From 9b2fdca7f03911ac40fe0f8a0b5da534bee4554b Mon Sep 17 00:00:00 2001 From: glozow Date: Fri, 16 Jul 2021 10:29:11 +0100 Subject: [packages] add static IsChildWithParents function --- src/policy/packages.cpp | 17 +++++++++++++++++ src/policy/packages.h | 6 ++++++ 2 files changed, 23 insertions(+) (limited to 'src/policy') diff --git a/src/policy/packages.cpp b/src/policy/packages.cpp index cfd0539965..21f5488816 100644 --- a/src/policy/packages.cpp +++ b/src/policy/packages.cpp @@ -60,3 +60,20 @@ bool CheckPackage(const Package& txns, PackageValidationState& state) } return true; } + +bool IsChildWithParents(const Package& package) +{ + assert(std::all_of(package.cbegin(), package.cend(), [](const auto& tx){return tx != nullptr;})); + if (package.size() < 2) return false; + + // The package is expected to be sorted, so the last transaction is the child. + const auto& child = package.back(); + std::unordered_set input_txids; + std::transform(child->vin.cbegin(), child->vin.cend(), + std::inserter(input_txids, input_txids.end()), + [](const auto& input) { return input.prevout.hash; }); + + // Every transaction must be a parent of the last transaction in the package. + return std::all_of(package.cbegin(), package.cend() - 1, + [&input_txids](const auto& ptx) { return input_txids.count(ptx->GetHash()) > 0; }); +} diff --git a/src/policy/packages.h b/src/policy/packages.h index 6b7ac3e450..d2744f1265 100644 --- a/src/policy/packages.h +++ b/src/policy/packages.h @@ -41,4 +41,10 @@ class PackageValidationState : public ValidationState { */ bool CheckPackage(const Package& txns, PackageValidationState& state); +/** Context-free check that a package is exactly one child and its parents; not all parents need to + * be present, but the package must not contain any transactions that are not the child's parents. + * It is expected to be sorted, which means the last transaction must be the child. + */ +bool IsChildWithParents(const Package& package); + #endif // BITCOIN_POLICY_PACKAGES_H -- cgit v1.2.3