Commit Graph

40944 Commits

Author SHA1 Message Date
Heikki Linnakangas ec136d19b2 Move code shared between libpq and backend from backend/libpq/ to common/.
When building libpq, ip.c and md5.c were symlinked or copied from
src/backend/libpq into src/interfaces/libpq, but now that we have a
directory specifically for routines that are shared between the server and
client binaries, src/common/, move them there.

Some routines in ip.c were only used in the backend. Keep those in
src/backend/libpq, but rename to ifaddr.c to avoid confusion with the file
that's now in common.

Fix the comment in src/common/Makefile to reflect how libpq actually links
those files.

There are two more files that libpq symlinks directly from src/backend:
encnames.c and wchar.c. I don't feel compelled to move those right now,
though.

Patch by Michael Paquier, with some changes by me.

Discussion: <69938195-9c76-8523-0af8-eb718ea5b36e@iki.fi>
2016-09-02 13:49:59 +03:00
Heikki Linnakangas 9cca11c915 Speed up SUM calculation in numeric aggregates.
This introduces a numeric sum accumulator, which performs better than
repeatedly calling add_var(). The performance comes from using wider digits
and delaying carry propagation, tallying positive and negative values
separately, and avoiding a round of palloc/pfree on every value. This
speeds up SUM(), as well as other standard aggregates like AVG() and
STDDEV() that also calculate a sum internally.

Reviewed-by: Andrey Borodin
Discussion: <c0545351-a467-5b76-6d46-4840d1ea8aa4@iki.fi>
2016-09-02 11:51:49 +03:00
Heikki Linnakangas 9f85784cae Support multiple iterators in the Red-Black Tree implementation.
While we don't need multiple iterators at the moment, the interface is
nicer and less dangerous this way.

Aleksander Alekseev, with some changes by me.
2016-09-02 08:39:39 +03:00
Kevin Grittner 76f9dd4fa8 Improve tab completion for BEGIN & START|SET TRANSACTION.
Andreas Karlsson with minor change by me for SET TRANSACTION
SNAPSHOT.
2016-09-01 16:10:30 -05:00
Tom Lane 6c03d981a6 Change API of ShmemAlloc() so it throws error rather than returning NULL.
A majority of callers seem to have believed that this was the API spec
already, because they omitted any check for a NULL result, and hence
would crash on an out-of-shared-memory failure.  The original proposal
was to just add such error checks everywhere, but that does nothing to
prevent similar omissions in future.  Instead, let's make ShmemAlloc()
throw the error (so we can remove the caller-side checks that do exist),
and introduce a new function ShmemAllocNoError() that has the previous
behavior of returning NULL, for the small number of callers that need
that and are prepared to do the right thing.  This also lets us remove
the rather wishy-washy behavior of printing a WARNING for out-of-shmem,
which never made much sense: either the caller has a strategy for
dealing with that, or it doesn't.  It's not ShmemAlloc's business to
decide whether a warning is appropriate.

The v10 release notes will need to call this out as a significant
source-code change.  It's likely that it will be a bug fix for
extension callers too, but if not, they'll need to change to using
ShmemAllocNoError().

This is nominally a bug fix, but the odds that it's fixing any live
bug are actually rather small, because in general the requests
being made by the unchecked callers were already accounted for in
determining the overall shmem size, so really they ought not fail.
Between that and the possible impact on extensions, no back-patch.

Discussion: <24843.1472563085@sss.pgh.pa.us>
2016-09-01 10:13:55 -04:00
Tom Lane 6f7c0ea32f Improve memory management for PL/Perl functions.
Unlike PL/Tcl, PL/Perl at least made an attempt to clean up after itself
when a function gets redefined.  But it was still using TopMemoryContext
for the fn_mcxt of argument/result I/O functions, resulting in the
potential for memory leaks depending on what those functions did, and the
retail alloc/free logic was pretty bulky as well.  Fix things to use a
per-function memory context like the other PLs now do.  Tweak a couple of
places where things were being done in a not-very-safe order (on the
principle that a memory leak is better than leaving global state
inconsistent after an error).  Also make some minor cosmetic adjustments,
mostly in field names, to make the code look similar to the way PL/Tcl does
now wherever it's essentially the same logic.

