Ejemplo n.º 1
0
/* ----------------------------------------------------------------
 *		ExecMaterial
 *
 *		As long as we are at the end of the data collected in the tuplestore,
 *		we collect one new row from the subplan on each call, and stash it
 *		aside in the tuplestore before returning it.  The tuplestore is
 *		only read if we are asked to scan backwards, rescan, or mark/restore.
 *
 * ----------------------------------------------------------------
 */
TupleTableSlot *				/* result tuple from subplan */
ExecMaterial(MaterialState *node)
{
	EState	   *estate;
	ScanDirection dir;
	bool		forward;
	Tuplestorestate *tuplestorestate;
	HeapTuple	heapTuple = NULL;
	bool		should_free = false;
	bool		eof_tuplestore;
	TupleTableSlot *slot;

	/*
	 * get state info from node
	 */
	estate = node->ss.ps.state;
	dir = estate->es_direction;
	forward = ScanDirectionIsForward(dir);
	tuplestorestate = (Tuplestorestate *) node->tuplestorestate;

	/*
	 * If first time through, and we need a tuplestore, initialize it.
	 */
	if (tuplestorestate == NULL && node->randomAccess)
	{
		tuplestorestate = tuplestore_begin_heap(true, false, work_mem);

		node->tuplestorestate = (void *) tuplestorestate;
	}

	/*
	 * If we are not at the end of the tuplestore, or are going backwards, try
	 * to fetch a tuple from tuplestore.
	 */
	eof_tuplestore = (tuplestorestate == NULL) ||
		tuplestore_ateof(tuplestorestate);

	if (!forward && eof_tuplestore)
	{
		if (!node->eof_underlying)
		{
			/*
			 * When reversing direction at tuplestore EOF, the first
			 * getheaptuple call will fetch the last-added tuple; but we want
			 * to return the one before that, if possible. So do an extra
			 * fetch.
			 */
			heapTuple = tuplestore_getheaptuple(tuplestorestate,
												forward,
												&should_free);
			if (heapTuple == NULL)
				return NULL;	/* the tuplestore must be empty */
			if (should_free)
				heap_freetuple(heapTuple);
		}
		eof_tuplestore = false;
	}

	if (!eof_tuplestore)
	{
		heapTuple = tuplestore_getheaptuple(tuplestorestate,
											forward,
											&should_free);
		if (heapTuple == NULL && forward)
			eof_tuplestore = true;
	}

	/*
	 * If necessary, try to fetch another row from the subplan.
	 *
	 * Note: the eof_underlying state variable exists to short-circuit further
	 * subplan calls.  It's not optional, unfortunately, because some plan
	 * node types are not robust about being called again when they've already
	 * returned NULL.
	 */
	if (eof_tuplestore && !node->eof_underlying)
	{
		PlanState  *outerNode;
		TupleTableSlot *outerslot;

		/*
		 * We can only get here with forward==true, so no need to worry about
		 * which direction the subplan will go.
		 */
		outerNode = outerPlanState(node);
		outerslot = ExecProcNode(outerNode);
		if (TupIsNull(outerslot))
		{
			node->eof_underlying = true;
			return NULL;
		}
		heapTuple = ExecFetchSlotTuple(outerslot);
		should_free = false;

		/*
		 * Append returned tuple to tuplestore, too.  NOTE: because the
		 * tuplestore is certainly in EOF state, its read position will move
		 * forward over the added tuple.  This is what we want.
		 */
		if (tuplestorestate)
			tuplestore_puttuple(tuplestorestate, (void *) heapTuple);
	}

	/*
	 * Return the obtained tuple, if any.
	 */
	slot = (TupleTableSlot *) node->ss.ps.ps_ResultTupleSlot;
	if (heapTuple)
		return ExecStoreTuple(heapTuple, slot, InvalidBuffer, should_free);
	else
		return ExecClearTuple(slot);
}
Ejemplo n.º 2
0
/*
 * Note: plperl_return_next is called both in Postgres and Perl contexts.
 * We report any errors in Postgres fashion (via ereport).	If called in
 * Perl context, it is SPI.xs's responsibility to catch the error and
 * convert to a Perl error.  We assume (perhaps without adequate justification)
 * that we need not abort the current transaction if the Perl code traps the
 * error.
 */
void
plperl_return_next(SV *sv)
{
	plperl_proc_desc *prodesc = plperl_current_prodesc;
	FunctionCallInfo fcinfo = plperl_current_caller_info;
	ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
	MemoryContext cxt;
	HeapTuple	tuple;
	TupleDesc	tupdesc;

	if (!sv)
		return;

	if (!prodesc->fn_retisset)
		ereport(ERROR,
				(errcode(ERRCODE_SYNTAX_ERROR),
				 errmsg("cannot use return_next in a non-SETOF function")));

	if (prodesc->fn_retistuple &&
		!(SvOK(sv) && SvTYPE(sv) == SVt_RV && SvTYPE(SvRV(sv)) == SVt_PVHV))
		ereport(ERROR,
				(errcode(ERRCODE_DATATYPE_MISMATCH),
				 errmsg("setof-composite-returning Perl function "
						"must call return_next with reference to hash")));

	cxt = MemoryContextSwitchTo(rsi->econtext->ecxt_per_query_memory);

	if (!plperl_current_tuple_store)
		plperl_current_tuple_store =
			tuplestore_begin_heap(true, false, work_mem);

	if (prodesc->fn_retistuple)
	{
		TypeFuncClass rettype;
		AttInMetadata *attinmeta;

		rettype = get_call_result_type(fcinfo, NULL, &tupdesc);
		tupdesc = CreateTupleDescCopy(tupdesc);
		attinmeta = TupleDescGetAttInMetadata(tupdesc);
		tuple = plperl_build_tuple_result((HV *) SvRV(sv), attinmeta);
	}
	else
	{
		Datum		ret;
		bool		isNull;

		tupdesc = CreateTupleDescCopy(rsi->expectedDesc);

		if (SvOK(sv) && SvTYPE(sv) != SVt_NULL)
		{
			char	   *val = SvPV(sv, PL_na);

			ret = FunctionCall3(&prodesc->result_in_func,
								PointerGetDatum(val),
								ObjectIdGetDatum(prodesc->result_typioparam),
								Int32GetDatum(-1));
			isNull = false;
		}
		else
		{
			ret = (Datum) 0;
			isNull = true;
		}

		tuple = heap_form_tuple(tupdesc, &ret, &isNull);
	}

	if (!plperl_current_tuple_desc)
		plperl_current_tuple_desc = tupdesc;

	tuplestore_puttuple(plperl_current_tuple_store, tuple);
	heap_freetuple(tuple);
	MemoryContextSwitchTo(cxt);
}
Ejemplo n.º 3
0
void
tuplestore_putvalues(Tuplestorestate *state, TupleDesc tdesc,
					 Datum *values, bool *isnull)
{
	tuplestore_puttuple(state, heap_form_tuple(tdesc, values, isnull));
}
Ejemplo n.º 4
0
static void
populate_recordset_object_end(void *state)
{
	PopulateRecordsetState _state = (PopulateRecordsetState) state;
	HTAB	   *json_hash = _state->json_hash;
	Datum	   *values;
	bool	   *nulls;
	char		fname[NAMEDATALEN];
	int			i;
	RecordIOData *my_extra = _state->my_extra;
	int			ncolumns = my_extra->ncolumns;
	TupleDesc	tupdesc = _state->ret_tdesc;
	JsonHashEntry hashentry;
	HeapTupleHeader rec = _state->rec;
	HeapTuple	rettuple;

	if (_state->lex->lex_level > 1)
		return;

	values = (Datum *) palloc(ncolumns * sizeof(Datum));
	nulls = (bool *) palloc(ncolumns * sizeof(bool));

	if (_state->rec)
	{
		HeapTupleData tuple;

