functions.h File Reference

#include "nodes/execnodes.h"
#include "tcop/dest.h"

Include dependency graph for functions.h:

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Go to the source code of this file.

Data Structures
struct	SQLFunctionParseInfo

Typedefs
typedef struct SQLFunctionParseInfo	SQLFunctionParseInfo
typedef SQLFunctionParseInfo *	SQLFunctionParseInfoPtr

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)
DestReceiver *	CreateSQLFunctionDestReceiver (void)

Typedef Documentation

SQLFunctionParseInfo

typedef struct SQLFunctionParseInfo SQLFunctionParseInfo

SQLFunctionParseInfoPtr

typedef 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 1607 of file functions.c.

{
    bool        is_tuple_result = false;
    Query      *parse;
    ListCell   *parse_cell;
    List       *tlist;
    int         tlistlen;
    bool        tlist_is_modifiable;
    char        fn_typtype;
    List       *upper_tlist = NIL;
    bool        upper_tlist_nontrivial = false;
    ListCell   *lc;
 
    if (resultTargetList)
        *resultTargetList = NIL;    /* initialize in case of VOID result */
 
    /*
     * If it's declared to return VOID, we don't care what's in the function.
     * (This takes care of the procedure case, as well.)
     */
    if (rettype == VOIDOID)
        return false;
 
    /*
     * Find the last canSetTag query in the function body (which is presented
     * to us as a list of sublists of Query nodes).  This isn't necessarily
     * the last parsetree, because rule rewriting can insert queries after
     * what the user wrote.  Note that it might not even be in the last
     * sublist, for example if the last query rewrites to DO INSTEAD NOTHING.
     * (It might not be unreasonable to throw an error in such a case, but
     * this is the historical behavior and it doesn't seem worth changing.)
     */
    parse = NULL;
    parse_cell = NULL;
    foreach(lc, queryTreeLists)
    {
        List       *sublist = lfirst_node(List, lc);
        ListCell   *lc2;
 
        foreach(lc2, sublist)
        {
            Query      *q = lfirst_node(Query, lc2);
 
            if (q->canSetTag)
            {
                parse = q;
                parse_cell = lc2;
            }
        }
    }
 
    /*
     * If it's a plain SELECT, it returns whatever the targetlist says.
     * Otherwise, if it's INSERT/UPDATE/DELETE with RETURNING, it returns
     * that. Otherwise, the function return type must be VOID.
     *
     * Note: eventually replace this test with QueryReturnsTuples?  We'd need
     * a more general method of determining the output type, though.  Also, it
     * seems too dangerous to consider FETCH or EXECUTE as returning a
     * determinable rowtype, since they depend on relatively short-lived
     * entities.
     */
    if (parse &&
        parse->commandType == CMD_SELECT)
    {
        tlist = parse->targetList;
        /* tlist is modifiable unless it's a dummy in a setop query */
        tlist_is_modifiable = (parse->setOperations == NULL);
    }
    else if (parse &&
             (parse->commandType == CMD_INSERT ||
              parse->commandType == CMD_UPDATE ||
              parse->commandType == CMD_DELETE) &&
             parse->returningList)
    {
        tlist = parse->returningList;
        /* returningList can always be modified */
        tlist_is_modifiable = true;
    }
    else
    {
        /* Empty function body, or last statement is a utility command */
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
                 errmsg("return type mismatch in function declared to return %s",
                        format_type_be(rettype)),
                 errdetail("Function's final statement must be SELECT or INSERT/UPDATE/DELETE RETURNING.")));
        return false;           /* keep compiler quiet */
    }
 
    /*
     * OK, check that the targetlist returns something matching the declared
     * type, and modify it if necessary.  If possible, we insert any coercion
     * steps right into the final statement's targetlist.  However, that might
     * risk changes in the statement's semantics --- we can't safely change
     * the output type of a grouping column, for instance.  In such cases we
     * handle coercions by inserting an extra level of Query that effectively
     * just does a projection.
     */
 
