bench.md

This is a benchmark of the proposed new utf8 encoding strategy for node.js. The main reason for this is that node needs to have its "own" utf-8 encoder that properly handles surrogate pairs.

Encoding strategies:

• new - Uses the proposed new utf8 encoder and v8::String::Memory api.
• old_nohint - Uses v8::String::WriteUTF8 without the HINT_MANY_WRITES_EXPECTED flag.
• old_hint - Uses v8::String::WriteUTF8 with the HINT_MANY_WRITES_EXPECTED flag. This means that v8 will try to flatten the string before writing. That means that most likely it will look much better than it is in reality, because typical applications don't convert the same string over and over again. This benchmark however does.

String shapes:

• shape: flat - produced by s = some_buffer.toString()
• shape: left-tailed - produced by repeatedly running s = 'abcdefgh' + s;
• shape: right-tailed - produced by repeatedly running s = s + 'abcdefgh';
• shape: tree - produced by repeatedly running s = s + s;

Content:

• ascii - string contains only ascii characters
• single nonascii - string contains exactly one non-ascii character
• mixed - string contains many non-ascii characters

General observations:

• When the string contains only ascii characters the old encoder is unbeatable.
• As soon as unicode characters appear, the new encoder is faster.
• When the string grows beyond 10k and the string contains any non-ascii character, v8's performance becomes extremely bad.

Updated benchmark (29/2)

size: 8, shape: left_tailed, content: ascii, iterations: 10000000
new: 2.412 s    old_nohint: 1.877 s     old_hint: 1.907 s

size: 8, shape: left_tailed, content: single nonascii, iterations: 10000000
new: 2.931 s    old_nohint: 3.084 s     old_hint: 3.085 s

size: 8, shape: left_tailed, content: mixed, iterations: 10000000
new: 2.89 s     old_nohint: 3.008 s     old_hint: 3.067 s

size: 8, shape: right_tailed, content: ascii, iterations: 10000000
new: 2.164 s    old_nohint: 1.89 s      old_hint: 1.9 s

size: 8, shape: right_tailed, content: single nonascii, iterations: 10000000
new: 2.876 s    old_nohint: 3.005 s     old_hint: 3.057 s

size: 8, shape: right_tailed, content: mixed, iterations: 10000000
new: 2.878 s    old_nohint: 3.001 s     old_hint: 3.075 s

size: 16, shape: tree, content: ascii, iterations: 10000000
new: 2.251 s    old_nohint: 2.018 s     old_hint: 2.032 s

size: 16, shape: tree, content: single nonascii, iterations: 10000000
new: 3.152 s    old_nohint: 3.924 s     old_hint: 4.209 s

size: 16, shape: tree, content: mixed, iterations: 10000000
new: 3.457 s    old_nohint: 4.474 s     old_hint: 4.295 s

size: 16, shape: flat, content: ascii, iterations: 10000000
new: 2.122 s    old_nohint: 1.877 s     old_hint: 1.885 s

size: 16, shape: flat, content: single nonascii, iterations: 10000000
new: 3.149 s    old_nohint: 3.957 s     old_hint: 4.017 s

size: 16, shape: flat, content: mixed, iterations: 10000000
new: 3.205 s    old_nohint: 3.988 s     old_hint: 4.036 s

size: 64, shape: left_tailed, content: ascii, iterations: 5000000
new: 1.532 s    old_nohint: 2.247 s     old_hint: 2.246 s

size: 64, shape: left_tailed, content: single nonascii, iterations: 5000000
new: 2.303 s    old_nohint: 5.103 s     old_hint: 5.152 s

size: 64, shape: left_tailed, content: mixed, iterations: 5000000
new: 3.548 s    old_nohint: 6.974 s     old_hint: 5.295 s

size: 64, shape: right_tailed, content: ascii, iterations: 5000000
new: 1.621 s    old_nohint: 1.409 s     old_hint: 1.418 s

size: 64, shape: right_tailed, content: single nonascii, iterations: 5000000
new: 2.514 s    old_nohint: 5.286 s     old_hint: 5.104 s

size: 64, shape: right_tailed, content: mixed, iterations: 5000000
new: 3.609 s    old_nohint: 7.14 s      old_hint: 5.289 s

size: 72, shape: tree, content: ascii, iterations: 5000000
new: 1.717 s    old_nohint: 1.9 s       old_hint: 1.903 s

size: 72, shape: tree, content: single nonascii, iterations: 5000000
new: 2.647 s    old_nohint: 5.044 s     old_hint: 5.575 s

