aboutsummaryrefslogtreecommitdiff
path: root/src/main.h
blob: 4a5131776243f59b4e63077dbc283c95735d6b88 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2015 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_MAIN_H
#define BITCOIN_MAIN_H

#if defined(HAVE_CONFIG_H)
#include "config/bitcoin-config.h"
#endif

#include "amount.h"
#include "chain.h"
#include "coins.h"
#include "net.h"
#include "script/script_error.h"
#include "sync.h"

#include <algorithm>
#include <exception>
#include <map>
#include <set>
#include <stdint.h>
#include <string>
#include <utility>
#include <vector>

#include <boost/unordered_map.hpp>

class CBlockIndex;
class CBlockTreeDB;
class CBloomFilter;
class CChainParams;
class CInv;
class CScriptCheck;
class CTxMemPool;
class CValidationInterface;
class CValidationState;

struct CNodeStateStats;

/** Default for accepting alerts from the P2P network. */
static const bool DEFAULT_ALERTS = true;
/** Default for DEFAULT_WHITELISTALWAYSRELAY. */
static const bool DEFAULT_WHITELISTALWAYSRELAY = true;
/** Default for -minrelaytxfee, minimum relay fee for transactions */
static const unsigned int DEFAULT_MIN_RELAY_TX_FEE = 1000;
/** Default for -maxorphantx, maximum number of orphan transactions kept in memory */
static const unsigned int DEFAULT_MAX_ORPHAN_TRANSACTIONS = 100;
/** 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 = 72;
/** 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;
/** 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 in the future perhaps 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;
/** Average delay between local address broadcasts in seconds. */
static const unsigned int AVG_LOCAL_ADDRESS_BROADCAST_INTERVAL = 24 * 24 * 60;
/** Average delay between peer address broadcasts in seconds. */
static const unsigned int AVG_ADDRESS_BROADCAST_INTERVAL = 30;
/** Average delay between trickled inventory broadcasts in seconds.
 *  Blocks, whitelisted receivers, and a random 25% of transactions bypass this. */
static const unsigned int AVG_INVENTORY_BROADCAST_INTERVAL = 5;

static const unsigned int DEFAULT_LIMITFREERELAY = 15;
static const bool DEFAULT_RELAYPRIORITY = true;
static const int64_t DEFAULT_MAX_TIP_AGE = 24 * 60 * 60;

/** Default for -permitbaremultisig */
static const bool DEFAULT_PERMIT_BAREMULTISIG = true;
static const unsigned int DEFAULT_BYTES_PER_SIGOP = 20;
static const bool DEFAULT_CHECKPOINTS_ENABLED = true;
static const bool DEFAULT_TXINDEX = false;
static const unsigned int DEFAULT_BANSCORE_THRESHOLD = 100;

static const bool DEFAULT_TESTSAFEMODE = false;
/** Default for -permitrbf */
static const bool DEFAULT_PERMIT_REPLACEMENT = true;

/** Maximum number of headers to announce when relaying blocks with headers message.*/
static const unsigned int MAX_BLOCKS_TO_ANNOUNCE = 8;

struct BlockHasher
{
    size_t operator()(const uint256& hash) const { return hash.GetCheapHash(); }
};

extern CScript COINBASE_FLAGS;
extern CCriticalSection cs_main;
extern CTxMemPool mempool;
typedef boost::unordered_map<uint256, CBlockIndex*, BlockHasher> BlockMap;
extern BlockMap mapBlockIndex;
extern uint64_t nLastBlockTx;
extern uint64_t nLastBlockSize;
extern const std::string strMessageMagic;
extern CWaitableCriticalSection csBestBlock;
extern CConditionVariable cvBlockChange;
extern bool fImporting;
extern bool fReindex;
extern int nScriptCheckThreads;
extern bool fTxIndex;
extern bool fIsBareMultisigStd;
extern bool fRequireStandard;
extern unsigned int nBytesPerSigOp;
extern bool fCheckBlockIndex;
extern bool fCheckpointsEnabled;
extern size_t nCoinCacheUsage;
extern CFeeRate minRelayTxFee;
extern bool fAlerts;
extern int64_t nMaxTipAge;
extern bool fPermitReplacement;

/** Best header we've seen so far (used for getheaders queries' starting points). */
extern CBlockIndex *pindexBestHeader;

/** Minimum disk space required - used in CheckDiskSpace() */
static const uint64_t nMinDiskSpace = 52428800;

/** 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;

static const signed int DEFAULT_CHECKBLOCKS = MIN_BLOCKS_TO_KEEP;
static const unsigned int DEFAULT_CHECKLEVEL = 3;