		/* Build a temporary HeapTuple control structure */
		tuple.t_len = HeapTupleHeaderGetDatumLength(_state->rec);
		ItemPointerSetInvalid(&(tuple.t_self));
		tuple.t_data = _state->rec;

		/* Break down the tuple into fields */
		heap_deform_tuple(&tuple, tupdesc, values, nulls);
	}
	else
	{
		for (i = 0; i < ncolumns; ++i)
		{
			values[i] = (Datum) 0;
			nulls[i] = true;
		}
	}

	for (i = 0; i < ncolumns; ++i)
	{
		ColumnIOData *column_info = &my_extra->columns[i];
		Oid			column_type = tupdesc->attrs[i]->atttypid;
		char	   *value;

		/* Ignore dropped columns in datatype */
		if (tupdesc->attrs[i]->attisdropped)
		{
			nulls[i] = true;
			continue;
		}

		memset(fname, 0, NAMEDATALEN);
		strncpy(fname, NameStr(tupdesc->attrs[i]->attname), NAMEDATALEN);
		hashentry = hash_search(json_hash, fname, HASH_FIND, NULL);

		/*
		 * we can't just skip here if the key wasn't found since we might have
		 * a domain to deal with. If we were passed in a non-null record
		 * datum, we assume that the existing values are valid (if they're
		 * not, then it's not our fault), but if we were passed in a null,
		 * then every field which we don't populate needs to be run through
		 * the input function just in case it's a domain type.
		 */
		if (hashentry == NULL && rec)
			continue;

		/*
		 * Prepare to convert the column value from text
		 */
		if (column_info->column_type != column_type)
		{
			getTypeInputInfo(column_type,
							 &column_info->typiofunc,
							 &column_info->typioparam);
			fmgr_info_cxt(column_info->typiofunc, &column_info->proc,
						  _state->fn_mcxt);
			column_info->column_type = column_type;
		}
		if (hashentry == NULL || hashentry->isnull)
		{
			/*
			 * need InputFunctionCall to happen even for nulls, so that domain
			 * checks are done
			 */
			values[i] = InputFunctionCall(&column_info->proc, NULL,
										  column_info->typioparam,
										  tupdesc->attrs[i]->atttypmod);
			nulls[i] = true;
		}
		else
		{
			value = hashentry->val;

			values[i] = InputFunctionCall(&column_info->proc, value,
										  column_info->typioparam,
										  tupdesc->attrs[i]->atttypmod);
			nulls[i] = false;
		}
	}

	rettuple = heap_form_tuple(tupdesc, values, nulls);

	tuplestore_puttuple(_state->tuple_store, rettuple);

	hash_destroy(json_hash);
}
Ejemplo n.º 5
0
/*
 * create and populate the crosstab tuplestore using the provided source query
 */
static Tuplestorestate *
get_crosstab_tuplestore(char *sql,
						HTAB *crosstab_hash,
						TupleDesc tupdesc,
						MemoryContext per_query_ctx,
						bool randomAccess)
{
	Tuplestorestate *tupstore;
	int			num_categories = hash_get_num_entries(crosstab_hash);
	AttInMetadata *attinmeta = TupleDescGetAttInMetadata(tupdesc);
	char	  **values;
	HeapTuple	tuple;
	int			ret;
	uint64		proc;

	/* initialize our tuplestore (while still in query context!) */
	tupstore = tuplestore_begin_heap(randomAccess, false, work_mem);

	/* Connect to SPI manager */
	if ((ret = SPI_connect()) < 0)
		/* internal error */
		elog(ERROR, "get_crosstab_tuplestore: SPI_connect returned %d", ret);

	/* Now retrieve the crosstab source rows */
	ret = SPI_execute(sql, true, 0);
	proc = SPI_processed;

	/* Check for qualifying tuples */
	if ((ret == SPI_OK_SELECT) && (proc > 0))
	{
		SPITupleTable *spi_tuptable = SPI_tuptable;
		TupleDesc	spi_tupdesc = spi_tuptable->tupdesc;
		int			ncols = spi_tupdesc->natts;
		char	   *rowid;
		char	   *lastrowid = NULL;
		bool		firstpass = true;
		uint64		i;
		int			j;
		int			result_ncols;

		if (num_categories == 0)
		{
			/* no qualifying category tuples */
			ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
					 errmsg("provided \"categories\" SQL must " \
							"return 1 column of at least one row")));
		}

		/*
		 * The provided SQL query must always return at least three columns:
		 *
		 * 1. rowname	the label for each row - column 1 in the final result
		 * 2. category	the label for each value-column in the final result 3.
		 * value	 the values used to populate the value-columns
		 *
		 * If there are more than three columns, the last two are taken as
		 * "category" and "values". The first column is taken as "rowname".
		 * Additional columns (2 thru N-2) are assumed the same for the same
		 * "rowname", and are copied into the result tuple from the first time
		 * we encounter a particular rowname.
		 */
		if (ncols < 3)
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
					 errmsg("invalid source data SQL statement"),
					 errdetail("The provided SQL must return 3 " \
							   " columns; rowid, category, and values.")));

		result_ncols = (ncols - 2) + num_categories;

		/* Recheck to make sure we tuple descriptor still looks reasonable */
		if (tupdesc->natts != result_ncols)
			ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
					 errmsg("invalid return type"),
					 errdetail("Query-specified return " \
							   "tuple has %d columns but crosstab " \
							   "returns %d.", tupdesc->natts, result_ncols)));

		/* allocate space */
		values = (char **) palloc(result_ncols * sizeof(char *));

		/* and make sure it's clear */
		memset(values, '\0', result_ncols * sizeof(char *));

		for (i = 0; i < proc; i++)
		{
			HeapTuple	spi_tuple;
			crosstab_cat_desc *catdesc;
			char	   *catname;

			/* get the next sql result tuple */
			spi_tuple = spi_tuptable->vals[i];

			/* get the rowid from the current sql result tuple */
			rowid = SPI_getvalue(spi_tuple, spi_tupdesc, 1);

