. */ 404 [[nodiscard]] bool IsPruneMode() const { return m_prune_mode; } 405 406 /** Attempt to stay below this number of bytes of block files. */ 407 [[nodiscard]] uint64_t GetPruneTarget() const { return m_opts.prune_target; } 408 static constexpr auto PRUNE_TARGET_MANUAL{std::numeric_limits<uint64_t>::max()}; 409 410 [[nodiscard]] bool LoadingBlocks() const { return m_importing || !m_blockfiles_indexed; } 411 412 /** Calculate the amount of disk space the block & undo files currently use */ 413 uint64_t CalculateCurrentUsage(); 414 415 //! Check if all blocks in the [upper_block, lower_block] range have data available as 416 //! defined by the status mask. 417 //! The caller is responsible for ensuring that lower_block is an ancestor of upper_block 418 //! (part of the same chain). 419 bool CheckBlockDataAvailability(const CBlockIndex& upper_block, const CBlockIndex& lower_block, BlockStatus block_status = BLOCK_HAVE_DATA) EXCLUSIVE_LOCKS_REQUIRED(::cs_main); 420 421 /** 422 * @brief Returns the earliest block with specified `status_mask` flags set after 423 * the latest block _not_ having those flags. 424 * 425 * This function starts from `upper_block`, which must have all 426 * `status_mask` flags set, and iterates backwards through its ancestors. It 427 * continues as long as each block has all `status_mask` flags set, until 428 * reaching the oldest ancestor or `lower_block`. 429 * 430 * @pre `upper_block` must have all `status_mask` flags set. 431 * @pre `lower_block` must be null or an ancestor of `upper_block` 432 * 433 * @param upper_block The starting block for the search, which must have all 434 * `status_mask` flags set. 435 * @param status_mask Bitmask specifying required status flags. 436 * @param lower_block The earliest possible block to return. If null, the 437 * search can extend to the genesis block. 438 * 439 * @return A reference to the earliest block between `upper_block` 440 * and `lower_block`, inclusive, such that every block between the 441 * returned block and `upper_block` has `status_mask` flags set. 442 */ 443 const CBlockIndex& GetFirstBlock( 444 const CBlockIndex& upper_block LIFETIMEBOUND, 445 uint32_t status_mask, 446 const CBlockIndex* lower_block LIFETIMEBOUND = nullptr 447 ) const EXCLUSIVE_LOCKS_REQUIRED(::cs_main); 448 449 /** True if any block files have ever been pruned. */ 450 bool m_have_pruned = false; 451 452 //! Check whether the block associated with this index entry is pruned or not. 453 bool IsBlockPruned(const CBlockIndex& block) const EXCLUSIVE_LOCKS_REQUIRED(::cs_main); 454 455 //! Create or update a prune lock identified by its name 456 void UpdatePruneLock(const std::string& name, const PruneLockInfo& lock_info) EXCLUSIVE_LOCKS_REQUIRED(::cs_main); 457 458 /** Open a block file (blk?????.dat) */ 459 AutoFile OpenBlockFile(const FlatFilePos& pos, bool fReadOnly) const; 460 461 /** Translation to a filesystem path */ 462 fs::path GetBlockPosFilename(const FlatFilePos& pos) const; 463 464 /** 465 * Actually unlink the specified files 466 */ 467 void UnlinkPrunedFiles(const std::set<int>& setFilesToPrune) const; 468 469 /** Functions for disk access for blocks */ 470 bool ReadBlock(CBlock& block, const FlatFilePos& pos, const std::optional<uint256>& expected_hash) const; 471 bool ReadBlock(CBlock& block, const CBlockIndex& index) const; 472 ReadRawBlockResult ReadRawBlock(const FlatFilePos& pos, std::optional<std::pair<size_t, size_t>> block_part = std::nullopt) const; 473 474 bool ReadBlockUndo(CBlockUndo& blockundo, const CBlockIndex& index) const; 475 476 void CleanupBlockRevFiles() const; 477 }; 478 479 // Calls ActivateBestChain() even if no blocks are imported. 480 void ImportBlocks(ChainstateManager& chainman, std::span<const fs::path> import_paths); 481 } // namespace node 482 483 #endif // BITCOIN_NODE_BLOCKSTORAGE_H