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author | glozow <gloriajzhao@gmail.com> | 2021-07-15 07:18:18 +0100 |
---|---|---|
committer | glozow <gloriajzhao@gmail.com> | 2021-08-05 12:37:28 +0100 |
commit | c6e016aa139c8363e9b38bbc1ba0dca55700b8a7 (patch) | |
tree | 961309b2b056b1fdb25284b8e1f9371fc269883f /src | |
parent | f551841d3ec080a2d7a7988c7b35088dff6c5830 (diff) | |
download | bitcoin-c6e016aa139c8363e9b38bbc1ba0dca55700b8a7.tar.xz |
[mempool] check ancestor/descendant limits for packages
When calculating ancestor/descendant counts for transactions in the
package, as a heuristic, count every transaction in the package as an
ancestor and descendant of every other transaction in the package.
This may overestimate, but will not underestimate, the
ancestor/descendant counts. This shortcut still produces an accurate
count for packages of 1 parent + 1 child.
Diffstat (limited to 'src')
-rw-r--r-- | src/txmempool.cpp | 35 | ||||
-rw-r--r-- | src/txmempool.h | 23 |
2 files changed, 58 insertions, 0 deletions
diff --git a/src/txmempool.cpp b/src/txmempool.cpp index 4a992bf2a4..d5a888ac67 100644 --- a/src/txmempool.cpp +++ b/src/txmempool.cpp @@ -200,6 +200,41 @@ bool CTxMemPool::CalculateAncestorsAndCheckLimits(size_t entry_size, return true; } +bool CTxMemPool::CheckPackageLimits(const Package& package, + uint64_t limitAncestorCount, + uint64_t limitAncestorSize, + uint64_t limitDescendantCount, + uint64_t limitDescendantSize, + std::string &errString) const +{ + CTxMemPoolEntry::Parents staged_ancestors; + size_t total_size = 0; + for (const auto& tx : package) { + total_size += GetVirtualTransactionSize(*tx); + for (const auto& input : tx->vin) { + std::optional<txiter> piter = GetIter(input.prevout.hash); + if (piter) { + staged_ancestors.insert(**piter); + if (staged_ancestors.size() + package.size() > limitAncestorCount) { + errString = strprintf("too many unconfirmed parents [limit: %u]", limitAncestorCount); + return false; + } + } + } + } + // When multiple transactions are passed in, the ancestors and descendants of all transactions + // considered together must be within limits even if they are not interdependent. This may be + // stricter than the limits for each individual transaction. + setEntries setAncestors; + const auto ret = CalculateAncestorsAndCheckLimits(total_size, package.size(), + setAncestors, staged_ancestors, + limitAncestorCount, limitAncestorSize, + limitDescendantCount, limitDescendantSize, errString); + // It's possible to overestimate the ancestor/descendant totals. + if (!ret) errString.insert(0, "possibly "); + return ret; +} + bool CTxMemPool::CalculateMemPoolAncestors(const CTxMemPoolEntry &entry, setEntries &setAncestors, uint64_t limitAncestorCount, diff --git a/src/txmempool.h b/src/txmempool.h index 71345ffb5d..0a84a6e6b1 100644 --- a/src/txmempool.h +++ b/src/txmempool.h @@ -18,6 +18,7 @@ #include <coins.h> #include <indirectmap.h> #include <policy/feerate.h> +#include <policy/packages.h> #include <primitives/transaction.h> #include <random.h> #include <sync.h> @@ -700,6 +701,28 @@ public: */ bool CalculateMemPoolAncestors(const CTxMemPoolEntry& entry, setEntries& setAncestors, uint64_t limitAncestorCount, uint64_t limitAncestorSize, uint64_t limitDescendantCount, uint64_t limitDescendantSize, std::string& errString, bool fSearchForParents = true) const EXCLUSIVE_LOCKS_REQUIRED(cs); + /** Calculate all in-mempool ancestors of a set of transactions not already in the mempool and + * check ancestor and descendant limits. Heuristics are used to estimate the ancestor and + * descendant count of all entries if the package were to be added to the mempool. The limits + * are applied to the union of all package transactions. For example, if the package has 3 + * transactions and limitAncestorCount = 25, the union of all 3 sets of ancestors (including the + * transactions themselves) must be <= 22. + * @param[in] package Transaction package being evaluated for acceptance + * to mempool. The transactions need not be direct + * ancestors/descendants of each other. + * @param[in] limitAncestorCount Max number of txns including ancestors. + * @param[in] limitAncestorSize Max virtual size including ancestors. + * @param[in] limitDescendantCount Max number of txns including descendants. + * @param[in] limitDescendantSize Max virtual size including descendants. + * @param[out] errString Populated with error reason if a limit is hit. + */ + bool CheckPackageLimits(const Package& package, + uint64_t limitAncestorCount, + uint64_t limitAncestorSize, + uint64_t limitDescendantCount, + uint64_t limitDescendantSize, + std::string &errString) const EXCLUSIVE_LOCKS_REQUIRED(cs); + /** Populate setDescendants with all in-mempool descendants of hash. * Assumes that setDescendants includes all in-mempool descendants of anything * already in it. */ |