plperl.c

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

{
	TriggerData *tdata;
	TupleDesc	tupdesc;
	int			i;
	char	   *level;
	char	   *event;
	char	   *relid;
	char	   *when;
	HV		   *hv;

	hv = newHV();

	tdata = (TriggerData *) fcinfo->context;
	tupdesc = tdata->tg_relation->rd_att;

	relid = DatumGetCString(
							DirectFunctionCall1(oidout,
								  ObjectIdGetDatum(tdata->tg_relation->rd_id)
												)
		);

	hv_store(hv, "name", 4, newSVpv(tdata->tg_trigger->tgname, 0), 0);
	hv_store(hv, "relid", 5, newSVpv(relid, 0), 0);

	if (TRIGGER_FIRED_BY_INSERT(tdata->tg_event))
	{
		event = "INSERT";
		if (TRIGGER_FIRED_FOR_ROW(tdata->tg_event))
			hv_store(hv, "new", 3,
					 plperl_hash_from_tuple(tdata->tg_trigtuple, tupdesc),
					 0);
	}
	else if (TRIGGER_FIRED_BY_DELETE(tdata->tg_event))
	{
		event = "DELETE";
		if (TRIGGER_FIRED_FOR_ROW(tdata->tg_event))
			hv_store(hv, "old", 3,
					 plperl_hash_from_tuple(tdata->tg_trigtuple, tupdesc),
					 0);
	}
	else if (TRIGGER_FIRED_BY_UPDATE(tdata->tg_event))
	{
		event = "UPDATE";
		if (TRIGGER_FIRED_FOR_ROW(tdata->tg_event))
		{
			hv_store(hv, "old", 3,
					 plperl_hash_from_tuple(tdata->tg_trigtuple, tupdesc),
					 0);
			hv_store(hv, "new", 3,
					 plperl_hash_from_tuple(tdata->tg_newtuple, tupdesc),
					 0);
		}
	}
	else
		event = "UNKNOWN";

	hv_store(hv, "event", 5, newSVpv(event, 0), 0);
	hv_store(hv, "argc", 4, newSViv(tdata->tg_trigger->tgnargs), 0);

	if (tdata->tg_trigger->tgnargs > 0)
	{
		AV		   *av = newAV();

		for (i = 0; i < tdata->tg_trigger->tgnargs; i++)
			av_push(av, newSVpv(tdata->tg_trigger->tgargs[i], 0));
		hv_store(hv, "args", 4, newRV_noinc((SV *) av), 0);
	}

	hv_store(hv, "relname", 7,
			 newSVpv(SPI_getrelname(tdata->tg_relation), 0), 0);

	if (TRIGGER_FIRED_BEFORE(tdata->tg_event))
		when = "BEFORE";
	else if (TRIGGER_FIRED_AFTER(tdata->tg_event))
		when = "AFTER";
	else
		when = "UNKNOWN";
	hv_store(hv, "when", 4, newSVpv(when, 0), 0);

	if (TRIGGER_FIRED_FOR_ROW(tdata->tg_event))
		level = "ROW";
	else if (TRIGGER_FIRED_FOR_STATEMENT(tdata->tg_event))
		level = "STATEMENT";
	else
		level = "UNKNOWN";
	hv_store(hv, "level", 5, newSVpv(level, 0), 0);

	return newRV_noinc((SV *) hv);
}


/* Set up the new tuple returned from a trigger. */

static HeapTuple
plperl_modify_tuple(HV *hvTD, TriggerData *tdata, HeapTuple otup)
{
	SV		  **svp;
	HV		   *hvNew;
	HeapTuple	rtup;
	SV		   *val;
	char	   *key;
	I32			klen;
	int			slotsused;
	int		   *modattrs;
	Datum	   *modvalues;
	char	   *modnulls;

	TupleDesc	tupdesc;

	tupdesc = tdata->tg_relation->rd_att;

	svp = hv_fetch(hvTD, "new", 3, FALSE);
	if (!svp)
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_COLUMN),
				 errmsg("$_TD->{new} does not exist")));
	if (!SvOK(*svp) || SvTYPE(*svp) != SVt_RV || SvTYPE(SvRV(*svp)) != SVt_PVHV)
		ereport(ERROR,
				(errcode(ERRCODE_DATATYPE_MISMATCH),
				 errmsg("$_TD->{new} is not a hash reference")));
	hvNew = (HV *) SvRV(*svp);

	modattrs = palloc(tupdesc->natts * sizeof(int));
	modvalues = palloc(tupdesc->natts * sizeof(Datum));
	modnulls = palloc(tupdesc->natts * sizeof(char));
	slotsused = 0;

	hv_iterinit(hvNew);
	while ((val = hv_iternextsv(hvNew, &key, &klen)))
	{
		int			attn = SPI_fnumber(tupdesc, key);

		if (attn <= 0 || tupdesc->attrs[attn - 1]->attisdropped)
			ereport(ERROR,
					(errcode(ERRCODE_UNDEFINED_COLUMN),
					 errmsg("Perl hash contains nonexistent column \"%s\"",
							key)));
		if (SvOK(val) && SvTYPE(val) != SVt_NULL)
		{
			Oid			typinput;
			Oid			typioparam;
			FmgrInfo	finfo;