			/*
			 * if we're on a new output row, grab the column values up to
			 * column N-2 now
			 */
			if (firstpass || !xstreq(lastrowid, rowid))
			{
				/*
				 * a new row means we need to flush the old one first, unless
				 * we're on the very first row
				 */
				if (!firstpass)
				{
					/* rowid changed, flush the previous output row */
					tuple = BuildTupleFromCStrings(attinmeta, values);

					tuplestore_puttuple(tupstore, tuple);

					for (j = 0; j < result_ncols; j++)
						xpfree(values[j]);
				}

				values[0] = rowid;
				for (j = 1; j < ncols - 2; j++)
					values[j] = SPI_getvalue(spi_tuple, spi_tupdesc, j + 1);

				/* we're no longer on the first pass */
				firstpass = false;
			}

			/* look up the category and fill in the appropriate column */
			catname = SPI_getvalue(spi_tuple, spi_tupdesc, ncols - 1);

			if (catname != NULL)
			{
				crosstab_HashTableLookup(crosstab_hash, catname, catdesc);

				if (catdesc)
					values[catdesc->attidx + ncols - 2] =
						SPI_getvalue(spi_tuple, spi_tupdesc, ncols);
			}

			xpfree(lastrowid);
			xpstrdup(lastrowid, rowid);
		}

		/* flush the last output row */
		tuple = BuildTupleFromCStrings(attinmeta, values);

		tuplestore_puttuple(tupstore, tuple);
	}

	if (SPI_finish() != SPI_OK_FINISH)
		/* internal error */
		elog(ERROR, "get_crosstab_tuplestore: SPI_finish() failed");

	tuplestore_donestoring(tupstore);

	return tupstore;
}
Ejemplo n.º 6
0
Datum
xpath_table(PG_FUNCTION_ARGS)
{
	/* Function parameters */
	char	   *pkeyfield = text_to_cstring(PG_GETARG_TEXT_PP(0));
	char	   *xmlfield = text_to_cstring(PG_GETARG_TEXT_PP(1));
	char	   *relname = text_to_cstring(PG_GETARG_TEXT_PP(2));
	char	   *xpathset = text_to_cstring(PG_GETARG_TEXT_PP(3));
	char	   *condition = text_to_cstring(PG_GETARG_TEXT_PP(4));

	/* SPI (input tuple) support */
	SPITupleTable *tuptable;
	HeapTuple	spi_tuple;
	TupleDesc	spi_tupdesc;

	/* Output tuple (tuplestore) support */
	Tuplestorestate *tupstore = NULL;
	TupleDesc	ret_tupdesc;
	HeapTuple	ret_tuple;

	ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
	AttInMetadata *attinmeta;
	MemoryContext per_query_ctx;
	MemoryContext oldcontext;

	char	  **values;
	xmlChar   **xpaths;
	char	   *pos;
	const char *pathsep = "|";

	int			numpaths;
	int			ret;
	int			proc;
	int			i;
	int			j;
	int			rownr;			/* For issuing multiple rows from one original
								 * document */
	bool		had_values;		/* To determine end of nodeset results */
	StringInfoData query_buf;
	PgXmlErrorContext *xmlerrcxt;
	volatile xmlDocPtr doctree = NULL;

	/* We only have a valid tuple description in table function mode */
	if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
		ereport(ERROR,
				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
				 errmsg("set-valued function called in context that cannot accept a set")));
	if (rsinfo->expectedDesc == NULL)
		ereport(ERROR,
				(errcode(ERRCODE_SYNTAX_ERROR),
				 errmsg("xpath_table must be called as a table function")));

	/*
	 * We want to materialise because it means that we don't have to carry
	 * libxml2 parser state between invocations of this function
	 */
	if (!(rsinfo->allowedModes & SFRM_Materialize))
		ereport(ERROR,
				(errcode(ERRCODE_SYNTAX_ERROR),
			   errmsg("xpath_table requires Materialize mode, but it is not "
					  "allowed in this context")));

	/*
	 * The tuplestore must exist in a higher context than this function call
	 * (per_query_ctx is used)
	 */
	per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
	oldcontext = MemoryContextSwitchTo(per_query_ctx);

	/*
	 * Create the tuplestore - work_mem is the max in-memory size before a
	 * file is created on disk to hold it.
	 */
	tupstore =
		tuplestore_begin_heap(rsinfo->allowedModes & SFRM_Materialize_Random,
							  false, work_mem);

	MemoryContextSwitchTo(oldcontext);

	/* get the requested return tuple description */
	ret_tupdesc = CreateTupleDescCopy(rsinfo->expectedDesc);

	/* must have at least one output column (for the pkey) */
	if (ret_tupdesc->natts < 1)
		ereport(ERROR,
				(errcode(ERRCODE_SYNTAX_ERROR),
				 errmsg("xpath_table must have at least one output column")));

	/*
	 * At the moment we assume that the returned attributes make sense for the
	 * XPath specififed (i.e. we trust the caller). It's not fatal if they get
	 * it wrong - the input function for the column type will raise an error
	 * if the path result can't be converted into the correct binary
	 * representation.
	 */

	attinmeta = TupleDescGetAttInMetadata(ret_tupdesc);

	/* Set return mode and allocate value space. */
	rsinfo->returnMode = SFRM_Materialize;
	rsinfo->setDesc = ret_tupdesc;

	values = (char **) palloc(ret_tupdesc->natts * sizeof(char *));
	xpaths = (xmlChar **) palloc(ret_tupdesc->natts * sizeof(xmlChar *));

	/*
	 * Split XPaths. xpathset is a writable CString.
	 *
	 * Note that we stop splitting once we've done all needed for tupdesc
	 */
	numpaths = 0;
	pos = xpathset;
	while (numpaths < (ret_tupdesc->natts - 1))
	{
		xpaths[numpaths++] = (xmlChar *) pos;
		pos = strstr(pos, pathsep);
		if (pos != NULL)
		{
			*pos = '\0';
			pos++;
		}
		else
			break;
	}

	/* Now build query */
	initStringInfo(&query_buf);

	/* Build initial sql statement */
	appendStringInfo(&query_buf, "SELECT %s, %s FROM %s WHERE %s",
					 pkeyfield,
					 xmlfield,
					 relname,
					 condition);

	if ((ret = SPI_connect()) < 0)
		elog(ERROR, "xpath_table: SPI_connect returned %d", ret);

	if ((ret = SPI_exec(query_buf.data, 0)) != SPI_OK_SELECT)
		elog(ERROR, "xpath_table: SPI execution failed for query %s",
			 query_buf.data);

	proc = SPI_processed;
	/* elog(DEBUG1,"xpath_table: SPI returned %d rows",proc); */
	tuptable = SPI_tuptable;
	spi_tupdesc = tuptable->tupdesc;

	/* Switch out of SPI context */
	MemoryContextSwitchTo(oldcontext);

	/*
	 * Check that SPI returned correct result. If you put a comma into one of
	 * the function parameters, this will catch it when the SPI query returns
	 * e.g. 3 columns.
	 */
	if (spi_tupdesc->natts != 2)
	{
		ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
						errmsg("expression returning multiple columns is not valid in parameter list"),
						errdetail("Expected two columns in SPI result, got %d.", spi_tupdesc->natts)));
	}