// Require that user allocate at least 550MB 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 > than 550MB will make it likely we can respect the target.
static const uint64_t MIN_DISK_SPACE_FOR_BLOCK_FILES = 550 * 1024 * 1024;

/** Register with a network node to receive its signals */
void RegisterNodeSignals(CNodeSignals& nodeSignals);
/** Unregister a network node */
void UnregisterNodeSignals(CNodeSignals& nodeSignals);

/** 
 * 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!
 * 
 * @param[out]  state   This may be set to an Error state if any error occurred processing it, including during validation/connection/etc of otherwise unrelated blocks during reorganisation; or it may be set to an Invalid state if pblock is itself invalid (but this is not guaranteed even when the block is checked). If you want to *possibly* get feedback on whether pblock is valid, you must also install a CValidationInterface (see validationinterface.h) - this will have its BlockChecked method called whenever *any* block completes validation.
 * @param[in]   pfrom   The node which we are receiving the block from; it is added to mapBlockSource and may be penalised if the block is invalid.
 * @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]  dbp     If pblock is stored to disk (or already there), this will be set to its location.
 * @return True if state.IsValid()
 */
bool ProcessNewBlock(CValidationState& state, const CChainParams& chainparams, const CNode* pfrom, const CBlock* pblock, bool fForceProcessing, CDiskBlockPos* dbp);
/** Check whether enough disk space is available for an incoming block */
bool CheckDiskSpace(uint64_t nAdditionalBytes = 0);
/** Open a block file (blk?????.dat) */
FILE* OpenBlockFile(const CDiskBlockPos &pos, bool fReadOnly = false);
/** Open an undo file (rev?????.dat) */
FILE* OpenUndoFile(const CDiskBlockPos &pos, bool fReadOnly = false);
/** Translation to a filesystem path */
boost::filesystem::path GetBlockPosFilename(const CDiskBlockPos &pos, const char *prefix);
/** Import blocks from an external file */
bool LoadExternalBlockFile(const CChainParams& chainparams, FILE* fileIn, CDiskBlockPos *dbp = NULL);
/** Initialize a new block tree database + block data on disk */
bool InitBlockIndex(const CChainParams& chainparams);
/** Load the block tree and coins database from disk */
bool LoadBlockIndex();
/** Unload database information */
void UnloadBlockIndex();
/** Process protocol messages received from a given node */
bool ProcessMessages(CNode* pfrom);
/**
 * Send queued protocol messages to be sent to a give node.
 *
 * @param[in]   pto             The node which we are sending messages to.
 */
bool SendMessages(CNode* pto);
/** Run an instance of the script checking thread */
void ThreadScriptCheck();
/** Try to detect Partition (network isolation) attacks against us */
void PartitionCheck(bool (*initialDownloadCheck)(), CCriticalSection& cs, const CBlockIndex *const &bestHeader, int64_t nPowTargetSpacing);
/** Check whether we are doing an initial block download (synchronizing from disk or network) */
bool IsInitialBlockDownload();
/** Format a string that describes several potential problems detected by the core.
 * strFor can have three values:
 * - "rpc": get critical warnings, which should put the client in safe mode if non-empty
 * - "statusbar": get all warnings
 * - "gui": get all warnings, translated (where possible) for GUI
 * This function only returns the highest priority warning of the set selected by strFor.
 */
std::string GetWarnings(const std::string& strFor);
/** Retrieve a transaction (from memory pool, or from disk, if possible) */
bool GetTransaction(const uint256 &hash, CTransaction &tx, const Consensus::Params& params, uint256 &hashBlock, bool fAllowSlow = false);
/** Find the best known block, and make it the tip of the block chain */
bool ActivateBestChain(CValidationState& state, const CChainParams& chainparams, const CBlock* pblock = NULL);
CAmount GetBlockSubsidy(int nHeight, const Consensus::Params& consensusParams);

/**
 * 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);

/**
 *  Actually unlink the specified files
 */
void UnlinkPrunedFiles(std::set<int>& setFilesToPrune);

/** Create a new block index entry for a given block hash */
CBlockIndex * InsertBlockIndex(uint256 hash);
/** Get statistics from node state */
bool GetNodeStateStats(NodeId nodeid, CNodeStateStats &stats);
/** Increase a node's misbehavior score. */
void Misbehaving(NodeId nodeid, int howmuch);
/** Flush all state, indexes and buffers to disk. */
void FlushStateToDisk();
/** Prune block files and flush state to disk. */
void PruneAndFlush();

