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|
// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2020 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 <attributes.h>
#include <coins.h>
#include <consensus/validation.h>
#include <crypto/common.h> // for ReadLE64
#include <fs.h>
#include <node/utxo_snapshot.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 <serialize.h>
#include <util/check.h>
#include <util/hasher.h>
#include <atomic>
#include <map>
#include <memory>
#include <optional>
#include <set>
#include <stdint.h>
#include <string>
#include <thread>
#include <utility>
#include <vector>
class CChainState;
class BlockValidationState;
class CBlockIndex;
class CBlockTreeDB;
class CBlockUndo;
class CChainParams;
struct CCheckpointData;
class CInv;
class CConnman;
class CScriptCheck;
class CTxMemPool;
class ChainstateManager;
struct ChainTxData;
struct DisconnectedBlockTransactions;
struct PrecomputedTransactionData;
struct LockPoints;
struct AssumeutxoData;
/** 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;
/** Default for -mempoolexpiry, expiration time for mempool transactions in hours */
static const unsigned int DEFAULT_MEMPOOL_EXPIRY = 336;
/** The maximum size of a blk?????.dat file (since 0.8) */
static const unsigned int MAX_BLOCKFILE_SIZE = 0x8000000; // 128 MiB
/** Maximum number of dedicated script-checking threads allowed */
static const int MAX_SCRIPTCHECK_THREADS = 15;
/** -par default (number of script-checking threads, 0 = auto) */
static const int DEFAULT_SCRIPTCHECK_THREADS = 0;
static const int64_t DEFAULT_MAX_TIP_AGE = 24 * 60 * 60;
static const bool DEFAULT_CHECKPOINTS_ENABLED = true;
static const bool DEFAULT_TXINDEX = false;
static const char* const DEFAULT_BLOCKFILTERINDEX = "0";
/** Default for -persistmempool */
static const bool DEFAULT_PERSIST_MEMPOOL = true;
/** Default for using fee filter */
static const bool DEFAULT_FEEFILTER = true;
/** Default for -stopatheight */
static const int DEFAULT_STOPATHEIGHT = 0;
/** 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;
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;
/** Current sync state passed to tip changed callbacks. */
enum class SynchronizationState {
INIT_REINDEX,
INIT_DOWNLOAD,
POST_INIT
};
extern RecursiveMutex cs_main;
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;
/** Whether there are dedicated script-checking threads running.
* False indicates all script checking is done on the main threadMessageHandler thread.
*/
extern bool g_parallel_script_checks;
extern bool fRequireStandard;
extern bool fCheckBlockIndex;
extern bool fCheckpointsEnabled;
/** 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;
/** Documentation for argument 'checklevel'. */
extern const std::vector<std::string> CHECKLEVEL_DOC;
/** 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);
/** Unload database information */
void UnloadBlockIndex(CTxMemPool* mempool, ChainstateManager& chainman);
/** Run instances of script checking worker threads */
void StartScriptCheckWorkerThreads(int threads_num);
/** Stop all of the script checking worker threads */
void StopScriptCheckWorkerThreads();
/**
* Return transaction from the block at block_index.
* If block_index is not provided, fall back to mempool.
* If mempool is not provided or the tx couldn't be found in mempool, fall back to g_txindex.
*
* @param[in] block_index The block to read from disk, or nullptr
* @param[in] mempool If block_index is not provided, look in the mempool, if provided
* @param[in] hash The txid
* @param[in] consensusParams The params
* @param[out] hashBlock The hash of block_index, if the tx was found via block_index
* @returns The tx if found, otherwise nullptr
*/
CTransactionRef GetTransaction(const CBlockIndex* const block_index, const CTxMemPool* const mempool, const uint256& hash, const Consensus::Params& consensusParams, uint256& hashBlock);
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();
/**
* Actually unlink the specified files
*/
void UnlinkPrunedFiles(const std::set<int>& setFilesToPrune);
/** Prune block files up to a given height */
void PruneBlockFilesManual(CChainState& active_chainstate, int nManualPruneHeight);
/**
* Validation result for a single transaction mempool acceptance.
*/
struct MempoolAcceptResult {
/** Used to indicate the results of mempool validation,
* including the possibility of unfinished validation.
*/
enum class ResultType {
VALID, //!> Fully validated, valid.
INVALID, //!> Invalid.
