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author | glozow <gloriajzhao@gmail.com> | 2021-12-17 14:18:02 +0000 |
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committer | glozow <gloriajzhao@gmail.com> | 2022-01-17 12:17:51 +0000 |
commit | 9ad211c5753dbd148ba6f0ed56854f6364362ca8 (patch) | |
tree | 4755a3e6265226be87b82c429e9edbbace1b2ad4 | |
parent | 83d4fb71260f268abd41d083fb3458476aed83ce (diff) |
[doc] more detailed explanation for deduplication
-rw-r--r-- | src/validation.cpp | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/src/validation.cpp b/src/validation.cpp index 616873057c..b48eb6ac3c 100644 --- a/src/validation.cpp +++ b/src/validation.cpp @@ -1250,10 +1250,14 @@ PackageMempoolAcceptResult MemPoolAccept::AcceptPackage(const Package& package, LOCK(m_pool.cs); std::map<const uint256, const MempoolAcceptResult> results; - // As node operators are free to set their mempool policies however they please, it's possible - // for package transaction(s) to already be in the mempool, and we don't want to reject the - // entire package in that case (as that could be a censorship vector). Filter the transactions - // that are already in mempool and add their information to results, since we already have them. + // Node operators are free to set their mempool policies however they please, nodes may receive + // transactions in different orders, and malicious counterparties may try to take advantage of + // policy differences to pin or delay propagation of transactions. As such, it's possible for + // some package transaction(s) to already be in the mempool, and we don't want to reject the + // entire package in that case (as that could be a censorship vector). De-duplicate the + // transactions that are already in the mempool, and only call AcceptMultipleTransactions() with + // the new transactions. This ensures we don't double-count transaction counts and sizes when + // checking ancestor/descendant limits, or double-count transaction fees for fee-related policy. std::vector<CTransactionRef> txns_new; for (const auto& tx : package) { const auto& wtxid = tx->GetWitnessHash(); |