Wrong use of SI/metric unit prefixes

[DerEnderKeks]

This library falsely uses SI/metric unit prefixes (power of 10), both in the code and the documentation/readme, while actually using power of 2 math.

Thus anything parsed/formatted with this library results in wrong numbers.

See https://en.wikipedia.org/wiki/Byte#Multiple-byte_units

[ccoVeille]

You meant 1000 vs 1024 for bytes?

[DerEnderKeks]

Yup, where 1000 bytes = 1 kB and 1024 = kiB. This library switches up the units and uses the decimal/metric/SI abbreviations and words, while actually using binary numbers.

[ccoVeille]

I checked at the code, then at the Wikipedia page again

The code could be easily fixed, but then there is something strange in what you report compared to what the Wikipedia page mentions.

1 kB is indeed 1000 bytes

But one KB is 1024 bytes

this lib only uses the KB, MB ... notation so something you can find in the Memory column

The lib is not about using kB, only KB.

I do agree the lib doesn't respect the SI/metrics units, but I'm unsure the results provided are wrong.

They are simply not what you might be looking for, or what anyone could be looking for maybe.

These could be better candidates for what you are looking for

https://pkg.go.dev/code.cloudfoundry.org/bytefmt#ByteSize
https://pkg.go.dev/github.com/dustin/go-humanize#SI
https://pkg.go.dev/github.com/johnstarich/go/datasize
https://github.com/docker/go-units

[ccoVeille]

Was is useful @DerEnderKeks ?

What do you think?

[DerEnderKeks]

Since you couldn't call the exported constant kB, KB is basically the same in this context. Also, the Readme even lists an example how lower case sizes can also be parsed (v.UnmarshalText([]byte("100 mb"))). And since the JEDEC standard, that caused these invalid units to even be used in the first place, doesn't mention anything >GB, this library is simply wrong.

From the Wikipedia article:

An alternative system of nomenclature for the same units (referred to here as the customary convention), in which 1 kilobyte (KB) is equal to 1,024 bytes,[38][39][40] 1 megabyte (MB) is equal to 10242 bytes and 1 gigabyte (GB) is equal to 10243 bytes is mentioned by a 1990s JEDEC standard. Only the first three multiples (up to GB) are mentioned by the JEDEC standard, which makes no mention of TB and larger. While confusing and incorrect,[41] the customary convention is used by the Microsoft Windows operating system[42][better source needed] and random-access memory capacity, such as main memory and CPU cache size[...]

Either way, my issue was mostly inteded to serve as a warning for others, since this library is unfortunately ranked quite high on Google. The alternatives you listed are certainly better options, I specifically went with go-humanize.

[ccoVeille]

Thanks for your detail and feedbacks

@c2h5oh what do you think about all these ? do you want to address these ?

Thanks