};
const ResultType m_result_type;
const TxValidationState m_state;
// The following fields are only present when m_result_type = ResultType::VALID
/** Mempool transactions replaced by the tx per BIP 125 rules. */
const std::optional<std::list<CTransactionRef>> m_replaced_transactions;
/** Raw base fees in satoshis. */
const std::optional<CAmount> m_base_fees;
/** Constructor for failure case */
explicit MempoolAcceptResult(TxValidationState state)
: m_result_type(ResultType::INVALID), m_state(state) {
Assume(!state.IsValid()); // Can be invalid or error
}
/** Constructor for success case */
explicit MempoolAcceptResult(std::list<CTransactionRef>&& replaced_txns, CAmount fees)
: m_result_type(ResultType::VALID),
m_replaced_transactions(std::move(replaced_txns)), m_base_fees(fees) {}
};
/**
* (Try to) add a transaction to the memory pool.
* @param[in] bypass_limits When true, don't enforce mempool fee limits.
* @param[in] test_accept When true, run validation checks but don't submit to mempool.
*/
MempoolAcceptResult AcceptToMemoryPool(CChainState& active_chainstate, CTxMemPool& pool, const CTransactionRef& tx,
bool bypass_limits, bool test_accept=false) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
/** 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 CBlockIndex* active_chain_tip, 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(CChain& active_chain, 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(CChainState& active_chainstate,
const CTxMemPool& pool,
const CTransaction& tx,
int flags,
LockPoints* lp = nullptr,
bool useExistingLockPoints = false) EXCLUSIVE_LOCKS_REQUIRED(::cs_main, pool.cs);
/**
* 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 validating blocks and updating the block tree */
/** Context-independent validity checks */
bool CheckBlock(const CBlock& block, BlockValidationState& 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(BlockValidationState& state,
const CChainParams& chainparams,
CChainState& chainstate,
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);
/** 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(
CChainState& chainstate,
const CChainParams& chainparams,
CCoinsView& coinsview,
int nCheckLevel,
int nCheckDepth) 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
{
friend CChainState;
private:
/* Calculate the block/rev files to delete based on height specified by user with RPC command pruneblockchain */
void FindFilesToPruneManual(std::set<int>& setFilesToPrune, int nManualPruneHeight, int chain_tip_height);
/**
* Prune block and undo files (blk???.dat and undo???.dat) so that the disk space used is less than a user-defined target.
* The user sets the target (in MB) on the command line or in config file. This will be run on startup and whenever new
* space is allocated in a block or undo file, staying below the target. Changing back to unpruned requires a reindex
* (which in this case means the blockchain must be re-downloaded.)
*
* Pruning functions are called from FlushStateToDisk when the global fCheckForPruning flag has been set.
* Block and undo files are deleted in lock-step (when blk00003.dat is deleted, so is rev00003.dat.)
* Pruning cannot take place until the longest chain is at least a certain length (100000 on mainnet, 1000 on testnet, 1000 on regtest).
* Pruning will never delete a block within a defined distance (currently 288) from the active chain's tip.
* The block index is updated by unsetting HAVE_DATA and HAVE_UNDO for any blocks that were stored in the deleted files.
* A db flag records the fact that at least some block files have been pruned.
*
* @param[out] setFilesToPrune The set of file indices that can be unlinked will be returned
*/
void FindFilesToPrune(std::set<int>& setFilesToPrune, uint64_t nPruneAfterHeight, int chain_tip_height, int prune_height, bool is_ibd);
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);
//! Mark one block file as pruned (modify associated database entries)
void PruneOneBlockFile(const int fileNumber) 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,
BlockValidationState& state,
const CChainParams& chainparams,
CBlockIndex** ppindex) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
CBlockIndex* LookupBlockIndex(const uint256& hash) const 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);
//! Returns last CBlockIndex* that is a checkpoint
CBlockIndex* GetLastCheckpoint(const CCheckpointData& data) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
/**
* 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) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
~BlockManager() {
Unload();
}
};
/**
* 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);
};
enum class CoinsCacheSizeState
{
//! The coins cache is in immediate need of a flush.
CRITICAL = 2,
//! The cache is at >= 90% capacity.
LARGE = 1,
OK = 0
};
/**
* 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
{
protected:
/**
* Every received block is assigned a unique and increasing identifier, so we
* know which one to give priority in case of a fork.
