Commit Graph

4 Commits

Author SHA1 Message Date
Robert Haas f9143d102f Rework custom scans to work more like the new extensible node stuff.
Per discussion, the new extensible node framework is thought to be
better designed than the custom path/scan/scanstate stuff we added
in PostgreSQL 9.5.  Rework the latter to be more like the former.

This is not backward-compatible, but we generally don't promise that
for C APIs, and there probably aren't many people using this yet
anyway.

KaiGai Kohei, reviewed by Petr Jelinek and me.  Some further
cosmetic changes by me.
2016-03-29 11:28:04 -04:00
Robert Haas 3adf9ced17 Improve check for overly-long extensible node name.
The old code is bad for two reasons.  First, it has an off-by-one
error.  Second, it won't help if you aren't running with assertions
enabled.  Per discussion, we want a check here in that case too.

Author: KaiGai Kohei, adjusted by me.
Reviewed-by: Petr Jelinek
Discussion: 56E0D547.1030101@2ndquadrant.com
2016-03-14 13:52:52 -04:00
Robert Haas aec64e8f45 Fix mistake in extensible node code.
I believe that I (rhaas) introduced this bug while editing the patch
that became bcac23de73.

Report and patch from KaiGai Kohei.
2016-03-01 13:17:09 -05:00
Robert Haas bcac23de73 Introduce extensible node types.
An extensible node is always tagged T_Extensible, but the extnodename
field identifies it more specifically; it may also include arbitrary
private data.  Extensible nodes can be copied, tested for equality,
serialized, and deserialized, but the core system doesn't know
anything about them otherwise.  Some extensions may find it useful to
include these nodes in fdw_private or custom_private lists in lieu of
arm-wrestling their data into a format that the core code can
understand.

Along the way, so as not to burden the authors of such extensible
node types too much, expose the functions for writing serialized
tokens, and for serializing and deserializing bitmapsets.

KaiGai Kohei, per a design suggested by me.  Reviewed by Andres Freund
and by me, and further edited by me.
2016-02-12 09:38:11 -05:00