/** (try to) add transaction to memory pool **/
bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransaction &tx, bool fLimitFree,
                        bool* pfMissingInputs, bool fOverrideMempoolLimit=false, bool fRejectAbsurdFee=false);

/** Convert CValidationState to a human-readable message for logging */
std::string FormatStateMessage(const CValidationState &state);

struct CNodeStateStats {
    int nMisbehavior;
    int nSyncHeight;
    int nCommonHeight;
    std::vector<int> vHeightInFlight;
};

struct CDiskTxPos : public CDiskBlockPos
{
    unsigned int nTxOffset; // after header

    ADD_SERIALIZE_METHODS;

    template <typename Stream, typename Operation>
    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
        READWRITE(*(CDiskBlockPos*)this);
        READWRITE(VARINT(nTxOffset));
    }

    CDiskTxPos(const CDiskBlockPos &blockIn, unsigned int nTxOffsetIn) : CDiskBlockPos(blockIn.nFile, blockIn.nPos), nTxOffset(nTxOffsetIn) {
    }

    CDiskTxPos() {
        SetNull();
    }

    void SetNull() {
        CDiskBlockPos::SetNull();
        nTxOffset = 0;
    }
};


/** 
 * Count ECDSA signature operations the old-fashioned (pre-0.6) way
 * @return number of sigops this transaction's outputs will produce when spent
 * @see CTransaction::FetchInputs
 */
unsigned int GetLegacySigOpCount(const CTransaction& tx);

/**
 * Count ECDSA signature operations in pay-to-script-hash inputs.
 * 
 * @param[in] mapInputs Map of previous transactions that have outputs we're spending
 * @return maximum number of sigops required to validate this transaction's inputs
 * @see CTransaction::FetchInputs
 */
unsigned int GetP2SHSigOpCount(const CTransaction& tx, const CCoinsViewCache& mapInputs);


/**
 * Check whether all inputs of this transaction are valid (no double spends, scripts & sigs, amounts)
 * This does not modify the UTXO set. If pvChecks is not NULL, script checks are pushed onto it
 * instead of being performed inline.
 */
bool CheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &view, bool fScriptChecks,
                 unsigned int flags, bool cacheStore, std::vector<CScriptCheck> *pvChecks = NULL);

/** Apply the effects of this transaction on the UTXO set represented by view */
void UpdateCoins(const CTransaction& tx, CValidationState &state, CCoinsViewCache &inputs, int nHeight);

/** Context-independent validity checks */
bool CheckTransaction(const CTransaction& tx, CValidationState& state);

/**
 * Check if transaction is final and can be included in a block with the
 * specified height and time. Consensus critical.
 */
bool IsFinalTx(const CTransaction &tx, int nBlockHeight, int64_t nBlockTime);

/**
 * 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);

/** 
 * Closure representing one script verification
 * Note that this stores references to the spending transaction 
 */
class CScriptCheck
{
private:
    CScript scriptPubKey;
    const CTransaction *ptxTo;
    unsigned int nIn;
    unsigned int nFlags;
    bool cacheStore;
    ScriptError error;

public:
    CScriptCheck(): ptxTo(0), nIn(0), nFlags(0), cacheStore(false), error(SCRIPT_ERR_UNKNOWN_ERROR) {}
    CScriptCheck(const CCoins& txFromIn, const CTransaction& txToIn, unsigned int nInIn, unsigned int nFlagsIn, bool cacheIn) :
        scriptPubKey(txFromIn.vout[txToIn.vin[nInIn].prevout.n].scriptPubKey),
        ptxTo(&txToIn), nIn(nInIn), nFlags(nFlagsIn), cacheStore(cacheIn), error(SCRIPT_ERR_UNKNOWN_ERROR) { }

    bool operator()();

    void swap(CScriptCheck &check) {
        scriptPubKey.swap(check.scriptPubKey);
        std::swap(ptxTo, check.ptxTo);
        std::swap(nIn, check.nIn);
        std::swap(nFlags, check.nFlags);
        std::swap(cacheStore, check.cacheStore);
        std::swap(error, check.error);
    }

    ScriptError GetScriptError() const { return error; }
};


/** Functions for disk access for blocks */
bool WriteBlockToDisk(const CBlock& block, CDiskBlockPos& pos, const CMessageHeader::MessageStartChars& messageStart);
bool ReadBlockFromDisk(CBlock& block, const CDiskBlockPos& pos, const Consensus::Params& consensusParams);
bool ReadBlockFromDisk(CBlock& block, const CBlockIndex* pindex, const Consensus::Params& consensusParams);

