boost/openmethod
2
0
Fork 0
mirror of https://github.com/boostorg/openmethod.git synced 2026-01-19 04:22:12 +00:00
Code Issues Projects Releases Wiki Activity

Fix potential overflow in group hash calculation by using uint32_t multiplier

Browse Source 
Co-authored-by: jll63 <5083077+jll63@users.noreply.github.com>
This commit is contained in:
copilot-swe-agent[bot]
2025-12-18 06:05:28 +00:00
parent 508687c5d7
commit 22673b0f45
1 changed files with 6 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
include/boost/openmethod/policies/minimal_perfect_hash.hpp
View File

@@ -88,7 +88,7 @@ struct minimal_perfect_hash : type_hash {
static std::size_t shift;
static std::size_t table_size; // N for minimal perfect hash
static std::size_t num_groups;
static std::size_t group_mult;
static std::uint32_t group_mult; // Smaller type to avoid overflow
static std::size_t group_shift;
static void check(std::size_t index, type_id type);
@@ -179,7 +179,7 @@ template<class Registry>
std::size_t minimal_perfect_hash::fn<Registry>::num_groups;
template<class Registry>
std::size_t minimal_perfect_hash::fn<Registry>::group_mult;
std::uint32_t minimal_perfect_hash::fn<Registry>::group_mult;
template<class Registry>
std::size_t minimal_perfect_hash::fn<Registry>::group_shift;
@@ -275,7 +275,10 @@ void minimal_perfect_hash::fn<Registry>::initialize(
// Try different pilot hash parameters
for (std::size_t pass = 0; pass < MAX_PASSES && total_attempts < MAX_ATTEMPTS; ++pass) {
mult = uniform_dist(rnd) | 1;
group_mult = uniform_dist(rnd) | 1;
// Use a smaller multiplier for group hash to avoid overflow
// We only need enough bits to distinguish between num_groups
std::uniform_int_distribution<std::uint32_t> group_dist;
group_mult = group_dist(rnd) | 1;
// Calculate M for pilot hash (number of bits for table_size range)
std::size_t M = 0;