On Thu, Nov 19, 2009 at 05:04:22PM -0700, Joshua Tolley wrote:
> The body of the function is ordinary Perl code. In fact, the PL/Perl
> ! glue code wraps it inside a Perl subroutine. Anonymous code blocks cannot
> ! return a value; PL/Perl functions created with CREATE FUNCTION must
> always
> ! return a scalar value. You can return more complex structures (arrays,
> ! records, and sets) by returning a reference, as discussed below. Never
> ! return a list.
> </para>
The "must always" and "Never return a list" seem needlessly strong, not
very helpful, and slightly misleading. The key point is that the call is
made in a scalar context. The implications of that follow naturally.
I'd suggest:
...; PL/Perl functions created with CREATE FUNCTION are called in a
scalar context, so can't return a list. You can return more complex
structures (arrays, records, and sets) by returning a reference, as
discussed below.
That only mentions "functions created with CREATE FUNCTION" though.
Perhaps it needs to be generalized to cover DO as well.
> + Datum
> + plperl_inline_handler(PG_FUNCTION_ARGS)
> + {
> + desc.proname = "Do Inline Block";
> + PG_TRY();
> + {
> +
> + desc.reference = plperl_create_sub("DO Inline Block",
> +
> codeblock->source_text,
> +
> desc.lanpltrusted);
> +
> + (void) plperl_call_perl_func(&desc, &fake_fcinfo);
> + }
> + PG_CATCH();
> + {
> + error_context_stack = pl_error_context.previous;
> + current_call_data = save_call_data;
> + restore_context(oldcontext);
> + PG_RE_THROW();
> + }
> + PG_END_TRY();
> +
> + if (SPI_finish() != SPI_OK_FINISH)
> + elog(ERROR, "SPI_finish() failed");
> +
> + error_context_stack = pl_error_context.previous;
> + current_call_data = save_call_data;
> + restore_context(oldcontext);
> +
> + PG_RETURN_VOID();
When does the reference held by desc.reference get freed?
At the moment it looks like this would leak memory for each DO.
> + static void
> + plperl_inline_callback(void *arg)
> + {
> + errcontext("PL/Perl anonymous code block");
> + }
I'd like to see more consistent terminlogy:
desc.proname = "Do Inline Block";
plperl_create_sub("DO Inline Block",
errcontext("PL/Perl anonymous code block");
Tim.
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