On Fri, Feb 05, 2021 at 08:27:14AM -0600, Eric Blake wrote: > On 2/5/21 5:02 AM, Daniel P. Berrangé wrote: > > >> /* > >> - * Convert string to bytes, allowing either B/b for bytes, K/k for KB, > >> - * M/m for MB, G/g for GB or T/t for TB. End pointer will be returned > >> - * in *end, if not NULL. Return -ERANGE on overflow, and -EINVAL on > >> - * other error. > >> + * Convert size string to bytes. > >> + * > >> + * Allow either B/b for bytes, K/k for KB, M/m for MB, G/g for GB or > >> + * T/t for TB, with scaling based on @unit, and with @default_suffix > >> + * implied if no explicit suffix was given. > >> + * > >> + * The end pointer will be returned in *end, if not NULL. If there is > >> + * no fraction, the input can be decimal or hexadecimal; if there is a > >> + * fraction, then the input must be decimal and there must be a suffix > >> + * (possibly by @default_suffix) larger than Byte, and the fractional > >> + * portion may suffer from precision loss or rounding. The input must > >> + * be positive. > > > > Even though the test suite gives some illustrations, I think we should > > document here the patterns we're intending to support. IIUC, we aim for > > > > [quote] > > The size parsing supports the following syntaxes > > > > - 12345 - decimal, bytes > > - 12345{bBkKmMgGtT} - decimal, scaled bytes > > Yes. Actually 12345{bBkKmMgGtTpPeE}, as long as it doesn't overflow 16E. > > > - 12345.678 - fractional decimal, bytes > > No - this was already rejected prior to my patch, and my patch keeps it > as rejected (that's the whole mul_required bool, which checks whether > mul > 1).
Oh yes, of course. > > - 12345.678{bBkKmMgGtT} - fractional decimal, scaled bytes > > Close; we reject bB in this situation for the same reason that we reject > fractional decimal without suffix. Also, patch 3/3 was questioning > whether the fractional portion must be exact or is permitted to round Yep, rejecting bB makes sense. > > > - 0x7FEE - hex, bytes > > Yes, and with the additional note that 'E' and 'B' are treated as hex > digits, not scale suffixes, in this form. > > > > > The following are intentionally not supported > > > > - octal > > Never has worked. > > > - fractional hex > > worked by accident, dropping it in this patch is not deemed worth a > deprecation period. > > > - floating point exponents > > worked by accident, dropping it in this patch is not deemed worth a > deprecation period. > > > [/quote] > > and with one more form: > > patch 2/3 > - 0x123abc{kKmMgGtTpP} - hex, scaled bytes, with limited set of working > suffixes, and slated for future removal (this one is barely plausible > enough that we need the deprecation period to see who uses it) Ok Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|