Michael Paquier and Tom Lane

Discussion: <CAB7nPqSOyAsHC6jL24J1B+oK3p=yyNoFU0Vs_B6fd2kdd5g5WQ@mail.gmail.com>
2016-08-31 19:54:58 -04:00
Tom Lane d062245b5b Improve memory management for PL/Tcl functions.
Formerly, the memory used to represent a PL/Tcl function was allocated with
malloc() or in TopMemoryContext, and we'd leak it all if the function got
redefined during the session.  Instead, create a per-function context and
keep everything in or under that context.  Add a reference-counting
mechanism (like the one plpgsql has long had) so that we can safely clean
up an old function definition, either immediately if it's not being
executed or at the end of the outermost execution.

Currently, we only detect that a cached function is obsolete when we next
attempt to call that function.  So this covers the updated-definition case
but leaves cruft around after DROP FUNCTION.  It's not clear whether it's
worth installing a syscache invalidation callback to watch for drops;
none of the other PLs do, so for now we won't do it here either.

Michael Paquier and Tom Lane

Discussion: <CAB7nPqSOyAsHC6jL24J1B+oK3p=yyNoFU0Vs_B6fd2kdd5g5WQ@mail.gmail.com>
2016-08-31 17:27:09 -04:00
Tom Lane 65a588b4c3 Try to fix portability issue in enum renumbering (again).
The hack embodied in commit 4ba61a487 no longer works after today's change
to allow DatumGetFloat4/Float4GetDatum to be inlined (commit 14cca1bf8).
Probably what's happening is that the faulty compilers are deciding that
the now-inlined assignment is a no-op and so they're not required to
round to float4 width.

We had a bunch of similar issues earlier this year in the degree-based
trig functions, and eventually settled on using volatile intermediate
variables as the least ugly method of forcing recalcitrant compilers
to do what the C standard says (cf commit 82311bcdd).  Let's see if
that method works here.

Discussion: <4640.1472664476@sss.pgh.pa.us>
2016-08-31 13:58:01 -04:00
Tom Lane 679226337a Remove no-longer-useful SSL-specific Port.count field.
Since we removed SSL renegotiation, there's no longer any reason to
keep track of the amount of data transferred over the link.

Daniel Gustafsson

Discussion: <FEA7F89C-ECDF-4799-B789-2F8DDCBA467F@yesql.se>
2016-08-31 09:24:19 -04:00
Heikki Linnakangas 14cca1bf8e Use static inline functions for float <-> Datum conversions.
Now that we are OK with using static inline functions, we can use them
to avoid function call overhead of pass-by-val versions of Float4GetDatum,
DatumGetFloat8, and Float8GetDatum. Those functions are only a few CPU
instructions long, but they could not be written into macros previously,
because we need a local union variable for the conversion.

I kept the pass-by-ref versions as regular functions. They are very simple
too, but they call palloc() anyway, so shaving a few instructions from the
function call doesn't seem so important there.

Discussion: <dbb82a4a-2c15-ba27-dd0a-009d2aa72b77@iki.fi>
2016-08-31 16:00:28 +03:00
Tom Lane 0e0f43d6fd Prevent starting a standalone backend with standby_mode on.
This can't really work because standby_mode expects there to be more
WAL arriving, which there will not ever be because there's no WAL
receiver process to fetch it.  Moreover, if standby_mode is on then
hot standby might also be turned on, causing even more strangeness
because that expects read-only sessions to be executing in parallel.
Bernd Helmle reported a case where btree_xlog_delete_get_latestRemovedXid
got confused, but rather than band-aiding individual problems it seems
best to prevent getting anywhere near this state in the first place.
Back-patch to all supported branches.

In passing, also fix some omissions of errcodes in other ereport's in
readRecoveryCommandFile().