    /*
     * Count the non-junk entries in the result targetlist.
     */
    tlistlen = ExecCleanTargetListLength(tlist);
 
    fn_typtype = get_typtype(rettype);
 
    if (fn_typtype == TYPTYPE_BASE ||
        fn_typtype == TYPTYPE_DOMAIN ||
        fn_typtype == TYPTYPE_ENUM ||
        fn_typtype == TYPTYPE_RANGE ||
        fn_typtype == TYPTYPE_MULTIRANGE)
    {
        /*
         * For scalar-type returns, the target list must have exactly one
         * non-junk entry, and its type must be coercible to rettype.
         */
        TargetEntry *tle;
 
        if (tlistlen != 1)
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
                     errmsg("return type mismatch in function declared to return %s",
                            format_type_be(rettype)),
                     errdetail("Final statement must return exactly one column.")));
 
        /* We assume here that non-junk TLEs must come first in tlists */
        tle = (TargetEntry *) linitial(tlist);
        Assert(!tle->resjunk);
 
        if (!coerce_fn_result_column(tle, rettype, -1,
                                     tlist_is_modifiable,
                                     &upper_tlist,
                                     &upper_tlist_nontrivial))
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
                     errmsg("return type mismatch in function declared to return %s",
                            format_type_be(rettype)),
                     errdetail("Actual return type is %s.",
                               format_type_be(exprType((Node *) tle->expr)))));
    }
    else if (fn_typtype == TYPTYPE_COMPOSITE || rettype == RECORDOID)
    {
        /*
         * Returns a rowtype.
         *
         * Note that we will not consider a domain over composite to be a
         * "rowtype" return type; it goes through the scalar case above.  This
         * is because we only provide column-by-column implicit casting, and
         * will not cast the complete record result.  So the only way to
         * produce a domain-over-composite result is to compute it as an
         * explicit single-column result.  The single-composite-column code
         * path just below could handle such cases, but it won't be reached.
         */
        int         tupnatts;   /* physical number of columns in tuple */
        int         tuplogcols; /* # of nondeleted columns in tuple */
        int         colindex;   /* physical column index */
 
        /*
         * If the target list has one non-junk entry, and that expression has
         * or can be coerced to the declared return type, take it as the
         * result.  This allows, for example, 'SELECT func2()', where func2
         * has the same composite return type as the function that's calling
         * it.  This provision creates some ambiguity --- maybe the expression
         * was meant to be the lone field of the composite result --- but it
         * works well enough as long as we don't get too enthusiastic about
         * inventing coercions from scalar to composite types.
         *
         * XXX Note that if rettype is RECORD and the expression is of a named
         * composite type, or vice versa, this coercion will succeed, whether
         * or not the record type really matches.  For the moment we rely on
         * runtime type checking to catch any discrepancy, but it'd be nice to
         * do better at parse time.
         */
        if (tlistlen == 1)
        {
            TargetEntry *tle = (TargetEntry *) linitial(tlist);
 
            Assert(!tle->resjunk);
            if (coerce_fn_result_column(tle, rettype, -1,
                                        tlist_is_modifiable,
                                        &upper_tlist,
                                        &upper_tlist_nontrivial))
            {
                /* Note that we're NOT setting is_tuple_result */
                goto tlist_coercion_finished;
            }
        }
 
        /*
         * If the caller didn't provide an expected tupdesc, we can't do any
         * further checking.  Assume we're returning the whole tuple.
         */
        if (rettupdesc == NULL)
        {
            /* Return tlist if requested */
            if (resultTargetList)
                *resultTargetList = tlist;
            return true;
        }
 
        /*
         * Verify that the targetlist matches the return tuple type.  We scan
         * the non-resjunk columns, and coerce them if necessary to match the
         * datatypes of the non-deleted attributes.  For deleted attributes,
         * insert NULL result columns if the caller asked for that.
         */
        tupnatts = rettupdesc->natts;
        tuplogcols = 0;         /* we'll count nondeleted cols as we go */
        colindex = 0;
 
        foreach(lc, tlist)
        {
            TargetEntry *tle = (TargetEntry *) lfirst(lc);
            Form_pg_attribute attr;
 
