Re: pgcrypto: PGP armor headers

On 9/25/14 4:08 PM, Heikki Linnakangas wrote:
> On 09/25/2014 04:56 PM, Marko Tiikkaja wrote:
>> On 9/25/14 3:50 PM, Heikki Linnakangas wrote:
>>> On 09/10/2014 04:35 PM, Marko Tiikkaja wrote:
>>> It might've been a tad more efficient to return
>>> the StringInfo buffer directly from pgp_armor/dearmor, and avoid the
>>> extra palloc and memcpy, but this isn't performance critical enough for
>>> it to really matter.
>>
>> I couldn't see any way of doing that without breaking the VARDATA
>> abstraction. I even went looking for similar cases in the source code,
>> but couldn't find any. If you can come up with a way, feel free to
>> change that -- I'd like to learn myself.
>
> You could first append VARHDRSZ zeros to the StringInfo, then append the
> base64-encoded data, and last replace the zeros with the real length,
> using SET_VARSIZE.

That's assuming that VARDATA() is at exactly VARHDRSZ bytes. I couldn't
find any callers making that assumption.

.marko