size: 72, shape: tree, content: mixed, iterations: 5000000
new: 3.98 s     old_nohint: 8.452 s     old_hint: 6.022 s

size: 72, shape: flat, content: ascii, iterations: 5000000
new: 1.12 s     old_nohint: 0.97 s      old_hint: 0.974 s

size: 72, shape: flat, content: single nonascii, iterations: 5000000
new: 2.345 s    old_nohint: 5.43 s      old_hint: 5.475 s

size: 72, shape: flat, content: mixed, iterations: 5000000
new: 2.813 s    old_nohint: 5.593 s     old_hint: 5.652 s

size: 512, shape: left_tailed, content: ascii, iterations: 1000000
new: 1.069 s    old_nohint: 2.809 s     old_hint: 2.81 s

size: 512, shape: left_tailed, content: single nonascii, iterations: 1000000
new: 1.843 s    old_nohint: 6.107 s     old_hint: 6.48 s

size: 512, shape: left_tailed, content: mixed, iterations: 1000000
new: 3.87 s     old_nohint: 9.05 s      old_hint: 6.822 s

size: 512, shape: right_tailed, content: ascii, iterations: 1000000
new: 1.274 s    old_nohint: 1.026 s     old_hint: 1.03 s

size: 512, shape: right_tailed, content: single nonascii, iterations: 1000000
new: 2.273 s    old_nohint: 7.059 s     old_hint: 6.473 s

size: 512, shape: right_tailed, content: mixed, iterations: 1000000
new: 4.21 s     old_nohint: 9.97 s      old_hint: 6.848 s

size: 520, shape: tree, content: ascii, iterations: 1000000
new: 1.356 s    old_nohint: 2.32 s      old_hint: 2.311 s

size: 520, shape: tree, content: single nonascii, iterations: 1000000
new: 2.446 s    old_nohint: 6.144 s     old_hint: 6.628 s

size: 520, shape: tree, content: mixed, iterations: 1000000
new: 4.829 s    old_nohint: 11.454 s    old_hint: 6.912 s

size: 520, shape: flat, content: ascii, iterations: 1000000
new: 0.318 s    old_nohint: 0.209 s     old_hint: 0.21 s

size: 520, shape: flat, content: single nonascii, iterations: 1000000
new: 1.549 s    old_nohint: 6.583 s     old_hint: 6.607 s

size: 520, shape: flat, content: mixed, iterations: 1000000
new: 2.616 s    old_nohint: 6.89 s      old_hint: 6.889 s

size: 4096, shape: left_tailed, content: ascii, iterations: 200000
new: 1.423 s    old_nohint: 4.152 s     old_hint: 4.158 s

size: 4096, shape: left_tailed, content: single nonascii, iterations: 200000
new: 2.504 s    old_nohint: 9.505 s     old_hint: 9.664 s

size: 4096, shape: left_tailed, content: mixed, iterations: 200000
new: 5.471 s    old_nohint: 14.7 s      old_hint: 10.109 s

size: 4096, shape: right_tailed, content: ascii, iterations: 200000
new: 1.719 s    old_nohint: 1.399 s     old_hint: 1.397 s

size: 4096, shape: right_tailed, content: single nonascii, iterations: 200000
new: 3.141 s    old_nohint: 10.98 s     old_hint: 9.683 s

size: 4096, shape: right_tailed, content: mixed, iterations: 200000
new: 6.218 s    old_nohint: 17.037 s    old_hint: 10.173 s

size: 4104, shape: tree, content: ascii, iterations: 200000
new: 1.885 s    old_nohint: 3.441 s     old_hint: 3.439 s

size: 4104, shape: tree, content: single nonascii, iterations: 200000
new: 3.377 s    old_nohint: 8.822 s     old_hint: 9.683 s

size: 4104, shape: tree, content: mixed, iterations: 200000
new: 6.881 s    old_nohint: 17.913 s    old_hint: 10.219 s

size: 4104, shape: flat, content: ascii, iterations: 200000
new: 0.209 s    old_nohint: 0.072 s     old_hint: 0.072 s

size: 4104, shape: flat, content: single nonascii, iterations: 200000
new: 2.053 s    old_nohint: 9.686 s     old_hint: 9.687 s

size: 4104, shape: flat, content: mixed, iterations: 200000
new: 3.449 s    old_nohint: 10.207 s    old_hint: 10.161 s

