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Use division to detect unsigned wrap-around

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Reviewers: mislav.bradac, buda

Reviewed By: mislav.bradac

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D550
This commit is contained in:
Teon Banek 2017-07-13 14:39:47 +02:00
parent 99e27cb7e9
commit 387c0621cb
1 changed files with 2 additions and 3 deletions
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5
src/query/plan/variable_start_planner.cpp
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@ -171,13 +171,12 @@ std::uint64_t CartesianProductSize(const std::vector<std::vector<T>> &sets) {
if (set.empty()) { if (set.empty()) {
return 0U; return 0U;
} }
std::uint64_t new_n = n * set.size(); if (std::numeric_limits<std::uint64_t>::max() / n < set.size()) {
if (new_n < n || new_n < set.size()) {
DLOG(WARNING) << "Unsigned wrap-around when calculating expected size of " DLOG(WARNING) << "Unsigned wrap-around when calculating expected size of "
"Cartesian product."; "Cartesian product.";
return std::numeric_limits<std::uint64_t>::max(); return std::numeric_limits<std::uint64_t>::max();
} }
n = new_n; n *= set.size();
} }
return n; return n;
} }