PostgreSQL Source Code  git master
functions.h File Reference
#include "nodes/execnodes.h"
#include "tcop/dest.h"
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Data Structures

struct  SQLFunctionParseInfo
 

Typedefs

typedef struct SQLFunctionParseInfo SQLFunctionParseInfo
 
typedef SQLFunctionParseInfoSQLFunctionParseInfoPtr
 

Functions

Datum fmgr_sql (PG_FUNCTION_ARGS)
 
SQLFunctionParseInfoPtr prepare_sql_fn_parse_info (HeapTuple procedureTuple, Node *call_expr, Oid inputCollation)
 
void sql_fn_parser_setup (struct ParseState *pstate, SQLFunctionParseInfoPtr pinfo)
 
void check_sql_fn_statements (List *queryTreeLists)
 
bool check_sql_fn_retval (List *queryTreeLists, Oid rettype, TupleDesc rettupdesc, bool insertDroppedCols, List **resultTargetList)
 
DestReceiverCreateSQLFunctionDestReceiver (void)
 

Typedef Documentation

◆ SQLFunctionParseInfo

◆ SQLFunctionParseInfoPtr

Definition at line 35 of file functions.h.

Function Documentation

◆ check_sql_fn_retval()

bool check_sql_fn_retval ( List queryTreeLists,
Oid  rettype,
TupleDesc  rettupdesc,
bool  insertDroppedCols,
List **  resultTargetList 
)

Definition at line 1612 of file functions.c.