size: 32768, shape: left_tailed, content: ascii, iterations: 20000
new: 1.056 s    old_nohint: 3.132 s     old_hint: 3.131 s

size: 32768, shape: left_tailed, content: single nonascii, iterations: 20000
new: 1.897 s    old_nohint: 10.655 s    old_hint: 7.623 s

size: 32768, shape: left_tailed, content: mixed, iterations: 20000
new: 4.312 s    old_nohint: 16.506 s    old_hint: 8.181 s

size: 32768, shape: right_tailed, content: ascii, iterations: 20000
new: 1.42 s     old_nohint: 1.082 s     old_hint: 1.098 s

size: 32768, shape: right_tailed, content: single nonascii, iterations: 20000
new: 2.63 s     old_nohint: 12.007 s    old_hint: 7.608 s

size: 32768, shape: right_tailed, content: mixed, iterations: 20000
new: 5.074 s    old_nohint: 18.602 s    old_hint: 8.006 s

size: 32776, shape: tree, content: ascii, iterations: 20000
new: 1.428 s    old_nohint: 2.692 s     old_hint: 2.695 s

size: 32776, shape: tree, content: single nonascii, iterations: 20000
new: 2.58 s     old_nohint: 6.889 s     old_hint: 7.63 s

size: 32776, shape: tree, content: mixed, iterations: 20000
new: 5.359 s    old_nohint: 14.128 s    old_hint: 8.015 s

size: 32776, shape: flat, content: ascii, iterations: 20000
new: 0.142 s    old_nohint: 0.046 s     old_hint: 0.045 s

size: 32776, shape: flat, content: single nonascii, iterations: 20000
new: 1.567 s    old_nohint: 7.606 s     old_hint: 7.613 s

size: 32776, shape: flat, content: mixed, iterations: 20000
new: 2.681 s    old_nohint: 8.009 s     old_hint: 8.013 s

size: 262144, shape: left_tailed, content: ascii, iterations: 2000
new: 0.827 s    old_nohint: 2.075 s     old_hint: 2.042 s

size: 262144, shape: left_tailed, content: single nonascii, iterations: 2000
new: 1.498 s    old_nohint: 29.098 s    old_hint: 6.067 s

size: 262144, shape: left_tailed, content: mixed, iterations: 2000
new: 3.429 s    old_nohint: 43.923 s    old_hint: 6.374 s

size: 262144, shape: right_tailed, content: ascii, iterations: 2000
new: 1.124 s    old_nohint: 0.85 s      old_hint: 0.853 s

size: 262144, shape: right_tailed, content: single nonascii, iterations: 2000
new: 2.095 s    old_nohint: 30.873 s    old_hint: 6.07 s

size: 262144, shape: right_tailed, content: mixed, iterations: 2000
new: 4.075 s    old_nohint: 46.872 s    old_hint: 6.391 s

size: 262152, shape: tree, content: ascii, iterations: 2000
new: 1.124 s    old_nohint: 2.154 s     old_hint: 2.151 s

size: 262152, shape: tree, content: single nonascii, iterations: 2000
new: 2.046 s    old_nohint: 5.537 s     old_hint: 6.115 s

size: 262152, shape: tree, content: mixed, iterations: 2000
new: 4.267 s    old_nohint: 11.451 s    old_hint: 6.424 s

size: 262152, shape: flat, content: ascii, iterations: 2000
new: 0.105 s    old_nohint: 0.047 s     old_hint: 0.047 s

size: 262152, shape: flat, content: single nonascii, iterations: 2000
new: 1.234 s    old_nohint: 6.079 s     old_hint: 6.086 s

size: 262152, shape: flat, content: mixed, iterations: 2000
new: 2.133 s    old_nohint: 6.417 s     old_hint: 6.392 s

size: 2097152, shape: left_tailed, content: ascii, iterations: 300
new: 1.156 s    old_nohint: 2.058 s     old_hint: 2.051 s

size: 2097152, shape: left_tailed, content: single nonascii, iterations: 300
new: 1.991 s    old_nohint: 241.691 s   old_hint: 7.46 s

size: 2097152, shape: left_tailed, content: mixed, iterations: 300
new: 4.324 s    old_nohint: ^C