            /* resjunk columns can simply be ignored */
            if (tle->resjunk)
                continue;
 
            do
            {
                colindex++;
                if (colindex > tupnatts)
                    ereport(ERROR,
                            (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
                             errmsg("return type mismatch in function declared to return %s",
                                    format_type_be(rettype)),
                             errdetail("Final statement returns too many columns.")));
                attr = TupleDescAttr(rettupdesc, colindex - 1);
                if (attr->attisdropped && insertDroppedCols)
                {
                    Expr       *null_expr;
 
                    /* The type of the null we insert isn't important */
                    null_expr = (Expr *) makeConst(INT4OID,
                                                   -1,
                                                   InvalidOid,
                                                   sizeof(int32),
                                                   (Datum) 0,
                                                   true,    /* isnull */
                                                   true /* byval */ );
                    upper_tlist = lappend(upper_tlist,
                                          makeTargetEntry(null_expr,
                                                          list_length(upper_tlist) + 1,
                                                          NULL,
                                                          false));
                    upper_tlist_nontrivial = true;
                }
            } while (attr->attisdropped);
            tuplogcols++;
 
            if (!coerce_fn_result_column(tle,
                                         attr->atttypid, attr->atttypmod,
                                         tlist_is_modifiable,
                                         &upper_tlist,
                                         &upper_tlist_nontrivial))
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
                         errmsg("return type mismatch in function declared to return %s",
                                format_type_be(rettype)),
                         errdetail("Final statement returns %s instead of %s at column %d.",
                                   format_type_be(exprType((Node *) tle->expr)),
                                   format_type_be(attr->atttypid),
                                   tuplogcols)));
        }
 
        /* remaining columns in rettupdesc had better all be dropped */
        for (colindex++; colindex <= tupnatts; colindex++)
        {
            if (!TupleDescAttr(rettupdesc, colindex - 1)->attisdropped)
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
                         errmsg("return type mismatch in function declared to return %s",
                                format_type_be(rettype)),
                         errdetail("Final statement returns too few columns.")));
            if (insertDroppedCols)
            {
                Expr       *null_expr;
 
                /* The type of the null we insert isn't important */
                null_expr = (Expr *) makeConst(INT4OID,
                                               -1,
                                               InvalidOid,
                                               sizeof(int32),
                                               (Datum) 0,
                                               true,    /* isnull */
                                               true /* byval */ );
                upper_tlist = lappend(upper_tlist,
                                      makeTargetEntry(null_expr,
                                                      list_length(upper_tlist) + 1,
                                                      NULL,
                                                      false));
                upper_tlist_nontrivial = true;
            }
        }
 
        /* Report that we are returning entire tuple result */
        is_tuple_result = true;
    }
    else
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
                 errmsg("return type %s is not supported for SQL functions",
                        format_type_be(rettype))));
 
tlist_coercion_finished:
 
    /*
     * If necessary, modify the final Query by injecting an extra Query level
     * that just performs a projection.  (It'd be dubious to do this to a
     * non-SELECT query, but we never have to; RETURNING lists can always be
     * modified in-place.)
     */
    if (upper_tlist_nontrivial)
    {
        Query      *newquery;
        List       *colnames;
        RangeTblEntry *rte;
        RangeTblRef *rtr;
 
        Assert(parse->commandType == CMD_SELECT);
 
        /* Most of the upper Query struct can be left as zeroes/nulls */
        newquery = makeNode(Query);
        newquery->commandType = CMD_SELECT;
        newquery->querySource = parse->querySource;
        newquery->canSetTag = true;
        newquery->targetList = upper_tlist;
 
        /* We need a moderately realistic colnames list for the subquery RTE */
        colnames = NIL;
        foreach(lc, parse->targetList)
        {
            TargetEntry *tle = (TargetEntry *) lfirst(lc);
 
            if (tle->resjunk)
                continue;
            colnames = lappend(colnames,
                               makeString(tle->resname ? tle->resname : ""));
        }
 
