chain.h
1 // Copyright (c) 2018-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_INTERFACES_CHAIN_H 6 #define BITCOIN_INTERFACES_CHAIN_H 7 8 #include <blockfilter.h> 9 #include <common/settings.h> 10 #include <node/types.h> 11 #include <primitives/transaction.h> 12 #include <util/result.h> 13 14 #include <cstddef> 15 #include <cstdint> 16 #include <functional> 17 #include <map> 18 #include <memory> 19 #include <optional> 20 #include <string> 21 #include <vector> 22 23 class ArgsManager; 24 class CBlock; 25 class CBlockUndo; 26 class CFeeRate; 27 class CRPCCommand; 28 class CScheduler; 29 class Coin; 30 class uint256; 31 enum class MemPoolRemovalReason; 32 enum class RBFTransactionState; 33 enum class ChainstateRole; 34 struct bilingual_str; 35 struct CBlockLocator; 36 struct FeeCalculation; 37 namespace node { 38 struct NodeContext; 39 } // namespace node 40 41 namespace interfaces { 42 43 class Handler; 44 class Wallet; 45 46 //! Helper for findBlock to selectively return pieces of block data. If block is 47 //! found, data will be returned by setting specified output variables. If block 48 //! is not found, output variables will keep their previous values. 49 class FoundBlock 50 { 51 public: 52 FoundBlock& hash(uint256& hash) { m_hash = &hash; return *this; } 53 FoundBlock& height(int& height) { m_height = &height; return *this; } 54 FoundBlock& time(int64_t& time) { m_time = &time; return *this; } 55 FoundBlock& maxTime(int64_t& max_time) { m_max_time = &max_time; return *this; } 56 FoundBlock& mtpTime(int64_t& mtp_time) { m_mtp_time = &mtp_time; return *this; } 57 //! Return whether block is in the active (most-work) chain. 58 FoundBlock& inActiveChain(bool& in_active_chain) { m_in_active_chain = &in_active_chain; return *this; } 59 //! Return locator if block is in the active chain. 60 FoundBlock& locator(CBlockLocator& locator) { m_locator = &locator; return *this; } 61 //! Return next block in the active chain if current block is in the active chain. 62 FoundBlock& nextBlock(const FoundBlock& next_block) { m_next_block = &next_block; return *this; } 63 //! Read block data from disk. If the block exists but doesn't have data 64 //! (for example due to pruning), the CBlock variable will be set to null. 65 FoundBlock& data(CBlock& data) { m_data = &data; return *this; } 66 67 uint256* m_hash = nullptr; 68 int* m_height = nullptr; 69 int64_t* m_time = nullptr; 70 int64_t* m_max_time = nullptr; 71 int64_t* m_mtp_time = nullptr; 72 bool* m_in_active_chain = nullptr; 73 CBlockLocator* m_locator = nullptr; 74 const FoundBlock* m_next_block = nullptr; 75 CBlock* m_data = nullptr; 76 mutable bool found = false; 77 }; 78 79 //! Block data sent with blockConnected, blockDisconnected notifications. 80 struct BlockInfo { 81 const uint256& hash; 82 const uint256* prev_hash = nullptr; 83 int height = -1; 84 int file_number = -1; 85 unsigned data_pos = 0; 86 const CBlock* data = nullptr; 87 const CBlockUndo* undo_data = nullptr; 88 // The maximum time in the chain up to and including this block. 89 // A timestamp that can only move forward. 90 unsigned int chain_time_max{0}; 91 92 BlockInfo(const uint256& hash LIFETIMEBOUND) : hash(hash) {} 93 }; 94 95 //! The action to be taken after updating a settings value. 96 //! WRITE indicates that the updated value must be written to disk, 97 //! while SKIP_WRITE indicates that the change will be kept in memory-only 98 //! without persisting it. 99 enum class SettingsAction { 100 WRITE, 101 SKIP_WRITE 102 }; 103 104 using SettingsUpdate = std::function<std::optional<interfaces::SettingsAction>(common::SettingsValue&)>; 105 106 //! Interface giving clients (wallet processes, maybe other analysis tools in 107 //! the future) ability to access to the chain state, receive notifications, 108 //! estimate fees, and submit transactions. 109 //! 110 //! TODO: Current chain methods are too low level, exposing too much of the 111 //! internal workings of the bitcoin node, and not being very convenient to use. 112 //! Chain methods should be cleaned up and simplified over time. Examples: 113 //! 