First benchmark (28/2)

size: 8, shape: left_tailed, content: ascii, iterations: 10000000
new: 2.113 s    old_nohint: 1.848 s     old_hint: 1.836 s

size: 8, shape: left_tailed, content: single nonascii, iterations: 10000000
new: 2.891 s    old_nohint: 2.885 s     old_hint: 2.916 s

size: 8, shape: left_tailed, content: mixed, iterations: 10000000
new: 2.888 s    old_nohint: 2.88 s      old_hint: 2.914 s

size: 8, shape: right_tailed, content: ascii, iterations: 10000000
new: 2.082 s    old_nohint: 1.828 s     old_hint: 1.83 s

size: 8, shape: right_tailed, content: single nonascii, iterations: 10000000
new: 2.886 s    old_nohint: 2.877 s     old_hint: 2.91 s

size: 8, shape: right_tailed, content: mixed, iterations: 10000000
new: 2.895 s    old_nohint: 2.872 s     old_hint: 2.915 s

size: 16, shape: tree, content: ascii, iterations: 10000000
new: 2.229 s    old_nohint: 1.979 s     old_hint: 1.972 s

size: 16, shape: tree, content: single nonascii, iterations: 10000000
new: 3.165 s    old_nohint: 3.724 s     old_hint: 3.937 s

size: 16, shape: tree, content: mixed, iterations: 10000000
new: 3.554 s    old_nohint: 4.253 s     old_hint: 3.984 s

size: 16, shape: flat, content: ascii, iterations: 10000000
new: 2.105 s    old_nohint: 1.842 s     old_hint: 1.834 s

size: 16, shape: flat, content: single nonascii, iterations: 10000000
new: 3.255 s    old_nohint: 3.714 s     old_hint: 3.751 s

size: 16, shape: flat, content: mixed, iterations: 10000000
new: 3.311 s    old_nohint: 3.751 s     old_hint: 3.809 s

size: 64, shape: left_tailed, content: ascii, iterations: 5000000
new: 1.51 s     old_nohint: 1.552 s     old_hint: 1.543 s

size: 64, shape: left_tailed, content: single nonascii, iterations: 5000000
new: 2.286 s    old_nohint: 4.86 s      old_hint: 4.798 s

size: 64, shape: left_tailed, content: mixed, iterations: 5000000
new: 3.783 s    old_nohint: 6.482 s     old_hint: 4.955 s

size: 64, shape: right_tailed, content: ascii, iterations: 5000000
new: 1.585 s    old_nohint: 1.381 s     old_hint: 1.386 s

size: 64, shape: right_tailed, content: single nonascii, iterations: 5000000
new: 2.472 s    old_nohint: 5.051 s     old_hint: 4.713 s

size: 64, shape: right_tailed, content: mixed, iterations: 5000000
new: 3.865 s    old_nohint: 6.583 s     old_hint: 4.963 s

size: 72, shape: tree, content: ascii, iterations: 5000000
new: 1.746 s    old_nohint: 2.115 s     old_hint: 2.119 s

size: 72, shape: tree, content: single nonascii, iterations: 5000000
new: 2.606 s    old_nohint: 5.054 s     old_hint: 5.193 s

size: 72, shape: tree, content: mixed, iterations: 5000000
new: 4.684 s    old_nohint: 8.018 s     old_hint: 5.321 s

size: 72, shape: flat, content: ascii, iterations: 5000000
new: 1.147 s    old_nohint: 0.961 s     old_hint: 0.957 s

size: 72, shape: flat, content: single nonascii, iterations: 5000000
new: 2.568 s    old_nohint: 5.058 s     old_hint: 5.065 s

size: 72, shape: flat, content: mixed, iterations: 5000000
new: 3.2 s      old_nohint: 5.236 s     old_hint: 5.269 s

size: 512, shape: left_tailed, content: ascii, iterations: 1000000
new: 1.024 s    old_nohint: 1.037 s     old_hint: 1.031 s

size: 512, shape: left_tailed, content: single nonascii, iterations: 1000000
new: 1.781 s    old_nohint: 5.952 s     old_hint: 6.138 s

size: 512, shape: left_tailed, content: mixed, iterations: 1000000
new: 4.439 s    old_nohint: 8.472 s     old_hint: 6.456 s

size: 512, shape: right_tailed, content: ascii, iterations: 1000000
new: 1.196 s    old_nohint: 1.007 s     old_hint: 1.007 s

size: 512, shape: right_tailed, content: single nonascii, iterations: 1000000
new: 2.152 s    old_nohint: 6.821 s     old_hint: 6.119 s

size: 512, shape: right_tailed, content: mixed, iterations: 1000000
new: 5.146 s    old_nohint: 9.494 s     old_hint: 6.495 s