*/
RecursiveMutex 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()
*/
RecursiveMutex 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};
//! mempool that is kept in sync with the chain
CTxMemPool& m_mempool;
//! Manages the UTXO set, which is a reflection of the contents of `m_chain`.
std::unique_ptr<CoinsViews> m_coins_views;
public:
//! Reference to a BlockManager instance which itself is shared across all
//! CChainState instances.
BlockManager& m_blockman;
explicit CChainState(CTxMemPool& mempool, BlockManager& blockman, uint256 from_snapshot_blockhash = uint256());
/**
* 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(size_t cache_size_bytes) 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() const 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 blockhash which is the base of the snapshot this chainstate was created from.
*
* IsNull() if this chainstate was not created from a snapshot.
*/
const uint256 m_from_snapshot_blockhash{};
/**
* 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(); }
//! The cache size of the on-disk coins view.
size_t m_coinsdb_cache_size_bytes{0};
//! The cache size of the in-memory coins view.
size_t m_coinstip_cache_size_bytes{0};
//! Resize the CoinsViews caches dynamically and flush state to disk.
//! @returns true unless an error occurred during the flush.
bool ResizeCoinsCaches(size_t coinstip_size, size_t coinsdb_size)
EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
/** Import blocks from an external file */
void LoadExternalBlockFile(const CChainParams& chainparams, FILE* fileIn, FlatFilePos* dbp = nullptr);
/**
* 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,
BlockValidationState &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();
/**
* Find the best known block, and make it the tip of the block chain. 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(
BlockValidationState& state,
const CChainParams& chainparams,
std::shared_ptr<const CBlock> pblock = nullptr) LOCKS_EXCLUDED(cs_main);
bool AcceptBlock(const std::shared_ptr<const CBlock>& pblock, BlockValidationState& 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, BlockValidationState& 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(BlockValidationState& state, const CChainParams& chainparams, DisconnectedBlockTransactions* disconnectpool) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_mempool.cs);
// Manual block validity manipulation:
/** Mark a block as precious and reorganize.
*
* May not be called in a validationinterface callback.
*/
bool PreciousBlock(BlockValidationState& state, const CChainParams& params, CBlockIndex* pindex) LOCKS_EXCLUDED(cs_main);
/** Mark a block as invalid. */
bool InvalidateBlock(BlockValidationState& 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);
/** Replay blocks that aren't fully applied to the database. */
bool ReplayBlocks(const CChainParams& params);
/** Whether the chain state needs to be redownloaded due to lack of witness data */
[[nodiscard]] bool NeedsRedownload(const CChainParams& params) const EXCLUSIVE_LOCKS_REQUIRED(cs_main);
/** Ensures we have a genesis block in the block tree, possibly writing one to disk. */
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);
/** Load the persisted mempool from disk */
void LoadMempool(const ArgsManager& args);
/** Update the chain tip based on database information, i.e. CoinsTip()'s best block. */
bool LoadChainTip(const CChainParams& chainparams) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
//! Dictates whether we need to flush the cache to disk or not.
//!
//! @return the state of the size of the coins cache.
CoinsCacheSizeState GetCoinsCacheSizeState(const CTxMemPool* tx_pool)
EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
CoinsCacheSizeState GetCoinsCacheSizeState(
const CTxMemPool* tx_pool,
size_t max_coins_cache_size_bytes,
size_t max_mempool_size_bytes) EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
std::string ToString() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
private:
bool ActivateBestChainStep(BlockValidationState& state, const CChainParams& chainparams, CBlockIndex* pindexMostWork, const std::shared_ptr<const CBlock>& pblock, bool& fInvalidFound, ConnectTrace& connectTrace) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_mempool.cs);
bool ConnectTip(BlockValidationState& state, const CChainParams& chainparams, CBlockIndex* pindexNew, const std::shared_ptr<const CBlock>& pblock, ConnectTrace& connectTrace, DisconnectedBlockTransactions& disconnectpool) EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_mempool.cs);
void InvalidBlockFound(CBlockIndex *pindex, const BlockValidationState &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);
void CheckForkWarningConditions() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
void InvalidChainFound(CBlockIndex* pindexNew) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
bool LoadBlockIndexDB(const CChainParams& chainparams) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
friend ChainstateManager;
};
/**
* Provides an interface for creating and interacting with one or two
* chainstates: an IBD chainstate generated by downloading blocks, and
* an optional snapshot chainstate loaded from a UTXO snapshot. Managed
* chainstates can be maintained at different heights simultaneously.
