ruby-grape / grape / 34777960477

99%

master: 99%

Pull #2943

github

Speed up matching among many parameterized routes

A request the static table cannot answer is matched against its method's
whole union: every route's pattern, each expanding every literal character
into an alternation with its percent-encodings. On an API with 200
parameterized routes that match is most of the request -- 43-53 µs of
~68 µs without a JIT -- and it grows with every route registered ahead of
the one that matches.

A route that spells out a literal at some path segment, with only literals
and plain params ahead of it, can only match paths carrying that literal
there. Router#compile! now picks, per method, the segment position that
splits the routes best and builds one union per literal there. Each holds
the routes that literal names plus every route the segment cannot tell
apart, in registration order, so matching a request against the union for
its own segment picks the route the full union would have picked.

Paths holding a '%' (a literal may match its percent-encoding) or a newline
(the patterns end in \Z) still go through the full union, as do methods
with fewer than eight routes or with no segment that halves them. A route
matched through a bucket reads its params off its own pattern, since its
capture groups are numbered for the full union.

The buckets ride in the per-method entry #transaction already reads, so a
method without them pays no extra lookup. A bucket whose alternatives
another method already compiled -- the HEAD routes mirroring GET's --
reuses that union instead of compiling it again.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

1411 of 1465 branches covered (96.31%)

Branch coverage included in aggregate %.

87 of 87 new or added lines in 2 files covered. (100.0%)

4238 of 4238 relevant lines covered (100.0%)

27816.16 hits per line