Michael Paquier (errcode hacking by me)

Discussion: <00F0B2CEF6D0CEF8A90119D4@eje.credativ.lan>
2016-08-31 08:52:13 -04:00
Robert Haas 530fb68e0f Update comments to reflect code rearrangement.
Commit f9143d102f falsified these.

KaiGai Kohei
2016-08-31 12:36:18 +05:30
Tom Lane 052cc223d5 Fix a bunch of places that called malloc and friends with no NULL check.
Where possible, use palloc or pg_malloc instead; otherwise, insert
explicit NULL checks.

Generally speaking, these are places where an actual OOM is quite
unlikely, either because they're in client programs that don't
allocate all that much, or they're very early in process startup
so that we'd likely have had a fork() failure instead.  Hence,
no back-patch, even though this is nominally a bug fix.

Michael Paquier, with some adjustments by me

Discussion: <CAB7nPqRu07Ot6iht9i9KRfYLpDaF2ZuUv5y_+72uP23ZAGysRg@mail.gmail.com>
2016-08-30 18:22:43 -04:00
Tom Lane 9daec77e16 Simplify correct use of simple_prompt().
The previous API for this function had it returning a malloc'd string.
That meant that callers had to check for NULL return, which few of them
were doing, and it also meant that callers had to remember to free()
the string later, which required extra logic in most cases.

Instead, make simple_prompt() write into a buffer supplied by the caller.
Anywhere that the maximum required input length is reasonably small,
which is almost all of the callers, we can just use a local or static
array as the buffer instead of dealing with malloc/free.

A fair number of callers used "pointer == NULL" as a proxy for "haven't
requested the password yet".  Maintaining the same behavior requires
adding a separate boolean flag for that, which adds back some of the
complexity we save by removing free()s.  Nonetheless, this nets out
at a small reduction in overall code size, and considerably less code
than we would have had if we'd added the missing NULL-return checks
everywhere they were needed.

In passing, clean up the API comment for simple_prompt() and get rid
of a very-unnecessary malloc/free in its Windows code path.

This is nominally a bug fix, but it does not seem worth back-patching,
because the actual risk of an OOM failure in any of these places seems
pretty tiny, and all of them are client-side not server-side anyway.

This patch is by me, but it owes a great deal to Michael Paquier
who identified the problem and drafted a patch for fixing it the
other way.

Discussion: <CAB7nPqRu07Ot6iht9i9KRfYLpDaF2ZuUv5y_+72uP23ZAGysRg@mail.gmail.com>
2016-08-30 17:02:02 -04:00
Tom Lane 37f6fd1eaa Fix initdb misbehavior when user mis-enters superuser password.
While testing simple_prompt() revisions, I happened to notice that
current initdb behaves rather badly when --pwprompt is specified and
the user miskeys the second password.  It complains about the mismatch,
does "rm -rf" on the data directory, and exits.  The problem is that
since commit c4a8812cf, there's a standalone backend sitting waiting
for commands at that point.  It gets unhappy about its datadir having
gone away, and spews a PANIC message at the user, which is not nice.
(And the shell then adds to the mess with meaningless bleating about a
core dump...)  We don't really want that sort of thing to happen unless
there's an internal failure in initdb, which this surely is not.

The best fix seems to be to move the collection of the password
earlier, so that it's done essentially as part of argument collection,
rather than at the rather ad-hoc time it was done before.

Back-patch to 9.6 where the problem was introduced.
2016-08-30 15:25:01 -04:00
Alvaro Herrera 8e1e3f958f Split hash.h → hash_xlog.h
Since the hash AM is going to be revamped to have WAL, this is a good
opportunity to clean up the include file a little bit to avoid including
a lot of extra stuff in the future.

Author: Amit Kapila
2016-08-29 18:55:49 -03:00
Heikki Linnakangas 9b7cd59af1 Remove support for OpenSSL versions older than 0.9.8.
OpenSSL officially only supports 1.0.1 and newer. Some OS distributions
still provide patches for 0.9.8, but anything older than that is not
interesting anymore. Let's simplify things by removing compatibility code.