	/*
	 * Setup the parser.  This should happen after we are done evaluating the
	 * query, in case it calls functions that set up libxml differently.
	 */
	xmlerrcxt = pgxml_parser_init(PG_XML_STRICTNESS_LEGACY);

	PG_TRY();
	{
		/* For each row i.e. document returned from SPI */
		for (i = 0; i < proc; i++)
		{
			char	   *pkey;
			char	   *xmldoc;
			xmlXPathContextPtr ctxt;
			xmlXPathObjectPtr res;
			xmlChar    *resstr;
			xmlXPathCompExprPtr comppath;

			/* Extract the row data as C Strings */
			spi_tuple = tuptable->vals[i];
			pkey = SPI_getvalue(spi_tuple, spi_tupdesc, 1);
			xmldoc = SPI_getvalue(spi_tuple, spi_tupdesc, 2);

			/*
			 * Clear the values array, so that not-well-formed documents
			 * return NULL in all columns.	Note that this also means that
			 * spare columns will be NULL.
			 */
			for (j = 0; j < ret_tupdesc->natts; j++)
				values[j] = NULL;

			/* Insert primary key */
			values[0] = pkey;

			/* Parse the document */
			if (xmldoc)
				doctree = xmlParseMemory(xmldoc, strlen(xmldoc));
			else	/* treat NULL as not well-formed */
				doctree = NULL;

			if (doctree == NULL)
			{
				/* not well-formed, so output all-NULL tuple */
				ret_tuple = BuildTupleFromCStrings(attinmeta, values);
				tuplestore_puttuple(tupstore, ret_tuple);
				heap_freetuple(ret_tuple);
			}
			else
			{
				/* New loop here - we have to deal with nodeset results */
				rownr = 0;

				do
				{
					/* Now evaluate the set of xpaths. */
					had_values = false;
					for (j = 0; j < numpaths; j++)
					{
						ctxt = xmlXPathNewContext(doctree);
						ctxt->node = xmlDocGetRootElement(doctree);

						/* compile the path */
						comppath = xmlXPathCompile(xpaths[j]);
						if (comppath == NULL)
							xml_ereport(xmlerrcxt, ERROR,
										ERRCODE_EXTERNAL_ROUTINE_EXCEPTION,
										"XPath Syntax Error");

						/* Now evaluate the path expression. */
						res = xmlXPathCompiledEval(comppath, ctxt);
						xmlXPathFreeCompExpr(comppath);

						if (res != NULL)
						{
							switch (res->type)
							{
								case XPATH_NODESET:
									/* We see if this nodeset has enough nodes */
									if (res->nodesetval != NULL &&
										rownr < res->nodesetval->nodeNr)
									{
										resstr = xmlXPathCastNodeToString(res->nodesetval->nodeTab[rownr]);
										had_values = true;
									}
									else
										resstr = NULL;

									break;

								case XPATH_STRING:
									resstr = xmlStrdup(res->stringval);
									break;

								default:
									elog(NOTICE, "unsupported XQuery result: %d", res->type);
									resstr = xmlStrdup((const xmlChar *) "<unsupported/>");
							}

							/*
							 * Insert this into the appropriate column in the
							 * result tuple.
							 */
							values[j + 1] = (char *) resstr;
						}
						xmlXPathFreeContext(ctxt);
					}

					/* Now add the tuple to the output, if there is one. */
					if (had_values)
					{
						ret_tuple = BuildTupleFromCStrings(attinmeta, values);
						tuplestore_puttuple(tupstore, ret_tuple);
						heap_freetuple(ret_tuple);
					}

					rownr++;
				} while (had_values);
			}

			if (doctree != NULL)
				xmlFreeDoc(doctree);
			doctree = NULL;

			if (pkey)
				pfree(pkey);
			if (xmldoc)
				pfree(xmldoc);
		}
	}
	PG_CATCH();
	{
		if (doctree != NULL)
			xmlFreeDoc(doctree);

		pg_xml_done(xmlerrcxt, true);

		PG_RE_THROW();
	}
	PG_END_TRY();

	if (doctree != NULL)
		xmlFreeDoc(doctree);

	pg_xml_done(xmlerrcxt, false);

	tuplestore_donestoring(tupstore);

	SPI_finish();

	rsinfo->setResult = tupstore;

	/*
	 * SFRM_Materialize mode expects us to return a NULL Datum. The actual
	 * tuples are in our tuplestore and passed back through rsinfo->setResult.
	 * rsinfo->setDesc is set to the tuple description that we actually used
	 * to build our tuples with, so the caller can verify we did what it was
	 * expecting.
	 */
	return (Datum) 0;
}
Ejemplo n.º 7
0
Datum
crosstab(PG_FUNCTION_ARGS)
{
	char	   *sql = text_to_cstring(PG_GETARG_TEXT_PP(0));
	ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
	Tuplestorestate *tupstore;
	TupleDesc	tupdesc;
	uint64		call_cntr;
	uint64		max_calls;
	AttInMetadata *attinmeta;
	SPITupleTable *spi_tuptable;
	TupleDesc	spi_tupdesc;
	bool		firstpass;
	char	   *lastrowid;
	int			i;
	int			num_categories;
	MemoryContext per_query_ctx;
	MemoryContext oldcontext;
	int			ret;
	uint64		proc;

	/* check to see if caller supports us returning a tuplestore */
	if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
		ereport(ERROR,
				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
				 errmsg("set-valued function called in context that cannot accept a set")));
	if (!(rsinfo->allowedModes & SFRM_Materialize))
		ereport(ERROR,
				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
				 errmsg("materialize mode required, but it is not " \
						"allowed in this context")));

	per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;

	/* Connect to SPI manager */
	if ((ret = SPI_connect()) < 0)
		/* internal error */
		elog(ERROR, "crosstab: SPI_connect returned %d", ret);

	/* Retrieve the desired rows */
	ret = SPI_execute(sql, true, 0);
	proc = SPI_processed;

	/* If no qualifying tuples, fall out early */
	if (ret != SPI_OK_SELECT || proc == 0)
	{
		SPI_finish();
		rsinfo->isDone = ExprEndResult;
		PG_RETURN_NULL();
	}

	spi_tuptable = SPI_tuptable;
	spi_tupdesc = spi_tuptable->tupdesc;

	/*----------
	 * The provided SQL query must always return three columns.
	 *
	 * 1. rowname
	 *	the label or identifier for each row in the final result
	 * 2. category
	 *	the label or identifier for each column in the final result
	 * 3. values
	 *	the value for each column in the final result
	 *----------
	 */
	if (spi_tupdesc->natts != 3)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
				 errmsg("invalid source data SQL statement"),
				 errdetail("The provided SQL must return 3 "
						   "columns: rowid, category, and values.")));

	/* get a tuple descriptor for our result type */
	switch (get_call_result_type(fcinfo, NULL, &tupdesc))
	{
		case TYPEFUNC_COMPOSITE:
			/* success */
			break;
		case TYPEFUNC_RECORD:
			/* failed to determine actual type of RECORD */
			ereport(ERROR,
					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
					 errmsg("function returning record called in context "
							"that cannot accept type record")));
			break;
		default:
			/* result type isn't composite */
			ereport(ERROR,
					(errcode(ERRCODE_DATATYPE_MISMATCH),
					 errmsg("return type must be a row type")));
			break;
	}