*
* This class provides abstractions that allow the retrieval of the current
* most-work chainstate ("Active") as well as chainstates which may be in
* background use to validate UTXO snapshots.
*
* Definitions:
*
* *IBD chainstate*: a chainstate whose current state has been "fully"
* validated by the initial block download process.
*
* *Snapshot chainstate*: a chainstate populated by loading in an
* assumeutxo UTXO snapshot.
*
* *Active chainstate*: the chainstate containing the current most-work
* chain. Consulted by most parts of the system (net_processing,
* wallet) as a reflection of the current chain and UTXO set.
* This may either be an IBD chainstate or a snapshot chainstate.
*
* *Background IBD chainstate*: an IBD chainstate for which the
* IBD process is happening in the background while use of the
* active (snapshot) chainstate allows the rest of the system to function.
*
* *Validated chainstate*: the most-work chainstate which has been validated
* locally via initial block download. This will be the snapshot chainstate
* if a snapshot was loaded and all blocks up to the snapshot starting point
* have been downloaded and validated (via background validation), otherwise
* it will be the IBD chainstate.
*/
class ChainstateManager
{
private:
//! The chainstate used under normal operation (i.e. "regular" IBD) or, if
//! a snapshot is in use, for background validation.
//!
//! Its contents (including on-disk data) will be deleted *upon shutdown*
//! after background validation of the snapshot has completed. We do not
//! free the chainstate contents immediately after it finishes validation
//! to cautiously avoid a case where some other part of the system is still
//! using this pointer (e.g. net_processing).
//!
//! Once this pointer is set to a corresponding chainstate, it will not
//! be reset until init.cpp:Shutdown().
//!
//! This is especially important when, e.g., calling ActivateBestChain()
//! on all chainstates because we are not able to hold ::cs_main going into
//! that call.
std::unique_ptr<CChainState> m_ibd_chainstate GUARDED_BY(::cs_main);
//! A chainstate initialized on the basis of a UTXO snapshot. If this is
//! non-null, it is always our active chainstate.
//!
//! Once this pointer is set to a corresponding chainstate, it will not
//! be reset until init.cpp:Shutdown().
//!
//! This is especially important when, e.g., calling ActivateBestChain()
//! on all chainstates because we are not able to hold ::cs_main going into
//! that call.
std::unique_ptr<CChainState> m_snapshot_chainstate GUARDED_BY(::cs_main);
//! Points to either the ibd or snapshot chainstate; indicates our
//! most-work chain.
//!
//! Once this pointer is set to a corresponding chainstate, it will not
//! be reset until init.cpp:Shutdown().
//!
//! This is especially important when, e.g., calling ActivateBestChain()
//! on all chainstates because we are not able to hold ::cs_main going into
//! that call.
CChainState* m_active_chainstate GUARDED_BY(::cs_main) {nullptr};
//! If true, the assumed-valid chainstate has been fully validated
//! by the background validation chainstate.
bool m_snapshot_validated{false};
//! Internal helper for ActivateSnapshot().
[[nodiscard]] bool PopulateAndValidateSnapshot(
CChainState& snapshot_chainstate,
CAutoFile& coins_file,
const SnapshotMetadata& metadata);
// For access to m_active_chainstate.
friend CChainState& ChainstateActive();
friend CChain& ChainActive();
public:
std::thread m_load_block;
//! A single BlockManager instance is shared across each constructed
//! chainstate to avoid duplicating block metadata.
BlockManager m_blockman GUARDED_BY(::cs_main);
//! The total number of bytes available for us to use across all in-memory
//! coins caches. This will be split somehow across chainstates.
int64_t m_total_coinstip_cache{0};
//
//! The total number of bytes available for us to use across all leveldb
//! coins databases. This will be split somehow across chainstates.
int64_t m_total_coinsdb_cache{0};
//! Instantiate a new chainstate and assign it based upon whether it is
//! from a snapshot.
//!
//! @param[in] mempool The mempool to pass to the chainstate
// constructor
//! @param[in] snapshot_blockhash If given, signify that this chainstate
//! is based on a snapshot.
