Presumably we don't need to allow for use of antiquated C compilers that
don't allow structures as return values. So this:
typedef struct
{
char *data;
int length;
}
TSVarLenData;
TSVarLenData TSSomething(x, y, z);
Is another alternative.
On Thu, Sep 1, 2022 at 5:32 PM Masakazu Kitajo <mas...@apache.org> wrote:
> Using encapsulation/data abstraction is fine, but it doesn't seem like
> TSHeapBuf makes sense. No TS API receives it. If plugin code is the only
> user and it has to deal with a non-const raw pointer and a data length
> after all, why do we want to wrap them in the first place?
>
> As for smaller steps, like I suggested on the PR, you could introduce
> TSHeapBuf separately from the fix, I think. And if there are similar TS
> APIs that could return TSHeapBuf, supporting TSHeapBuf on only one of them
> makes inconsistency in TS API. IMO, the two changes, the fix and the new
> API, should be made like 1 + 1, but not 1.5 + 0.5 nor 1 + 0.5 + 0.5.
>
> Masakazu
>
> On Thu, Sep 1, 2022 at 10:08 AM Walt Karas <wka...@yahooinc.com.invalid>
> wrote:
>
> > As a rule of thumb, I prefer using encapsulation/data abstraction. I
> think
> > perhaps that is one reason I've been a poor match to this project. There
> > doesn't seem to be a consensus that we should follow this rule of thumb.
> >
> > KIt, that would be my preference. But I am part of the consensus I think
> > we have, that we should favor a series of smaller steps, rather than
> doing
> > all of them in one big step.
> >
> > On Wed, Aug 31, 2022 at 12:13 PM Shu Kit Chan <chanshu...@gmail.com>
> > wrote:
> >
> > > Also are we planning to eventually rewrite our existing APIs (where
> > > applicable) to use this?
> > >
> > > On Wed, Aug 31, 2022 at 8:36 AM Masakazu Kitajo <mas...@apache.org>
> > wrote:
> > > >
> > > > What's the advantage of using TSHeapBuf? What issue does it solve?
> > > >
> > > >
> > > > On Wed, Aug 31, 2022 at 7:48 AM Walt Karas
> <wka...@yahooinc.com.invalid
> > >
> > > > wrote:
> > > >
> > > > > Described here:
> > > > >
> > > > >
> > >
> >
> https://urldefense.com/v3/__https://github.com/apache/trafficserver/blob/os_pkey_cnf_reload/doc/developer-guide/api/functions/TSHeapBuf.en.rst*tsheapbufdata__;Iw!!Op6eflyXZCqGR5I!Du0fBfMhb4pdM2ECFijJ7aJ-jT70jEPeZwjhsvWt2Dr2cSZ5G7HWY20wZOmFHIR3MxnvPZpoRDMlII5dgow$
> > >
> > > > > ,
> > > > >
> > > > > In PR
> > >
> >
> https://urldefense.com/v3/__https://github.com/apache/trafficserver/pull/8790__;!!Op6eflyXZCqGR5I!Du0fBfMhb4pdM2ECFijJ7aJ-jT70jEPeZwjhsvWt2Dr2cSZ5G7HWY20wZOmFHIR3MxnvPZpoRDMlYh9lIuc$
> > > .
> > > > >
> > > > > This allows a dynamically allocated buffer, of any reasonable
> length,
> > > to be
> > > > > returned by a TS API function, like this:
> > > > >
> > > > > TSHeapBuf hb = TSSomething(x, y, z);
> > > > >
> > > > > One alternative is an interface like this:
> > > > >
> > > > > int length;
> > > > > char *data = TSSomething(x, y, z, &length);
> > > > >
> > > > > The data is dynamically allocated, and would be freed with
> TSfree().
> > > > >
> > > > > Another alternative is:
> > > > >
> > > > > char *buf = TSalloc(BUF_SIZE);
> > > > > int actual_size = TSSomething(x, y, z, buf, BUF_SIZE);
> > > > > if (actual_size > BUF_SIZE) {
> > > > > // buf was too small, unchanged.
> > > > > TSfree(buf);
> > > > > buf = TSalloc(actual_size);
> > > > > TSSomething(x, y, z, buf, actual_size);
> > > > > }
> > > > >
> > >
> >
>