1616 {
1617  bool is_tuple_result = false;
1618  Query *parse;
1619  ListCell *parse_cell;
1620  List *tlist;
1621  int tlistlen;
1622  bool tlist_is_modifiable;
1623  char fn_typtype;
1624  List *upper_tlist = NIL;
1625  bool upper_tlist_nontrivial = false;
1626  ListCell *lc;
1627 
1628  if (resultTargetList)
1629  *resultTargetList = NIL; /* initialize in case of VOID result */
1630 
1631  /*
1632  * If it's declared to return VOID, we don't care what's in the function.
1633  * (This takes care of the procedure case, as well.)
1634  */
1635  if (rettype == VOIDOID)
1636  return false;
1637 
1638  /*
1639  * Find the last canSetTag query in the function body (which is presented
1640  * to us as a list of sublists of Query nodes). This isn't necessarily
1641  * the last parsetree, because rule rewriting can insert queries after
1642  * what the user wrote. Note that it might not even be in the last
1643  * sublist, for example if the last query rewrites to DO INSTEAD NOTHING.
1644  * (It might not be unreasonable to throw an error in such a case, but
1645  * this is the historical behavior and it doesn't seem worth changing.)
1646  */
1647  parse = NULL;
1648  parse_cell = NULL;
1649  foreach(lc, queryTreeLists)
1650  {
1651  List *sublist = lfirst_node(List, lc);
1652  ListCell *lc2;
1653 
1654  foreach(lc2, sublist)
1655  {
1656  Query *q = lfirst_node(Query, lc2);
1657 
1658  if (q->canSetTag)
1659  {
1660  parse = q;
1661  parse_cell = lc2;
1662  }
1663  }
1664  }
1665 
1666  /*
1667  * If it's a plain SELECT, it returns whatever the targetlist says.
1668  * Otherwise, if it's INSERT/UPDATE/DELETE with RETURNING, it returns
1669  * that. Otherwise, the function return type must be VOID.
1670  *
1671  * Note: eventually replace this test with QueryReturnsTuples? We'd need
1672  * a more general method of determining the output type, though. Also, it
1673  * seems too dangerous to consider FETCH or EXECUTE as returning a
1674  * determinable rowtype, since they depend on relatively short-lived
1675  * entities.
1676  */
1677  if (parse &&
1678  parse->commandType == CMD_SELECT)
1679  {
1680  tlist = parse->targetList;
1681  /* tlist is modifiable unless it's a dummy in a setop query */
1682  tlist_is_modifiable = (parse->setOperations == NULL);
1683  }
1684  else if (parse &&
1685  (parse->commandType == CMD_INSERT ||
1686  parse->commandType == CMD_UPDATE ||
1687  parse->commandType == CMD_DELETE) &&
1688  parse->returningList)
1689  {
1690  tlist = parse->returningList;
1691  /* returningList can always be modified */
1692  tlist_is_modifiable = true;
1693  }
1694  else
1695  {
1696  /* Empty function body, or last statement is a utility command */
1697  ereport(ERROR,
1698  (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
1699  errmsg("return type mismatch in function declared to return %s",
1700  format_type_be(rettype)),
1701  errdetail("Function's final statement must be SELECT or INSERT/UPDATE/DELETE RETURNING.")));
1702  return false; /* keep compiler quiet */
1703  }
1704 
1705  /*
1706  * OK, check that the targetlist returns something matching the declared
1707  * type, and modify it if necessary. If possible, we insert any coercion
1708  * steps right into the final statement's targetlist. However, that might
1709  * risk changes in the statement's semantics --- we can't safely change
1710  * the output type of a grouping column, for instance. In such cases we
1711  * handle coercions by inserting an extra level of Query that effectively
1712  * just does a projection.
1713  */
1714 
1715  /*
1716  * Count the non-junk entries in the result targetlist.
1717  */
1718  tlistlen = ExecCleanTargetListLength(tlist);
1719 
1720  fn_typtype = get_typtype(rettype);
1721 
1722  if (fn_typtype == TYPTYPE_BASE ||
1723  fn_typtype == TYPTYPE_DOMAIN ||
1724  fn_typtype == TYPTYPE_ENUM ||
1725  fn_typtype == TYPTYPE_RANGE ||
1726  fn_typtype == TYPTYPE_MULTIRANGE)
1727  {
1728  /*
1729  * For scalar-type returns, the target list must have exactly one
1730  * non-junk entry, and its type must be coercible to rettype.
1731  */
1732  TargetEntry *tle;
1733 
1734  if (tlistlen != 1)
1735  ereport(ERROR,
1736  (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
1737  errmsg("return type mismatch in function declared to return %s",
1738  format_type_be(rettype)),
1739  errdetail("Final statement must return exactly one column.")));
1740 
1741  /* We assume here that non-junk TLEs must come first in tlists */
1742  tle = (TargetEntry *) linitial(tlist);
1743  Assert(!tle->resjunk);
1744 
1745  if (!coerce_fn_result_column(tle, rettype, -1,
1746  tlist_is_modifiable,
1747  &upper_tlist,
1748  &upper_tlist_nontrivial))
1749  ereport(ERROR,
1750  (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
1751  errmsg("return type mismatch in function declared to return %s",
1752  format_type_be(rettype)),
1753  errdetail("Actual return type is %s.",
1754  format_type_be(exprType((Node *) tle->expr)))));
1755  }
1756  else if (fn_typtype == TYPTYPE_COMPOSITE || rettype == RECORDOID)
1757  {
1758  /*
1759  * Returns a rowtype.
1760  *
1761  * Note that we will not consider a domain over composite to be a
1762  * "rowtype" return type; it goes through the scalar case above. This
1763  * is because we only provide column-by-column implicit casting, and
1764  * will not cast the complete record result. So the only way to
1765  * produce a domain-over-composite result is to compute it as an
1766  * explicit single-column result. The single-composite-column code
1767  * path just below could handle such cases, but it won't be reached.
1768  */
1769  int tupnatts; /* physical number of columns in tuple */
1770  int tuplogcols; /* # of nondeleted columns in tuple */
1771  int colindex; /* physical column index */
1772 
1773  /*
1774  * If the target list has one non-junk entry, and that expression has
1775  * or can be coerced to the declared return type, take it as the
1776  * result. This allows, for example, 'SELECT func2()', where func2
1777  * has the same composite return type as the function that's calling
1778  * it. This provision creates some ambiguity --- maybe the expression
1779  * was meant to be the lone field of the composite result --- but it
1780  * works well enough as long as we don't get too enthusiastic about
1781  * inventing coercions from scalar to composite types.
1782  *
1783  * XXX Note that if rettype is RECORD and the expression is of a named
1784  * composite type, or vice versa, this coercion will succeed, whether
1785  * or not the record type really matches. For the moment we rely on
1786  * runtime type checking to catch any discrepancy, but it'd be nice to
1787  * do better at parse time.
1788  */
1789  if (tlistlen == 1)
1790  {
1791  TargetEntry *tle = (TargetEntry *) linitial(tlist);
1792 
1793  Assert(!tle->resjunk);
1794  if (coerce_fn_result_column(tle, rettype, -1,
1795  tlist_is_modifiable,
1796  &upper_tlist,
1797  &upper_tlist_nontrivial))
1798  {
1799  /* Note that we're NOT setting is_tuple_result */
1800  goto tlist_coercion_finished;
1801  }
1802  }
1803 
1804  /*
1805  * If the caller didn't provide an expected tupdesc, we can't do any
1806  * further checking. Assume we're returning the whole tuple.
1807  */
1808  if (rettupdesc == NULL)
1809  {
1810  /* Return tlist if requested */
1811  if (resultTargetList)
1812  *resultTargetList = tlist;
1813  return true;
1814  }
1815 
1816  /*
1817  * Verify that the targetlist matches the return tuple type. We scan
1818  * the non-resjunk columns, and coerce them if necessary to match the
1819  * datatypes of the non-deleted attributes. For deleted attributes,
1820  * insert NULL result columns if the caller asked for that.
1821  */
1822  tupnatts = rettupdesc->natts;
