| Message ID | 20210211204438.1184395-4-eblake@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | improve do_strtosz precision | expand |
On 2/11/21 9:44 PM, Eric Blake wrote: > Supporting '0x20M' looks odd, particularly since we have a 'B' suffix > that is ambiguous for bytes, as well as a less-frequently-used 'E' > suffix for extremely large exibytes. In practice, people using hex > inputs are specifying values in bytes (and would have written > 0x2000000, or possibly relied on default_suffix in the case of > qemu_strtosz_MiB), and the use of scaling suffixes makes the most > sense for inputs in decimal (where the user would write 32M). But > rather than outright dropping support for hex-with-suffix, let's > follow our deprecation policy. Sadly, since qemu_strtosz() does not > have an Err** parameter, and plumbing that in would be a much larger > task, we instead go with just directly emitting the deprecation > warning to stderr. > > Signed-off-by: Eric Blake <eblake@redhat.com> > --- > docs/system/deprecated.rst | 8 ++++++++ > util/cutils.c | 10 +++++++++- > 2 files changed, 17 insertions(+), 1 deletion(-) Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
On Thu, Feb 11, 2021 at 02:44:37PM -0600, Eric Blake wrote: > Supporting '0x20M' looks odd, particularly since we have a 'B' suffix > that is ambiguous for bytes, as well as a less-frequently-used 'E' > suffix for extremely large exibytes. In practice, people using hex > inputs are specifying values in bytes (and would have written > 0x2000000, or possibly relied on default_suffix in the case of > qemu_strtosz_MiB), and the use of scaling suffixes makes the most > sense for inputs in decimal (where the user would write 32M). But > rather than outright dropping support for hex-with-suffix, let's > follow our deprecation policy. Sadly, since qemu_strtosz() does not > have an Err** parameter, and plumbing that in would be a much larger > task, we instead go with just directly emitting the deprecation > warning to stderr. > > Signed-off-by: Eric Blake <eblake@redhat.com> > --- > docs/system/deprecated.rst | 8 ++++++++ > util/cutils.c | 10 +++++++++- > 2 files changed, 17 insertions(+), 1 deletion(-) Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Regards, Daniel
diff --git a/docs/system/deprecated.rst b/docs/system/deprecated.rst index 2fcac7861e07..113c2e933f1b 100644 --- a/docs/system/deprecated.rst +++ b/docs/system/deprecated.rst @@ -146,6 +146,14 @@ library enabled as a cryptography provider. Neither the ``nettle`` library, or the built-in cryptography provider are supported on FIPS enabled hosts. +hexadecimal sizes with scaling multipliers (since 6.0) +'''''''''''''''''''''''''''''''''''''''''''''''''''''' + +Input parameters that take a size value should only use a size suffix +(such as 'k' or 'M') when the base is written in decimal, and not when +the value is hexadecimal. That is, '0x20M' is deprecated, and should +be written either as '32M' or as '0x2000000'. + QEMU Machine Protocol (QMP) commands ------------------------------------ diff --git a/util/cutils.c b/util/cutils.c index 22d27b0fd21b..6a8a175e0d71 100644 --- a/util/cutils.c +++ b/util/cutils.c @@ -250,6 +250,9 @@ static int64_t suffix_mul(char suffix, int64_t unit) * fractional portion is truncated to byte * - 0x7fEE - hexadecimal, unit determined by @default_suffix * + * The following cause a deprecation warning, and may be removed in the future + * - 0xabc{kKmMgGtTpP} - hex with scaling suffix + * * The following are intentionally not supported * - octal, such as 08 * - fractional hex, such as 0x1.8 @@ -272,7 +275,7 @@ static int do_strtosz(const char *nptr, const char **end, int retval; const char *endptr, *f; unsigned char c; - bool mul_required = false; + bool mul_required = false, hex = false; uint64_t val; int64_t mul; double fraction = 0.0; @@ -298,6 +301,7 @@ static int do_strtosz(const char *nptr, const char **end, retval = -EINVAL; goto out; } + hex = true; } else if (*endptr == '.') { /* * Input looks like a fraction. Make sure even 1.k works @@ -320,6 +324,10 @@ static int do_strtosz(const char *nptr, const char **end, c = *endptr; mul = suffix_mul(c, unit); if (mul > 0) { + if (hex) { + warn_report("Using a multiplier suffix on hex numbers " + "is deprecated: %s", nptr); + } endptr++; } else { mul = suffix_mul(default_suffix, unit);
Supporting '0x20M' looks odd, particularly since we have a 'B' suffix that is ambiguous for bytes, as well as a less-frequently-used 'E' suffix for extremely large exibytes. In practice, people using hex inputs are specifying values in bytes (and would have written 0x2000000, or possibly relied on default_suffix in the case of qemu_strtosz_MiB), and the use of scaling suffixes makes the most sense for inputs in decimal (where the user would write 32M). But rather than outright dropping support for hex-with-suffix, let's follow our deprecation policy. Sadly, since qemu_strtosz() does not have an Err** parameter, and plumbing that in would be a much larger task, we instead go with just directly emitting the deprecation warning to stderr. Signed-off-by: Eric Blake <eblake@redhat.com> --- docs/system/deprecated.rst | 8 ++++++++ util/cutils.c | 10 +++++++++- 2 files changed, 17 insertions(+), 1 deletion(-)