This library implements encoding and decoding a ByteArray into base-16.
We make use of primitive GHC operations including simd operations that GHC currently supports with the llvm backend in order to try to extract the highest performance.
A base-16 encoding takes a stream of bytes which we might think of as base-256 and converts it into an ascii representation of hexadecimal:
┌───────┐ ┌───────┐ ┌───────┐
··· ───│ 129 │───│ 188 │───│ 15 │───···
└───────┘ └───────┘ └───────┘
|| ||
|| encode ||
|| ||
┌───────┐ ┌───────┐ ┌───────┐ ┌───────┐ ┌───────┐ ┌───────┐
··· ───│ '8' │───│ '1' │───│ 'b' │───│ 'c' │───│ '0' │───│ 'f' │───···
└───────┘ └───────┘ └───────┘ └───────┘ └───────┘ └───────┘
Note here that:
129 = 8 * 16 + 1
188 = 11 * 16 + 12
15 = 0 * 16 + 15
There are currently two other libraries that provide these encodings:
Here are the initial benchmarks showing this library's performance compared to these two:
benchmarking base16 benchmarks:/bytes16-encode
time 8.164 μs (8.103 μs .. 8.222 μs)
1.000 R² (0.999 R² .. 1.000 R²)
mean 8.139 μs (8.097 μs .. 8.189 μs)
std dev 155.5 ns (128.2 ns .. 194.9 ns)
variance introduced by outliers: 18% (moderately inflated)
benchmarking base16 benchmarks:/base16-bytestring-encode
time 38.95 μs (38.75 μs .. 39.18 μs)
1.000 R² (0.999 R² .. 1.000 R²)
mean 38.90 μs (38.71 μs .. 39.16 μs)
std dev 771.0 ns (542.0 ns .. 1.220 μs)
variance introduced by outliers: 16% (moderately inflated)
benchmarking base16 benchmarks:/base16-encode
time 9.186 μs (9.121 μs .. 9.292 μs)
0.999 R² (0.997 R² .. 1.000 R²)
mean 9.289 μs (9.185 μs .. 9.493 μs)
std dev 462.8 ns (263.1 ns .. 700.3 ns)
variance introduced by outliers: 61% (severely inflated)
benchmarking base16 benchmarks:/bytes16-decode-encode
time 14.64 μs (14.56 μs .. 14.75 μs)
1.000 R² (0.999 R² .. 1.000 R²)
mean 14.58 μs (14.52 μs .. 14.66 μs)
std dev 235.3 ns (181.6 ns .. 368.0 ns)
variance introduced by outliers: 13% (moderately inflated)
benchmarking base16 benchmarks:/base16-bytestring-decode-encode
time 94.45 μs (93.68 μs .. 95.26 μs)
0.999 R² (0.998 R² .. 1.000 R²)
mean 95.98 μs (94.88 μs .. 98.01 μs)
std dev 4.762 μs (2.825 μs .. 8.233 μs)
variance introduced by outliers: 52% (severely inflated)
benchmarking base16 benchmarks:/base16-decode-encode
time 21.86 μs (21.52 μs .. 22.18 μs)
0.999 R² (0.998 R² .. 1.000 R²)
mean 21.61 μs (21.46 μs .. 21.77 μs)
std dev 509.8 ns (395.2 ns .. 761.4 ns)
variance introduced by outliers: 23% (moderately inflated)
In particular, encoding and decoding is about 4-6x faster than the base16-bytestring library.
work in progress