1823  tuplogcols = 0; /* we'll count nondeleted cols as we go */
1824  colindex = 0;
1825 
1826  foreach(lc, tlist)
1827  {
1828  TargetEntry *tle = (TargetEntry *) lfirst(lc);
1829  Form_pg_attribute attr;
1830 
1831  /* resjunk columns can simply be ignored */
1832  if (tle->resjunk)
1833  continue;
1834 
1835  do
1836  {
1837  colindex++;
1838  if (colindex > tupnatts)
1839  ereport(ERROR,
1840  (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
1841  errmsg("return type mismatch in function declared to return %s",
1842  format_type_be(rettype)),
1843  errdetail("Final statement returns too many columns.")));
1844  attr = TupleDescAttr(rettupdesc, colindex - 1);
1845  if (attr->attisdropped && insertDroppedCols)
1846  {
1847  Expr *null_expr;
1848 
1849  /* The type of the null we insert isn't important */
1850  null_expr = (Expr *) makeConst(INT4OID,
1851  -1,
1852  InvalidOid,
1853  sizeof(int32),
1854  (Datum) 0,
1855  true, /* isnull */
1856  true /* byval */ );
1857  upper_tlist = lappend(upper_tlist,
1858  makeTargetEntry(null_expr,
1859  list_length(upper_tlist) + 1,
1860  NULL,
1861  false));
1862  upper_tlist_nontrivial = true;
1863  }
1864  } while (attr->attisdropped);
1865  tuplogcols++;
1866 
1867  if (!coerce_fn_result_column(tle,
1868  attr->atttypid, attr->atttypmod,
1869  tlist_is_modifiable,
1870  &upper_tlist,
1871  &upper_tlist_nontrivial))
1872  ereport(ERROR,
1873  (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
1874  errmsg("return type mismatch in function declared to return %s",
1875  format_type_be(rettype)),
1876  errdetail("Final statement returns %s instead of %s at column %d.",
1877  format_type_be(exprType((Node *) tle->expr)),
1878  format_type_be(attr->atttypid),
1879  tuplogcols)));
1880  }
1881 
1882  /* remaining columns in rettupdesc had better all be dropped */
1883  for (colindex++; colindex <= tupnatts; colindex++)
1884  {
1885  if (!TupleDescAttr(rettupdesc, colindex - 1)->attisdropped)
1886  ereport(ERROR,
1887  (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
1888  errmsg("return type mismatch in function declared to return %s",
1889  format_type_be(rettype)),
1890  errdetail("Final statement returns too few columns.")));
1891  if (insertDroppedCols)
1892  {
1893  Expr *null_expr;
1894 
1895  /* The type of the null we insert isn't important */
1896  null_expr = (Expr *) makeConst(INT4OID,
1897  -1,
1898  InvalidOid,
1899  sizeof(int32),
1900  (Datum) 0,
1901  true, /* isnull */
1902  true /* byval */ );
1903  upper_tlist = lappend(upper_tlist,
1904  makeTargetEntry(null_expr,
1905  list_length(upper_tlist) + 1,
1906  NULL,
1907  false));
1908  upper_tlist_nontrivial = true;
1909  }
1910  }
1911 
1912  /* Report that we are returning entire tuple result */
1913  is_tuple_result = true;
1914  }
1915  else
1916  ereport(ERROR,
1917  (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
1918  errmsg("return type %s is not supported for SQL functions",
1919  format_type_be(rettype))));
1920 
1921 tlist_coercion_finished:
1922 
1923  /*
1924  * If necessary, modify the final Query by injecting an extra Query level
1925  * that just performs a projection. (It'd be dubious to do this to a
1926  * non-SELECT query, but we never have to; RETURNING lists can always be
1927  * modified in-place.)
1928  */
1929  if (upper_tlist_nontrivial)
1930  {
1931  Query *newquery;
1932  List *colnames;
1933  RangeTblEntry *rte;
1934  RangeTblRef *rtr;
1935 
1936  Assert(parse->commandType == CMD_SELECT);
1937 
1938  /* Most of the upper Query struct can be left as zeroes/nulls */
1939  newquery = makeNode(Query);
1940  newquery->commandType = CMD_SELECT;
1941  newquery->querySource = parse->querySource;
1942  newquery->canSetTag = true;
1943  newquery->targetList = upper_tlist;
1944 
1945  /* We need a moderately realistic colnames list for the subquery RTE */
1946  colnames = NIL;
1947  foreach(lc, parse->targetList)
1948  {
1949  TargetEntry *tle = (TargetEntry *) lfirst(lc);
1950 
1951  if (tle->resjunk)
1952  continue;
1953  colnames = lappend(colnames,
1954  makeString(tle->resname ? tle->resname : ""));
1955  }
1956 
1957  /* Build a suitable RTE for the subquery */
1958  rte = makeNode(RangeTblEntry);
1959  rte->rtekind = RTE_SUBQUERY;
1960  rte->subquery = parse;
1961  rte->eref = rte->alias = makeAlias("*SELECT*", colnames);
1962  rte->lateral = false;
1963  rte->inh = false;
1964  rte->inFromCl = true;
1965  newquery->rtable = list_make1(rte);
1966 
1967  rtr = makeNode(RangeTblRef);
1968  rtr->rtindex = 1;
1969  newquery->jointree = makeFromExpr(list_make1(rtr), NULL);
1970 
1971  /* Replace original query in the correct element of the query list */
1972  lfirst(parse_cell) = newquery;
1973  }
1974 
1975  /* Return tlist (possibly modified) if requested */
1976  if (resultTargetList)
1977  *resultTargetList = upper_tlist;
1978 
1979  return is_tuple_result;
1980 }
signed int int32
Definition: c.h:430
int errdetail(const char *fmt,...)
Definition: elog.c:1039
int errcode(int sqlerrcode)
Definition: elog.c:695
int errmsg(const char *fmt,...)
Definition: elog.c:906
#define ERROR
Definition: elog.h:35
#define ereport(elevel,...)
Definition: elog.h:145
int ExecCleanTargetListLength(List *targetlist)
Definition: execUtils.c:1148
char * format_type_be(Oid type_oid)
Definition: format_type.c:339
static bool coerce_fn_result_column(TargetEntry *src_tle, Oid res_type, int32 res_typmod, bool tlist_is_modifiable, List **upper_tlist, bool *upper_tlist_nontrivial)
Definition: functions.c:1993
Assert(fmt[strlen(fmt) - 1] !='\n')
List * lappend(List *list, void *datum)
Definition: list.c:338
char get_typtype(Oid typid)
Definition: lsyscache.c:2587
Alias * makeAlias(const char *aliasname, List *colnames)
Definition: makefuncs.c:387
TargetEntry * makeTargetEntry(Expr *expr, AttrNumber resno, char *resname, bool resjunk)
Definition: makefuncs.c:238
Const * makeConst(Oid consttype, int32 consttypmod, Oid constcollid, int constlen, Datum constvalue, bool constisnull, bool constbyval)
Definition: makefuncs.c:299
FromExpr * makeFromExpr(List *fromlist, Node *quals)
Definition: makefuncs.c:285
Oid exprType(const Node *expr)
Definition: nodeFuncs.c:43
@ CMD_INSERT
Definition: nodes.h:261
@ CMD_DELETE
Definition: nodes.h:262
@ CMD_UPDATE
Definition: nodes.h:260
@ CMD_SELECT
Definition: nodes.h:259
#define makeNode(_type_)
Definition: nodes.h:159
@ RTE_SUBQUERY
Definition: parsenodes.h:1012
FormData_pg_attribute * Form_pg_attribute
Definition: pg_attribute.h:207
#define lfirst(lc)
Definition: pg_list.h:170
#define lfirst_node(type, lc)
Definition: pg_list.h:174
static int list_length(const List *l)
Definition: pg_list.h:150
#define NIL
Definition: pg_list.h:66
#define list_make1(x1)
Definition: pg_list.h:210
#define linitial(l)
Definition: pg_list.h:176
uintptr_t Datum
Definition: postgres.h:412
#define InvalidOid
Definition: postgres_ext.h:36
static struct subre * parse(struct vars *v, int stopper, int type, struct state *init, struct state *final)
Definition: regcomp.c:717
Definition: pg_list.h:52
Definition: nodes.h:112
FromExpr * jointree
Definition: parsenodes.h:156
bool canSetTag
Definition: parsenodes.h:134
List * rtable
Definition: parsenodes.h:155
QuerySource querySource
Definition: parsenodes.h:126
CmdType commandType
Definition: parsenodes.h:124
List * targetList
Definition: parsenodes.h:162
Query * subquery
Definition: parsenodes.h:1065
Alias * eref
Definition: parsenodes.h:1176
Alias * alias
Definition: parsenodes.h:1175
RTEKind rtekind
Definition: parsenodes.h:1030
Expr * expr
Definition: primnodes.h:1555
char * resname
Definition: primnodes.h:1557
bool resjunk
Definition: primnodes.h:1562
#define TupleDescAttr(tupdesc, i)
Definition: tupdesc.h:92
String * makeString(char *str)
Definition: value.c:63

