replace libflate with flate2

[quininer]

flate2 now supports gzip nonblocking decode.

This PR removes some Hacks, and there are some improvements in performance.

    Running target/release/deps/gzip-bf12b85379c041af
flate2                  time:   [54.453 us 54.718 us 55.025 us]
                        change: [+6.9623% +8.3377% +9.5093%] (p = 0.00 < 0.05)
                        Performance has regressed.
Found 6 outliers among 100 measurements (6.00%)
  5 (5.00%) high mild
  1 (1.00%) high severe

libflate                time:   [96.230 us 97.628 us 99.244 us]
                        change: [+1.1208% +3.6339% +6.4683%] (p = 0.01 < 0.05)
                        Performance has regressed.
Found 7 outliers among 100 measurements (7.00%)
  2 (2.00%) high mild
  5 (5.00%) high severe

libflate-nonblocking    time:   [162.50 us 163.17 us 163.92 us]
                        change: [-8.1219% -6.6838% -5.2822%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 13 outliers among 100 measurements (13.00%)
  7 (7.00%) high mild
  6 (6.00%) high severe

libflate-nonblocking-peeked
                        time:   [180.34 us 181.06 us 181.87 us]
                        change: [-8.5667% -7.7753% -6.9742%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 9 outliers among 100 measurements (9.00%)
  4 (4.00%) high mild
  5 (5.00%) high severe

libflate-peeked         time:   [126.75 us 127.74 us 129.08 us]
                        change: [-9.8191% -9.0841% -8.3352%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 6 outliers among 100 measurements (6.00%)
  3 (3.00%) high mild
  3 (3.00%) high severe

[seanmonstar]

This looks exciting! So flate2 fixed its Windows compilation error?

Looks like this is pointing at a branch, once there's a crate.io release, we can merge!

[quininer]

Yes, flate2 now has a pure rust backend.

[seanmonstar]

❤️

[seanmonstar]

Thanks, this is exciting!