diff options
Diffstat (limited to 'src/validation.h')
| -rw-r--r-- | src/validation.h | 806 |
1 files changed, 806 insertions, 0 deletions
diff --git a/src/validation.h b/src/validation.h new file mode 100644 index 0000000000..4490a75e18 --- /dev/null +++ b/src/validation.h @@ -0,0 +1,806 @@ +// Copyright (c) 2009-2010 Satoshi Nakamoto +// Copyright (c) 2009-2019 The Bitcoin Core developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#ifndef BITCOIN_VALIDATION_H +#define BITCOIN_VALIDATION_H + +#if defined(HAVE_CONFIG_H) +#include <config/bitcoin-config.h> +#endif + +#include <amount.h> +#include <coins.h> +#include <crypto/common.h> // for ReadLE64 +#include <fs.h> +#include <policy/feerate.h> +#include <protocol.h> // For CMessageHeader::MessageStartChars +#include <script/script_error.h> +#include <sync.h> +#include <txmempool.h> // For CTxMemPool::cs +#include <txdb.h> +#include <versionbits.h> + +#include <atomic> +#include <exception> +#include <map> +#include <memory> +#include <set> +#include <stdint.h> +#include <string> +#include <utility> +#include <vector> + +class CChainState; +class CBlockIndex; +class CBlockTreeDB; +class CBlockUndo; +class CChainParams; +class CInv; +class CConnman; +class CScriptCheck; +class CBlockPolicyEstimator; +class CTxMemPool; +class CValidationState; +struct ChainTxData; + +struct DisconnectedBlockTransactions; +struct PrecomputedTransactionData; +struct LockPoints; + +/** Default for -minrelaytxfee, minimum relay fee for transactions */ +static const unsigned int DEFAULT_MIN_RELAY_TX_FEE = 1000; +/** Default for -limitancestorcount, max number of in-mempool ancestors */ +static const unsigned int DEFAULT_ANCESTOR_LIMIT = 25; +/** Default for -limitancestorsize, maximum kilobytes of tx + all in-mempool ancestors */ +static const unsigned int DEFAULT_ANCESTOR_SIZE_LIMIT = 101; +/** Default for -limitdescendantcount, max number of in-mempool descendants */ +static const unsigned int DEFAULT_DESCENDANT_LIMIT = 25; +/** Default for -limitdescendantsize, maximum kilobytes of in-mempool descendants */ +static const unsigned int DEFAULT_DESCENDANT_SIZE_LIMIT = 101; +/** + * An extra transaction can be added to a package, as long as it only has one + * ancestor and is no larger than this. Not really any reason to make this + * configurable as it doesn't materially change DoS parameters. + */ +static const unsigned int EXTRA_DESCENDANT_TX_SIZE_LIMIT = 10000; +/** Default for -mempoolexpiry, expiration time for mempool transactions in hours */ +static const unsigned int DEFAULT_MEMPOOL_EXPIRY = 336; +/** Maximum kilobytes for transactions to store for processing during reorg */ +static const unsigned int MAX_DISCONNECTED_TX_POOL_SIZE = 20000; +/** The maximum size of a blk?????.dat file (since 0.8) */ +static const unsigned int MAX_BLOCKFILE_SIZE = 0x8000000; // 128 MiB +/** The pre-allocation chunk size for blk?????.dat files (since 0.8) */ +static const unsigned int BLOCKFILE_CHUNK_SIZE = 0x1000000; // 16 MiB +/** The pre-allocation chunk size for rev?????.dat files (since 0.8) */ +static const unsigned int UNDOFILE_CHUNK_SIZE = 0x100000; // 1 MiB + +/** Maximum number of script-checking threads allowed */ +static const int MAX_SCRIPTCHECK_THREADS = 16; +/** -par default (number of script-checking threads, 0 = auto) */ +static const int DEFAULT_SCRIPTCHECK_THREADS = 0; +/** Number of blocks that can be requested at any given time from a single peer. */ +static const int MAX_BLOCKS_IN_TRANSIT_PER_PEER = 16; +/** Timeout in seconds during which a peer must stall block download progress before being disconnected. */ +static const unsigned int BLOCK_STALLING_TIMEOUT = 2; +/** Number of headers sent in one getheaders result. We rely on the assumption that if a peer sends + * less than this number, we reached its tip. Changing this value is a protocol upgrade. */ +static const unsigned int MAX_HEADERS_RESULTS = 2000; +/** Maximum depth of blocks we're willing to serve as compact blocks to peers + * when requested. For older blocks, a regular BLOCK response will be sent. */ +static const int MAX_CMPCTBLOCK_DEPTH = 5; +/** Maximum depth of blocks we're willing to respond to GETBLOCKTXN requests for. */ +static const int MAX_BLOCKTXN_DEPTH = 10; +/** Size of the "block download window": how far ahead of our current height do we fetch? + * Larger windows tolerate larger download speed differences between peer, but increase the potential + * degree of disordering of blocks on disk (which make reindexing and pruning harder). We'll probably + * want