			/* XXX would be better to cache these lookups */
			getTypeInputInfo(tupdesc->attrs[attn - 1]->atttypid,
							 &typinput, &typioparam);
			fmgr_info(typinput, &finfo);
			modvalues[slotsused] = FunctionCall3(&finfo,
										   CStringGetDatum(SvPV(val, PL_na)),
												 ObjectIdGetDatum(typioparam),
						 Int32GetDatum(tupdesc->attrs[attn - 1]->atttypmod));
			modnulls[slotsused] = ' ';
		}
		else
		{
			modvalues[slotsused] = (Datum) 0;
			modnulls[slotsused] = 'n';
		}
		modattrs[slotsused] = attn;
		slotsused++;
	}
	hv_iterinit(hvNew);

	rtup = SPI_modifytuple(tdata->tg_relation, otup, slotsused,
						   modattrs, modvalues, modnulls);

	pfree(modattrs);
	pfree(modvalues);
	pfree(modnulls);

	if (rtup == NULL)
		elog(ERROR, "SPI_modifytuple failed: %s",
			 SPI_result_code_string(SPI_result));

	return rtup;
}


/*
 * This is the only externally-visible part of the plperl call interface.
 * The Postgres function and trigger managers call it to execute a
 * perl function.
 */
PG_FUNCTION_INFO_V1(plperl_call_handler);

Datum
plperl_call_handler(PG_FUNCTION_ARGS)
{
	Datum		retval;
	plperl_call_data *save_call_data;

	plperl_init_all();

	save_call_data = current_call_data;
	PG_TRY();
	{
		if (CALLED_AS_TRIGGER(fcinfo))
			retval = PointerGetDatum(plperl_trigger_handler(fcinfo));
		else
			retval = plperl_func_handler(fcinfo);
	}
	PG_CATCH();
	{
		current_call_data = save_call_data;
		PG_RE_THROW();
	}
	PG_END_TRY();

	current_call_data = save_call_data;
	return retval;
}

/*
 * This is the other externally visible function - it is called when CREATE
 * FUNCTION is issued to validate the function being created/replaced.
 */
PG_FUNCTION_INFO_V1(plperl_validator);

Datum
plperl_validator(PG_FUNCTION_ARGS)
{
	Oid			funcoid = PG_GETARG_OID(0);
	HeapTuple	tuple;
	Form_pg_proc proc;
	bool		istrigger = false;
	plperl_proc_desc *prodesc;

	plperl_init_all();

	/* Get the new function's pg_proc entry */
	tuple = SearchSysCache(PROCOID,
						   ObjectIdGetDatum(funcoid),
						   0, 0, 0);
	if (!HeapTupleIsValid(tuple))
		elog(ERROR, "cache lookup failed for function %u", funcoid);
	proc = (Form_pg_proc) GETSTRUCT(tuple);

	/* we assume OPAQUE with no arguments means a trigger */
	if (proc->prorettype == TRIGGEROID ||
		(proc->prorettype == OPAQUEOID && proc->pronargs == 0))
		istrigger = true;

	ReleaseSysCache(tuple);

	prodesc = compile_plperl_function(funcoid, istrigger);

	/* the result of a validator is ignored */
	PG_RETURN_VOID();
}


/* Uses mksafefunc/mkunsafefunc to create an anonymous sub whose text is
 * supplied in s, and returns a reference to the closure. */

static SV  *
plperl_create_sub(char *s, bool trusted)
{
	dSP;
	SV		   *subref;
	int			count;
	char	   *compile_sub;

	if (trusted && !plperl_safe_init_done)
	{
		plperl_safe_init();
		SPAGAIN;
	}

	ENTER;
	SAVETMPS;
	PUSHMARK(SP);
	XPUSHs(sv_2mortal(newSVpv("my $_TD=$_[0]; shift;", 0)));
	XPUSHs(sv_2mortal(newSVpv(s, 0)));
	PUTBACK;

	/*
	 * G_KEEPERR seems to be needed here, else we don't recognize compile
	 * errors properly.  Perhaps it's because there's another level of eval
	 * inside mksafefunc?
	 */

	if (trusted && plperl_use_strict)
		compile_sub = "::mk_strict_safefunc";
	else if (plperl_use_strict)
		compile_sub = "::mk_strict_unsafefunc";
	else if (trusted)
		compile_sub = "::mksafefunc";
	else
		compile_sub = "::mkunsafefunc";

	count = perl_call_pv(compile_sub, G_SCALAR | G_EVAL | G_KEEPERR);
	SPAGAIN;

	if (count != 1)
	{
		PUTBACK;
		FREETMPS;
		LEAVE;
		elog(ERROR, "didn't get a return item from mksafefunc");
	}

	if (SvTRUE(ERRSV))
	{
		(void) POPs;
		PUTBACK;
		FREETMPS;
		LEAVE;
		ereport(ERROR,
				(errcode(ERRCODE_SYNTAX_ERROR),
				 errmsg("creation of Perl function failed: %s",
						strip_trailing_ws(SvPV(ERRSV, PL_na)))));
	}

