perf: faster Cache::write_contiguous() (#5715)

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Charles Kerr 2023-07-02 15:23:32 -05:00 committed by GitHub
parent d2d30c2734
commit d76d26a580
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1 changed files with 5 additions and 4 deletions

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@ -74,20 +74,21 @@ int Cache::write_contiguous(CIter const begin, CIter const end) const
if (end - begin > 1)
{
// Yes, there are.
// copy blocks into contiguous memory
auto const buflen = std::accumulate(
begin,
end,
size_t{},
[](size_t sum, auto const& block) { return sum + std::size(*block.buf); });
buf.reserve(buflen);
buf.resize(buflen);
auto* walk = std::data(buf);
for (auto iter = begin; iter != end; ++iter)
{
TR_ASSERT(begin->key.first == iter->key.first);
TR_ASSERT(begin->key.second + std::distance(begin, iter) == iter->key.second);
buf.insert(std::end(buf), std::begin(*iter->buf), std::end(*iter->buf));
walk = std::copy_n(std::data(*iter->buf), std::size(*iter->buf), walk);
}
TR_ASSERT(std::size(buf) == buflen);
TR_ASSERT(std::data(buf) + std::size(buf) == walk);
out = std::data(buf);
outlen = std::size(buf);
}