CChainState& InitializeChainstate(CTxMemPool& mempool, const uint256& snapshot_blockhash = uint256())
EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
//! Get all chainstates currently being used.
std::vector<CChainState*> GetAll();
//! Construct and activate a Chainstate on the basis of UTXO snapshot data.
//!
//! Steps:
//!
//! - Initialize an unused CChainState.
//! - Load its `CoinsViews` contents from `coins_file`.
//! - Verify that the hash of the resulting coinsdb matches the expected hash
//! per assumeutxo chain parameters.
//! - Wait for our headers chain to include the base block of the snapshot.
//! - "Fast forward" the tip of the new chainstate to the base of the snapshot,
//! faking nTx* block index data along the way.
//! - Move the new chainstate to `m_snapshot_chainstate` and make it our
//! ChainstateActive().
[[nodiscard]] bool ActivateSnapshot(
CAutoFile& coins_file, const SnapshotMetadata& metadata, bool in_memory);
//! The most-work chain.
CChainState& ActiveChainstate() const;
CChain& ActiveChain() const { return ActiveChainstate().m_chain; }
int ActiveHeight() const { return ActiveChain().Height(); }
CBlockIndex* ActiveTip() const { return ActiveChain().Tip(); }
BlockMap& BlockIndex() EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
{
return m_blockman.m_block_index;
}
//! @returns true if a snapshot-based chainstate is in use. Also implies
//! that a background validation chainstate is also in use.
bool IsSnapshotActive() const;
std::optional<uint256> SnapshotBlockhash() const;
//! Is there a snapshot in use and has it been fully validated?
bool IsSnapshotValidated() const { return m_snapshot_validated; }
//! @returns true if this chainstate is being used to validate an active
//! snapshot in the background.
bool IsBackgroundIBD(CChainState* chainstate) const;
//! Return the most-work chainstate that has been fully validated.
//!
//! During background validation of a snapshot, this is the IBD chain. After
//! background validation has completed, this is the snapshot chain.
CChainState& ValidatedChainstate() const;
CChain& ValidatedChain() const { return ValidatedChainstate().m_chain; }
CBlockIndex* ValidatedTip() const { return ValidatedChain().Tip(); }
/**
* 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.
* @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
*/
bool ProcessNewBlockHeaders(const std::vector<CBlockHeader>& block, BlockValidationState& state, const CChainParams& chainparams, const CBlockIndex** ppindex = nullptr) LOCKS_EXCLUDED(cs_main);
//! 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 block index and chain data before shutdown.
void Unload() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
//! Clear (deconstruct) chainstate data.
void Reset();
//! Check to see if caches are out of balance and if so, call
//! ResizeCoinsCaches() as needed.
void MaybeRebalanceCaches() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
};
/** DEPRECATED! Please use node.chainman instead. May only be used in validation.cpp internally */
extern ChainstateManager g_chainman GUARDED_BY(::cs_main);
/** Please prefer the identical ChainstateManager::ActiveChainstate */
CChainState& ChainstateActive();
/** Please prefer the identical ChainstateManager::ActiveChain */
CChain& ChainActive();
/** Global variable that points to the active block tree (protected by cs_main) */
extern std::unique_ptr<CBlockTreeDB> pblocktree;
extern VersionBitsCache versionbitscache;
/**
* Determine what nVersion a new block should use.
*/
int32_t ComputeBlockVersion(const CBlockIndex* pindexPrev, const Consensus::Params& params);
/** Get block file info entry for one block file */
CBlockFileInfo* GetBlockFileInfo(size_t n);
using FopenFn = std::function<FILE*(const fs::path&, const char*)>;
/** Dump the mempool to disk. */
bool DumpMempool(const CTxMemPool& pool, FopenFn mockable_fopen_function = fsbridge::fopen, bool skip_file_commit = false);
/** Load the mempool from disk. */
bool LoadMempool(CTxMemPool& pool, CChainState& active_chainstate, FopenFn mockable_fopen_function = fsbridge::fopen);
//! 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);
}
/**
* Return the expected assumeutxo value for a given height, if one exists.
*
* @param[in] height Get the assumeutxo value for this height.
*
* @returns empty if no assumeutxo configuration exists for the given height.
*/
const AssumeutxoData* ExpectedAssumeutxo(const int height, const CChainParams& params);
#endif // BITCOIN_VALIDATION_H
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