	/*
	 * need to make a deep copy of the return. it comes off the stack as a
	 * temporary.
	 */
	subref = newSVsv(POPs);

	if (!SvROK(subref) || SvTYPE(SvRV(subref)) != SVt_PVCV)
	{
		PUTBACK;
		FREETMPS;
		LEAVE;

		/*
		 * subref is our responsibility because it is not mortal
		 */
		SvREFCNT_dec(subref);
		elog(ERROR, "didn't get a code ref");
	}

	PUTBACK;
	FREETMPS;
	LEAVE;

	return subref;
}


/**********************************************************************
 * plperl_init_shared_libs()		-
 *
 * We cannot use the DynaLoader directly to get at the Opcode
 * module (used by Safe.pm). So, we link Opcode into ourselves
 * and do the initialization behind perl's back.
 *
 **********************************************************************/

EXTERN_C void boot_DynaLoader(pTHX_ CV *cv);
EXTERN_C void boot_SPI(pTHX_ CV *cv);

static void
plperl_init_shared_libs(pTHX)
{
	char	   *file = __FILE__;

	newXS("DynaLoader::boot_DynaLoader", boot_DynaLoader, file);
	newXS("SPI::bootstrap", boot_SPI, file);
}


static SV  *
plperl_call_perl_func(plperl_proc_desc *desc, FunctionCallInfo fcinfo)
{
	dSP;
	SV		   *retval;
	int			i;
	int			count;
	SV		   *sv;

	ENTER;
	SAVETMPS;

	PUSHMARK(SP);

	XPUSHs(&PL_sv_undef);		/* no trigger data */

	for (i = 0; i < desc->nargs; i++)
	{
		if (fcinfo->argnull[i])
			XPUSHs(&PL_sv_undef);
		else if (desc->arg_is_rowtype[i])
		{
			HeapTupleHeader td;
			Oid			tupType;
			int32		tupTypmod;
			TupleDesc	tupdesc;
			HeapTupleData tmptup;
			SV		   *hashref;

			td = DatumGetHeapTupleHeader(fcinfo->arg[i]);
			/* Extract rowtype info and find a tupdesc */
			tupType = HeapTupleHeaderGetTypeId(td);
			tupTypmod = HeapTupleHeaderGetTypMod(td);
			tupdesc = lookup_rowtype_tupdesc(tupType, tupTypmod);
			tupdesc = CreateTupleDescCopy(tupdesc);
			/* Build a temporary HeapTuple control structure */
			tmptup.t_len = HeapTupleHeaderGetDatumLength(td);
			tmptup.t_data = td;

			hashref = plperl_hash_from_tuple(&tmptup, tupdesc);
			XPUSHs(sv_2mortal(hashref));
			FreeTupleDesc(tupdesc);
		}
		else
		{
			char	   *tmp;

			tmp = DatumGetCString(FunctionCall1(&(desc->arg_out_func[i]),
												fcinfo->arg[i]));
			sv = newSVpv(tmp, 0);
#if PERL_BCDVERSION >= 0x5006000L
			if (GetDatabaseEncoding() == PG_UTF8)
				SvUTF8_on(sv);
#endif
			XPUSHs(sv_2mortal(sv));
			pfree(tmp);
		}
	}
	PUTBACK;

	/* Do NOT use G_KEEPERR here */
	count = perl_call_sv(desc->reference, G_SCALAR | G_EVAL);

	SPAGAIN;

	if (count != 1)
	{
		PUTBACK;
		FREETMPS;
		LEAVE;
		elog(ERROR, "didn't get a return item from function");
	}

	if (SvTRUE(ERRSV))
	{
		(void) POPs;
		PUTBACK;
		FREETMPS;
		LEAVE;
		/* XXX need to find a way to assign an errcode here */
		ereport(ERROR,
				(errmsg("error from Perl function: %s",
						strip_trailing_ws(SvPV(ERRSV, PL_na)))));
	}

	retval = newSVsv(POPs);

	PUTBACK;
	FREETMPS;
	LEAVE;

	return retval;
}


static SV  *
plperl_call_perl_trigger_func(plperl_proc_desc *desc, FunctionCallInfo fcinfo,
							  SV *td)
{
	dSP;
	SV		   *retval;
	Trigger    *tg_trigger;
	int			i;
	int			count;

	ENTER;
	SAVETMPS;

	PUSHMARK(sp);

	XPUSHs(td);

	tg_trigger = ((TriggerData *) fcinfo->context)->tg_trigger;
	for (i = 0; i < tg_trigger->tgnargs; i++)
		XPUSHs(sv_2mortal(newSVpv(tg_trigger->tgargs[i], 0)));
	PUTBACK;

	/* Do NOT use G_KEEPERR here */
	count = perl_call_sv(desc->reference, G_SCALAR | G_EVAL);