	/*
	 * Check that return tupdesc is compatible with the data we got from SPI,
	 * at least based on number and type of attributes
	 */
	if (!compatCrosstabTupleDescs(tupdesc, spi_tupdesc))
		ereport(ERROR,
				(errcode(ERRCODE_SYNTAX_ERROR),
				 errmsg("return and sql tuple descriptions are " \
						"incompatible")));

	/*
	 * switch to long-lived memory context
	 */
	oldcontext = MemoryContextSwitchTo(per_query_ctx);

	/* make sure we have a persistent copy of the result tupdesc */
	tupdesc = CreateTupleDescCopy(tupdesc);

	/* initialize our tuplestore in long-lived context */
	tupstore =
		tuplestore_begin_heap(rsinfo->allowedModes & SFRM_Materialize_Random,
							  false, work_mem);

	MemoryContextSwitchTo(oldcontext);

	/*
	 * Generate attribute metadata needed later to produce tuples from raw C
	 * strings
	 */
	attinmeta = TupleDescGetAttInMetadata(tupdesc);

	/* total number of tuples to be examined */
	max_calls = proc;

	/* the return tuple always must have 1 rowid + num_categories columns */
	num_categories = tupdesc->natts - 1;

	firstpass = true;
	lastrowid = NULL;

	for (call_cntr = 0; call_cntr < max_calls; call_cntr++)
	{
		bool		skip_tuple = false;
		char	  **values;

		/* allocate and zero space */
		values = (char **) palloc0((1 + num_categories) * sizeof(char *));

		/*
		 * now loop through the sql results and assign each value in sequence
		 * to the next category
		 */
		for (i = 0; i < num_categories; i++)
		{
			HeapTuple	spi_tuple;
			char	   *rowid;

			/* see if we've gone too far already */
			if (call_cntr >= max_calls)
				break;

			/* get the next sql result tuple */
			spi_tuple = spi_tuptable->vals[call_cntr];

			/* get the rowid from the current sql result tuple */
			rowid = SPI_getvalue(spi_tuple, spi_tupdesc, 1);

			/*
			 * If this is the first pass through the values for this rowid,
			 * set the first column to rowid
			 */
			if (i == 0)
			{
				xpstrdup(values[0], rowid);

				/*
				 * Check to see if the rowid is the same as that of the last
				 * tuple sent -- if so, skip this tuple entirely
				 */
				if (!firstpass && xstreq(lastrowid, rowid))
				{
					xpfree(rowid);
					skip_tuple = true;
					break;
				}
			}

			/*
			 * If rowid hasn't changed on us, continue building the output
			 * tuple.
			 */
			if (xstreq(rowid, values[0]))
			{
				/*
				 * Get the next category item value, which is always attribute
				 * number three.
				 *
				 * Be careful to assign the value to the array index based on
				 * which category we are presently processing.
				 */
				values[1 + i] = SPI_getvalue(spi_tuple, spi_tupdesc, 3);

				/*
				 * increment the counter since we consume a row for each
				 * category, but not for last pass because the outer loop will
				 * do that for us
				 */
				if (i < (num_categories - 1))
					call_cntr++;
				xpfree(rowid);
			}
			else
			{
				/*
				 * We'll fill in NULLs for the missing values, but we need to
				 * decrement the counter since this sql result row doesn't
				 * belong to the current output tuple.
				 */
				call_cntr--;
				xpfree(rowid);
				break;
			}
		}

		if (!skip_tuple)
		{
			HeapTuple	tuple;

			/* build the tuple and store it */
			tuple = BuildTupleFromCStrings(attinmeta, values);
			tuplestore_puttuple(tupstore, tuple);
			heap_freetuple(tuple);
		}

		/* Remember current rowid */
		xpfree(lastrowid);
		xpstrdup(lastrowid, values[0]);
		firstpass = false;

		/* Clean up */
		for (i = 0; i < num_categories + 1; i++)
			if (values[i] != NULL)
				pfree(values[i]);
		pfree(values);
	}

	/* let the caller know we're sending back a tuplestore */
	rsinfo->returnMode = SFRM_Materialize;
	rsinfo->setResult = tupstore;
	rsinfo->setDesc = tupdesc;

	/* release SPI related resources (and return to caller's context) */
	SPI_finish();

	return (Datum) 0;
}
Ejemplo n.º 8
0
static void
build_tuplestore_recursively(char *key_fld,
							 char *parent_key_fld,
							 char *relname,
							 char *orderby_fld,
							 char *branch_delim,
							 char *start_with,
							 char *branch,
							 int level,
							 int *serial,
							 int max_depth,
							 bool show_branch,
							 bool show_serial,
							 MemoryContext per_query_ctx,
							 AttInMetadata *attinmeta,
							 Tuplestorestate *tupstore)
{
	TupleDesc	tupdesc = attinmeta->tupdesc;
	int			ret;
	uint64		proc;
	int			serial_column;
	StringInfoData sql;
	char	  **values;
	char	   *current_key;
	char	   *current_key_parent;
	char		current_level[INT32_STRLEN];
	char		serial_str[INT32_STRLEN];
	char	   *current_branch;
	HeapTuple	tuple;

	if (max_depth > 0 && level > max_depth)
		return;

	initStringInfo(&sql);

	/* Build initial sql statement */
	if (!show_serial)
	{
		appendStringInfo(&sql, "SELECT %s, %s FROM %s WHERE %s = %s AND %s IS NOT NULL AND %s <> %s",
						 key_fld,
						 parent_key_fld,
						 relname,
						 parent_key_fld,
						 quote_literal_cstr(start_with),
						 key_fld, key_fld, parent_key_fld);
		serial_column = 0;
	}
	else
	{
		appendStringInfo(&sql, "SELECT %s, %s FROM %s WHERE %s = %s AND %s IS NOT NULL AND %s <> %s ORDER BY %s",
						 key_fld,
						 parent_key_fld,
						 relname,
						 parent_key_fld,
						 quote_literal_cstr(start_with),
						 key_fld, key_fld, parent_key_fld,
						 orderby_fld);
		serial_column = 1;
	}

	if (show_branch)
		values = (char **) palloc((CONNECTBY_NCOLS + serial_column) * sizeof(char *));
	else
		values = (char **) palloc((CONNECTBY_NCOLS_NOBRANCH + serial_column) * sizeof(char *));

	/* First time through, do a little setup */
	if (level == 0)
	{
		/* root value is the one we initially start with */
		values[0] = start_with;

		/* root value has no parent */
		values[1] = NULL;

		/* root level is 0 */
		sprintf(current_level, "%d", level);
		values[2] = current_level;

		/* root branch is just starting root value */
		if (show_branch)
			values[3] = start_with;

		/* root starts the serial with 1 */
		if (show_serial)
		{
			sprintf(serial_str, "%d", (*serial)++);
			if (show_branch)
				values[4] = serial_str;
			else
				values[3] = serial_str;
		}

