On Mon, Dec 15, 2025 at 4:12 PM Bertrand Drouvot < [email protected]> wrote:
> Hi, > > On Sat, Dec 13, 2025 at 10:37:40AM +0800, Chao Li wrote: > > On Dec 12, 2025, at 18:29, Daniel Gustafsson <[email protected]> wrote: > > > > On 12 Dec 2025, at 11:27, Heikki Linnakangas <[email protected]> wrote: > > > > > > If we're going to bother changing this at all, let's consider reusing the > > buffer. So instead of initStringInfo()+pfree on every tuple, allocate it > > once and use resetStringInfo(). > > > > > > +1 > > > > As Heikki suggested, I switched to using resetStringInfo() in 0002. One > > thing I’d like to highlight is that this function only uses the > StringInfo > > buffer under certain conditions. If we initialize the StringInfo > > unconditionally, that feels wasteful; if we initialize it lazily, as in > > 0002, then we need some extra checks to manage its state. > > I think that 0002 works fine. > > I'm just wondering if: > > + StringInfoData buf = {0}; /* mark as uninitialized */ > > does not "break" the semantic of "maxlen == 0" means "read-only". > > According to the StringInfoData definition comments: > > " > * As a special case, a StringInfoData can be initialized with a read-only > * string buffer. In this case "data" does not necessarily point at a > * palloc'd chunk, and management of the buffer storage is the caller's > * responsibility. maxlen is set to zero to indicate that this is the > case. > * Read-only StringInfoDatas cannot be appended to or reset. > * Also, it is caller's option whether a read-only string buffer has a > * terminating '\0' or not. This depends on the intended usage." > > The patch uses maxlen == 0 to detect "uninitialized", but the documentation > explicitly says maxlen == 0 indicates "read-only". Maybe adjust the doc a > bit or > add a buf_initialized bool in gist_page_items instead? > > Hi Bertrand, I think your point is valid. Let's not break the current meaning of maxlen. I added buf_initialized in v3. As 0001 has been pushed, v2-0002 now becomes v3-0001. Best regards, Chao Li (Evan) --------------------- HighGo Software Co., Ltd. https://www.highgo.com/