References RangeTblEntry::alias, Assert(), Query::canSetTag, CMD_DELETE, CMD_INSERT, CMD_SELECT, CMD_UPDATE, coerce_fn_result_column(), Query::commandType, RangeTblEntry::eref, ereport, errcode(), errdetail(), errmsg(), ERROR, ExecCleanTargetListLength(), TargetEntry::expr, exprType(), format_type_be(), get_typtype(), RangeTblEntry::inFromCl, RangeTblEntry::inh, InvalidOid, Query::jointree, lappend(), RangeTblEntry::lateral, lfirst, lfirst_node, linitial, list_length(), list_make1, makeAlias(), makeConst(), makeFromExpr(), makeNode, makeString(), makeTargetEntry(), TupleDescData::natts, NIL, parse(), Query::querySource, TargetEntry::resjunk, TargetEntry::resname, Query::rtable, RTE_SUBQUERY, RangeTblEntry::rtekind, RangeTblRef::rtindex, RangeTblEntry::subquery, Query::targetList, and TupleDescAttr.

Referenced by fmgr_sql_validator(), init_sql_fcache(), inline_function(), and inline_set_returning_function().

◆ check_sql_fn_statements()

void check_sql_fn_statements ( List queryTreeLists)

Definition at line 1537 of file functions.c.

1538 {
1539  ListCell *lc;
1540 
1541  /* We are given a list of sublists of Queries */
1542  foreach(lc, queryTreeLists)
1543  {
1544  List *sublist = lfirst_node(List, lc);
1545  ListCell *lc2;
1546 
1547  foreach(lc2, sublist)
1548  {
1549  Query *query = lfirst_node(Query, lc2);
1550 
1551  /*
1552  * Disallow calling procedures with output arguments. The current
1553  * implementation would just throw the output values away, unless
1554  * the statement is the last one. Per SQL standard, we should
1555  * assign the output values by name. By disallowing this here, we
1556  * preserve an opportunity for future improvement.
1557  */
1558  if (query->commandType == CMD_UTILITY &&
1559  IsA(query->utilityStmt, CallStmt))
1560  {
1561  CallStmt *stmt = (CallStmt *) query->utilityStmt;
1562 
1563  if (stmt->outargs != NIL)
1564  ereport(ERROR,
1565  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1566  errmsg("calling procedures with output arguments is not supported in SQL functions")));
1567  }
1568  }
1569  }
1570 }
if(TABLE==NULL||TABLE_index==NULL)
Definition: isn.c:77
#define IsA(nodeptr, _type_)
Definition: nodes.h:162
@ CMD_UTILITY
Definition: nodes.h:264
List * outargs
Definition: parsenodes.h:3122
Node * utilityStmt
Definition: parsenodes.h:136

References CMD_UTILITY, Query::commandType, ereport, errcode(), errmsg(), ERROR, if(), IsA, lfirst_node, NIL, execution_state::stmt, and Query::utilityStmt.

Referenced by fmgr_sql_validator(), and init_sql_fcache().

◆ CreateSQLFunctionDestReceiver()

DestReceiver* CreateSQLFunctionDestReceiver ( void  )

Definition at line 2059 of file functions.c.

2060 {
2061  DR_sqlfunction *self = (DR_sqlfunction *) palloc0(sizeof(DR_sqlfunction));
2062 
2063  self->pub.receiveSlot = sqlfunction_receive;
2064  self->pub.rStartup = sqlfunction_startup;
2065  self->pub.rShutdown = sqlfunction_shutdown;
2066  self->pub.rDestroy = sqlfunction_destroy;
2067  self->pub.mydest = DestSQLFunction;
2068 
2069  /* private fields will be set by postquel_start */
2070 
2071  return (DestReceiver *) self;
2072 }
@ DestSQLFunction
Definition: dest.h:98
static void sqlfunction_startup(DestReceiver *self, int operation, TupleDesc typeinfo)
Definition: functions.c:2078
static bool sqlfunction_receive(TupleTableSlot *slot, DestReceiver *self)
Definition: functions.c:2087
static void sqlfunction_destroy(DestReceiver *self)
Definition: functions.c:2113
static void sqlfunction_shutdown(DestReceiver *self)
Definition: functions.c:2104
void * palloc0(Size size)
Definition: mcxt.c:1230

References DestSQLFunction, palloc0(), sqlfunction_destroy(), sqlfunction_receive(), sqlfunction_shutdown(), and sqlfunction_startup().

Referenced by CreateDestReceiver().

◆ fmgr_sql()

Datum fmgr_sql ( PG_FUNCTION_ARGS  )

Definition at line 1032 of file functions.c.

