Option (-o/--output-file) to write output to a file

[dhruvmanila]

Summary

A new CLI option (-o/--output-file) to write output to a file instead of stdout.

Major change is to remove the lock acquired on stdout. The argument is that the output is buffered and thus the lock is acquired only when writing a block (8kb). As per the benchmark below there is a slight performance penalty.

Reference: https://rustmagazine.org/issue-3/javascript-compiler/#printing-is-slow

Benchmarks

Output is truncated to only contain useful information:

Command: check --isolated --no-cache --select=ALL --show-source ./test-repos/cpython"

Latest HEAD (361d45f) with and without the manual lock on stdout:

Benchmark 1: With lock
  Time (mean ± σ):      5.687 s ±  0.075 s    [User: 17.110 s, System: 0.486 s]
  Range (min … max):    5.615 s …  5.860 s    10 runs

Benchmark 2: Without lock
  Time (mean ± σ):      5.719 s ±  0.064 s    [User: 17.095 s, System: 0.491 s]
  Range (min … max):    5.640 s …  5.865 s    10 runs

Summary
  (1) ran 1.01 ± 0.02 times faster than (2)

This PR:

Benchmark 1: This PR
  Time (mean ± σ):      5.855 s ±  0.058 s    [User: 17.197 s, System: 0.491 s]
  Range (min … max):    5.786 s …  5.987 s    10 runs
 
Benchmark 2: Latest HEAD with lock
  Time (mean ± σ):      5.645 s ±  0.033 s    [User: 16.922 s, System: 0.495 s]
  Range (min … max):    5.600 s …  5.712 s    10 runs
 
Summary
  (2) ran 1.04 ± 0.01 times faster than (1)

Test Plan

Run all of the commands which gives output with and without the --output-file=ruff.out option:

• --show-settings
• --show-files
• --show-fixes
• --diff
• --select=ALL
• --select=All --show-source
• --watch (only stdout allowed)

resolves: #4754

[github-actions]

PR Check Results

Ecosystem

✅ ecosystem check detected no changes.

Benchmark

Linux

group                                      main                                   pr
-----                                      ----                                   --
formatter/large/dataset.py                 1.00      6.8±0.02ms     6.0 MB/sec    1.03      6.9±0.02ms     5.9 MB/sec
formatter/numpy/ctypeslib.py               1.00   1369.1±2.92µs    12.2 MB/sec    1.03   1406.0±1.71µs    11.8 MB/sec
formatter/numpy/globals.py                 1.00    133.3±0.29µs    22.1 MB/sec    1.04    138.3±0.43µs    21.3 MB/sec
formatter/pydantic/types.py                1.00      2.8±0.01ms     9.2 MB/sec    1.02      2.8±0.01ms     9.1 MB/sec
linter/all-rules/large/dataset.py          1.00     13.9±0.06ms     2.9 MB/sec    1.04     14.4±0.08ms     2.8 MB/sec
linter/all-rules/numpy/ctypeslib.py        1.00      3.5±0.00ms     4.8 MB/sec    1.03      3.6±0.01ms     4.7 MB/sec
linter/all-rules/numpy/globals.py          1.00    364.0±1.40µs     8.1 MB/sec    1.01    367.0±1.12µs     8.0 MB/sec
linter/all-rules/pydantic/types.py         1.00      6.1±0.02ms     4.2 MB/sec    1.01      6.2±0.02ms     4.1 MB/sec
linter/default-rules/large/dataset.py      1.00      7.1±0.02ms     5.7 MB/sec    1.04      7.4±0.02ms     5.5 MB/sec
linter/default-rules/numpy/ctypeslib.py    1.00   1486.4±2.80µs    11.2 MB/sec    1.04   1540.7±3.16µs    10.8 MB/sec
linter/default-rules/numpy/globals.py      1.00    159.5±0.21µs    18.5 MB/sec    1.04    165.2±0.12µs    17.9 MB/sec
linter/default-rules/pydantic/types.py     1.00      3.2±0.01ms     7.9 MB/sec    1.04      3.3±0.02ms     7.6 MB/sec

Windows

group                                      main                                   pr
-----                                      ----                                   --
formatter/large/dataset.py                 1.04     10.6±0.47ms     3.8 MB/sec    1.00     10.2±0.54ms     4.0 MB/sec
formatter/numpy/ctypeslib.py               1.05      2.1±0.09ms     7.8 MB/sec    1.00      2.0±0.09ms     8.2 MB/sec
formatter/numpy/globals.py                 1.05   227.7±15.42µs    13.0 MB/sec    1.00   217.8±14.80µs    13.5 MB/sec
formatter/pydantic/types.py                1.02      4.4±0.19ms     5.8 MB/sec    1.00      4.3±0.18ms     5.9 MB/sec
linter/all-rules/large/dataset.py          1.00     20.4±0.81ms  2047.1 KB/sec    1.03     20.9±0.74ms  1990.0 KB/sec
linter/all-rules/numpy/ctypeslib.py        1.01      5.5±0.21ms     3.0 MB/sec    1.00      5.5±0.20ms     3.0 MB/sec
linter/all-rules/numpy/globals.py          1.04   691.0±48.25µs     4.3 MB/sec    1.00   663.1±46.81µs     4.4 MB/sec
linter/all-rules/pydantic/types.py         1.06      9.6±0.38ms     2.7 MB/sec    1.00      9.1±0.40ms     2.8 MB/sec
linter/default-rules/large/dataset.py      1.01     11.2±0.32ms     3.6 MB/sec    1.00     11.1±0.43ms     3.7 MB/sec
linter/default-rules/numpy/ctypeslib.py    1.00      2.3±0.21ms     7.1 MB/sec    1.00      2.3±0.10ms     7.1 MB/sec
linter/default-rules/numpy/globals.py      1.05   285.8±13.64µs    10.3 MB/sec    1.00   271.0±14.19µs    10.9 MB/sec
linter/default-rules/pydantic/types.py     1.01      5.0±0.53ms     5.1 MB/sec    1.00      4.9±0.15ms     5.2 MB/sec

[MichaReiser]

Sorry for the back and forth and thanks for working on this.

[dhruvmanila]

Sorry for the back and forth and thanks for working on this.

No problem at all! Thanks for being patient and answering all of my questions ;)

[TalAmuyal]

Thanks!