Optimize formatting by 80-90% by avoiding write!. #303

Merged

huonw merged 2 commits from string-formatting into master

2018-08-23 01:48:43 -05:00

huonw commented

2018-08-23 00:58:11 -05:00

(Migrated from github.com)

I'm submitting a(n) refactor.

Description

Using a temporary byte buffer along with manual decomposition of the
UUID means the code compiles down to a nice loop, instead of doing
multiple virtual function calls as it does with write!.

Motivation

The code was unnecessarily slow.

Tests

All the existing formatting tests pass, and I introduced a benchmark. Here's the output of cargo benchcmp on before/after results for that benchmark:

name          before.txt ns/iter  after.txt ns/iter  diff ns/iter   diff %  speedup
bench_hyphen  270                 49                         -221  -81.85%   x 5.51
bench_simple  418                 40                         -378  -90.43%  x 10.45
bench_urn     281                 56                         -225  -80.07%   x 5.02

**I'm submitting a(n)** refactor. # Description Using a temporary byte buffer along with manual decomposition of the UUID means the code compiles down to a nice loop, instead of doing multiple virtual function calls as it does with `write!`. # Motivation The code was unnecessarily slow. # Tests All the existing formatting tests pass, and I introduced a benchmark. Here's the output of `cargo benchcmp` on before/after results for that benchmark: name before.txt ns/iter after.txt ns/iter diff ns/iter diff % speedup bench_hyphen 270 49 -221 -81.85% x 5.51 bench_simple 418 40 -378 -90.43% x 10.45 bench_urn 281 56 -225 -80.07% x 5.02

radix (Migrated from github.com) reviewed

2018-08-23 00:58:11 -05:00

Dylan-DPC-zz (Migrated from github.com) reviewed

2018-08-23 00:58:11 -05:00

kinggoesgaming (Migrated from github.com) reviewed

2018-08-23 00:58:11 -05:00

KodrAus commented

2018-08-23 01:42:25 -05:00

(Migrated from github.com)

Looks good to me! Thanks @huonw

bors r+

Looks good to me! Thanks @huonw bors r+

KodrAus (Migrated from github.com) approved these changes

2018-08-23 01:44:11 -05:00

bors[bot] commented

2018-08-23 01:48:42 -05:00

(Migrated from github.com)

Build succeeded

# Build succeeded * [continuous-integration/travis-ci/push](https://travis-ci.org/uuid-rs/uuid/builds/419512259?utm_source=github_status&utm_medium=notification) * [continuous-integration/appveyor/branch](https://ci.appveyor.com/project/KodrAus/uuid/build/1.0.889)