		/* construct the tuple */
		tuple = BuildTupleFromCStrings(attinmeta, values);

		/* now store it */
		tuplestore_puttuple(tupstore, tuple);

		/* increment level */
		level++;
	}

	/* Retrieve the desired rows */
	ret = SPI_execute(sql.data, true, 0);
	proc = SPI_processed;

	/* Check for qualifying tuples */
	if ((ret == SPI_OK_SELECT) && (proc > 0))
	{
		HeapTuple	spi_tuple;
		SPITupleTable *tuptable = SPI_tuptable;
		TupleDesc	spi_tupdesc = tuptable->tupdesc;
		uint64		i;
		StringInfoData branchstr;
		StringInfoData chk_branchstr;
		StringInfoData chk_current_key;

		/*
		 * Check that return tupdesc is compatible with the one we got from
		 * the query.
		 */
		compatConnectbyTupleDescs(tupdesc, spi_tupdesc);

		initStringInfo(&branchstr);
		initStringInfo(&chk_branchstr);
		initStringInfo(&chk_current_key);

		for (i = 0; i < proc; i++)
		{
			/* initialize branch for this pass */
			appendStringInfoString(&branchstr, branch);
			appendStringInfo(&chk_branchstr, "%s%s%s", branch_delim, branch, branch_delim);

			/* get the next sql result tuple */
			spi_tuple = tuptable->vals[i];

			/* get the current key (might be NULL) */
			current_key = SPI_getvalue(spi_tuple, spi_tupdesc, 1);

			/* get the parent key (might be NULL) */
			current_key_parent = SPI_getvalue(spi_tuple, spi_tupdesc, 2);

			/* get the current level */
			sprintf(current_level, "%d", level);

			/* check to see if this key is also an ancestor */
			if (current_key)
			{
				appendStringInfo(&chk_current_key, "%s%s%s",
								 branch_delim, current_key, branch_delim);
				if (strstr(chk_branchstr.data, chk_current_key.data))
					ereport(ERROR,
							(errcode(ERRCODE_INVALID_RECURSION),
							 errmsg("infinite recursion detected")));
			}

			/* OK, extend the branch */
			if (current_key)
				appendStringInfo(&branchstr, "%s%s", branch_delim, current_key);
			current_branch = branchstr.data;

			/* build a tuple */
			values[0] = current_key;
			values[1] = current_key_parent;
			values[2] = current_level;
			if (show_branch)
				values[3] = current_branch;
			if (show_serial)
			{
				sprintf(serial_str, "%d", (*serial)++);
				if (show_branch)
					values[4] = serial_str;
				else
					values[3] = serial_str;
			}

			tuple = BuildTupleFromCStrings(attinmeta, values);

			/* store the tuple for later use */
			tuplestore_puttuple(tupstore, tuple);

			heap_freetuple(tuple);

			/* recurse using current_key as the new start_with */
			if (current_key)
				build_tuplestore_recursively(key_fld,
											 parent_key_fld,
											 relname,
											 orderby_fld,
											 branch_delim,
											 current_key,
											 current_branch,
											 level + 1,
											 serial,
											 max_depth,
											 show_branch,
											 show_serial,
											 per_query_ctx,
											 attinmeta,
											 tupstore);

			xpfree(current_key);
			xpfree(current_key_parent);

			/* reset branch for next pass */
			resetStringInfo(&branchstr);
			resetStringInfo(&chk_branchstr);
			resetStringInfo(&chk_current_key);
		}

		xpfree(branchstr.data);
		xpfree(chk_branchstr.data);
		xpfree(chk_current_key.data);
	}
}
Ejemplo n.º 9
0
/*
 *		ExecMakeTableFunctionResult
 *
 * Evaluate a table function, producing a materialized result in a Tuplestore
 * object.
 *
 * This is used by nodeFunctionscan.c.
 */
Tuplestorestate *
ExecMakeTableFunctionResult(SetExprState *setexpr,
							ExprContext *econtext,
							MemoryContext argContext,
							TupleDesc expectedDesc,
							bool randomAccess)
{
	Tuplestorestate *tupstore = NULL;
	TupleDesc	tupdesc = NULL;
	Oid			funcrettype;
	bool		returnsTuple;
	bool		returnsSet = false;
	FunctionCallInfoData fcinfo;
	PgStat_FunctionCallUsage fcusage;
	ReturnSetInfo rsinfo;
	HeapTupleData tmptup;
	MemoryContext callerContext;
	MemoryContext oldcontext;
	bool		first_time = true;

	callerContext = CurrentMemoryContext;

	funcrettype = exprType((Node *) setexpr->expr);

	returnsTuple = type_is_rowtype(funcrettype);

	/*
	 * Prepare a resultinfo node for communication.  We always do this even if
	 * not expecting a set result, so that we can pass expectedDesc.  In the
	 * generic-expression case, the expression doesn't actually get to see the
	 * resultinfo, but set it up anyway because we use some of the fields as
	 * our own state variables.
	 */
	rsinfo.type = T_ReturnSetInfo;
	rsinfo.econtext = econtext;
	rsinfo.expectedDesc = expectedDesc;
	rsinfo.allowedModes = (int) (SFRM_ValuePerCall | SFRM_Materialize | SFRM_Materialize_Preferred);
	if (randomAccess)
		rsinfo.allowedModes |= (int) SFRM_Materialize_Random;
	rsinfo.returnMode = SFRM_ValuePerCall;
	/* isDone is filled below */
	rsinfo.setResult = NULL;
	rsinfo.setDesc = NULL;

	/*
	 * Normally the passed expression tree will be a SetExprState, since the
	 * grammar only allows a function call at the top level of a table
	 * function reference.  However, if the function doesn't return set then
	 * the planner might have replaced the function call via constant-folding
	 * or inlining.  So if we see any other kind of expression node, execute
	 * it via the general ExecEvalExpr() code; the only difference is that we
	 * don't get a chance to pass a special ReturnSetInfo to any functions
	 * buried in the expression.
	 */
	if (!setexpr->elidedFuncState)
	{
		/*
		 * This path is similar to ExecMakeFunctionResultSet.
		 */
		returnsSet = setexpr->funcReturnsSet;
		InitFunctionCallInfoData(fcinfo, &(setexpr->func),
								 list_length(setexpr->args),
								 setexpr->fcinfo_data.fncollation,
								 NULL, (Node *) &rsinfo);

		/*
		 * Evaluate the function's argument list.
		 *
		 * We can't do this in the per-tuple context: the argument values
		 * would disappear when we reset that context in the inner loop.  And
		 * the caller's CurrentMemoryContext is typically a query-lifespan
		 * context, so we don't want to leak memory there.  We require the
		 * caller to pass a separate memory context that can be used for this,
		 * and can be reset each time through to avoid bloat.
		 */
		MemoryContextReset(argContext);
		oldcontext = MemoryContextSwitchTo(argContext);
		ExecEvalFuncArgs(&fcinfo, setexpr->args, econtext);
		MemoryContextSwitchTo(oldcontext);