1033 {
1034  SQLFunctionCachePtr fcache;
1035  ErrorContextCallback sqlerrcontext;
1036  MemoryContext oldcontext;
1037  bool randomAccess;
1038  bool lazyEvalOK;
1039  bool is_first;
1040  bool pushed_snapshot;
1041  execution_state *es;
1042  TupleTableSlot *slot;
1043  Datum result;
1044  List *eslist;
1045  ListCell *eslc;
1046 
1047  /*
1048  * Setup error traceback support for ereport()
1049  */
1050  sqlerrcontext.callback = sql_exec_error_callback;
1051  sqlerrcontext.arg = fcinfo->flinfo;
1052  sqlerrcontext.previous = error_context_stack;
1053  error_context_stack = &sqlerrcontext;
1054 
1055  /* Check call context */
1056  if (fcinfo->flinfo->fn_retset)
1057  {
1058  ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
1059 
1060  /*
1061  * For simplicity, we require callers to support both set eval modes.
1062  * There are cases where we must use one or must use the other, and
1063  * it's not really worthwhile to postpone the check till we know. But
1064  * note we do not require caller to provide an expectedDesc.
1065  */
1066  if (!rsi || !IsA(rsi, ReturnSetInfo) ||
1067  (rsi->allowedModes & SFRM_ValuePerCall) == 0 ||
1068  (rsi->allowedModes & SFRM_Materialize) == 0)
1069  ereport(ERROR,
1070  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1071  errmsg("set-valued function called in context that cannot accept a set")));
1072  randomAccess = rsi->allowedModes & SFRM_Materialize_Random;
1073  lazyEvalOK = !(rsi->allowedModes & SFRM_Materialize_Preferred);
1074  }
1075  else
1076  {
1077  randomAccess = false;
1078  lazyEvalOK = true;
1079  }
1080 
1081  /*
1082  * Initialize fcache (build plans) if first time through; or re-initialize
1083  * if the cache is stale.
1084  */
1085  fcache = (SQLFunctionCachePtr) fcinfo->flinfo->fn_extra;
1086 
1087  if (fcache != NULL)
1088  {
1089  if (fcache->lxid != MyProc->lxid ||
1090  !SubTransactionIsActive(fcache->subxid))
1091  {
1092  /* It's stale; unlink and delete */
1093  fcinfo->flinfo->fn_extra = NULL;
1094  MemoryContextDelete(fcache->fcontext);
1095  fcache = NULL;
1096  }
1097  }
1098 
1099  if (fcache == NULL)
1100  {
1101  init_sql_fcache(fcinfo, PG_GET_COLLATION(), lazyEvalOK);
1102  fcache = (SQLFunctionCachePtr) fcinfo->flinfo->fn_extra;
1103  }
1104 
1105  /*
1106  * Switch to context in which the fcache lives. This ensures that our
1107  * tuplestore etc will have sufficient lifetime. The sub-executor is
1108  * responsible for deleting per-tuple information. (XXX in the case of a
1109  * long-lived FmgrInfo, this policy represents more memory leakage, but
1110  * it's not entirely clear where to keep stuff instead.)
1111  */
1112  oldcontext = MemoryContextSwitchTo(fcache->fcontext);
1113 
1114  /*
1115  * Find first unfinished query in function, and note whether it's the
1116  * first query.
1117  */
1118  eslist = fcache->func_state;
1119  es = NULL;
1120  is_first = true;
1121  foreach(eslc, eslist)
1122  {
1123  es = (execution_state *) lfirst(eslc);
1124 
1125  while (es && es->status == F_EXEC_DONE)
1126  {
1127  is_first = false;
1128  es = es->next;
1129  }
1130 
1131  if (es)
1132  break;
1133  }
1134 
1135  /*
1136  * Convert params to appropriate format if starting a fresh execution. (If
1137  * continuing execution, we can re-use prior params.)
1138  */
1139  if (is_first && es && es->status == F_EXEC_START)
1140  postquel_sub_params(fcache, fcinfo);
1141 
1142  /*
1143  * Build tuplestore to hold results, if we don't have one already. Note
1144  * it's in the query-lifespan context.
1145  */
1146  if (!fcache->tstore)
1147  fcache->tstore = tuplestore_begin_heap(randomAccess, false, work_mem);
1148 
1149  /*
1150  * Execute each command in the function one after another until we either
1151  * run out of commands or get a result row from a lazily-evaluated SELECT.
1152  *
1153  * Notes about snapshot management:
1154  *
1155  * In a read-only function, we just use the surrounding query's snapshot.
1156  *
1157  * In a non-read-only function, we rely on the fact that we'll never
1158  * suspend execution between queries of the function: the only reason to
1159  * suspend execution before completion is if we are returning a row from a
1160  * lazily-evaluated SELECT. So, when first entering this loop, we'll
1161  * either start a new query (and push a fresh snapshot) or re-establish
1162  * the active snapshot from the existing query descriptor. If we need to
1163  * start a new query in a subsequent execution of the loop, either we need
1164  * a fresh snapshot (and pushed_snapshot is false) or the existing
1165  * snapshot is on the active stack and we can just bump its command ID.
1166  */
1167  pushed_snapshot = false;
1168  while (es)
1169  {
1170  bool completed;
1171 
1172  if (es->status == F_EXEC_START)
1173  {
1174  /*
1175  * If not read-only, be sure to advance the command counter for
1176  * each command, so that all work to date in this transaction is
1177  * visible. Take a new snapshot if we don't have one yet,
1178  * otherwise just bump the command ID in the existing snapshot.
1179  */
1180  if (!fcache->readonly_func)
1181  {
1183  if (!pushed_snapshot)
1184  {
1186  pushed_snapshot = true;
1187  }
1188  else
1190  }
1191 
1192  postquel_start(es, fcache);
1193  }
1194  else if (!fcache->readonly_func && !pushed_snapshot)
1195  {
1196  /* Re-establish active snapshot when re-entering function */
1198  pushed_snapshot = true;
1199  }
1200 
1201  completed = postquel_getnext(es, fcache);
1202 
1203  /*
1204  * If we ran the command to completion, we can shut it down now. Any
1205  * row(s) we need to return are safely stashed in the tuplestore, and
1206  * we want to be sure that, for example, AFTER triggers get fired
1207  * before we return anything. Also, if the function doesn't return
1208  * set, we can shut it down anyway because it must be a SELECT and we
1209  * don't care about fetching any more result rows.
1210  */
1211  if (completed || !fcache->returnsSet)
1212  postquel_end(es);
1213 
1214  /*
1215  * Break from loop if we didn't shut down (implying we got a
1216  * lazily-evaluated row). Otherwise we'll press on till the whole
1217  * function is done, relying on the tuplestore to keep hold of the
1218  * data to eventually be returned. This is necessary since an
1219  * INSERT/UPDATE/DELETE RETURNING that sets the result might be
1220  * followed by additional rule-inserted commands, and we want to
1221  * finish doing all those commands before we return anything.
1222  */
1223  if (es->status != F_EXEC_DONE)
1224  break;
1225 
1226  /*
1227  * Advance to next execution_state, which might be in the next list.
1228  */
1229  es = es->next;
1230  while (!es)
1231  {
1232  eslc = lnext(eslist, eslc);
1233  if (!eslc)
1234  break; /* end of function */
1235 
1236  es = (execution_state *) lfirst(eslc);
1237 
1238  /*
1239  * Flush the current snapshot so that we will take a new one for
1240  * the new query list. This ensures that new snaps are taken at
1241  * original-query boundaries, matching the behavior of interactive
1242  * execution.
1243  */
1244  if (pushed_snapshot)
1245  {
1247  pushed_snapshot = false;
1248  }
1249  }
1250  }
1251 
1252  /*
1253  * The tuplestore now contains whatever row(s) we are supposed to return.
1254  */
1255  if (fcache->returnsSet)
1256  {
1257  ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
1258 
1259  if (es)
1260  {
1261  /*
1262  * If we stopped short of being done, we must have a lazy-eval