Andreas Karlsson, with small changes by me.
2016-08-29 20:16:02 +03:00
Tom Lane cf34fdbbe1 Make AllocSetContextCreate throw an error for bad context-size parameters.
The previous behavior was to silently change them to something valid.
That obscured the bugs fixed in commit ea268cdc9, and generally seems
less useful than complaining.  Unlike the previous commit, though,
we'll do this in HEAD only --- it's a bit too late to be possibly
breaking third-party code in 9.6.

Discussion: <CA+TgmobNcELVd3QmLD3tx=w7+CokRQiC4_U0txjz=WHpfdkU=w@mail.gmail.com>
2016-08-29 09:29:26 -04:00
Simon Riggs 49340627f9 Fix pg_receivexlog --synchronous
Make pg_receivexlog work correctly with --synchronous without slots

Backpatch to 9.5

Gabriele Bartolini, reviewed by Michael Paquier and Simon Riggs
2016-08-29 12:16:18 +01:00
Fujii Masao bd082231ed Fix typos in comments. 2016-08-29 16:06:40 +09:00
Fujii Masao bab7823a49 Fix pg_xlogdump so that it handles cross-page XLP_FIRST_IS_CONTRECORD record.
Previously pg_xlogdump failed to dump the contents of the WAL file
if the file starts with the continuation WAL record which spans
more than one pages. Since pg_xlogdump assumed that the continuation
record always fits on a page, it could not find the valid WAL record to
start reading from in that case.

This patch changes pg_xlogdump so that it can handle a continuation
WAL record which crosses a page boundary and find the valid record
to start reading from.

Back-patch to 9.3 where pg_xlogdump was introduced.

Author: Pavan Deolasee
Reviewed-By: Michael Paquier and Craig Ringer
Discussion: CABOikdPsPByMiG6J01DKq6om2+BNkxHTPkOyqHM2a4oYwGKsqQ@mail.gmail.com
2016-08-29 14:34:58 +09:00
Tom Lane b899ccbb49 Fix stray reference to the old genbki.sh script.
Per Tomas Vondra.
2016-08-28 17:44:29 -04:00
Tom Lane 39d866433e Make another editorial pass over the 9.6 release notes.
I think they're pretty much release-quality now.
2016-08-28 17:40:06 -04:00
Tom Lane a6f0dc701b Update 9.6 release notes through today. 2016-08-28 12:37:23 -04:00
Tom Lane ea268cdc9a Add macros to make AllocSetContextCreate() calls simpler and safer.
I found that half a dozen (nearly 5%) of our AllocSetContextCreate calls
had typos in the context-sizing parameters.  While none of these led to
especially significant problems, they did create minor inefficiencies,
and it's now clear that expecting people to copy-and-paste those calls
accurately is not a great idea.  Let's reduce the risk of future errors
by introducing single macros that encapsulate the common use-cases.
Three such macros are enough to cover all but two special-purpose contexts;
those two calls can be left as-is, I think.

While this patch doesn't in itself improve matters for third-party
extensions, it doesn't break anything for them either, and they can
gradually adopt the simplified notation over time.

In passing, change TopMemoryContext to use the default allocation
parameters.  Formerly it could only be extended 8K at a time.  That was
probably reasonable when this code was written; but nowadays we create
many more contexts than we did then, so that it's not unusual to have a
couple hundred K in TopMemoryContext, even without considering various
dubious code that sticks other things there.  There seems no good reason
not to let it use growing blocks like most other contexts.

Back-patch to 9.6, mostly because that's still close enough to HEAD that
it's easy to do so, and keeping the branches in sync can be expected to
avoid some future back-patching pain.  The bugs fixed by these changes
don't seem to be significant enough to justify fixing them further back.

