Benchmark GeoTIFF read speeds

[weiji14]

Measuring how fast it takes to read GeoTIFF files (in terms of duration/time and throughput), setting up a baseline level of performance as we work towards addressing #5.

• Using three 50MB GeoTIFF files from https://github.com/kokoalberti/geotiff-benchmark of dtype u8, i16 and f32
• Set up CI to run the criterion.rs benchmarks that will be tracked on Codspeed over time
  • Note that the benchmarks will only run on PRs labelled run/benchmark, on the main branch, or on release.

To run locally:

# Download and extract GeoTIFF files
wget https://s3.us-east-2.amazonaws.com/geotiff-benchmark-sample-files/geotiff_sample_files.tar.gz -P resources
tar --extract --verbose --file resources/geotiff_sample_files.tar.gz

# Run benchmarks
cargo bench

Example output on my laptop:

     Running benches/read_geotiff.rs (target/release/deps/read_geotiff-adb36ae75c76df4d)
Gnuplot not found, using plotters backend
read_geotiff_50MB/u8_dtype
                        time:   [15.652 ms 15.730 ms 15.822 ms]
                        thrpt:  [3.1601 GB/s 3.1786 GB/s 3.1945 GB/s]
Found 3 outliers among 100 measurements (3.00%)
  2 (2.00%) high mild
  1 (1.00%) high severe
read_geotiff_50MB/i16_dtype
                        time:   [15.104 ms 15.154 ms 15.207 ms]
                        thrpt:  [3.2879 GB/s 3.2995 GB/s 3.3103 GB/s]
Found 3 outliers among 100 measurements (3.00%)
  1 (1.00%) low mild
  1 (1.00%) high mild
  1 (1.00%) high severe
read_geotiff_50MB/f32_dtype
                        time:   [1.4039 ms 1.4068 ms 1.4099 ms]
                        thrpt:  [35.463 GB/s 35.541 GB/s 35.616 GB/s]
Found 18 outliers among 100 measurements (18.00%)
  4 (4.00%) low severe
  9 (9.00%) low mild
  3 (3.00%) high mild
  2 (2.00%) high severe

References:

• https://kokoalberti.com/articles/geotiff-compression-optimization-guide/
• https://docs.codspeed.io/benchmarks/rust

[weiji14]

Ok, so the Codspeed Action (for tracking benchmarks over time) requires someone with admin permissions to install the CodspeedHQ GitHub App (see docs at https://docs.codspeed.io/importing-repositories). Have requested the install, and will re-run the benchmarks CI once that is enabled.