Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Don't unnecessarily read string offsets when doing concatenate overflow checking. #8968

Merged
merged 2 commits into from
Aug 6, 2021
Merged

Don't unnecessarily read string offsets when doing concatenate overflow checking. #8968

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
73ebadc
During overflow checking, if we are dealing with unsliced columns, do…
nvdbaranec Aug 5, 2021
124272d
Flipped the logic on the is-unsliced check.
nvdbaranec Aug 5, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
17 changes: 12 additions & 5 deletions cpp/src/copying/concatenate.cu
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -374,11 +374,18 @@ void traverse_children::operator()<cudf::string_view>(host_span<column_view cons
size_t const total_char_count = std::accumulate(
cols.begin(), cols.end(), std::size_t{}, [stream](size_t a, auto const& b) -> size_t {
strings_column_view scv(b);
return a + (b.is_empty()
? 0
: cudf::detail::get_value<offset_type>(
scv.offsets(), scv.offset() + b.size(), stream) -
cudf::detail::get_value<offset_type>(scv.offsets(), scv.offset(), stream));
return a + (scv.is_empty() ? 0
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Not urgent but this feels ripe for refactoring to a lambda given we have dual nested ternary statements.

something like

auto computed_length = [](...)
{
....
}; 
return a + (scv.is_empty() ? 0 : computed_length);

// if the column is unsliced, skip the offset retrieval.
: scv.offset() > 0
? cudf::detail::get_value<offset_type>(
scv.offsets(), scv.offset() + scv.size(), stream) -
cudf::detail::get_value<offset_type>(scv.offsets(), scv.offset(), stream)
// if the offset() is 0, it can still be sliced to a shorter length. in this case
// we only need to read a single offset. otherwise just return the full length
// (chars_size())
: scv.size() + 1 == scv.offsets().size()
? scv.chars_size()
: cudf::detail::get_value<offset_type>(scv.offsets(), scv.size(), stream));
});
// note: output text must include "exceeds size_type range" for python error handling
CUDF_EXPECTS(total_char_count <= static_cast<size_t>(std::numeric_limits<size_type>::max()),
Expand Down