Discussion: <21072.1472321324@sss.pgh.pa.us>
2016-08-27 17:50:38 -04:00
Tom Lane 26fa446da6 Add a nonlocalized version of the severity field to client error messages.
This has been requested a few times, but the use-case for it was never
entirely clear.  The reason for adding it now is that transmission of
error reports from parallel workers fails when NLS is active, because
pq_parse_errornotice() wrongly assumes that the existing severity field
is nonlocalized.  There are other ways we could have fixed that, but the
other options were basically kluges, whereas this way provides something
that's at least arguably a useful feature along with the bug fix.

Per report from Jakob Egger.  Back-patch into 9.6, because otherwise
parallel query is essentially unusable in non-English locales.  The
problem exists in 9.5 as well, but we don't want to risk changing
on-the-wire behavior in 9.5 (even though the possibility of new error
fields is specifically called out in the protocol document).  It may
be sufficient to leave the issue unfixed in 9.5, given the very limited
usefulness of pq_parse_errornotice in that version.

Discussion: <A88E0006-13CB-49C6-95CC-1A77D717213C@eggerapps.at>
2016-08-26 16:20:17 -04:00
Tom Lane 78dcd027e8 Fix potential memory leakage from HandleParallelMessages().
HandleParallelMessages leaked memory into the caller's context.  Since it's
called from ProcessInterrupts, there is basically zero certainty as to what
CurrentMemoryContext is, which means we could be leaking into long-lived
contexts.  Over the processing of many worker messages that would grow to
be a problem.  Things could be even worse than just a leak, if we happened
to service the interrupt while ErrorContext is current: elog.c thinks it
can reset that on its own whim, possibly yanking storage out from under
HandleParallelMessages.

Give HandleParallelMessages its own dedicated context instead, which we can
reset during each call to ensure there's no accumulation of wasted memory.

Discussion: <16610.1472222135@sss.pgh.pa.us>
2016-08-26 15:04:05 -04:00
Tom Lane 45a36e6853 Put static forward declarations in elog.c back into same order as code.
The guiding principle for the last few patches in this area apparently
involved throwing darts.

Cosmetic only, but back-patch to 9.6 because there is no reason for
9.6 and HEAD to diverge yet in this file.
2016-08-26 14:19:03 -04:00
Tom Lane 8529036b53 Fix assorted small bugs in ThrowErrorData().
Copy the palloc'd strings into the correct context, ie ErrorContext
not wherever the source ErrorData is.  This would be a large bug,
except that it appears that all catchers of thrown errors do either
EmitErrorReport or CopyErrorData before doing anything that would
cause transient memory contexts to be cleaned up.  Still, it's wrong
and it will bite somebody someday.

Fix failure to copy cursorpos and internalpos.

Utter the appropriate incantations involving recursion_depth, so that
we'll behave sanely if we get an error inside pstrdup.  (In general,
the body of this function ought to act like, eg, errdetail().)

Per code reading induced by Jakob Egger's report.
2016-08-26 14:15:47 -04:00
Tom Lane fbf28b6b52 Fix logic for adding "parallel worker" context line to worker errors.
The previous coding here was capable of adding a "parallel worker" context
line to errors that were not, in fact, returned from a parallel worker.
Instead of using an errcontext callback to add that annotation, just paste
it onto the message by hand; this looks uglier but is more reliable.

Discussion: <19757.1472151987@sss.pgh.pa.us>
2016-08-26 10:07:28 -04:00
Heikki Linnakangas ae025a1598 Support OID system column in postgres_fdw.
You can use ALTER FOREIGN TABLE SET WITH OIDS on a foreign table, but the
oid column read out as zeros, because the postgres_fdw didn't know about
it. Teach postgres_fdw how to fetch it.

Etsuro Fujita, with an additional test case by me.

Discussion: <56E90A76.5000503@lab.ntt.co.jp>
2016-08-26 16:33:57 +03:00
Tom Lane 2533ff0aa5 Fix instability in parallel regression tests.
Commit f0c7b789a added a test case in case.sql that creates and then drops
both an '=' operator and the type it's for.  Given the right timing, that
can cause a "cache lookup failed for type" failure in concurrent sessions,
which see the '=' operator as a potential match for '=' in a query, but
then the type is gone by the time they inquire into its properties.
It might be nice to make that behavior more robust someday, but as a
back-patchable solution, adjust the new test case so that the operator
is never visible to other sessions.  Like the previous commit, back-patch
to all supported branches.

