| commit | 64cb04e86054b58b5c3658c2d7dfbdbb81753f05 | [log] [tgz] |
|---|---|---|
| author | Joe Tsai <joetsai@digital-static.net> | Wed Feb 27 10:28:44 2019 -0800 |
| committer | GitHub <noreply@github.com> | Wed Feb 27 10:28:44 2019 -0800 |
| tree | 973d7739896348c9c086b9aa59e4602143d84710 | |
| parent | fd81a2bda5e4727f3671d01a5a3c1d54be06f19d [diff] |
Add BenchmarkBytes (#125)
Add a benchmark that uses cmp.{Equal,Diff} to measure performance of
comparing large byte slices. Comparing large slices of primitives is
generally considered the most pathological use-case for cmp since the
rules of cmp dictate that it must run the filters on every element
of the slice even if the filters never apply.
In theory, a user of cmp could short-circuit comparison of slices by
providing a comparer for slices (e.g., cmp.Comparer(bytes.Equal)),
but it would be ideal for cmp to be sufficiently optimized that comparing
large slices is not too costly.
BenchmarkBytes/4KiB/EqualFilter0-4 300 3792755 ns/op 2.16 MB/s 628702 B/op 8276 allocs/op
BenchmarkBytes/4KiB/EqualFilter1-4 200 6058637 ns/op 1.35 MB/s 890920 B/op 16471 allocs/op
BenchmarkBytes/4KiB/EqualFilter2-4 200 7498098 ns/op 1.09 MB/s 890952 B/op 16472 allocs/op
BenchmarkBytes/4KiB/EqualFilter3-4 100 10094237 ns/op 0.81 MB/s 891016 B/op 16473 allocs/op
BenchmarkBytes/4KiB/EqualFilter4-4 100 11128655 ns/op 0.74 MB/s 891016 B/op 16473 allocs/op
BenchmarkBytes/4KiB/EqualFilter5-4 100 12952062 ns/op 0.63 MB/s 891144 B/op 16474 allocs/op
BenchmarkBytes/4KiB/DiffFilter0-4 300 4015119 ns/op 2.04 MB/s 629425 B/op 8305 allocs/op
BenchmarkBytes/4KiB/DiffFilter1-4 200 6457963 ns/op 1.27 MB/s 891738 B/op 16501 allocs/op
BenchmarkBytes/4KiB/DiffFilter2-4 200 8371022 ns/op 0.98 MB/s 891770 B/op 16502 allocs/op
BenchmarkBytes/4KiB/DiffFilter3-4 200 9420398 ns/op 0.87 MB/s 891834 B/op 16503 allocs/op
BenchmarkBytes/4KiB/DiffFilter4-4 100 12493540 ns/op 0.66 MB/s 891835 B/op 16503 allocs/op
BenchmarkBytes/4KiB/DiffFilter5-4 100 14208928 ns/op 0.58 MB/s 891965 B/op 16504 allocs/op
BenchmarkBytes/64KiB/EqualFilter0-4 20 66146276 ns/op 1.98 MB/s 10826734 B/op 131206 allocs/op
BenchmarkBytes/64KiB/EqualFilter1-4 10 102687117 ns/op 1.28 MB/s 15021123 B/op 262281 allocs/op
BenchmarkBytes/64KiB/EqualFilter2-4 10 125444269 ns/op 1.04 MB/s 15021174 B/op 262282 allocs/op
BenchmarkBytes/64KiB/EqualFilter3-4 10 154392619 ns/op 0.85 MB/s 15021219 B/op 262283 allocs/op
BenchmarkBytes/64KiB/EqualFilter4-4 10 183307772 ns/op 0.72 MB/s 15021219 B/op 262283 allocs/op
BenchmarkBytes/64KiB/EqualFilter5-4 5 212334761 ns/op 0.62 MB/s 15021340 B/op 262284 allocs/op
BenchmarkBytes/64KiB/DiffFilter0-4 20 67147375 ns/op 1.95 MB/s 10828312 B/op 131244 allocs/op
BenchmarkBytes/64KiB/DiffFilter1-4 10 105385709 ns/op 1.24 MB/s 15022724 B/op 262319 allocs/op
BenchmarkBytes/64KiB/DiffFilter2-4 10 135994379 ns/op 0.96 MB/s 15022763 B/op 262320 allocs/op
BenchmarkBytes/64KiB/DiffFilter3-4 10 159346836 ns/op 0.82 MB/s 15022820 B/op 262321 allocs/op
BenchmarkBytes/64KiB/DiffFilter4-4 10 190129916 ns/op 0.69 MB/s 15022843 B/op 262321 allocs/op
BenchmarkBytes/64KiB/DiffFilter5-4 5 208805873 ns/op 0.63 MB/s 15022996 B/op 262322 allocs/op
BenchmarkBytes/1MiB/EqualFilter0-4 2 978302544 ns/op 2.14 MB/s 173184064 B/op 2097346 allocs/op
BenchmarkBytes/1MiB/EqualFilter1-4 1 1543190869 ns/op 1.36 MB/s 240293104 B/op 4194502 allocs/op