114 //! * The initMessages() and showProgress() methods which the wallet uses to send 115 //! notifications to the GUI should go away when GUI and wallet can directly 116 //! communicate with each other without going through the node 117 //! (https://github.com/bitcoin/bitcoin/pull/15288#discussion_r253321096). 118 //! 119 //! * The handleRpc, registerRpcs, rpcEnableDeprecated methods and other RPC 120 //! methods can go away if wallets listen for HTTP requests on their own 121 //! ports instead of registering to handle requests on the node HTTP port. 122 //! 123 //! * Move fee estimation queries to an asynchronous interface and let the 124 //! wallet cache it, fee estimation being driven by node mempool, wallet 125 //! should be the consumer. 126 //! 127 //! * `guessVerificationProgress` and similar methods can go away if rescan 128 //! logic moves out of the wallet, and the wallet just requests scans from the 129 //! node (https://github.com/bitcoin/bitcoin/issues/11756) 130 class Chain 131 { 132 public: 133 virtual ~Chain() = default; 134 135 //! Get current chain height, not including genesis block (returns 0 if 136 //! chain only contains genesis block, nullopt if chain does not contain 137 //! any blocks) 138 virtual std::optional<int> getHeight() = 0; 139 140 //! Get block hash. Height must be valid or this function will abort. 141 virtual uint256 getBlockHash(int height) = 0; 142 143 //! Check that the block is available on disk (i.e. has not been 144 //! pruned), and contains transactions. 145 virtual bool haveBlockOnDisk(int height) = 0; 146 147 //! Return height of the highest block on chain in common with the locator, 148 //! which will either be the original block used to create the locator, 149 //! or one of its ancestors. 150 virtual std::optional<int> findLocatorFork(const CBlockLocator& locator) = 0; 151 152 //! Returns whether a block filter index is available. 153 virtual bool hasBlockFilterIndex(BlockFilterType filter_type) = 0; 154 155 //! Returns whether any of the elements match the block via a BIP 157 block filter 156 //! or std::nullopt if the block filter for this block couldn't be found. 157 virtual std::optional<bool> blockFilterMatchesAny(BlockFilterType filter_type, const uint256& block_hash, const GCSFilter::ElementSet& filter_set) = 0; 158 159 //! Return whether node has the block and optionally return block metadata 160 //! or contents. 161 virtual bool findBlock(const uint256& hash, const FoundBlock& block={}) = 0; 162 163 //! Find first block in the chain with timestamp >= the given time 164 //! and height >= than the given height, return false if there is no block 165 //! with a high enough timestamp and height. Optionally return block 166 //! information. 167 virtual bool findFirstBlockWithTimeAndHeight(int64_t min_time, int min_height, const FoundBlock& block={}) = 0; 168 169 //! Find ancestor of block at specified height and optionally return 170 //! ancestor information. 171 virtual bool findAncestorByHeight(const uint256& block_hash, int ancestor_height, const FoundBlock& ancestor_out={}) = 0; 172 173 //! Return whether block descends from a specified ancestor, and 174 //! optionally return ancestor information. 175 virtual bool findAncestorByHash(const uint256& block_hash, 176 const uint256& ancestor_hash, 177 const FoundBlock& ancestor_out={}) = 0; 178 179 //! Find most recent common ancestor between two blocks and optionally 180 //! return block information. 181 virtual bool findCommonAncestor(const uint256& block_hash1, 182 const uint256& block_hash2, 183 const FoundBlock& ancestor_out={}, 184 const FoundBlock& block1_out={}, 185 const FoundBlock& block2_out={}) = 0; 186 187 //! Look up unspent output information. Returns coins in the mempool and in 188 //! the current chain UTXO set. Iterates through all the keys in the map and 189 //! populates the values. 