Discussion: <5983.1471371667@sss.pgh.pa.us>
2016-08-25 09:57:09 -04:00
Tom Lane ae4760d667 Fix small query-lifespan memory leak in bulk updates.
When there is an identifiable REPLICA IDENTITY index on the target table,
heap_update leaks the id_attrs bitmapset.  That's not many bytes, but it
adds up over enough rows, since the code typically runs in a query-lifespan
context.  Bug introduced in commit e55704d8b, which did a rather poor job
of cloning the existing use-pattern for RelationGetIndexAttrBitmap().

Per bug #14293 from Zhou Digoal.  Back-patch to 9.4 where the bug was
introduced.

Report: <20160824114320.15676.45171@wrigleys.postgresql.org>
2016-08-24 22:20:25 -04:00
Bruce Momjian ca9cb940d2 doc: more replacement of <literal> with something better
Reported-by: Alexander Law

Author: Alexander Law

Backpatch-through: 9.6
2016-08-24 21:11:44 -04:00
Robert Haas dcb7a54bd1 postgres_fdw: Cosmetic cleanup.
Etsuro Fujita
2016-08-24 16:29:10 -04:00
Tom Lane 2c00fad286 Fix improper repetition of previous results from a hashed aggregate.
ExecReScanAgg's check for whether it could re-use a previously calculated
hashtable neglected the possibility that the Agg node might reference
PARAM_EXEC Params that are not referenced by its input plan node.  That's
okay if the Params are in upper tlist or qual expressions; but if one
appears in aggregate input expressions, then the hashtable contents need
to be recomputed when the Param's value changes.

To avoid unnecessary performance degradation in the case of a Param that
isn't within an aggregate input, add logic to the planner to determine
which Params are within aggregate inputs.  This requires a new field in
struct Agg, but fortunately we never write plans to disk, so this isn't
an initdb-forcing change.

Per report from Jeevan Chalke.  This has been broken since forever,
so back-patch to all supported branches.

Andrew Gierth, with minor adjustments by me

Report: <CAM2+6=VY8ykfLT5Q8vb9B6EbeBk-NGuLbT6seaQ+Fq4zXvrDcA@mail.gmail.com>
2016-08-24 14:38:12 -04:00
Kevin Grittner 5cd3864075 Remove unnecessary #include.
Accidentally added in 8b65cf4c5e.

Pointed out by Álvaro Herrera
2016-08-24 13:17:21 -05:00
Peter Eisentraut 0e4cc1fc51 doc: Fix XSLT speedup with older upstream stylesheet versions
From: Alexander Law <exclusion@gmail.com>
2016-08-24 12:00:00 -04:00
Noah Misch 0395198728 Build libpgfeutils before src/bin/pg_basebackup programs.
Oversight in commit 9132c01429.
2016-08-23 23:40:38 -04:00
Noah Misch b6418a0919 Build libpgfeutils before pg_isready.
Every program having -lpgfeutils in LDFLAGS must have this dependency,
whether or not the program uses a libpgfeutils symbol.  Back-patch to
9.6, where libpgfeutils was introduced.
2016-08-23 23:40:38 -04:00
Tom Lane 71e006f031 Suppress compiler warnings in non-cassert builds.
With Asserts off, these variables are set but never used, resulting
in warnings from pickier compilers.  Fix that with our standard solution.
Per report from Jeff Janes.
2016-08-23 23:21:10 -04:00
Tom Lane 32909a57f9 Fix network_spgist.c build failures from missing AF_INET definition.
AF_INET is apparently defined in something that's pulled in automatically
on Linux, but the buildfarm says that's not true everywhere.  Comparing
to network_gist.c suggests that including <sys/socket.h> ought to fix it,
and the POSIX standard concurs.
2016-08-23 16:25:35 -04:00
Tom Lane 77e2906821 Create an SP-GiST opclass for inet/cidr.
This seems to offer significantly better search performance than the
existing GiST opclass for inet/cidr, at least on data with a wide mix
of network mask lengths.  (That may suggest that the data splitting
heuristics in the GiST opclass could be improved.)