        /* Build a suitable RTE for the subquery */
        rte = makeNode(RangeTblEntry);
        rte->rtekind = RTE_SUBQUERY;
        rte->subquery = parse;
        rte->eref = rte->alias = makeAlias("*SELECT*", colnames);
        rte->lateral = false;
        rte->inh = false;
        rte->inFromCl = true;
        newquery->rtable = list_make1(rte);
 
        rtr = makeNode(RangeTblRef);
        rtr->rtindex = 1;
        newquery->jointree = makeFromExpr(list_make1(rtr), NULL);
 
        /* Replace original query in the correct element of the query list */
        lfirst(parse_cell) = newquery;
    }
 
    /* Return tlist (possibly modified) if requested */
    if (resultTargetList)
        *resultTargetList = upper_tlist;
 
    return is_tuple_result;
}

References RangeTblEntry::alias, Assert(), 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::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 1532 of file functions.c.

{
    ListCell   *lc;
 
    /* We are given a list of sublists of Queries */
    foreach(lc, queryTreeLists)
    {
        List       *sublist = lfirst_node(List, lc);
        ListCell   *lc2;
 
        foreach(lc2, sublist)
        {
            Query      *query = lfirst_node(Query, lc2);
 
            /*
             * Disallow calling procedures with output arguments.  The current
             * implementation would just throw the output values away, unless
             * the statement is the last one.  Per SQL standard, we should
             * assign the output values by name.  By disallowing this here, we
             * preserve an opportunity for future improvement.
             */
            if (query->commandType == CMD_UTILITY &&
                IsA(query->utilityStmt, CallStmt))
            {
                CallStmt   *stmt = (CallStmt *) query->utilityStmt;
 
                if (stmt->outargs != NIL)
                    ereport(ERROR,
                            (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                             errmsg("calling procedures with output arguments is not supported in SQL functions")));
            }
        }
    }
}

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

Referenced by fmgr_sql_validator(), and init_sql_fcache().

CreateSQLFunctionDestReceiver()

DestReceiver* CreateSQLFunctionDestReceiver

(

void

)

Definition at line 2054 of file functions.c.

{
    DR_sqlfunction *self = (DR_sqlfunction *) palloc0(sizeof(DR_sqlfunction));
 
    self->pub.receiveSlot = sqlfunction_receive;
    self->pub.rStartup = sqlfunction_startup;
    self->pub.rShutdown = sqlfunction_shutdown;
    self->pub.rDestroy = sqlfunction_destroy;
    self->pub.mydest = DestSQLFunction;
 
    /* private fields will be set by postquel_start */
 
    return (DestReceiver *) self;
}

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 1027 of file functions.c.

{
    SQLFunctionCachePtr fcache;
    ErrorContextCallback sqlerrcontext;
    MemoryContext oldcontext;
    bool        randomAccess;
    bool        lazyEvalOK;
    bool        is_first;
    bool        pushed_snapshot;
    execution_state *es;
    TupleTableSlot *slot;
    Datum       result;
    List       *eslist;
    ListCell   *eslc;
 
    /*
     * Setup error traceback support for ereport()
     */
    sqlerrcontext.callback = sql_exec_error_callback;
    sqlerrcontext.arg = fcinfo->flinfo;
    sqlerrcontext.previous = error_context_stack;
    error_context_stack = &sqlerrcontext;
 
    /* Check call context */
    if (fcinfo->flinfo->fn_retset)
    {
        ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
 
        /*
         * For simplicity, we require callers to support both set eval modes.
         * There are cases where we must use one or must use the other, and
         * it's not really worthwhile to postpone the check till we know. But
         * note we do not require caller to provide an expectedDesc.
         */
        if (!rsi || !IsA(rsi, ReturnSetInfo) ||
            (rsi->allowedModes & SFRM_ValuePerCall) == 0 ||
            (rsi->allowedModes & SFRM_Materialize) == 0)
            ereport(ERROR,
                    (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                     errmsg("set-valued function called in context that cannot accept a set")));
        randomAccess = rsi->allowedModes & SFRM_Materialize_Random;
        lazyEvalOK = !(rsi->allowedModes & SFRM_Materialize_Preferred);
    }
    else
    {
        randomAccess = false;
        lazyEvalOK = true;
    }
 