190 virtual void findCoins(std::map<COutPoint, Coin>& coins) = 0; 191 192 //! Estimate fraction of total transactions verified if blocks up to 193 //! the specified block hash are verified. 194 virtual double guessVerificationProgress(const uint256& block_hash) = 0; 195 196 //! Return true if data is available for all blocks in the specified range 197 //! of blocks. This checks all blocks that are ancestors of block_hash in 198 //! the height range from min_height to max_height, inclusive. 199 virtual bool hasBlocks(const uint256& block_hash, int min_height = 0, std::optional<int> max_height = {}) = 0; 200 201 //! Check if transaction is RBF opt in. 202 virtual RBFTransactionState isRBFOptIn(const CTransaction& tx) = 0; 203 204 //! Check if transaction is in mempool. 205 virtual bool isInMempool(const Txid& txid) = 0; 206 207 //! Check if transaction has descendants in mempool. 208 virtual bool hasDescendantsInMempool(const Txid& txid) = 0; 209 210 //! Process a local transaction, optionally adding it to the mempool and 211 //! optionally broadcasting it to the network. 212 //! @param[in] tx Transaction to process. 213 //! @param[in] max_tx_fee Don't add the transaction to the mempool or 214 //! broadcast it if its fee is higher than this. 215 //! @param[in] broadcast_method Whether to add the transaction to the 216 //! mempool and how/whether to broadcast it. 217 //! @param[out] err_string Set if an error occurs. 218 //! @return False if the transaction could not be added due to the fee or for another reason. 219 virtual bool broadcastTransaction(const CTransactionRef& tx, 220 const CAmount& max_tx_fee, 221 node::TxBroadcast broadcast_method, 222 std::string& err_string) = 0; 223 224 //! Calculate mempool ancestor and cluster counts for the given transaction. 225 virtual void getTransactionAncestry(const Txid& txid, size_t& ancestors, size_t& cluster_count, size_t* ancestorsize = nullptr, CAmount* ancestorfees = nullptr) = 0; 226 227 //! For each outpoint, calculate the fee-bumping cost to spend this outpoint at the specified 228 // feerate, including bumping its ancestors. For example, if the target feerate is 10sat/vbyte 229 // and this outpoint refers to a mempool transaction at 3sat/vbyte, the bump fee includes the 230 // cost to bump the mempool transaction to 10sat/vbyte (i.e. 7 * mempooltx.vsize). If that 231 // transaction also has, say, an unconfirmed parent with a feerate of 1sat/vbyte, the bump fee 232 // includes the cost to bump the parent (i.e. 9 * parentmempooltx.vsize). 233 // 234 // If the outpoint comes from an unconfirmed transaction that is already above the target 235 // feerate or bumped by its descendant(s) already, it does not need to be bumped. Its bump fee 236 // is 0. Likewise, if any of the transaction's ancestors are already bumped by a transaction 237 // in our mempool, they are not included in the transaction's bump fee. 238 // 239 // Also supported is bump-fee calculation in the case of replacements. If an outpoint 240 // conflicts with another transaction in the mempool, it is assumed that the goal is to replace 241 // that transaction. As such, the calculation will exclude the to-be-replaced transaction, but 242 // will include the fee-bumping cost. If bump fees of descendants of the to-be-replaced 243 // transaction are requested, the value will be 0. Fee-related RBF rules are not included as 244 // they are logically distinct. 245 // 246 // Any outpoints that are otherwise unavailable from the mempool (e.g. UTXOs from confirmed 247 // transactions or transactions not yet broadcast by the wallet) are given a bump fee of 0. 248 // 249 // If multiple outpoints come from the same transaction (which would be very rare because 250 // it means that one transaction has multiple change outputs or paid the same wallet using multiple 251 // outputs in the same transaction) or have shared ancestry, the bump fees are calculated 252 // independently, i.e. as if only one of them is spent. This may result in double-fee-bumping. This 253 // caveat can be rectified per use of the sister-function CalculateCombinedBumpFee(…). 