On 05/10/2014 01:32 AM, Tom Lane wrote:
Peter Geoghegan <p...@heroku.com> writes:
On Fri, May 9, 2014 at 2:54 PM, Tom Lane <t...@sss.pgh.pa.us> wrote:
However, what it looks to me like we've got here is a very bad
reimplementation of StringInfo buffers. There is for example no
integer-overflow checking here. Rather than try to bring this code
up to speed, I think we should rip it out and use StringInfo.
Heikki did specifically consider StringInfo buffers and said they were
not best suited to the task at hand. At the time I thought he meant
that he'd do something domain-specific to avoid unnecessary geometric
growth in the size of the buffer (I like to grow buffers to either
twice their previous size, or just big enough to fit the next thing,
whichever is larger), but that doesn't appear to be the case. Still,
it would be good to know what he meant before proceeding. It probably
had something to do with alignment.
It looks to me like he wanted an API that would let him reserve space
separately from filling it, which is not in stringinfo.c but is surely
easily built on top of it.
Right, the API to reserve space separately was what I had in mind.
For the moment, I've just gotten rid of
the buggy code fragment in favor of calling enlargeStringInfo, which
I trust to be right.
Thanks. I admit it didn't even occur to me to keep the localized API in
jsonb_utils as wrappers around appendString* functions. I only
considered two options: using appendString* directly, or doing
repalloc's in jsonb_utils.c. I like what you did there.
- Heikki
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