1263  * row.
1264  */
1265  Assert(es->lazyEval);
1266  /* Re-use the junkfilter's output slot to fetch back the tuple */
1267  Assert(fcache->junkFilter);
1268  slot = fcache->junkFilter->jf_resultSlot;
1269  if (!tuplestore_gettupleslot(fcache->tstore, true, false, slot))
1270  elog(ERROR, "failed to fetch lazy-eval tuple");
1271  /* Extract the result as a datum, and copy out from the slot */
1272  result = postquel_get_single_result(slot, fcinfo,
1273  fcache, oldcontext);
1274  /* Clear the tuplestore, but keep it for next time */
1275  /* NB: this might delete the slot's content, but we don't care */
1276  tuplestore_clear(fcache->tstore);
1277 
1278  /*
1279  * Let caller know we're not finished.
1280  */
1281  rsi->isDone = ExprMultipleResult;
1282 
1283  /*
1284  * Ensure we will get shut down cleanly if the exprcontext is not
1285  * run to completion.
1286  */
1287  if (!fcache->shutdown_reg)
1288  {
1291  PointerGetDatum(fcache));
1292  fcache->shutdown_reg = true;
1293  }
1294  }
1295  else if (fcache->lazyEval)
1296  {
1297  /*
1298  * We are done with a lazy evaluation. Clean up.
1299  */
1300  tuplestore_clear(fcache->tstore);
1301 
1302  /*
1303  * Let caller know we're finished.
1304  */
1305  rsi->isDone = ExprEndResult;
1306 
1307  fcinfo->isnull = true;
1308  result = (Datum) 0;
1309 
1310  /* Deregister shutdown callback, if we made one */
1311  if (fcache->shutdown_reg)
1312  {
1315  PointerGetDatum(fcache));
1316  fcache->shutdown_reg = false;
1317  }
1318  }
1319  else
1320  {
1321  /*
1322  * We are done with a non-lazy evaluation. Return whatever is in
1323  * the tuplestore. (It is now caller's responsibility to free the
1324  * tuplestore when done.)
1325  */
1327  rsi->setResult = fcache->tstore;
1328  fcache->tstore = NULL;
1329  /* must copy desc because execSRF.c will free it */
1330  if (fcache->junkFilter)
1332 
1333  fcinfo->isnull = true;
1334  result = (Datum) 0;
1335 
1336  /* Deregister shutdown callback, if we made one */
1337  if (fcache->shutdown_reg)
1338  {
1341  PointerGetDatum(fcache));
1342  fcache->shutdown_reg = false;
1343  }
1344  }
1345  }
1346  else
1347  {
1348  /*
1349  * Non-set function. If we got a row, return it; else return NULL.
1350  */
1351  if (fcache->junkFilter)
1352  {
1353  /* Re-use the junkfilter's output slot to fetch back the tuple */
1354  slot = fcache->junkFilter->jf_resultSlot;
1355  if (tuplestore_gettupleslot(fcache->tstore, true, false, slot))
1356  result = postquel_get_single_result(slot, fcinfo,
1357  fcache, oldcontext);
1358  else
1359  {
1360  fcinfo->isnull = true;
1361  result = (Datum) 0;
1362  }
1363  }
1364  else
1365  {
1366  /* Should only get here for VOID functions and procedures */
1367  Assert(fcache->rettype == VOIDOID);
1368  fcinfo->isnull = true;
1369  result = (Datum) 0;
1370  }
1371 
1372  /* Clear the tuplestore, but keep it for next time */
1373  tuplestore_clear(fcache->tstore);
1374  }
1375 
1376  /* Pop snapshot if we have pushed one */
1377  if (pushed_snapshot)
1379 
1380  /*
1381  * If we've gone through every command in the function, we are done. Reset
1382  * the execution states to start over again on next call.
1383  */
1384  if (es == NULL)
1385  {
1386  foreach(eslc, fcache->func_state)
1387  {
1388  es = (execution_state *) lfirst(eslc);
1389  while (es)
1390  {
1391  es->status = F_EXEC_START;
1392  es = es->next;
1393  }
1394  }
1395  }
1396 
1397  error_context_stack = sqlerrcontext.previous;
1398 
1399  MemoryContextSwitchTo(oldcontext);
1400 
1401  return result;
1402 }
ErrorContextCallback * error_context_stack
Definition: elog.c:94
void UnregisterExprContextCallback(ExprContext *econtext, ExprContextCallbackFunction function, Datum arg)
Definition: execUtils.c:952
void RegisterExprContextCallback(ExprContext *econtext, ExprContextCallbackFunction function, Datum arg)
Definition: execUtils.c:926
@ ExprMultipleResult
Definition: execnodes.h:296
@ ExprEndResult
Definition: execnodes.h:297
@ SFRM_Materialize_Preferred
Definition: execnodes.h:311
@ SFRM_ValuePerCall
Definition: execnodes.h:308
@ SFRM_Materialize_Random
Definition: execnodes.h:310
@ SFRM_Materialize
Definition: execnodes.h:309
#define PG_GET_COLLATION()
Definition: fmgr.h:198
static bool postquel_getnext(execution_state *es, SQLFunctionCachePtr fcache)
Definition: functions.c:879
static void postquel_end(execution_state *es)
Definition: functions.c:914
static void postquel_sub_params(SQLFunctionCachePtr fcache, FunctionCallInfo fcinfo)
Definition: functions.c:934
static void postquel_start(execution_state *es, SQLFunctionCachePtr fcache)
Definition: functions.c:817
static Datum postquel_get_single_result(TupleTableSlot *slot, FunctionCallInfo fcinfo, SQLFunctionCachePtr fcache, MemoryContext resultcontext)
Definition: functions.c:989
static void sql_exec_error_callback(void *arg)
Definition: functions.c:1409
static void init_sql_fcache(FunctionCallInfo fcinfo, Oid collation, bool lazyEvalOK)
Definition: functions.c:582
static void ShutdownSQLFunction(Datum arg)
Definition: functions.c:1491
@ F_EXEC_START
Definition: functions.c:62
@ F_EXEC_DONE
Definition: functions.c:62
SQLFunctionCache * SQLFunctionCachePtr
Definition: functions.c:130
int work_mem
Definition: globals.c:125
void MemoryContextDelete(MemoryContext context)
Definition: mcxt.c:376
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:135
static ListCell * lnext(const List *l, const ListCell *c)
Definition: pg_list.h:341
static Datum PointerGetDatum(const void *X)
Definition: postgres.h:670
Snapshot GetTransactionSnapshot(void)
Definition: snapmgr.c:251
void PushActiveSnapshot(Snapshot snapshot)
Definition: snapmgr.c:683
void UpdateActiveSnapshotCommandId(void)
Definition: snapmgr.c:747
void PopActiveSnapshot(void)
Definition: snapmgr.c:778
PGPROC * MyProc
Definition: proc.c:68
struct ErrorContextCallback * previous
Definition: elog.h:234
void(* callback)(void *arg)
Definition: elog.h:235
TupleDesc jf_cleanTupType
Definition: execnodes.h:387
TupleTableSlot * jf_resultSlot
Definition: execnodes.h:389
LocalTransactionId lxid
Definition: proc.h:183
Snapshot snapshot
Definition: execdesc.h:39
SetFunctionReturnMode returnMode
Definition: execnodes.h:328
ExprContext * econtext
Definition: execnodes.h:324
TupleDesc setDesc
Definition: execnodes.h:332
Tuplestorestate * setResult
Definition: execnodes.h:331
int allowedModes
Definition: execnodes.h:326
ExprDoneCond isDone
Definition: execnodes.h:329
MemoryContext fcontext
Definition: functions.c:123
LocalTransactionId lxid
Definition: functions.c:126
JunkFilter * junkFilter
Definition: functions.c:113
List * func_state
Definition: functions.c:121
Tuplestorestate * tstore
Definition: functions.c:111
SubTransactionId subxid
Definition: functions.c:127
ExecStatus status
Definition: functions.c:68
struct execution_state * next
Definition: functions.c:67
QueryDesc * qd
Definition: functions.c:72
TupleDesc CreateTupleDescCopy(TupleDesc tupdesc)
Definition: tupdesc.c:111
bool tuplestore_gettupleslot(Tuplestorestate *state, bool forward, bool copy, TupleTableSlot *slot)
Definition: tuplestore.c:1078
void tuplestore_clear(Tuplestorestate *state)
Definition: tuplestore.c:418
Tuplestorestate * tuplestore_begin_heap(bool randomAccess, bool interXact, int maxKBytes)
Definition: tuplestore.c:318
void CommandCounterIncrement(void)
Definition: xact.c:1077
bool SubTransactionIsActive(SubTransactionId subxid)
Definition: xact.c:793