254 virtual std::map<COutPoint, CAmount> calculateIndividualBumpFees(const std::vector<COutPoint>& outpoints, const CFeeRate& target_feerate) = 0; 255 256 //! Calculate the combined bump fee for an input set per the same strategy 257 // as in CalculateIndividualBumpFees(…). 258 // Unlike CalculateIndividualBumpFees(…), this does not return individual 259 // bump fees per outpoint, but a single bump fee for the shared ancestry. 260 // The combined bump fee may be used to correct overestimation due to 261 // shared ancestry by multiple UTXOs after coin selection. 262 virtual std::optional<CAmount> calculateCombinedBumpFee(const std::vector<COutPoint>& outpoints, const CFeeRate& target_feerate) = 0; 263 264 //! Get the node's package limits. 265 //! Currently only returns the ancestor and descendant count limits, but could be enhanced to 266 //! return more policy settings. 267 virtual void getPackageLimits(unsigned int& limit_ancestor_count, unsigned int& limit_descendant_count) = 0; 268 269 //! Check if transaction will pass the mempool's chain limits. 270 virtual util::Result<void> checkChainLimits(const CTransactionRef& tx) = 0; 271 272 //! Estimate smart fee. 273 virtual CFeeRate estimateSmartFee(int num_blocks, bool conservative, FeeCalculation* calc = nullptr) = 0; 274 275 //! Fee estimator max target. 276 virtual unsigned int estimateMaxBlocks() = 0; 277 278 //! Mempool minimum fee. 279 virtual CFeeRate mempoolMinFee() = 0; 280 281 //! Relay current minimum fee (from -minrelaytxfee and -incrementalrelayfee settings). 282 virtual CFeeRate relayMinFee() = 0; 283 284 //! Relay incremental fee setting (-incrementalrelayfee), reflecting cost of relay. 285 virtual CFeeRate relayIncrementalFee() = 0; 286 287 //! Relay dust fee setting (-dustrelayfee), reflecting lowest rate it's economical to spend. 288 virtual CFeeRate relayDustFee() = 0; 289 290 //! Check if any block has been pruned. 291 virtual bool havePruned() = 0; 292 293 //! Get the current prune height. 294 virtual std::optional<int> getPruneHeight() = 0; 295 296 //! Check if the node is ready to broadcast transactions. 297 virtual bool isReadyToBroadcast() = 0; 298 299 //! Check if in IBD. 300 virtual bool isInitialBlockDownload() = 0; 301 302 //! Check if shutdown requested. 303 virtual bool shutdownRequested() = 0; 304 305 //! Send init message. 306 virtual void initMessage(const std::string& message) = 0; 307 308 //! Send init warning. 309 virtual void initWarning(const bilingual_str& message) = 0; 310 311 //! Send init error. 312 virtual void initError(const bilingual_str& message) = 0; 313 314 //! Send progress indicator. 315 virtual void showProgress(const std::string& title, int progress, bool resume_possible) = 0; 316 317 //! Chain notifications. 318 class Notifications 319 { 320 public: 321 virtual ~Notifications() = default; 322 virtual void transactionAddedToMempool(const CTransactionRef& tx) {} 323 virtual void transactionRemovedFromMempool(const CTransactionRef& tx, MemPoolRemovalReason reason) {} 324 virtual void blockConnected(ChainstateRole role, const BlockInfo& block) {} 325 virtual void blockDisconnected(const BlockInfo& block) {} 326 virtual void updatedBlockTip() {} 327 virtual void chainStateFlushed(ChainstateRole role, const CBlockLocator& locator) {} 328 }; 329 330 //! Options specifying which chain notifications are required. 331 struct NotifyOptions 332 { 333 //! Include undo data with block connected notifications. 334 bool connect_undo_data = false; 335 //! Include block data with block disconnected notifications. 336 bool disconnect_data = false; 337 //! Include undo data with block disconnected notifications. 338 bool disconnect_undo_data = false; 339 }; 340 341 //! Register handler for notifications. 