    /*
     * Initialize fcache (build plans) if first time through; or re-initialize
     * if the cache is stale.
     */
    fcache = (SQLFunctionCachePtr) fcinfo->flinfo->fn_extra;
 
    if (fcache != NULL)
    {
        if (fcache->lxid != MyProc->lxid ||
            !SubTransactionIsActive(fcache->subxid))
        {
            /* It's stale; unlink and delete */
            fcinfo->flinfo->fn_extra = NULL;
            MemoryContextDelete(fcache->fcontext);
            fcache = NULL;
        }
    }
 
    if (fcache == NULL)
    {
        init_sql_fcache(fcinfo, PG_GET_COLLATION(), lazyEvalOK);
        fcache = (SQLFunctionCachePtr) fcinfo->flinfo->fn_extra;
    }
 
    /*
     * Switch to context in which the fcache lives.  This ensures that our
     * tuplestore etc will have sufficient lifetime.  The sub-executor is
     * responsible for deleting per-tuple information.  (XXX in the case of a
     * long-lived FmgrInfo, this policy represents more memory leakage, but
     * it's not entirely clear where to keep stuff instead.)
     */
    oldcontext = MemoryContextSwitchTo(fcache->fcontext);
 
    /*
     * Find first unfinished query in function, and note whether it's the
     * first query.
     */
    eslist = fcache->func_state;
    es = NULL;
    is_first = true;
    foreach(eslc, eslist)
    {
        es = (execution_state *) lfirst(eslc);
 
        while (es && es->status == F_EXEC_DONE)
        {
            is_first = false;
            es = es->next;
        }
 
        if (es)
            break;
    }
 
    /*
     * Convert params to appropriate format if starting a fresh execution. (If
     * continuing execution, we can re-use prior params.)
     */
    if (is_first && es && es->status == F_EXEC_START)
        postquel_sub_params(fcache, fcinfo);
 
    /*
     * Build tuplestore to hold results, if we don't have one already. Note
     * it's in the query-lifespan context.
     */
    if (!fcache->tstore)
        fcache->tstore = tuplestore_begin_heap(randomAccess, false, work_mem);
 
    /*
     * Execute each command in the function one after another until we either
     * run out of commands or get a result row from a lazily-evaluated SELECT.
     *
     * Notes about snapshot management:
     *
     * In a read-only function, we just use the surrounding query's snapshot.
     *
     * In a non-read-only function, we rely on the fact that we'll never
     * suspend execution between queries of the function: the only reason to
     * suspend execution before completion is if we are returning a row from a
     * lazily-evaluated SELECT.  So, when first entering this loop, we'll
     * either start a new query (and push a fresh snapshot) or re-establish
     * the active snapshot from the existing query descriptor.  If we need to
     * start a new query in a subsequent execution of the loop, either we need
     * a fresh snapshot (and pushed_snapshot is false) or the existing
     * snapshot is on the active stack and we can just bump its command ID.
     */
    pushed_snapshot = false;
    while (es)
    {
        bool        completed;
 
        if (es->status == F_EXEC_START)
        {
            /*
             * If not read-only, be sure to advance the command counter for
             * each command, so that all work to date in this transaction is
             * visible.  Take a new snapshot if we don't have one yet,
             * otherwise just bump the command ID in the existing snapshot.
             */
            if (!fcache->readonly_func)
            {
                CommandCounterIncrement();
                if (!pushed_snapshot)
                {
                    PushActiveSnapshot(GetTransactionSnapshot());
                    pushed_snapshot = true;
                }
                else
                    UpdateActiveSnapshotCommandId();
            }
 
            postquel_start(es, fcache);
        }
        else if (!fcache->readonly_func && !pushed_snapshot)
        {
            /* Re-establish active snapshot when re-entering function */
            PushActiveSnapshot(es->qd->snapshot);
            pushed_snapshot = true;
        }
 
        completed = postquel_getnext(es, fcache);
 
