Coding standards for 32/64-bits data
julien.coloos at atosorigin.com
Wed Jun 29 08:21:17 EDT 2011
I am currently wondering how to properly handle (ex-32/)64-bits data in
cyrus code. Since this may be useful for other developpers willing to
contribute to cyrus, I am asking on the mailing list instead of IRC
channel (that I have yet to join actually).
In previous versions of cyrus, some data could be 32 or 64-bits
depending on the architecture. For example the quota value (and the
associated printf format) was 64-bits if HAVE_LONG_LONG_INT was defined,
32-bits otherwise. To limit the impact on source code, typedef and
#define was used:
typedef unsigned long long int uquota_t;
typedef long long int quota_t;
#define UQUOTA_T_FMT "%llu"
#define QUOTA_T_FMT "%lld"
#define QUOTA_REPORT_FMT "%8llu"
typedef unsigned long uquota_t;
typedef long quota_t;
#define UQUOTA_T_FMT "%lu"
#define QUOTA_T_FMT "%ld"
#define QUOTA_REPORT_FMT "%8lu"
I used the same scheme for ticket 3374 (selection of most fitting
partition/backend) where I had to handle the partition/backend disk size.
But it appears a few months ago 64-bits support became mandatory in
master, and in the case of quota only the typedef and #define of the
64-bits section were kept.
Leaving aside legacy data, the question is how to handle new ones (like
the feature I worked on) ? Should we:
- keep on using typedef and #define, even if we now only use 64-bits
types: in that case it is easier to change the data type if needed (Who
will ever need more than 640kB memory ? ;p)
- just use plain "(unsigned) long long / (u)int64_t" types and
associated printf formats
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