/** Functions for validating blocks and updating the block tree */

/** Context-independent validity checks */
bool CheckBlockHeader(const CBlockHeader& block, CValidationState& state, bool fCheckPOW = true);
bool CheckBlock(const CBlock& block, CValidationState& state, bool fCheckPOW = true, bool fCheckMerkleRoot = true);

/** Context-dependent validity checks.
 *  By "context", we mean only the previous block headers, but not the UTXO
 *  set; UTXO-related validity checks are done in ConnectBlock(). */
bool ContextualCheckBlockHeader(const CBlockHeader& block, CValidationState& state, CBlockIndex *pindexPrev);
bool ContextualCheckBlock(const CBlock& block, CValidationState& state, CBlockIndex *pindexPrev);

/** Apply the effects of this block (with given index) on the UTXO set represented by coins.
 *  Validity checks that depend on the UTXO set are also done; ConnectBlock()
 *  can fail if those validity checks fail (among other reasons). */
bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pindex, CCoinsViewCache& coins, bool fJustCheck = false);

/** Undo the effects of this block (with given index) on the UTXO set represented by coins.
 *  In case pfClean is provided, operation will try to be tolerant about errors, and *pfClean
 *  will be true if no problems were found. Otherwise, the return value will be false in case
 *  of problems. Note that in any case, coins may be modified. */
bool DisconnectBlock(const CBlock& block, CValidationState& state, const CBlockIndex* pindex, CCoinsViewCache& coins, bool* pfClean = NULL);

/** Check a block is completely valid from start to finish (only works on top of our current best block, with cs_main held) */
bool TestBlockValidity(CValidationState& state, const CChainParams& chainparams, const CBlock& block, CBlockIndex* pindexPrev, bool fCheckPOW = true, bool fCheckMerkleRoot = true);


class CBlockFileInfo
{
public:
    unsigned int nBlocks;      //! number of blocks stored in file
    unsigned int nSize;        //! number of used bytes of block file
    unsigned int nUndoSize;    //! number of used bytes in the undo file
    unsigned int nHeightFirst; //! lowest height of block in file
    unsigned int nHeightLast;  //! highest height of block in file
    uint64_t nTimeFirst;         //! earliest time of block in file
    uint64_t nTimeLast;          //! latest time of block in file

    ADD_SERIALIZE_METHODS;

    template <typename Stream, typename Operation>
    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
        READWRITE(VARINT(nBlocks));
        READWRITE(VARINT(nSize));
        READWRITE(VARINT(nUndoSize));
        READWRITE(VARINT(nHeightFirst));
        READWRITE(VARINT(nHeightLast));
        READWRITE(VARINT(nTimeFirst));
        READWRITE(VARINT(nTimeLast));
    }

     void SetNull() {
         nBlocks = 0;
         nSize = 0;
         nUndoSize = 0;
         nHeightFirst = 0;
         nHeightLast = 0;
         nTimeFirst = 0;
         nTimeLast = 0;
     }

     CBlockFileInfo() {
         SetNull();
     }

     std::string ToString() const;

     /** update statistics (does not update nSize) */
     void AddBlock(unsigned int nHeightIn, uint64_t nTimeIn) {
         if (nBlocks==0 || nHeightFirst > nHeightIn)
             nHeightFirst = nHeightIn;
         if (nBlocks==0 || nTimeFirst > nTimeIn)
             nTimeFirst = nTimeIn;
         nBlocks++;
         if (nHeightIn > nHeightLast)
             nHeightLast = nHeightIn;
         if (nTimeIn > nTimeLast)
             nTimeLast = nTimeIn;
     }
};

/** 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);
};

/** Find the last common block between the parameter chain and a locator. */
CBlockIndex* FindForkInGlobalIndex(const CChain& chain, const CBlockLocator& locator);

/** Mark a block as invalid. */
bool InvalidateBlock(CValidationState& state, const Consensus::Params& consensusParams, CBlockIndex *pindex);

/** Remove invalidity status from a block and its descendants. */
bool ReconsiderBlock(CValidationState& state, CBlockIndex *pindex);

/** The currently-connected chain of blocks (protected by cs_main). */
extern CChain chainActive;

/** Global variable that points to the active CCoinsView (protected by cs_main) */
extern CCoinsViewCache *pcoinsTip;

/** Global variable that points to the active block tree (protected by cs_main) */
extern 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);

/** 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;
/** Transaction is already known (either in mempool or blockchain) */
static const unsigned int REJECT_ALREADY_KNOWN = 0x101;
/** Transaction conflicts with a transaction already known */
static const unsigned int REJECT_CONFLICT = 0x102;

#endif // BITCOIN_MAIN_H