        /*
         * If we ran the command to completion, we can shut it down now. Any
         * row(s) we need to return are safely stashed in the tuplestore, and
         * we want to be sure that, for example, AFTER triggers get fired
         * before we return anything.  Also, if the function doesn't return
         * set, we can shut it down anyway because it must be a SELECT and we
         * don't care about fetching any more result rows.
         */
        if (completed || !fcache->returnsSet)
            postquel_end(es);
 
        /*
         * Break from loop if we didn't shut down (implying we got a
         * lazily-evaluated row).  Otherwise we'll press on till the whole
         * function is done, relying on the tuplestore to keep hold of the
         * data to eventually be returned.  This is necessary since an
         * INSERT/UPDATE/DELETE RETURNING that sets the result might be
         * followed by additional rule-inserted commands, and we want to
         * finish doing all those commands before we return anything.
         */
        if (es->status != F_EXEC_DONE)
            break;
 
        /*
         * Advance to next execution_state, which might be in the next list.
         */
        es = es->next;
        while (!es)
        {
            eslc = lnext(eslist, eslc);
            if (!eslc)
                break;          /* end of function */
 
            es = (execution_state *) lfirst(eslc);
 
            /*
             * Flush the current snapshot so that we will take a new one for
             * the new query list.  This ensures that new snaps are taken at
             * original-query boundaries, matching the behavior of interactive
             * execution.
             */
            if (pushed_snapshot)
            {
                PopActiveSnapshot();
                pushed_snapshot = false;
            }
        }
    }
 
    /*
     * The tuplestore now contains whatever row(s) we are supposed to return.
     */
    if (fcache->returnsSet)
    {
        ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
 
        if (es)
        {
            /*
             * If we stopped short of being done, we must have a lazy-eval
             * row.
             */
            Assert(es->lazyEval);
            /* Re-use the junkfilter's output slot to fetch back the tuple */
            Assert(fcache->junkFilter);
            slot = fcache->junkFilter->jf_resultSlot;
            if (!tuplestore_gettupleslot(fcache->tstore, true, false, slot))
                elog(ERROR, "failed to fetch lazy-eval tuple");
            /* Extract the result as a datum, and copy out from the slot */
            result = postquel_get_single_result(slot, fcinfo,
                                                fcache, oldcontext);
            /* Clear the tuplestore, but keep it for next time */
            /* NB: this might delete the slot's content, but we don't care */
            tuplestore_clear(fcache->tstore);
 
            /*
             * Let caller know we're not finished.
             */
            rsi->isDone = ExprMultipleResult;
 
            /*
             * Ensure we will get shut down cleanly if the exprcontext is not
             * run to completion.
             */
            if (!fcache->shutdown_reg)
            {
                RegisterExprContextCallback(rsi->econtext,
                                            ShutdownSQLFunction,
                                            PointerGetDatum(fcache));
                fcache->shutdown_reg = true;
            }
        }
        else if (fcache->lazyEval)
        {
            /*
             * We are done with a lazy evaluation.  Clean up.
             */
            tuplestore_clear(fcache->tstore);
 
            /*
             * Let caller know we're finished.
             */
            rsi->isDone = ExprEndResult;
 
            fcinfo->isnull = true;
            result = (Datum) 0;
 