BenchmarkBytes/1MiB/EqualFilter2-4 1 1998443802 ns/op 1.05 MB/s 240293232 B/op 4194504 allocs/op
BenchmarkBytes/1MiB/EqualFilter3-4 1 2507293058 ns/op 0.84 MB/s 240293328 B/op 4194506 allocs/op
BenchmarkBytes/1MiB/EqualFilter4-4 1 2981132381 ns/op 0.70 MB/s 240293008 B/op 4194502 allocs/op
BenchmarkBytes/1MiB/EqualFilter5-4 1 3351177035 ns/op 0.63 MB/s 240293424 B/op 4194506 allocs/op
BenchmarkBytes/1MiB/DiffFilter0-4 1 1132136753 ns/op 1.85 MB/s 173185752 B/op 2097384 allocs/op
BenchmarkBytes/1MiB/DiffFilter1-4 1 1666196345 ns/op 1.26 MB/s 240294504 B/op 4194537 allocs/op
BenchmarkBytes/1MiB/DiffFilter2-4 1 2204467232 ns/op 0.95 MB/s 240294600 B/op 4194539 allocs/op
BenchmarkBytes/1MiB/DiffFilter3-4 1 2499107753 ns/op 0.84 MB/s 240294600 B/op 4194539 allocs/op
BenchmarkBytes/1MiB/DiffFilter4-4 1 2966222324 ns/op 0.71 MB/s 240295016 B/op 4194544 allocs/op
BenchmarkBytes/1MiB/DiffFilter5-4 1 3382045549 ns/op 0.62 MB/s 240294728 B/op 4194540 allocs/op
BenchmarkBytes/16MiB/EqualFilter0-4 1 16585516720 ns/op 2.02 MB/s 2967917664 B/op 33554689 allocs/op
BenchmarkBytes/16MiB/EqualFilter1-4 1 23980880452 ns/op 1.40 MB/s 4041659536 B/op 67109123 allocs/op
BenchmarkBytes/16MiB/EqualFilter2-4 1 30729382462 ns/op 1.09 MB/s 4041659568 B/op 67109124 allocs/op
BenchmarkBytes/16MiB/EqualFilter3-4 1 37830223988 ns/op 0.89 MB/s 4041660016 B/op 67109129 allocs/op
BenchmarkBytes/16MiB/EqualFilter4-4 1 44731081109 ns/op 0.75 MB/s 4041659536 B/op 67109124 allocs/op
BenchmarkBytes/16MiB/EqualFilter5-4 1 52110015114 ns/op 0.64 MB/s 4041659760 B/op 67109126 allocs/op
BenchmarkBytes/16MiB/DiffFilter0-4 1 20349410654 ns/op 1.65 MB/s 2967919128 B/op 33554724 allocs/op
BenchmarkBytes/16MiB/DiffFilter1-4 1 27073250483 ns/op 1.24 MB/s 4041661320 B/op 67109163 allocs/op
BenchmarkBytes/16MiB/DiffFilter2-4 1 32223912220 ns/op 1.04 MB/s 4041661064 B/op 67109160 allocs/op
BenchmarkBytes/16MiB/DiffFilter3-4 1 39189759283 ns/op 0.86 MB/s 4041661128 B/op 67109161 allocs/op
BenchmarkBytes/16MiB/DiffFilter4-4 1 48344470628 ns/op 0.69 MB/s 4041661256 B/op 67109163 allocs/op
BenchmarkBytes/16MiB/DiffFilter5-4 1 51184873999 ns/op 0.66 MB/s 4041661256 B/op 67109162 allocs/op
The last benchmark shows that the current implementation allocates
an astonishing 3.75GiB just to compare a 16MiB byte slice.
This package is intended to be a more powerful and safer alternative to reflect.DeepEqual for comparing whether two values are semantically equal.
The primary features of cmp are:
When the default behavior of equality does not suit the needs of the test, custom equality functions can override the equality operation. For example, an equality function may report floats as equal so long as they are within some tolerance of each other.
Types that have an Equal method may use that method to determine equality. This allows package authors to determine the equality operation for the types that they define.
If no custom equality functions are used and no Equal method is defined, equality is determined by recursively comparing the primitive kinds on both values, much like reflect.DeepEqual. Unlike reflect.DeepEqual, unexported fields are not compared by default; they result in panics unless suppressed by using an Ignore option (see cmpopts.IgnoreUnexported) or explicitly compared using the AllowUnexported option.
See the GoDoc documentation for more information.
This is not an official Google product.
go get -u github.com/google/go-cmp/cmp
BSD - See LICENSE file