to make this a per-peer adaptive value at some point. */ +static const unsigned int BLOCK_DOWNLOAD_WINDOW = 1024; +/** Time to wait (in seconds) between writing blocks/block index to disk. */ +static const unsigned int DATABASE_WRITE_INTERVAL = 60 * 60; +/** Time to wait (in seconds) between flushing chainstate to disk. */ +static const unsigned int DATABASE_FLUSH_INTERVAL = 24 * 60 * 60; +/** Maximum length of reject messages. */ +static const unsigned int MAX_REJECT_MESSAGE_LENGTH = 111; +/** Block download timeout base, expressed in millionths of the block interval (i.e. 10 min) */ +static const int64_t BLOCK_DOWNLOAD_TIMEOUT_BASE = 1000000; +/** Additional block download timeout per parallel downloading peer (i.e. 5 min) */ +static const int64_t BLOCK_DOWNLOAD_TIMEOUT_PER_PEER = 500000; + +static const int64_t DEFAULT_MAX_TIP_AGE = 24 * 60 * 60; +/** Maximum age of our tip in seconds for us to be considered current for fee estimation */ +static const int64_t MAX_FEE_ESTIMATION_TIP_AGE = 3 * 60 * 60; + +static const bool DEFAULT_CHECKPOINTS_ENABLED = true; +static const bool DEFAULT_TXINDEX = false; +static const char* const DEFAULT_BLOCKFILTERINDEX = "0"; +static const unsigned int DEFAULT_BANSCORE_THRESHOLD = 100; +/** Default for -persistmempool */ +static const bool DEFAULT_PERSIST_MEMPOOL = true; +/** Default for using fee filter */ +static const bool DEFAULT_FEEFILTER = true; + +/** Maximum number of headers to announce when relaying blocks with headers message.*/ +static const unsigned int MAX_BLOCKS_TO_ANNOUNCE = 8; + +/** Maximum number of unconnecting headers announcements before DoS score */ +static const int MAX_UNCONNECTING_HEADERS = 10; + +/** Default for -stopatheight */ +static const int DEFAULT_STOPATHEIGHT = 0; + +struct BlockHasher +{ + // this used to call `GetCheapHash()` in uint256, which was later moved; the + // cheap hash function simply calls ReadLE64() however, so the end result is + // identical + size_t operator()(const uint256& hash) const { return ReadLE64(hash.begin()); } +}; + +extern CScript COINBASE_FLAGS; +extern CCriticalSection cs_main; +extern CBlockPolicyEstimator feeEstimator; +extern CTxMemPool mempool; +typedef std::unordered_map<uint256, CBlockIndex*, BlockHasher> BlockMap; +extern Mutex g_best_block_mutex; +extern std::condition_variable g_best_block_cv; +extern uint256 g_best_block; +extern std::atomic_bool fImporting; +extern std::atomic_bool fReindex; +extern int nScriptCheckThreads; +extern bool fRequireStandard; +extern bool fCheckBlockIndex; +extern bool fCheckpointsEnabled; +extern size_t nCoinCacheUsage; +/** A fee rate smaller than this is considered zero fee (for relaying, mining and transaction creation) */ +extern CFeeRate minRelayTxFee; +/** If the tip is older than this (in seconds), the node is considered to be in initial block download. */ +extern int64_t nMaxTipAge; + +/** Block hash whose ancestors we will assume to have valid scripts without checking them. */ +extern uint256 hashAssumeValid; + +/** Minimum work we will assume exists on some valid chain. */ +extern arith_uint256 nMinimumChainWork; + +/** Best header we've seen so far (used for getheaders queries' starting points). */ +extern CBlockIndex *pindexBestHeader; + +/** Pruning-related variables and constants */ +/** True if any block files have ever been pruned. */ +extern bool fHavePruned; +/** True if we're running in -prune mode. */ +extern bool fPruneMode; +/** Number of MiB of block files that we're trying to stay below. */ +extern uint64_t nPruneTarget; +/** Block files containing a block-height within MIN_BLOCKS_TO_KEEP of ::ChainActive().Tip() will not be pruned. */ +static const unsigned int MIN_BLOCKS_TO_KEEP = 288; +/** Minimum blocks required to signal NODE_NETWORK_LIMITED */ +static const unsigned int NODE_NETWORK_LIMITED_MIN_BLOCKS = 288; + +static const signed int DEFAULT_CHECKBLOCKS = 6; +static const unsigned int DEFAULT_CHECKLEVEL = 3; + +// Require that user allocate at least 550 MiB for block & undo files (blk???.dat and rev???.dat) +// At 1MB per block, 288 blocks = 288MB. +// Add 15% for Undo data = 331MB +// Add 20% for Orphan block rate = 397MB +// We want the low water mark after pruning to be at least 397 MB and since we prune in +// full block file chunks, we need the high water mark which triggers the prune to be +// one 128MB block file + added 15% undo data = 147MB greater for a total of 545MB +// Setting the target to >= 550 MiB will make it likely we can respect the target. +static const uint64_t MIN_DISK_SPACE_FOR_BLOCK_FILES = 550 * 1024 * 1024; + +/** + * Process an incoming block. This only returns after the best known valid + * block is made active. Note that it does not, however, guarantee that the + * specific block passed to it has been checked for validity! + * + * If you want to *possibly* get feedback on whether pblock is valid, you must + * install a CValidationInterface (see validationinterface.h) - this will have + * its BlockChecked method called whenever *any* block completes validation. + * + * Note that we guarantee that either the proof-of-work is valid on pblock, or + * (and possibly also) BlockChecked will have been called. + * + * May not be called in a + * validationinterface callback. + * + * @param[in] pblock The block we want to process. + * @param[in] fForceProcessing Process this block even if unrequested; used for non-network block sources and whitelisted peers. + * @param[out] fNewBlock A boolean which is set to indicate if the block was first received via this call + * @returns If the block was processed, independently of block validity + */ +bool ProcessNewBlock(const CChainParams& chainparams, const std::shared_ptr<const CBlock> pblock, bool fForceProcessing, bool* fNewBlock) LOCKS_EXCLUDED(cs_main); + +/** + * Process incoming block headers. + * + * May not be called in a + * validationinterface callback. + * + * @param[in] block The block headers themselves + * @param[out] state This may be set to an Error state if any error occurred processing them + * @param[in] chainparams The params for the chain we want to connect to + * @param[out] ppindex If set, the pointer will be set to point to the last new block index object for the given headers + * @param[out] first_invalid First header that fails validation, if one exists + */ +bool ProcessNewBlockHeaders(const std::vector<CBlockHeader>& block, CValidationState& state, const CChainParams& chainparams, const CBlockIndex** ppindex = nullptr, CBlockHeader* first_invalid = nullptr) LOCKS_EXCLUDED(cs_main); + +/** Open a block file (blk?????.dat) */ +FILE* OpenBlockFile(const FlatFilePos &pos, bool fReadOnly = false); +/** Translation to a filesystem path */ +fs::path GetBlockPosFilename(const FlatFilePos &pos); +/** Import blocks from an external file */ +bool LoadExternalBlockFile(const CChainParams& chainparams, FILE* fileIn, FlatFilePos *dbp = nullptr); +/** Ensures we have a genesis block in the block tree, possibly writing one to disk. */ +bool LoadGenesisBlock(const CChainParams& chainparams); +/** Load the block tree and coins database from disk, + * initializing state if we're running with -reindex. */ +bool LoadBlockIndex(const CChainParams& chainparams) EXCLUSIVE_LOCKS_REQUIRED(cs_main); +/** Unload database information */ +void UnloadBlockIndex(); +/** Run an instance of the script checking thread */ +void ThreadScriptCheck(int worker_num); +/** Retrieve a transaction (from memory pool, or from disk, if possible) */ +bool GetTransaction(const uint256& hash, CTransactionRef& tx, const Consensus::Params& params, uint256& hashBlock, const CBlockIndex* const blockIndex = nullptr); +/** + * Find the best known block, and make it the tip of the block chain + * + * May not be called with cs_main held. May not be called in a + * validationinterface callback. + */ +bool ActivateBestChain(CValidationState& state, const CChainParams& chainparams, std::shared_ptr<const CBlock> pblock = std::shared_ptr<const CBlock>()); +CAmount GetBlockSubsidy(int nHeight, const Consensus::Params& consensusParams); + +/** Guess verification progress (as a fraction between 0.0=genesis and 1.0=current tip). */ +double GuessVerificationProgress(const ChainTxData& data, const CBlockIndex* pindex); + +/** Calculate the amount of disk space the block & undo files currently use */ +uint64_t CalculateCurrentUsage(); + +/** + * Mark one block file as pruned. + */ +void PruneOneBlockFile(const int fileNumber) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + +/** + * Actually unlink the specified files + */ +void UnlinkPrunedFiles(const std::set<int>& setFilesToPrune); + +/** Prune block files up to a given height */ +void PruneBlockFilesManual(int nManualPruneHeight); + +/** (try to) add transaction to memory pool + * plTxnReplaced will be appended to with all transactions replaced from mempool **/ +bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransactionRef &tx, + bool* pfMissingInputs, std::list<CTransactionRef>* plTxnReplaced, + bool bypass_limits, const CAmount nAbsurdFee, bool test_accept=false) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + +/** Get the BIP9 state for a given deployment at the current tip. */ +ThresholdState VersionBitsTipState(const Consensus::Params& params, Consensus::DeploymentPos pos); + +/** Get the numerical statistics for the BIP9 state for a given deployment at the current tip. */ +BIP9Stats VersionBitsTipStatistics(const Consensus::Params& params, Consensus::DeploymentPos pos); + +/** Get the block height at which the BIP9 deployment switched into the state for the block building on the current tip. */ +int VersionBitsTipStateSinceHeight(const Consensus::Params& params, Consensus::DeploymentPos pos); + + +/** Apply the effects of this transaction on the UTXO set represented by view */ +void UpdateCoins(const CTransaction& tx, CCoinsViewCache& inputs, int nHeight); + +/** Transaction validation functions */ + +/** + * Check if transaction will be final in the next block to be created. + * + * Calls IsFinalTx() with current block height and appropriate block time. + * + * See consensus/consensus.h for flag definitions. + */ +bool CheckFinalTx(const CTransaction &tx, int flags = -1) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + +/** + * Test whether the LockPoints height and time are still valid on the current chain + */ +bool TestLockPointValidity(const LockPoints* lp) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + +/** + * Check if transaction will be BIP 68 final in the next block to be created. + * + * Simulates calling SequenceLocks() with data from the tip of the current active chain. + * Optionally stores in LockPoints the resulting height and time calculated and the hash + * of the block needed for calculation or skips the calculation and uses the LockPoints + * passed in for evaluation. + * The LockPoints should not be considered valid if CheckSequenceLocks returns false. + * + * See consensus/consensus.h for flag definitions. + */ +bool CheckSequenceLocks(const CTxMemPool& pool, const CTransaction& tx, int flags, LockPoints* lp = nullptr, bool useExistingLockPoints = false) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + +/** + * Closure representing one script verification + * Note that this stores references to the spending transaction + */ +class CScriptCheck +{ +private: + CTxOut m_tx_out; + const CTransaction *ptxTo; + unsigned int nIn; + unsigned int nFlags; + bool cacheStore; + ScriptError error; + PrecomputedTransactionData *txdata; + +public: + CScriptCheck(): ptxTo(nullptr), nIn(0), nFlags(0), cacheStore(false), error(SCRIPT_ERR_UNKNOWN_ERROR) {} + CScriptCheck(const CTxOut& outIn, const CTransaction& txToIn, unsigned int nInIn, unsigned int nFlagsIn, bool cacheIn, PrecomputedTransactionData* txdataIn) : + m_tx_out(outIn), ptxTo(&txToIn), nIn(nInIn), nFlags(nFlagsIn), cacheStore(cacheIn), error(SCRIPT_ERR_UNKNOWN_ERROR), txdata(txdataIn) { } + + bool operator()(); + + void swap(CScriptCheck &check) { + std::swap(ptxTo, check.ptxTo); + std::swap(m_tx_out, check.m_tx_out); + std::swap(nIn, check.nIn); + std::swap(nFlags, check.nFlags); + std::swap(cacheStore, check.cacheStore); + std::swap(error, check.error); + std::swap(txdata, check.txdata); + } + + ScriptError GetScriptError() const { return error; } +}; + +/** Initializes the script-execution cache */ +void InitScriptExecutionCache(); + + +/** Functions for disk access for blocks */ +bool ReadBlockFromDisk(CBlock& block, const FlatFilePos& pos, const Consensus::Params& consensusParams); +bool ReadBlockFromDisk(CBlock& block, const CBlockIndex* pindex, const Consensus::Params& consensusParams); +bool ReadRawBlockFromDisk(std::vector<uint8_t>& block, const FlatFilePos& pos, const CMessageHeader::MessageStartChars& message_start); +bool ReadRawBlockFromDisk(std::vector<uint8_t>& block, const CBlockIndex* pindex, const CMessageHeader::MessageStartChars& message_start); + +bool UndoReadFromDisk(CBlockUndo& blockundo, const CBlockIndex* pindex); + +/** Functions for validating blocks and updating the block tree */ + +/** Context-independent validity checks */ +bool CheckBlock(const CBlock& block, CValidationState& state, const Consensus::Params& consensusParams, bool fCheckPOW = true, bool fCheckMerkleRoot = true); + +/** Check a block is completely valid from start to finish (only works on top of our current best block) */ +bool TestBlockValidity(CValidationState& state, const CChainParams& chainparams, const CBlock& block, CBlockIndex* pindexPrev, bool fCheckPOW = true, bool fCheckMerkleRoot = true) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + +/** Check whether