operations are now run as subtransactions, so that errors in them
can be reported as ordinary Perl or Tcl errors and caught by the
normal error handling convention of those languages.  Also do some
minor code cleanup in pltcl.c: extract a large chunk of duplicated
code in pltcl_SPI_execute and pltcl_SPI_execute_plan into a shared
subroutine.

rather than longjmp'ing clear out of Perl and thereby leaving Perl in
a broken state.  Also some minor prettification of error messages.
Still need to do something with spi_exec_query() error handling.

may expand the Perl stack, therefore we must SPAGAIN to reload the local
stack pointer after calling it.  Also a couple other marginal readability
improvements.

some of the bugs exposed thereby.  The remaining 'might be used uninitialized'
warnings look like live bugs, but I am not familiar enough with Perl/C hacking
to tell how to fix them.

patch, but allow srand and disallow sprintf as per subsequent discussion.

1. Two minor cleanups:

    - We don't need to call hv_exists+hv_fetch; we should just check the
      return value of hv_fetch.
    - newSVpv("undef",0) is the string "undef", not a real undef.

2. This should fix the bug Andrew Dunstan described in a recent -hackers
   post. It replaces three bogus "eval_pv(key, 0)" calls with newSVpv,
   and eliminates another redundant hv_exists+hv_fetch pair.

3. plperl_build_tuple_argument builds up a string of Perl code to create
   a hash representing the tuple. This patch creates the hash directly.

4. Another minor cleanup: replace a couple of av_store()s with av_push.

5. Analogous to #3 for plperl_trigger_build_args. This patch removes the
   static sv_add_tuple_value function, which does much the same as two
   other utility functions defined later, and merges the functionality
   into plperl_hash_from_tuple.

I have tested the patches to the best of my limited ability, but I would
appreciate it very much if someone else could review and test them too.

(Thanks to Andrew and David Fetter for their help with some testing.)

Abhijit Menon-Sen

uid_t/gid_t too.

mode see a fresh snapshot for each command in the function, rather than
using the latest interactive command's snapshot.  Also, suppress fresh
snapshots as well as CommandCounterIncrement inside STABLE and IMMUTABLE
functions, instead using the snapshot taken for the most closely nested
regular query.  (This behavior is only sane for read-only functions, so
the patch also enforces that such functions contain only SELECT commands.)
As per my proposal of 6-Sep-2004; I note that I floated essentially the
same proposal on 19-Jun-2002, but that discussion tailed off without any
action.  Since 8.0 seems like the right place to be taking possibly
nontrivial backwards compatibility hits, let's get it done now.

possible to trap an error inside a function rather than letting it
propagate out to PostgresMain.  You still have to use AbortCurrentTransaction
to clean up, but at least the error handling itself will cooperate.

foo()' where foo() is a plperl function that returns a single composite.

Andrew Dunstan

currently unapplied regarding spi_internal.c, makes some additional
fixes relating to return types, and also contains the fix for
preventing  the use of insecure versions of Safe.pm.

There is one remaing return case that does not appear to work, namely
return of a composite directly in a select, i.e. if  foo returns some
composite type, 'select * from foo()' works but 'select foo()' doesn't.
We will either fix that or document it as a limitation.

The function plperl_func_handler is a mess - I will try to get it
cleaned up (and split up) in a subsequent patch, time permitting.

Also, reiterating previous advice - this changes slightly the API for
spi_exec_query - the returned object has either 2 or 3 members: 'status'
(string) and 'proceesed' (int,- number of rows) and, if rows are
returned, 'rows' (array of tuple hashes).

Andrew Dunstan

plperlNG. Review and minor cleanup/improvements by Joe Conway.

