LogPrintf("CheckForkWarningConditions: Warning: Large valid fork found\n forking the chain at height %d (%s)\n lasting to height %d (%s).\nChain state database corruption likely.\n",
LogPrintf("CheckForkWarningConditions: Warning: Found invalid chain at least ~6 blocks longer than our best chain.\nChain state database corruption likely.\n");
assert(rangeGenesis.first == rangeGenesis.second); // There is only one index entry with parent NULL.
// Iterate over the entire block tree, using depth-first search.
// Along the way, remember whether there are blocks on the path from genesis
// block being explored which are the first to have certain properties.
size_t nNodes = 0;
int nHeight = 0;
CBlockIndex* pindexFirstInvalid = NULL; // Oldest ancestor of pindex which is invalid.
CBlockIndex* pindexFirstMissing = NULL; // Oldest ancestor of pindex which does not have BLOCK_HAVE_DATA.
CBlockIndex* pindexFirstNotTreeValid = NULL; // Oldest ancestor of pindex which does not have BLOCK_VALID_TREE (regardless of being valid or not).
CBlockIndex* pindexFirstNotTransactionsValid = NULL; // Oldest ancestor of pindex which does not have BLOCK_VALID_TRANSACTIONS (regardless of being valid or not).
CBlockIndex* pindexFirstNotChainValid = NULL; // Oldest ancestor of pindex which does not have BLOCK_VALID_CHAIN (regardless of being valid or not).
CBlockIndex* pindexFirstNotScriptsValid = NULL; // Oldest ancestor of pindex which does not have BLOCK_VALID_SCRIPTS (regardless of being valid or not).
// All parents having data is equivalent to all parents being VALID_TRANSACTIONS, which is equivalent to nChainTx being set.
assert((pindexFirstMissing != NULL) == (pindex->nChainTx == 0)); // nChainTx == 0 is used to signal that all parent block's transaction data is available.
assert(pindex->nHeight == nHeight); // nHeight must be consistent.
assert(pindex->pprev == NULL || pindex->nChainWork >= pindex->pprev->nChainWork); // For every block except the genesis block, the chainwork must be larger than the parent's.
assert(nHeight < 2 || (pindex->pskip && (pindex->pskip->nHeight < nHeight))); // The pskip pointer must point back for all but the first 2 blocks.
assert(pindexFirstNotTreeValid == NULL); // All mapBlockIndex entries must at least be TREE valid
if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_TREE) assert(pindexFirstNotTreeValid == NULL); // TREE valid implies all parents are TREE valid
if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_CHAIN) assert(pindexFirstNotChainValid == NULL); // CHAIN valid implies all parents are CHAIN valid
if ((pindex->nStatus & BLOCK_VALID_MASK) >= BLOCK_VALID_SCRIPTS) assert(pindexFirstNotScriptsValid == NULL); // SCRIPTS valid implies all parents are SCRIPTS valid
if (pindexFirstInvalid == NULL) {
// Checks for not-invalid blocks.
assert((pindex->nStatus & BLOCK_FAILED_MASK) == 0); // The failed mask cannot be set for blocks without invalid parents.
}
if (!CBlockIndexWorkComparator()(pindex, chainActive.Tip()) && pindexFirstMissing == NULL) {
if (pindexFirstInvalid == NULL) { // If this block sorts at least as good as the current tip and is valid, it must be in setBlockIndexCandidates.
assert(setBlockIndexCandidates.count(pindex));
}
} else { // If this block sorts worse than the current tip, it cannot be in setBlockIndexCandidates.
if (pindexFirstInvalid == NULL) { // If this block has block data available, some parent doesn't, and has no invalid parents, it must be in mapBlocksUnlinked.
assert(foundInUnlinked);
}
} else { // If this block does not have block data available, or all parents do, it cannot be in mapBlocksUnlinked.
assert(!foundInUnlinked);
}
// assert(pindex->GetBlockHash() == pindex->GetBlockHeader().GetHash()); // Perhaps too slow
// End: actual consistency checks.
// Try descending into the first subnode.
std::pair<std::multimap<CBlockIndex*,CBlockIndex*>::iterator,std::multimap<CBlockIndex*,CBlockIndex*>::iterator> range = forward.equal_range(pindex);
if (range.first != range.second) {
// A subnode was found.
pindex = range.first->second;
nHeight++;
continue;
}
// This is a leaf node.
// Move upwards until we reach a node of which we have not yet visited the last child.
while (pindex) {
// We are going to either move to a parent or a sibling of pindex.
// If pindex was the first with a certain property, unset the corresponding variable.
if (pindex == pindexFirstInvalid) pindexFirstInvalid = NULL;
if (pindex == pindexFirstMissing) pindexFirstMissing = NULL;
if (pindex == pindexFirstNotTreeValid) pindexFirstNotTreeValid = NULL;
if (pindex == pindexFirstNotTransactionsValid) pindexFirstNotTransactionsValid = NULL;
if (pindex == pindexFirstNotChainValid) pindexFirstNotChainValid = NULL;
if (pindex == pindexFirstNotScriptsValid) pindexFirstNotScriptsValid = NULL;
// Allow exceptions from under-length message on vRecv
LogPrintf("ProcessMessages(%s, %u bytes): Exception '%s' caught, normally caused by a message being shorter than its stated length\n", SanitizeString(strCommand), nMessageSize, e.what());
bool fFetch = state.fPreferredDownload || (nPreferredDownload == 0 && !pto->fClient && !pto->fOneShot); // Download if this is a nice peer, or we have no nice peers and this one might do.