witness commitments are required for a block, and whether to enforce NULLDUMMY (BIP 147) rules. + * Note that transaction witness validation rules are always enforced when P2SH is enforced. */ +bool IsWitnessEnabled(const CBlockIndex* pindexPrev, const Consensus::Params& params); + +/** When there are blocks in the active chain with missing data, rewind the chainstate and remove them from the block index */ +bool RewindBlockIndex(const CChainParams& params) LOCKS_EXCLUDED(cs_main); + +/** Compute at which vout of the block's coinbase transaction the witness commitment occurs, or -1 if not found */ +int GetWitnessCommitmentIndex(const CBlock& block); + +/** Update uncommitted block structures (currently: only the witness reserved value). This is safe for submitted blocks. */ +void UpdateUncommittedBlockStructures(CBlock& block, const CBlockIndex* pindexPrev, const Consensus::Params& consensusParams); + +/** Produce the necessary coinbase commitment for a block (modifies the hash, don't call for mined blocks). */ +std::vector<unsigned char> GenerateCoinbaseCommitment(CBlock& block, const CBlockIndex* pindexPrev, const Consensus::Params& consensusParams); + +/** RAII wrapper for VerifyDB: Verify consistency of the block and coin databases */ +class CVerifyDB { +public: + CVerifyDB(); + ~CVerifyDB(); + bool VerifyDB(const CChainParams& chainparams, CCoinsView *coinsview, int nCheckLevel, int nCheckDepth); +}; + +CBlockIndex* LookupBlockIndex(const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + +/** Find the last common block between the parameter chain and a locator. */ +CBlockIndex* FindForkInGlobalIndex(const CChain& chain, const CBlockLocator& locator) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + +enum DisconnectResult +{ + DISCONNECT_OK, // All good. + DISCONNECT_UNCLEAN, // Rolled back, but UTXO set was inconsistent with block. + DISCONNECT_FAILED // Something else went wrong. +}; + +class ConnectTrace; + +/** @see CChainState::FlushStateToDisk */ +enum class FlushStateMode { + NONE, + IF_NEEDED, + PERIODIC, + ALWAYS +}; + +struct CBlockIndexWorkComparator +{ + bool operator()(const CBlockIndex *pa, const CBlockIndex *pb) const; +}; + +/** + * Maintains a tree of blocks (stored in `m_block_index`) which is consulted + * to determine where the most-work tip is. + * + * This data is used mostly in `CChainState` - information about, e.g., + * candidate tips is not maintained here. + */ +class BlockManager { +public: + BlockMap m_block_index GUARDED_BY(cs_main); + + /** In order to efficiently track invalidity of headers, we keep the set of + * blocks which we tried to connect and found to be invalid here (ie which + * were set to BLOCK_FAILED_VALID since the last restart). We can then + * walk this set and check if a new header is a descendant of something in + * this set, preventing us from having to walk m_block_index when we try + * to connect a bad block and fail. + * + * While this is more complicated than marking everything which descends + * from an invalid block as invalid at the time we discover it to be + * invalid, doing so would require walking all of m_block_index to find all + * descendants. Since this case should be very rare, keeping track of all + * BLOCK_FAILED_VALID blocks in a set should be just fine and work just as + * well. + * + * Because we already walk m_block_index in height-order at startup, we go + * ahead and mark descendants of invalid blocks as FAILED_CHILD at that time, + * instead of putting things in this set. + */ + std::set<CBlockIndex*> m_failed_blocks; + + /** + * All pairs A->B, where A (or one of its ancestors) misses transactions, but B has transactions. + * Pruned nodes may have entries where B is missing data. + */ + std::multimap<CBlockIndex*, CBlockIndex*> m_blocks_unlinked; + + /** + * Load the blocktree off disk and into memory. Populate certain metadata + * per index entry (nStatus, nChainWork, nTimeMax, etc.) as well as peripheral + * collections like setDirtyBlockIndex. + * + * @param[out] block_index_candidates Fill this set with any valid blocks for + * which we've downloaded all transactions. + */ + bool LoadBlockIndex( + const Consensus::Params& consensus_params, + CBlockTreeDB& blocktree, + std::set<CBlockIndex*, CBlockIndexWorkComparator>& block_index_candidates) + EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + /** Clear all data members. */ + void Unload() EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + CBlockIndex* AddToBlockIndex(const CBlockHeader& block) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + /** Create a new block index entry for a given block hash */ + CBlockIndex* InsertBlockIndex(const uint256& hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + /** + * If a block header hasn't already been seen, call CheckBlockHeader on it, ensure + * that it doesn't descend from an invalid block, and then add it to m_block_index. + */ + bool AcceptBlockHeader( + const CBlockHeader& block, + CValidationState& state, + const CChainParams& chainparams, + CBlockIndex** ppindex) EXCLUSIVE_LOCKS_REQUIRED(cs_main); +}; + +/** + * A convenience class for constructing the CCoinsView* hierarchy used + * to facilitate access to the UTXO set. + * + * This class consists of an arrangement of layered CCoinsView objects, + * preferring to store and retrieve coins in memory via `m_cacheview` but + * ultimately falling back on cache misses to the canonical store of UTXOs on + * disk, `m_dbview`. + */ +class CoinsViews { + +public: + //! The lowest level of the CoinsViews cache hierarchy sits in a leveldb database on disk. + //! All unspent coins reside in this store. + CCoinsViewDB m_dbview GUARDED_BY(cs_main); + + //! This view wraps access to the leveldb instance and handles read errors gracefully. + CCoinsViewErrorCatcher m_catcherview GUARDED_BY(cs_main); + + //! This is the top layer of the cache hierarchy - it keeps as many coins in memory as + //! can fit per the dbcache setting. + std::unique_ptr<CCoinsViewCache> m_cacheview GUARDED_BY(cs_main); + + //! This constructor initializes CCoinsViewDB and CCoinsViewErrorCatcher instances, but it + //! *does not* create a CCoinsViewCache instance by default. This is done separately because the + //! presence of the cache has implications on whether or not we're allowed to flush the cache's + //! state to disk, which should not be done until the health of the database is verified. + //! + //! All arguments forwarded onto CCoinsViewDB. + CoinsViews(std::string ldb_name, size_t cache_size_bytes, bool in_memory, bool should_wipe); + + //! Initialize the CCoinsViewCache member. + void InitCache() EXCLUSIVE_LOCKS_REQUIRED(::cs_main); +}; + +/** + * CChainState stores and provides an API to update our local knowledge of the + * current best chain. + * + * Eventually, the API here is targeted at being exposed externally as a + * consumable libconsensus library, so any functions added must only call + * other class member functions, pure functions in other parts of the consensus + * library, callbacks via the validation interface, or read/write-to-disk + * functions (eventually this will also be via callbacks). + * + * Anything that is contingent on the current tip of the chain is stored here, + * whereas block information and metadata independent of the current tip is + * kept in `BlockMetadataManager`. + */ +class CChainState { +private: + + /** + * Every received block is assigned a unique and increasing identifier, so we + * know which one to give priority in case of a fork. + */ + CCriticalSection cs_nBlockSequenceId; + /** Blocks loaded from disk are assigned id 0, so start the counter at 1. */ + int32_t nBlockSequenceId = 1; + /** Decreasing counter (used by subsequent preciousblock calls). */ + int32_t nBlockReverseSequenceId = -1; + /** chainwork for the last block that preciousblock has been applied to. */ + arith_uint256 nLastPreciousChainwork = 0; + + /** + * the ChainState CriticalSection + * A lock that must be held when modifying this ChainState - held in ActivateBestChain() + */ + CCriticalSection m_cs_chainstate; + + /** + * Whether this chainstate is undergoing initial block download. + * + * Mutable because we need to be able to mark IsInitialBlockDownload() + * const, which latches this for caching purposes. + */ + mutable std::atomic<bool> m_cached_finished_ibd{false}; + + //! Reference to a BlockManager instance which itself is shared across all + //! CChainState instances. Keeping a local reference allows us to test more + //! easily as opposed to referencing a global. + BlockManager& m_blockman; + + //! Manages the UTXO set, which is a reflection of the contents of `m_chain`. + std::unique_ptr<CoinsViews> m_coins_views; + +public: + CChainState(BlockManager& blockman) : m_blockman(blockman) {} + CChainState(); + + /** + * Initialize the CoinsViews UTXO set database management data structures. The in-memory + * cache is initialized separately. + * + * All parameters forwarded to CoinsViews. + */ + void InitCoinsDB( + size_t cache_size_bytes, + bool in_memory, + bool should_wipe, + std::string