GlcoinCore/elements
1
0
Fork 0
mirror of https://github.com/ElementsProject/elements.git synced 2026-08-13 12:33:42 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Fix elements multiple-header-download issue.

Browse source 
This fixes an issue which causes Elements to download the blockchain headers
multiple times during initial block download.

In particular: each time we receive an INV P2P message with a new block
(about once a minute), we start downloading the headers, again, in parallel
with any existing download(s) in progress.

With this change, after we receive each batch of headers, we check whether
any of the headers in it were new to us. If not (they were all duplicates),
we stop there, and do not ask the peer for another batch. This reduces the
maximum amount of duplication to about 2x, which is not ideal, but a HUGE
improvement.
This commit is contained in:
Glenn Willen 2021-11-09 21:06:42 -08:00
parent f472126622
commit f5d33d8676
3 changed files with 23 additions and 7 deletions
Download patch file Download diff file Expand all files Collapse all files

6
src/net_processing.cpp
View file

@ -1423,7 +1423,8 @@ bool static ProcessHeadersMessage(CNode *pfrom, CConnman *connman, const std::ve
CValidationState state;
CBlockHeader first_invalid_header;
if (!ProcessNewBlockHeaders(headers, state, chainparams, &pindexLast, &first_invalid_header)) {
bool all_duplicate = false;
if (!ProcessNewBlockHeaders(headers, state, chainparams, &pindexLast, &first_invalid_header, &all_duplicate)) {
int nDoS;
if (state.IsInvalid(nDoS)) {
LOCK(cs_main);
@ -1489,10 +1490,11 @@ bool static ProcessHeadersMessage(CNode *pfrom, CConnman *connman, const std::ve
nodestate->m_last_block_announcement = GetTime();
}
if (nCount == MAX_HEADERS_RESULTS) {
if (nCount == MAX_HEADERS_RESULTS && !all_duplicate) {
// Headers message had its maximum size; the peer may have more headers.
// TODO: optimize: if pindexLast is an ancestor of chainActive.Tip or pindexBestHeader, continue
// from there instead.
// HOWEVER, if all headers we got this time were duplicates that we already had, don't ask for any more.
LogPrint(BCLog::NET, "more getheaders (%d) to end to peer=%d (startheight:%d)\n", pindexLast->nHeight, pfrom->GetId(), pfrom->nStartingHeight);
connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::GETHEADERS, chainActive.GetLocator(pindexLast), uint256()));
}

22
src/validation.cpp
View file

@ -169,7 +169,7 @@ public:
* 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 mapBlockIndex.
*/
bool AcceptBlockHeader(const CBlockHeader& block, CValidationState& state, const CChainParams& chainparams, CBlockIndex** ppindex) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
bool AcceptBlockHeader(const CBlockHeader& block, CValidationState& state, const CChainParams& chainparams, CBlockIndex** ppindex, bool* duplicate = nullptr) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
bool AcceptBlock(const std::shared_ptr<const CBlock>& pblock, CValidationState& state, const CChainParams& chainparams, CBlockIndex** ppindex, bool fRequested, const CDiskBlockPos* dbp, bool* fNewBlock) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
// Block (dis)connection on a given view:
@ -3765,16 +3765,22 @@ static bool ContextualCheckBlock(const CBlock& block, CValidationState& state, c
return true;
}
bool CChainState::AcceptBlockHeader(const CBlockHeader& block, CValidationState& state, const CChainParams& chainparams, CBlockIndex** ppindex)
bool CChainState::AcceptBlockHeader(const CBlockHeader& block, CValidationState& state, const CChainParams& chainparams, CBlockIndex** ppindex, bool* duplicate)
{
AssertLockHeld(cs_main);
// Check for duplicate
uint256 hash = block.GetHash();
BlockMap::iterator miSelf = mapBlockIndex.find(hash);
CBlockIndex *pindex = nullptr;
if (duplicate) {
*duplicate = false;
}
if (hash != chainparams.GetConsensus().hashGenesisBlock) {
if (miSelf != mapBlockIndex.end()) {
// Block header is already known.
if (duplicate) {
*duplicate = true;
}
pindex = miSelf->second;
if (ppindex)
*ppindex = pindex;
@ -3847,14 +3853,22 @@ bool CChainState::AcceptBlockHeader(const CBlockHeader& block, CValidationState&
}
// Exposed wrapper for AcceptBlockHeader
bool ProcessNewBlockHeaders(const std::vector<CBlockHeader>& headers, CValidationState& state, const CChainParams& chainparams, const CBlockIndex** ppindex, CBlockHeader *first_invalid)
bool ProcessNewBlockHeaders(const std::vector<CBlockHeader>& headers, CValidationState& state, const CChainParams& chainparams, const CBlockIndex** ppindex, CBlockHeader *first_invalid, bool* all_duplicate)
{
if (first_invalid != nullptr) first_invalid->SetNull();
{
LOCK(cs_main);
if (all_duplicate) {
*all_duplicate = true;
}
bool duplicate = false;
for (const CBlockHeader& header : headers) {
CBlockIndex *pindex = nullptr; // Use a temp pindex instead of ppindex to avoid a const_cast
if (!g_chainstate.AcceptBlockHeader(header, state, chainparams, &pindex)) {
bool accepted = g_chainstate.AcceptBlockHeader(header, state, chainparams, &pindex, &duplicate);
if (all_duplicate) {
(*all_duplicate) &= duplicate; // False if any are false
}
if (!accepted) {
if (first_invalid) *first_invalid = header;
return false;
}

2
src/validation.h
View file

@ -255,7 +255,7 @@ bool ProcessNewBlock(const CChainParams& chainparams, const std::shared_ptr<cons
* @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);
bool ProcessNewBlockHeaders(const std::vector<CBlockHeader>& block, CValidationState& state, const CChainParams& chainparams, const CBlockIndex** ppindex = nullptr, CBlockHeader* first_invalid = nullptr, bool* all_duplicate = nullptr) LOCKS_EXCLUDED(cs_main);
/** Check whether enough disk space is available for an incoming block */
bool CheckDiskSpace(uint64_t nAdditionalBytes = 0, bool blocks_dir = false);