Implements caching for the interpolations

[Radonirinaunimi]

This allows caching the interpolated results through the environment variable NEOPDF_ENABLE_CACHE.

[codecov]

Codecov Report

❌ Patch coverage is 66.66667% with 13 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
neopdf/src/caching.rs	43.47%	13 Missing ⚠️

📢 Thoughts on this report? Let us know!

[github-actions]

🚀 Benchmark Results 🚀

Here are the results from the benchmark run.

xfxq2                   time:   [275.93 ns 276.31 ns 276.77 ns]
Found 15 outliers among 100 measurements (15.00%)
  9 (9.00%) low mild
  3 (3.00%) high mild
  3 (3.00%) high severe

xfxq2s                  time:   [29.043 µs 29.264 µs 29.520 µs]
Found 2 outliers among 100 measurements (2.00%)
  2 (2.00%) high severe

xfxq2_members           time:   [311.10 ps 311.37 ps 311.71 ps]
Found 14 outliers among 100 measurements (14.00%)
  4 (4.00%) high mild
  10 (10.00%) high severe

[github-actions]

🚀 Benchmark Results 🚀

Here are the results from the benchmark run.

xfxq2                   time:   [272.61 ns 272.82 ns 273.07 ns]
                        change: [−1.0945% −0.8480% −0.5902%] (p = 0.00 < 0.05)
                        Change within noise threshold.
Found 5 outliers among 100 measurements (5.00%)
  2 (2.00%) high mild
  3 (3.00%) high severe

xfxq2s                  time:   [29.544 µs 29.641 µs 29.741 µs]
                        change: [−1.4289% +0.8170% +3.1419%] (p = 0.52 > 0.05)
                        No change in performance detected.
Found 26 outliers among 100 measurements (26.00%)
  9 (9.00%) low severe
  5 (5.00%) low mild
  4 (4.00%) high mild
  8 (8.00%) high severe

xfxq2_members           time:   [627.65 ps 631.88 ps 636.54 ps]
                        change: [+100.29% +101.10% +101.88%] (p = 0.00 < 0.05)
                        Performance has regressed.
Found 17 outliers among 100 measurements (17.00%)
  2 (2.00%) high mild
  15 (15.00%) high severe

[Radonirinaunimi]

For the record, this implementation of the caching did not yield better performance.