size: 520, shape: tree, content: ascii, iterations: 1000000
new: 1.288 s    old_nohint: 2.667 s     old_hint: 2.691 s

size: 520, shape: tree, content: single nonascii, iterations: 1000000
new: 2.214 s    old_nohint: 5.938 s     old_hint: 6.269 s

size: 520, shape: tree, content: mixed, iterations: 1000000
new: 5.62 s     old_nohint: 11.128 s    old_hint: 6.544 s

size: 520, shape: flat, content: ascii, iterations: 1000000
new: 0.33 s     old_nohint: 0.208 s     old_hint: 0.207 s

size: 520, shape: flat, content: single nonascii, iterations: 1000000
new: 1.946 s    old_nohint: 6.229 s     old_hint: 6.244 s

size: 520, shape: flat, content: mixed, iterations: 1000000
new: 3.061 s    old_nohint: 6.471 s     old_hint: 6.458 s

size: 4096, shape: left_tailed, content: ascii, iterations: 200000
new: 1.44 s     old_nohint: 1.422 s     old_hint: 1.42 s

size: 4096, shape: left_tailed, content: single nonascii, iterations: 200000
new: 2.457 s    old_nohint: 9.232 s     old_hint: 9.214 s

size: 4096, shape: left_tailed, content: mixed, iterations: 200000
new: 6.527 s    old_nohint: 13.933 s    old_hint: 9.669 s

size: 4096, shape: right_tailed, content: ascii, iterations: 200000
new: 1.643 s    old_nohint: 1.435 s     old_hint: 1.442 s

size: 4096, shape: right_tailed, content: single nonascii, iterations: 200000
new: 2.966 s    old_nohint: 10.505 s    old_hint: 9.194 s

size: 4096, shape: right_tailed, content: mixed, iterations: 200000
new: 7.051 s    old_nohint: 16.332 s    old_hint: 9.693 s

size: 4104, shape: tree, content: ascii, iterations: 200000
new: 1.784 s    old_nohint: 4.177 s     old_hint: 4.165 s

size: 4104, shape: tree, content: single nonascii, iterations: 200000
new: 3.233 s    old_nohint: 8.568 s     old_hint: 9.235 s

size: 4104, shape: tree, content: mixed, iterations: 200000
new: 7.538 s    old_nohint: 17.256 s    old_hint: 9.73 s

size: 4104, shape: flat, content: ascii, iterations: 200000
new: 0.208 s    old_nohint: 0.07 s      old_hint: 0.07 s

size: 4104, shape: flat, content: single nonascii, iterations: 200000
new: 2.703 s    old_nohint: 9.203 s     old_hint: 9.217 s

size: 4104, shape: flat, content: mixed, iterations: 200000
new: 4.456 s    old_nohint: 9.704 s     old_hint: 9.71 s

size: 32768, shape: left_tailed, content: ascii, iterations: 20000
new: 1.05 s     old_nohint: 1.077 s     old_hint: 1.079 s

size: 32768, shape: left_tailed, content: single nonascii, iterations: 20000
new: 1.883 s    old_nohint: 10.275 s    old_hint: 7.161 s

size: 32768, shape: left_tailed, content: mixed, iterations: 20000
new: 5.037 s    old_nohint: 15.538 s    old_hint: 7.586 s

size: 32768, shape: right_tailed, content: ascii, iterations: 20000
new: 1.362 s    old_nohint: 1.074 s     old_hint: 1.075 s

size: 32768, shape: right_tailed, content: single nonascii, iterations: 20000
new: 2.46 s     old_nohint: 11.396 s    old_hint: 7.152 s

size: 32768, shape: right_tailed, content: mixed, iterations: 20000
new: 5.492 s    old_nohint: 17.714 s    old_hint: 7.58 s

size: 32776, shape: tree, content: ascii, iterations: 20000
new: 1.384 s    old_nohint: 3.238 s     old_hint: 3.243 s

size: 32776, shape: tree, content: single nonascii, iterations: 20000
new: 2.465 s    old_nohint: 6.664 s     old_hint: 7.161 s

size: 32776, shape: tree, content: mixed, iterations: 20000
new: 5.826 s    old_nohint: 13.516 s    old_hint: 7.598 s

size: 32776, shape: flat, content: ascii, iterations: 20000
new: 0.147 s    old_nohint: 0.045 s     old_hint: 0.043 s