References ReturnSetInfo::allowedModes, ErrorContextCallback::arg, Assert(), ErrorContextCallback::callback, CommandCounterIncrement(), CreateTupleDescCopy(), ReturnSetInfo::econtext, elog(), ereport, errcode(), errmsg(), ERROR, error_context_stack, ExprEndResult, ExprMultipleResult, F_EXEC_DONE, F_EXEC_START, SQLFunctionCache::fcontext, SQLFunctionCache::func_state, GetTransactionSnapshot(), if(), init_sql_fcache(), IsA, ReturnSetInfo::isDone, JunkFilter::jf_cleanTupType, JunkFilter::jf_resultSlot, SQLFunctionCache::junkFilter, execution_state::lazyEval, SQLFunctionCache::lazyEval, lfirst, lnext(), SQLFunctionCache::lxid, PGPROC::lxid, MemoryContextDelete(), MemoryContextSwitchTo(), MyProc, execution_state::next, PG_GET_COLLATION, PointerGetDatum(), PopActiveSnapshot(), postquel_end(), postquel_get_single_result(), postquel_getnext(), postquel_start(), postquel_sub_params(), ErrorContextCallback::previous, PushActiveSnapshot(), execution_state::qd, SQLFunctionCache::readonly_func, RegisterExprContextCallback(), SQLFunctionCache::rettype, ReturnSetInfo::returnMode, SQLFunctionCache::returnsSet, ReturnSetInfo::setDesc, ReturnSetInfo::setResult, SFRM_Materialize, SFRM_Materialize_Preferred, SFRM_Materialize_Random, SFRM_ValuePerCall, SQLFunctionCache::shutdown_reg, ShutdownSQLFunction(), QueryDesc::snapshot, sql_exec_error_callback(), execution_state::status, SubTransactionIsActive(), SQLFunctionCache::subxid, SQLFunctionCache::tstore, tuplestore_begin_heap(), tuplestore_clear(), tuplestore_gettupleslot(), UnregisterExprContextCallback(), UpdateActiveSnapshotCommandId(), and work_mem.

