* Memory mapped file, single-pass parsing, custom hash map, fixed thread pool
The threading was a hasty addition and needs work
* Used arraylist instead of treemap to reduce a little overhead
We only need it sorted for output, so only construct a treemap for output
* Attempt to speed up double conversion
* Cap core count for low-core systems
* Fix wrong exponent
* Accumulate measurement value in double, seems marginally faster
Benchmark Mode Cnt Score Error Units
DoubleParsingBenchmark.ourToDouble thrpt 10 569.771 ± 7.065 ops/us
DoubleParsingBenchmark.ourToDoubleAccumulateInToDouble thrpt 10 648.026 ± 7.741 ops/us
DoubleParsingBenchmark.ourToDoubleDivideInsteadOfMultiply thrpt 10 570.412 ± 9.329 ops/us
DoubleParsingBenchmark.ourToDoubleNegative thrpt 10 512.618 ± 8.580 ops/us
DoubleParsingBenchmark.ourToDoubleNegativeAccumulateInToDouble thrpt 10 565.043 ± 18.137 ops/us
DoubleParsingBenchmark.ourToDoubleNegativeDivideInsteadOfMultiply thrpt 10 511.228 ± 13.967 ops/us
DoubleParsingBenchmark.stringToDouble thrpt 10 52.310 ± 1.351 ops/us
DoubleParsingBenchmark.stringToDoubleNegative thrpt 10 50.785 ± 1.252 ops/us
It is useful to debug differences between implementations, e.g.:
```sh
$ while ./create_measurements.sh 1000 && diff <(./calculate_average_royvanrijn.sh 2>/dev/null | ./tocsv.sh) <(./calculate_average.sh 2>/dev/null | ./tocsv.sh) ; do echo OK; done
Created file with 1,000 measurements in 50 ms
60c60
< Bucharest;-2.9;2.9;6.1
---
> Bucharest;-2.9;2.8;6.1
265c265
< Petropavlovsk-Kamchatsky;0.9;9.3;17.7
---
> Petropavlovsk-Kamchatsky;0.9;9.2;17.7
```
For #14