Summary of new functionality:
- Shared data space and namespace. There is a new global variable %_SHARED
  that functions can use to store and save data between invocations of a
  function, or between different functions. Also, all trusted plperl function
  now share a common Safe container (this is an optimization, also), which
  they can use for storing non-lexical variables, functions, etc.
- Triggers are now supported
- Records can now be returned (as a hash reference)
- Sets of records can now be returned (as a reference to an array of hash
  references).
- New function spi_exec_query() provided for performing db functions or
  getting data from db.
- Optimization for counting hash keys (Abhijit Menon-Sen)
- Allow return of 'record' and 'setof record'

of a composite type to get that type's OID as their second parameter,
in place of typelem which is useless.  The actual changes are mostly
centralized in getTypeInputInfo and siblings, but I had to fix a few
places that were fetching pg_type.typelem for themselves instead of
using the lsyscache.c routines.  Also, I renamed all the related variables
from 'typelem' to 'typioparam' to discourage people from assuming that
they necessarily contain array element types.

results with tuples as ordinary varlena Datums.  This commit does not
in itself do much for us, except eliminate the horrid memory leak
associated with evaluation of whole-row variables.  However, it lays the
groundwork for allowing composite types as table columns, and perhaps
some other useful features as well.  Per my proposal of a few days ago.

parameters to be declared with names.  pg_proc has a column to store
names, and CREATE FUNCTION can insert data into it, but that's all as
yet.  I need to do more work on the pg_dump and plpgsql portions of the
patch before committing those, but I thought I'd get the bulky changes
in before the tree drifts under me.
initdb forced due to pg_proc change.

$Header: -> $PostgreSQL Changes ...

function is not found.  Also, make all the PL libraries have initialization
functions with standard names.  Patch from Joe Conway.

look ... I'm not real certain which errors are strictly internal and which
are likely to be provoked by users.

with OPAQUE.  CREATE LANGUAGE, CREATE TRIGGER, and CREATE TYPE will all
accept references to functions declared with OPAQUE --- but they will
issue a NOTICE, and will modify the function entries in pg_proc to have
the preferred type-safe argument or result types instead of OPAQUE.
Per recent pghackers discussions.

remove unnecessary inclusions.

with OPAQUE, as per recent pghackers discussion.  I still want to do some
more work on the 'cstring' pseudo-type, but I'm going to commit the bulk
of the changes now before the tree starts shifting under me ...

HeapTupleHeaderData in setter and getter macros called
HeapTupleHeaderGetXmin, HeapTupleHeaderSetXmin etc.

It also introduces a "virtual" field xvac by defining
HeapTupleHeaderGetXvac and HeapTupleHeaderSetXvac.  Xvac is used by
VACUUM, in fact it is stored in t_cmin.

Manfred Koizar

As proof of concept, provide an alternate implementation based on POSIX
semaphores.  Also push the SysV shared-memory implementation into a
separate file so that it can be replaced conveniently.

still needed because only removed in 7.4.

cturner@redhat.com.

allows plperl routines to return NULL as intended.

initdb/regression tests pass.

tests pass.

REPLACE FUNCTION.  Clean up typlen/typmod errors inherited from pltcl.

lookup info in the relcache for index access method support functions.
This makes a huge difference for dynamically loaded support functions,
and should save a few cycles even for built-in ones.  Also tweak dfmgr.c
so that load_external_function is called only once, not twice, when
doing fmgr_info for a dynamically loaded function.  All per performance
gripe from Teodor Sigaev, 5-Oct-01.

modifiable repositories, I have a clean untrusted plperl patch to offer
you :)

Highlights:
* There's one perl interpreter used for both trusted and untrusted
procedures. I do think its unnecessary to keep two perl
interpreters around. If someone can break out from trusted "Safe" perl
mode, well, they can do what they want already. If someone disagrees, I
can change this.

* Opcode is not statically loaded anymore. Instead, we load Dynaloader,
which then can grab Opcode (and anything else you can 'use') on its own.

* Checked to work on FreeBSD 4.3 + perl 5.5.3 , OpenBSD 2.8 + perl5.6.1,
RedHat 6.2 + perl 5.5.3

* Uses ExtUtils::Embed to find what options are necessary to link with
perl shared libraries

* createlang is also updated, it can create untrusted perl using 'plperlu'

* Example script (assuming you have Mail::Sendmail installed):
create function foo() returns text as '
         use Mail::Sendmail;

         %mail = ( To      => q(you@yourname.com),
                   From    => q(me@here.com),
                   Message => "This is a very short message"
                  );
         sendmail(%mail) or die $Mail::Sendmail::error;
return          "OK. Log says:\n", $Mail::Sendmail::log;
' language 'plperlu';

Alex Pilosov