leveldb_name = "chainstate"); + + //! Initialize the in-memory coins cache (to be done after the health of the on-disk database + //! is verified). + void InitCoinsCache() EXCLUSIVE_LOCKS_REQUIRED(::cs_main); + + //! @returns whether or not the CoinsViews object has been fully initialized and we can + //! safely flush this object to disk. + bool CanFlushToDisk() EXCLUSIVE_LOCKS_REQUIRED(cs_main) { + return m_coins_views && m_coins_views->m_cacheview; + } + + //! The current chain of blockheaders we consult and build on. + //! @see CChain, CBlockIndex. + CChain m_chain; + + /** + * The set of all CBlockIndex entries with BLOCK_VALID_TRANSACTIONS (for itself and all ancestors) and + * as good as our current tip or better. Entries may be failed, though, and pruning nodes may be + * missing the data for the block. + */ + std::set<CBlockIndex*, CBlockIndexWorkComparator> setBlockIndexCandidates; + + //! @returns A reference to the in-memory cache of the UTXO set. + CCoinsViewCache& CoinsTip() EXCLUSIVE_LOCKS_REQUIRED(cs_main) + { + assert(m_coins_views->m_cacheview); + return *m_coins_views->m_cacheview.get(); + } + + //! @returns A reference to the on-disk UTXO set database. + CCoinsViewDB& CoinsDB() EXCLUSIVE_LOCKS_REQUIRED(cs_main) + { + return m_coins_views->m_dbview; + } + + //! @returns A reference to a wrapped view of the in-memory UTXO set that + //! handles disk read errors gracefully. + CCoinsViewErrorCatcher& CoinsErrorCatcher() EXCLUSIVE_LOCKS_REQUIRED(cs_main) + { + return m_coins_views->m_catcherview; + } + + //! Destructs all objects related to accessing the UTXO set. + void ResetCoinsViews() { m_coins_views.reset(); } + + /** + * Update the on-disk chain state. + * The caches and indexes are flushed depending on the mode we're called with + * if they're too large, if it's been a while since the last write, + * or always and in all cases if we're in prune mode and are deleting files. + * + * If FlushStateMode::NONE is used, then FlushStateToDisk(...) won't do anything + * besides checking if we need to prune. + * + * @returns true unless a system error occurred + */ + bool FlushStateToDisk( + const CChainParams& chainparams, + CValidationState &state, + FlushStateMode mode, + int nManualPruneHeight = 0); + + //! Unconditionally flush all changes to disk. + void ForceFlushStateToDisk(); + + //! Prune blockfiles from the disk if necessary and then flush chainstate changes + //! if we pruned. + void PruneAndFlush(); + + /** + * Make the best chain active, in multiple steps. The result is either failure + * or an activated best chain. pblock is either nullptr or a pointer to a block + * that is already loaded (to avoid loading it again from disk). + * + * ActivateBestChain is split into steps (see ActivateBestChainStep) so that + * we avoid holding cs_main for an extended period of time; the length of this + * call may be quite long during reindexing or a substantial reorg. + * + * May not be called with cs_main held. May not be called in a + * validationinterface callback. + * + * @returns true unless a system error occurred + */ + bool ActivateBestChain( + CValidationState& state, + const CChainParams& chainparams, + std::shared_ptr<const CBlock> pblock) LOCKS_EXCLUDED(cs_main); + + bool AcceptBlock(const std::shared_ptr<const CBlock>& pblock, CValidationState& state, const CChainParams& chainparams, CBlockIndex** ppindex, bool fRequested, const FlatFilePos* dbp, bool* fNewBlock) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + // Block (dis)connection on a given view: + DisconnectResult DisconnectBlock(const CBlock& block, const CBlockIndex* pindex, CCoinsViewCache& view); + bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pindex, + CCoinsViewCache& view, const CChainParams& chainparams, bool fJustCheck = false) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + // Apply the effects of a block disconnection on the UTXO set. + bool DisconnectTip(CValidationState& state, const CChainParams& chainparams, DisconnectedBlockTransactions* disconnectpool) EXCLUSIVE_LOCKS_REQUIRED(cs_main, ::mempool.cs); + + // Manual block validity manipulation: + bool PreciousBlock(CValidationState& state, const CChainParams& params, CBlockIndex* pindex) LOCKS_EXCLUDED(cs_main); + bool InvalidateBlock(CValidationState& state, const CChainParams& chainparams, CBlockIndex* pindex) LOCKS_EXCLUDED(cs_main); + void ResetBlockFailureFlags(CBlockIndex* pindex) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + /** Replay blocks that aren't fully applied to the database. */ + bool