size: 32776, shape: flat, content: single nonascii, iterations: 20000
new: 2.049 s    old_nohint: 7.129 s     old_hint: 7.134 s

size: 32776, shape: flat, content: mixed, iterations: 20000
new: 3.492 s    old_nohint: 7.598 s     old_hint: 7.568 s

size: 262144, shape: left_tailed, content: ascii, iterations: 2000
new: 0.813 s    old_nohint: 0.841 s     old_hint: 0.837 s

size: 262144, shape: left_tailed, content: single nonascii, iterations: 2000
new: 1.459 s    old_nohint: 27.958 s    old_hint: 5.653 s

size: 262144, shape: left_tailed, content: mixed, iterations: 2000
new: 4.039 s    old_nohint: 42.708 s    old_hint: 6.165 s

size: 262144, shape: right_tailed, content: ascii, iterations: 2000
new: 1.091 s    old_nohint: 0.843 s     old_hint: 0.843 s

size: 262144, shape: right_tailed, content: single nonascii, iterations: 2000
new: 1.985 s    old_nohint: 30.413 s    old_hint: 5.675 s

size: 262144, shape: right_tailed, content: mixed, iterations: 2000
new: 4.348 s    old_nohint: 45.028 s    old_hint: 6.027 s

size: 262152, shape: tree, content: ascii, iterations: 2000
new: 1.066 s    old_nohint: 2.539 s     old_hint: 2.548 s

size: 262152, shape: tree, content: single nonascii, iterations: 2000
new: 1.927 s    old_nohint: 5.271 s     old_hint: 5.664 s

size: 262152, shape: tree, content: mixed, iterations: 2000
new: 4.579 s    old_nohint: 10.792 s    old_hint: 6.094 s

size: 262152, shape: flat, content: ascii, iterations: 2000
new: 0.105 s    old_nohint: 0.046 s     old_hint: 0.046 s

size: 262152, shape: flat, content: single nonascii, iterations: 2000
new: 1.599 s    old_nohint: 5.624 s     old_hint: 5.63 s

size: 262152, shape: flat, content: mixed, iterations: 2000
new: 2.73 s     old_nohint: 6.052 s     old_hint: 6.019 s

size: 2097152, shape: left_tailed, content: ascii, iterations: 300
new: 1.153 s    old_nohint: 1.185 s     old_hint: 1.189 s

size: 2097152, shape: left_tailed, content: single nonascii, iterations: 300
new: 1.964 s    old_nohint: 233.748 s   old_hint: 7.002 s

size: 2097152, shape: left_tailed, content: mixed, iterations: 300
new: 5.013 s    old_nohint: 352.523 s   old_hint: 7.452 s

size: 2097152, shape: right_tailed, content: ascii, iterations: 300
new: 1.49 s     old_nohint: 1.179 s     old_hint: 1.18 s

size: 2097152, shape: right_tailed, content: single nonascii, iterations: 300
new: 2.571 s    old_nohint: 245.769 s   old_hint: 6.971 s

size: 2097152, shape: right_tailed, content: mixed, iterations: 300
new: 5.483 s    old_nohint: 362.439 s   old_hint: 7.484 s

size: 2097160, shape: tree, content: ascii, iterations: 300
new: 1.411 s    old_nohint: 3.17 s      old_hint: 3.18 s

size: 2097160, shape: tree, content: single nonascii, iterations: 300
new: 2.437 s    old_nohint: 6.448 s     old_hint: 6.956 s

size: 2097160, shape: tree, content: mixed, iterations: 300
new: 5.677 s    old_nohint: 13.35 s     old_hint: 7.614 s

size: 2097160, shape: flat, content: ascii, iterations: 300
new: 0.254 s    old_nohint: 0.21 s      old_hint: 0.211 s

size: 2097160, shape: flat, content: single nonascii, iterations: 300
new: 2.1 s      old_nohint: 7 s old_hint: 6.914 s

size: 2097160, shape: flat, content: mixed, iterations: 300
new: 3.469 s    old_nohint: 7.463 s     old_hint: 7.456 s

size: 16777216, shape: left_tailed, content: ascii, iterations: 40
new: 1.423 s    old_nohint: 1.265 s     old_hint: 1.262 s

size: 16777216, shape: left_tailed, content: single nonansi, iterations: 40
new: 2.109 s    old_nohint: 2343.456 s  old_hint: 7.837 s

size: 16777216, shape: left_tailed, content: mixed, iterations: 40
new: 5.547 s    old_nohint: ^C