		/*
		 * If function is strict, and there are any NULL arguments, skip
		 * calling the function and act like it returned NULL (or an empty
		 * set, in the returns-set case).
		 */
		if (setexpr->func.fn_strict)
		{
			int			i;

			for (i = 0; i < fcinfo.nargs; i++)
			{
				if (fcinfo.argnull[i])
					goto no_function_result;
			}
		}
	}
	else
	{
		/* Treat setexpr as a generic expression */
		InitFunctionCallInfoData(fcinfo, NULL, 0, InvalidOid, NULL, NULL);
	}

	/*
	 * Switch to short-lived context for calling the function or expression.
	 */
	MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory);

	/*
	 * Loop to handle the ValuePerCall protocol (which is also the same
	 * behavior needed in the generic ExecEvalExpr path).
	 */
	for (;;)
	{
		Datum		result;

		CHECK_FOR_INTERRUPTS();

		/*
		 * reset per-tuple memory context before each call of the function or
		 * expression. This cleans up any local memory the function may leak
		 * when called.
		 */
		ResetExprContext(econtext);

		/* Call the function or expression one time */
		if (!setexpr->elidedFuncState)
		{
			pgstat_init_function_usage(&fcinfo, &fcusage);

			fcinfo.isnull = false;
			rsinfo.isDone = ExprSingleResult;
			result = FunctionCallInvoke(&fcinfo);

			pgstat_end_function_usage(&fcusage,
									  rsinfo.isDone != ExprMultipleResult);
		}
		else
		{
			result =
				ExecEvalExpr(setexpr->elidedFuncState, econtext, &fcinfo.isnull);
			rsinfo.isDone = ExprSingleResult;
		}

		/* Which protocol does function want to use? */
		if (rsinfo.returnMode == SFRM_ValuePerCall)
		{
			/*
			 * Check for end of result set.
			 */
			if (rsinfo.isDone == ExprEndResult)
				break;

			/*
			 * If first time through, build tuplestore for result.  For a
			 * scalar function result type, also make a suitable tupdesc.
			 */
			if (first_time)
			{
				oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_query_memory);
				tupstore = tuplestore_begin_heap(randomAccess, false, work_mem);
				rsinfo.setResult = tupstore;
				if (!returnsTuple)
				{
					tupdesc = CreateTemplateTupleDesc(1, false);
					TupleDescInitEntry(tupdesc,
									   (AttrNumber) 1,
									   "column",
									   funcrettype,
									   -1,
									   0);
					rsinfo.setDesc = tupdesc;
				}
				MemoryContextSwitchTo(oldcontext);
			}

			/*
			 * Store current resultset item.
			 */
			if (returnsTuple)
			{
				if (!fcinfo.isnull)
				{
					HeapTupleHeader td = DatumGetHeapTupleHeader(result);

					if (tupdesc == NULL)
					{
						/*
						 * This is the first non-NULL result from the
						 * function.  Use the type info embedded in the
						 * rowtype Datum to look up the needed tupdesc.  Make
						 * a copy for the query.
						 */
						oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_query_memory);
						tupdesc = lookup_rowtype_tupdesc_copy(HeapTupleHeaderGetTypeId(td),
															  HeapTupleHeaderGetTypMod(td));
						rsinfo.setDesc = tupdesc;
						MemoryContextSwitchTo(oldcontext);
					}
					else
					{
						/*
						 * Verify all later returned rows have same subtype;
						 * necessary in case the type is RECORD.
						 */
						if (HeapTupleHeaderGetTypeId(td) != tupdesc->tdtypeid ||
							HeapTupleHeaderGetTypMod(td) != tupdesc->tdtypmod)
							ereport(ERROR,
									(errcode(ERRCODE_DATATYPE_MISMATCH),
									 errmsg("rows returned by function are not all of the same row type")));
					}

					/*
					 * tuplestore_puttuple needs a HeapTuple not a bare
					 * HeapTupleHeader, but it doesn't need all the fields.
					 */
					tmptup.t_len = HeapTupleHeaderGetDatumLength(td);
					tmptup.t_data = td;

					tuplestore_puttuple(tupstore, &tmptup);
				}
				else
				{
					/*
					 * NULL result from a tuple-returning function; expand it
					 * to a row of all nulls.  We rely on the expectedDesc to
					 * form such rows.  (Note: this would be problematic if
					 * tuplestore_putvalues saved the tdtypeid/tdtypmod from
					 * the provided descriptor, since that might not match
					 * what we get from the function itself.  But it doesn't.)
					 */
					int			natts = expectedDesc->natts;
					bool	   *nullflags;

					nullflags = (bool *) palloc(natts * sizeof(bool));
					memset(nullflags, true, natts * sizeof(bool));
					tuplestore_putvalues(tupstore, expectedDesc, NULL, nullflags);
				}
			}
			else
			{
				/* Scalar-type case: just store the function result */
				tuplestore_putvalues(tupstore, tupdesc, &result, &fcinfo.isnull);
			}

			/*
			 * Are we done?
			 */
			if (rsinfo.isDone != ExprMultipleResult)
				break;
		}
		else if (rsinfo.returnMode == SFRM_Materialize)
		{
			/* check we're on the same page as the function author */
			if (!first_time || rsinfo.isDone != ExprSingleResult)
				ereport(ERROR,
						(errcode(ERRCODE_E_R_I_E_SRF_PROTOCOL_VIOLATED),
						 errmsg("table-function protocol for materialize mode was not followed")));
			/* Done evaluating the set result */
			break;
		}
		else
			ereport(ERROR,
					(errcode(ERRCODE_E_R_I_E_SRF_PROTOCOL_VIOLATED),
					 errmsg("unrecognized table-function returnMode: %d",
							(int) rsinfo.returnMode)));

		first_time = false;
	}

no_function_result:

	/*
	 * If we got nothing from the function (ie, an empty-set or NULL result),
	 * we have to create the tuplestore to return, and if it's a
	 * non-set-returning function then insert a single all-nulls row.  As
	 * above, we depend on the expectedDesc to manufacture the dummy row.
	 */
	if (rsinfo.setResult == NULL)
	{
		MemoryContextSwitchTo(econtext->ecxt_per_query_memory);
		tupstore = tuplestore_begin_heap(randomAccess, false, work_mem);
		rsinfo.setResult = tupstore;
		if (!returnsSet)
		{
			int			natts = expectedDesc->natts;
			bool	   *nullflags;

			MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory);
			nullflags = (bool *) palloc(natts * sizeof(bool));
			memset(nullflags, true, natts * sizeof(bool));
			tuplestore_putvalues(tupstore, expectedDesc, NULL, nullflags);
		}
	}

	/*
	 * If function provided a tupdesc, cross-check it.  We only really need to
	 * do this for functions returning RECORD, but might as well do it always.
	 */
	if (rsinfo.setDesc)
	{
		tupledesc_match(expectedDesc, rsinfo.setDesc);

		/*
		 * If it is a dynamically-allocated TupleDesc, free it: it is
		 * typically allocated in a per-query context, so we must avoid
		 * leaking it across multiple usages.
		 */
		if (rsinfo.setDesc->tdrefcount == -1)
			FreeTupleDesc(rsinfo.setDesc);
	}

