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Reverse byte order and rename encode_hash_less. #749

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Merged
evoskuil merged 1 commit into from
Apr 7, 2026
+11 −7
Merged

Reverse byte order and rename encode_hash_less. #749

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18 changes: 11 additions & 7 deletions include/bitcoin/database/types.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -62,23 +62,27 @@ struct fee_rate { size_t bytes{}; uint64_t fee{}; };
using fee_rates = std::vector<fee_rate>;
using fee_rate_sets = std::vector<fee_rates>;

struct base16_less
struct encode_hash_less
{
bool operator()(const hash_digest& a, const hash_digest& b) const NOEXCEPT
{
using namespace system;
constexpr auto hi = to_half(byte_bits);
constexpr auto lo = sub1(power2<uint8_t>(hi));

for (size_t byte{}; byte < hash_size; ++byte)
// return encode_hash(a) < encode_hash(a)
for (auto byte{ hash_size }; !is_zero(byte); --byte)
{
const auto hi_a = shift_right(a[byte], hi);
const auto hi_b = shift_right(b[byte], hi);
const auto byte_a = a[sub1(byte)];
const auto byte_b = b[sub1(byte)];

const auto hi_a = shift_right(byte_a, hi);
const auto hi_b = shift_right(byte_b, hi);
if (hi_a != hi_b)
return hi_a < hi_b;

const auto lo_a = bit_and(a[byte], lo);
const auto lo_b = bit_and(b[byte], lo);
const auto lo_a = bit_and(byte_a, lo);
const auto lo_b = bit_and(byte_b, lo);
if (lo_a != lo_b)
return lo_a < lo_b;
}
Expand Down Expand Up @@ -111,7 +115,7 @@ struct history_less
return a.position < b.position;

// Both unconfirmed (0 or max), base16 lexical txid ascending.
return base16_less{}(a.tx.hash(), b.tx.hash());
return encode_hash_less{}(a.tx.hash(), b.tx.hash());
}
};
using histories = std::set<history, history_less>;
Expand Down