342 virtual std::unique_ptr<Handler> handleNotifications(std::shared_ptr<Notifications> notifications) = 0; 343 344 //! Wait for pending notifications to be processed unless block hash points to the current 345 //! chain tip. 346 virtual void waitForNotificationsIfTipChanged(const uint256& old_tip) = 0; 347 348 //! Register handler for RPC. Command is not copied, so reference 349 //! needs to remain valid until Handler is disconnected. 350 virtual std::unique_ptr<Handler> handleRpc(const CRPCCommand& command) = 0; 351 352 //! Check if deprecated RPC is enabled. 353 virtual bool rpcEnableDeprecated(const std::string& method) = 0; 354 355 //! Get settings value. 356 virtual common::SettingsValue getSetting(const std::string& arg) = 0; 357 358 //! Get list of settings values. 359 virtual std::vector<common::SettingsValue> getSettingsList(const std::string& arg) = 0; 360 361 //! Return <datadir>/settings.json setting value. 362 virtual common::SettingsValue getRwSetting(const std::string& name) = 0; 363 364 //! Updates a setting in <datadir>/settings.json. 365 //! Null can be passed to erase the setting. There is intentionally no 366 //! support for writing null values to settings.json. 367 //! Depending on the action returned by the update function, this will either 368 //! update the setting in memory or write the updated settings to disk. 369 virtual bool updateRwSetting(const std::string& name, const SettingsUpdate& update_function) = 0; 370 371 //! Replace a setting in <datadir>/settings.json with a new value. 372 //! Null can be passed to erase the setting. 373 //! This method provides a simpler alternative to updateRwSetting when 374 //! atomically reading and updating the setting is not required. 375 virtual bool overwriteRwSetting(const std::string& name, common::SettingsValue value, SettingsAction action = SettingsAction::WRITE) = 0; 376 377 //! Delete a given setting in <datadir>/settings.json. 378 //! This method provides a simpler alternative to overwriteRwSetting when 379 //! erasing a setting, for ease of use and readability. 380 virtual bool deleteRwSettings(const std::string& name, SettingsAction action = SettingsAction::WRITE) = 0; 381 382 //! Synchronously send transactionAddedToMempool notifications about all 383 //! current mempool transactions to the specified handler and return after 384 //! the last one is sent. These notifications aren't coordinated with async 385 //! notifications sent by handleNotifications, so out of date async 386 //! notifications from handleNotifications can arrive during and after 387 //! synchronous notifications from requestMempoolTransactions. Clients need 388 //! to be prepared to handle this by ignoring notifications about unknown 389 //! removed transactions and already added new transactions. 390 virtual void requestMempoolTransactions(Notifications& notifications) = 0; 391 392 //! Return true if an assumed-valid chain is in use. 393 virtual bool hasAssumedValidChain() = 0; 394 395 //! Get internal node context. Useful for testing, but not 396 //! accessible across processes. 397 virtual node::NodeContext* context() { return nullptr; } 398 }; 399 400 //! Interface to let node manage chain clients (wallets, or maybe tools for 401 //! monitoring and analysis in the future). 402 class ChainClient 403 { 404 public: 405 virtual ~ChainClient() = default; 406 407 //! Register rpcs. 408 virtual void registerRpcs() = 0; 409 410 //! Check for errors before loading. 411 virtual bool verify() = 0; 412 413 //! Load saved state. 414 virtual bool load() = 0; 415 416 //! Start client execution and provide a scheduler. 417 virtual void start(CScheduler& scheduler) = 0; 418 419 //! Shut down client. 420 virtual void stop() = 0; 421 422 //! Set mock time. 423 virtual void setMockTime(int64_t time) = 0; 424 425 //! Mock the scheduler to fast forward in time. 426 virtual void schedulerMockForward(std::chrono::seconds delta_seconds) = 0; 427 }; 428 429 //! Return implementation of Chain interface. 430 std::unique_ptr<Chain> MakeChain(node::NodeContext& node); 431 432 } // namespace interfaces 433 434 #endif // BITCOIN_INTERFACES_CHAIN_H