	MemoryContextSwitchTo(callerContext);

	/* All done, pass back the tuplestore */
	return rsinfo.setResult;
}
Ejemplo n.º 10
0
Datum
plr_environ(PG_FUNCTION_ARGS)
{
	ReturnSetInfo	   *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
	Tuplestorestate	   *tupstore;
	HeapTuple			tuple;
	TupleDesc			tupdesc;
	AttInMetadata	   *attinmeta;
	MemoryContext		per_query_ctx;
	MemoryContext		oldcontext;
	char			   *var_name;
	char			   *var_val;
	char			   *values[2];
#ifndef WIN32
	char			  **current_env;
#else
	char			   *buf;
	LPTSTR				envstr;
    int					count = 0;
	int					i;
#endif

	/* check to see if caller supports us returning a tuplestore */
	if (!rsinfo || !(rsinfo->allowedModes & SFRM_Materialize))
		ereport(ERROR,
				(errcode(ERRCODE_SYNTAX_ERROR),
				 errmsg("materialize mode required, but it is not "
						"allowed in this context")));

	per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
	oldcontext = MemoryContextSwitchTo(per_query_ctx);

	/* get the requested return tuple description */
	tupdesc = CreateTupleDescCopy(rsinfo->expectedDesc);

	/*
	 * Check to make sure we have a reasonable tuple descriptor
	 */
	if (tupdesc->natts != 2 ||
		tupdesc->attrs[0]->atttypid != TEXTOID ||
		tupdesc->attrs[1]->atttypid != TEXTOID)
		ereport(ERROR,
				(errcode(ERRCODE_SYNTAX_ERROR),
				 errmsg("query-specified return tuple and "
						"function return type are not compatible")));

	/* OK to use it */
	attinmeta = TupleDescGetAttInMetadata(tupdesc);

	/* let the caller know we're sending back a tuplestore */
	rsinfo->returnMode = SFRM_Materialize;

	/* initialize our tuplestore */
	tupstore = TUPLESTORE_BEGIN_HEAP;

#ifndef WIN32
	for (current_env = environ;
		 current_env != NULL && *current_env != NULL;
		 current_env++)
	{
		Size	name_len;

		var_val = strchr(*current_env, '=');
		if (!var_val)
			continue;

		name_len = var_val - *current_env;
		var_name = (char *) palloc0(name_len + 1);
		memcpy(var_name, *current_env, name_len);

		values[0] = var_name;
		values[1] = var_val + 1;

		tuple = BuildTupleFromCStrings(attinmeta, values);
		tuplestore_puttuple(tupstore, tuple);
		pfree(var_name);
	}
#else	
	buf = GetEnvironmentStrings();
	envstr = buf;

	while (true)
	{
		if (*envstr == 0)
			break;
		while (*envstr != 0)
			envstr++;
		envstr++;
		count++;
	}
	/* reset pointer to the environment buffer */
	envstr = buf;

	while(*buf == '=')
		buf++;
	for (i = 0; i < count; i++)
	{
		Size	name_len;

		var_val = strchr(buf, '=');
		if (!var_val)
			continue;

		name_len = var_val - buf;
		var_name = (char *) palloc0(name_len + 1);
		memcpy(var_name, buf, name_len);

		values[0] = var_name;
		values[1] = var_val + 1;

		tuple = BuildTupleFromCStrings(attinmeta, values);
		tuplestore_puttuple(tupstore, tuple);
		pfree(var_name);
		
		while(*buf != '\0')
			buf++;
		buf++;
	}

	FreeEnvironmentStrings(envstr);
#endif
	
	/*
	 * no longer need the tuple descriptor reference created by
	 * TupleDescGetAttInMetadata()
	 */
	ReleaseTupleDesc(tupdesc);

	tuplestore_donestoring(tupstore);
	rsinfo->setResult = tupstore;

	/*
	 * SFRM_Materialize mode expects us to return a NULL Datum. The actual
	 * tuples are in our tuplestore and passed back through
	 * rsinfo->setResult. rsinfo->setDesc is set to the tuple description
	 * that we actually used to build our tuples with, so the caller can
	 * verify we did what it was expecting.
	 */
	rsinfo->setDesc = tupdesc;
	MemoryContextSwitchTo(oldcontext);

	return (Datum) 0;
}
Ejemplo n.º 11
0
Datum
pg_config(PG_FUNCTION_ARGS)
{
	ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
	Tuplestorestate *tupstore;
	HeapTuple	tuple;
	TupleDesc	tupdesc;
	AttInMetadata *attinmeta;
	MemoryContext per_query_ctx;
	MemoryContext oldcontext;
	ConfigData *configdata;
	size_t		configdata_len;
	char	   *values[2];
	int			i = 0;

	/* check to see if caller supports us returning a tuplestore */
	if (!rsinfo || !(rsinfo->allowedModes & SFRM_Materialize))
		ereport(ERROR,
				(errcode(ERRCODE_SYNTAX_ERROR),
				 errmsg("materialize mode required, but it is not "
						"allowed in this context")));

	per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
	oldcontext = MemoryContextSwitchTo(per_query_ctx);

	/* get the requested return tuple description */
	tupdesc = CreateTupleDescCopy(rsinfo->expectedDesc);

	/*
	 * Check to make sure we have a reasonable tuple descriptor
	 */
	if (tupdesc->natts != 2 ||
		tupdesc->attrs[0]->atttypid != TEXTOID ||
		tupdesc->attrs[1]->atttypid != TEXTOID)
		ereport(ERROR,
				(errcode(ERRCODE_SYNTAX_ERROR),
				 errmsg("query-specified return tuple and "
						"function return type are not compatible")));

	/* OK to use it */
	attinmeta = TupleDescGetAttInMetadata(tupdesc);

	/* let the caller know we're sending back a tuplestore */
	rsinfo->returnMode = SFRM_Materialize;

	/* initialize our tuplestore */
	tupstore = tuplestore_begin_heap(true, false, work_mem);

	configdata = get_configdata(my_exec_path, &configdata_len);
	for (i = 0; i < configdata_len; i++)
	{
		values[0] = configdata[i].name;
		values[1] = configdata[i].setting;

		tuple = BuildTupleFromCStrings(attinmeta, values);
		tuplestore_puttuple(tupstore, tuple);
	}

	/*
	 * no longer need the tuple descriptor reference created by
	 * TupleDescGetAttInMetadata()
	 */
	ReleaseTupleDesc(tupdesc);

	tuplestore_donestoring(tupstore);
	rsinfo->setResult = tupstore;

	/*
	 * SFRM_Materialize mode expects us to return a NULL Datum. The actual
	 * tuples are in our tuplestore and passed back through rsinfo->setResult.
	 * rsinfo->setDesc is set to the tuple description that we actually used
	 * to build our tuples with, so the caller can verify we did what it was
	 * expecting.
	 */
	rsinfo->setDesc = tupdesc;
	MemoryContextSwitchTo(oldcontext);

	return (Datum) 0;
}