Emre Hasegeli, with mostly-cosmetic adjustments by me

Discussion: <CAE2gYzxtth9qatW_OAqdOjykS0bxq7AYHLuyAQLPgT7H9ZU0Cw@mail.gmail.com>
2016-08-23 15:16:30 -04:00
Robert Haas 0fda682e54 Extend dsm API with a new function dsm_unpin_segment.
If you have previously pinned a segment and decide that you don't
actually want to keep it around until shutdown, this new API lets you
remove the pin.  This is pretty trivial except on Windows, where it
requires closing the duplicate handle that was used to implement the
pin.

Thomas Munro and Amit Kapila, reviewed by Amit Kapila and by me.
2016-08-23 14:32:23 -04:00
Robert Haas 19998730ae Remove duplicate function prototype.
Kyotaro Horiguchi
2016-08-23 13:44:18 -04:00
Bruce Momjian ff066481b0 doc: fix incorrect 'literal' tags
Discussion: dcc4113d-1eda-4f60-d1c5-f50eee160bad@gmail.com

Author: Alexander Law <exclusion@gmail.com>

Backpatch-through: 9.6
2016-08-23 12:45:36 -04:00
Tom Lane d2ddee63b4 Improve SP-GiST opclass API to better support unlabeled nodes.
Previously, the spgSplitTuple action could only create a new upper tuple
containing a single labeled node.  This made it useless for opclasses
that prefer to work with fixed sets of nodes (labeled or otherwise),
which meant that restrictive prefixes could not be used with such
node definitions.  Change the output field set for the choose() method
to allow it to specify any valid node set for the new upper tuple,
and to specify which of these nodes to place the modified lower tuple in.

In addition to its primary use for fixed node sets, this feature could
allow existing opclasses that use variable node sets to skip a separate
spgAddNode action when splitting a tuple, by setting up the node needed
for the incoming value as part of the spgSplitTuple action.  However, care
would have to be taken to add the extra node only when it would not make
the tuple bigger than before.  (spgAddNode can enlarge the tuple,
spgSplitTuple can't.)

This is a prerequisite for an upcoming SP-GiST inet opclass, but is
being committed separately to increase the visibility of the API change.

In passing, improve the documentation about the traverse-values feature
that was added by commit ccd6eb49a.

Emre Hasegeli, with cosmetic adjustments and documentation rework by me

Discussion: <CAE2gYzxtth9qatW_OAqdOjykS0bxq7AYHLuyAQLPgT7H9ZU0Cw@mail.gmail.com>
2016-08-23 12:10:34 -04:00
Robert Haas 86f31695f3 Add txid_current_ifassigned().
Add a variant of txid_current() that returns NULL if no transaction ID
is assigned.  This version can be used even on a standby server,
although it will always return NULL since no transaction IDs can be
assigned during recovery.

Craig Ringer, per suggestion from Jim Nasby.  Reviewed by Petr Jelinek
and by me.
2016-08-23 10:30:52 -04:00
Robert Haas ff36700c3b Remove duplicate word from comment.
Erik Rijkers
2016-08-23 10:05:13 -04:00
Tom Lane 7b405b3e04 Refactor some network.c code to create cidr_set_masklen_internal().
Merge several copies of "copy an inet value and adjust the mask length"
code to create a single, conveniently C-callable function.  This function
is exported for future use by inet SPGiST support, but it's good cleanup
anyway since we had three slightly-different-for-no-good-reason copies.

(Extracted from a larger patch, to separate new code from refactoring
of old code)

Emre Hasegeli
2016-08-23 09:39:54 -04:00