ReplayBlocks(const CChainParams& params); + bool RewindBlockIndex(const CChainParams& params) LOCKS_EXCLUDED(cs_main); + bool LoadGenesisBlock(const CChainParams& chainparams); + + void PruneBlockIndexCandidates(); + + void UnloadBlockIndex(); + + /** Check whether we are doing an initial block download (synchronizing from disk or network) */ + bool IsInitialBlockDownload() const; + + /** + * Make various assertions about the state of the block index. + * + * By default this only executes fully when using the Regtest chain; see: fCheckBlockIndex. + */ + void CheckBlockIndex(const Consensus::Params& consensusParams); + + /** Update the chain tip based on database information, i.e. CoinsTip()'s best block. */ + bool LoadChainTip(const CChainParams& chainparams) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + +private: + bool ActivateBestChainStep(CValidationState& state, const CChainParams& chainparams, CBlockIndex* pindexMostWork, const std::shared_ptr<const CBlock>& pblock, bool& fInvalidFound, ConnectTrace& connectTrace) EXCLUSIVE_LOCKS_REQUIRED(cs_main, ::mempool.cs); + bool ConnectTip(CValidationState& state, const CChainParams& chainparams, CBlockIndex* pindexNew, const std::shared_ptr<const CBlock>& pblock, ConnectTrace& connectTrace, DisconnectedBlockTransactions& disconnectpool) EXCLUSIVE_LOCKS_REQUIRED(cs_main, ::mempool.cs); + + void InvalidBlockFound(CBlockIndex *pindex, const CValidationState &state) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + CBlockIndex* FindMostWorkChain() EXCLUSIVE_LOCKS_REQUIRED(cs_main); + void ReceivedBlockTransactions(const CBlock& block, CBlockIndex* pindexNew, const FlatFilePos& pos, const Consensus::Params& consensusParams) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + bool RollforwardBlock(const CBlockIndex* pindex, CCoinsViewCache& inputs, const CChainParams& params) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + + //! Mark a block as not having block data + void EraseBlockData(CBlockIndex* index) EXCLUSIVE_LOCKS_REQUIRED(cs_main); +}; + +/** Mark a block as precious and reorganize. + * + * May not be called in a + * validationinterface callback. + */ +bool PreciousBlock(CValidationState& state, const CChainParams& params, CBlockIndex *pindex) LOCKS_EXCLUDED(cs_main); + +/** Mark a block as invalid. */ +bool InvalidateBlock(CValidationState& state, const CChainParams& chainparams, CBlockIndex* pindex) LOCKS_EXCLUDED(cs_main); + +/** Remove invalidity status from a block and its descendants. */ +void ResetBlockFailureFlags(CBlockIndex* pindex) EXCLUSIVE_LOCKS_REQUIRED(cs_main); + +/** @returns the most-work valid chainstate. */ +CChainState& ChainstateActive(); + +/** @returns the most-work chain. */ +CChain& ChainActive(); + +/** @returns the global block index map. */ +BlockMap& BlockIndex(); + +// Most often ::ChainstateActive() should be used instead of this, but some code +// may not be able to assume that this has been initialized yet and so must use it +// directly, e.g. init.cpp. +extern std::unique_ptr<CChainState> g_chainstate; + +/** Global variable that points to the active block tree (protected by cs_main) */ +extern std::unique_ptr<CBlockTreeDB> pblocktree; + +/** + * Return the spend height, which is one more than the inputs.GetBestBlock(). + * While checking, GetBestBlock() refers to the parent block. (protected by cs_main) + * This is also true for mempool checks. + */ +int GetSpendHeight(const CCoinsViewCache& inputs); + +extern VersionBitsCache versionbitscache; + +/** + * Determine what nVersion a new block should use. + */ +int32_t ComputeBlockVersion(const CBlockIndex* pindexPrev, const Consensus::Params& params); + +/** Reject codes greater or equal to this can be returned by AcceptToMemPool + * for transactions, to signal internal conditions. They cannot and should not + * be sent over the P2P network. + */ +static const unsigned int REJECT_INTERNAL = 0x100; +/** Too high fee. Can not be triggered by P2P transactions */ +static const unsigned int REJECT_HIGHFEE = 0x100; + +/** Get block file info entry for one block file */ +CBlockFileInfo* GetBlockFileInfo(size_t n); + +/** Dump the mempool to disk. */ +bool DumpMempool(const CTxMemPool& pool); + +/** Load the mempool from disk. */ +bool LoadMempool(CTxMemPool& pool); + +//! Check whether the block associated with this index entry is pruned or not. +inline bool IsBlockPruned(const CBlockIndex* pblockindex) +{ + return (fHavePruned && !(pblockindex->nStatus & BLOCK_HAVE_DATA) && pblockindex->nTx > 0); +} + +#endif // BITCOIN_VALIDATION_H |