Referenced by fmgr_info_cxt_security().

◆ prepare_sql_fn_parse_info()

SQLFunctionParseInfoPtr prepare_sql_fn_parse_info ( HeapTuple  procedureTuple,
Node call_expr,
Oid  inputCollation 
)

Definition at line 176 of file functions.c.

179 {
181  Form_pg_proc procedureStruct = (Form_pg_proc) GETSTRUCT(procedureTuple);
182  int nargs;
183 
185 
186  /* Function's name (only) can be used to qualify argument names */
187  pinfo->fname = pstrdup(NameStr(procedureStruct->proname));
188 
189  /* Save the function's input collation */
190  pinfo->collation = inputCollation;
191 
192  /*
193  * Copy input argument types from the pg_proc entry, then resolve any
194  * polymorphic types.
195  */
196  pinfo->nargs = nargs = procedureStruct->pronargs;
197  if (nargs > 0)
198  {
199  Oid *argOidVect;
200  int argnum;
201 
202  argOidVect = (Oid *) palloc(nargs * sizeof(Oid));
203  memcpy(argOidVect,
204  procedureStruct->proargtypes.values,
205  nargs * sizeof(Oid));
206 
207  for (argnum = 0; argnum < nargs; argnum++)
208  {
209  Oid argtype = argOidVect[argnum];
210 
211  if (IsPolymorphicType(argtype))
212  {
213  argtype = get_call_expr_argtype(call_expr, argnum);
214  if (argtype == InvalidOid)
215  ereport(ERROR,
216  (errcode(ERRCODE_DATATYPE_MISMATCH),
217  errmsg("could not determine actual type of argument declared %s",
218  format_type_be(argOidVect[argnum]))));
219  argOidVect[argnum] = argtype;
220  }
221  }
222 
223  pinfo->argtypes = argOidVect;
224  }
225 
226  /*
227  * Collect names of arguments, too, if any
228  */
229  if (nargs > 0)
230  {
231  Datum proargnames;
232  Datum proargmodes;
233  int n_arg_names;
234  bool isNull;
235 
236  proargnames = SysCacheGetAttr(PROCNAMEARGSNSP, procedureTuple,
237  Anum_pg_proc_proargnames,
238  &isNull);
239  if (isNull)
240  proargnames = PointerGetDatum(NULL); /* just to be sure */
241 
242  proargmodes = SysCacheGetAttr(PROCNAMEARGSNSP, procedureTuple,
243  Anum_pg_proc_proargmodes,
244  &isNull);
245  if (isNull)
246  proargmodes = PointerGetDatum(NULL); /* just to be sure */
247 
248  n_arg_names = get_func_input_arg_names(proargnames, proargmodes,
249  &pinfo->argnames);
250 
251  /* Paranoia: ignore the result if too few array entries */
252  if (n_arg_names < nargs)
253  pinfo->argnames = NULL;
254  }
255  else
256  pinfo->argnames = NULL;
257 
258  return pinfo;
259 }
#define NameStr(name)
Definition: c.h:682
Oid get_call_expr_argtype(Node *expr, int argnum)
Definition: fmgr.c:1805
int get_func_input_arg_names(Datum proargnames, Datum proargmodes, char ***arg_names)
Definition: funcapi.c:1514
SQLFunctionParseInfo * SQLFunctionParseInfoPtr
Definition: functions.h:35
#define GETSTRUCT(TUP)
Definition: htup_details.h:649
char * pstrdup(const char *in)
Definition: mcxt.c:1483
void * palloc(Size size)
Definition: mcxt.c:1199
FormData_pg_proc * Form_pg_proc
Definition: pg_proc.h:136
unsigned int Oid
Definition: postgres_ext.h:31
Datum SysCacheGetAttr(int cacheId, HeapTuple tup, AttrNumber attributeNumber, bool *isNull)
Definition: syscache.c:1434
@ PROCNAMEARGSNSP
Definition: syscache.h:78

References SQLFunctionParseInfo::argnames, SQLFunctionParseInfo::argtypes, SQLFunctionParseInfo::collation, ereport, errcode(), errmsg(), ERROR, SQLFunctionParseInfo::fname, format_type_be(), get_call_expr_argtype(), get_func_input_arg_names(), GETSTRUCT, InvalidOid, NameStr, SQLFunctionParseInfo::nargs, palloc(), palloc0(), PointerGetDatum(), PROCNAMEARGSNSP, pstrdup(), and SysCacheGetAttr().

Referenced by fmgr_sql_validator(), init_sql_fcache(), inline_function(), and inline_set_returning_function().

◆ sql_fn_parser_setup()

void sql_fn_parser_setup ( struct ParseState pstate,
SQLFunctionParseInfoPtr  pinfo 
)

Definition at line 265 of file functions.c.

266 {
267  pstate->p_pre_columnref_hook = NULL;
270  /* no need to use p_coerce_param_hook */
271  pstate->p_ref_hook_state = (void *) pinfo;
272 }
static Node * sql_fn_param_ref(ParseState *pstate, ParamRef *pref)
Definition: functions.c:394
static Node * sql_fn_post_column_ref(ParseState *pstate, ColumnRef *cref, Node *var)
Definition: functions.c:278
void * p_ref_hook_state
Definition: parse_node.h:225
ParseParamRefHook p_paramref_hook
Definition: parse_node.h:223
PreParseColumnRefHook p_pre_columnref_hook
Definition: parse_node.h:221
PostParseColumnRefHook p_post_columnref_hook
Definition: parse_node.h:222

References ParseState::p_paramref_hook, ParseState::p_post_columnref_hook, ParseState::p_pre_columnref_hook, ParseState::p_ref_hook_state, sql_fn_param_ref(), and sql_fn_post_column_ref().

Referenced by fmgr_sql_validator(), init_sql_fcache(), inline_function(), inline_set_returning_function(), and interpret_AS_clause().