            /* Deregister shutdown callback, if we made one */
            if (fcache->shutdown_reg)
            {
                UnregisterExprContextCallback(rsi->econtext,
                                              ShutdownSQLFunction,
                                              PointerGetDatum(fcache));
                fcache->shutdown_reg = false;
            }
        }
        else
        {
            /*
             * We are done with a non-lazy evaluation.  Return whatever is in
             * the tuplestore.  (It is now caller's responsibility to free the
             * tuplestore when done.)
             */
            rsi->returnMode = SFRM_Materialize;
            rsi->setResult = fcache->tstore;
            fcache->tstore = NULL;
            /* must copy desc because execSRF.c will free it */
            if (fcache->junkFilter)
                rsi->setDesc = CreateTupleDescCopy(fcache->junkFilter->jf_cleanTupType);
 
            fcinfo->isnull = true;
            result = (Datum) 0;
 
            /* Deregister shutdown callback, if we made one */
            if (fcache->shutdown_reg)
            {
                UnregisterExprContextCallback(rsi->econtext,
                                              ShutdownSQLFunction,
                                              PointerGetDatum(fcache));
                fcache->shutdown_reg = false;
            }
        }
    }
    else
    {
        /*
         * Non-set function.  If we got a row, return it; else return NULL.
         */
        if (fcache->junkFilter)
        {
            /* Re-use the junkfilter's output slot to fetch back the tuple */
            slot = fcache->junkFilter->jf_resultSlot;
            if (tuplestore_gettupleslot(fcache->tstore, true, false, slot))
                result = postquel_get_single_result(slot, fcinfo,
                                                    fcache, oldcontext);
            else
            {
                fcinfo->isnull = true;
                result = (Datum) 0;
            }
        }
        else
        {
            /* Should only get here for VOID functions and procedures */
            Assert(fcache->rettype == VOIDOID);
            fcinfo->isnull = true;
            result = (Datum) 0;
        }
 
        /* Clear the tuplestore, but keep it for next time */
        tuplestore_clear(fcache->tstore);
    }
 
    /* Pop snapshot if we have pushed one */
    if (pushed_snapshot)
        PopActiveSnapshot();
 
    /*
     * If we've gone through every command in the function, we are done. Reset
     * the execution states to start over again on next call.
     */
    if (es == NULL)
    {
        foreach(eslc, fcache->func_state)
        {
            es = (execution_state *) lfirst(eslc);
            while (es)
            {
                es->status = F_EXEC_START;
                es = es->next;
            }
        }
    }
 
    error_context_stack = sqlerrcontext.previous;
 
    MemoryContextSwitchTo(oldcontext);
 
    return result;
}

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.

{
    SQLFunctionParseInfoPtr pinfo;
    Form_pg_proc procedureStruct = (Form_pg_proc) GETSTRUCT(procedureTuple);
    int         nargs;
 
    pinfo = (SQLFunctionParseInfoPtr) palloc0(sizeof(SQLFunctionParseInfo));
 
    /* Function's name (only) can be used to qualify argument names */
    pinfo->fname = pstrdup(NameStr(procedureStruct->proname));
 
    /* Save the function's input collation */
    pinfo->collation = inputCollation;
 
    /*
     * Copy input argument types from the pg_proc entry, then resolve any
     * polymorphic types.
     */
    pinfo->nargs = nargs = procedureStruct->pronargs;
    if (nargs > 0)
    {
        Oid        *argOidVect;
        int         argnum;
 
        argOidVect = (Oid *) palloc(nargs * sizeof(Oid));
        memcpy(argOidVect,
               procedureStruct->proargtypes.values,
               nargs * sizeof(Oid));
 
        for (argnum = 0; argnum < nargs; argnum++)
        {
            Oid         argtype = argOidVect[argnum];
 
            if (IsPolymorphicType(argtype))
            {
                argtype = get_call_expr_argtype(call_expr, argnum);
                if (argtype == InvalidOid)
                    ereport(ERROR,
                            (errcode(ERRCODE_DATATYPE_MISMATCH),
                             errmsg("could not determine actual type of argument declared %s",
                                    format_type_be(argOidVect[argnum]))));
                argOidVect[argnum] = argtype;
            }
        }
 
        pinfo->argtypes = argOidVect;
    }
 
    /*
     * Collect names of arguments, too, if any
     */
    if (nargs > 0)
    {
        Datum       proargnames;
        Datum       proargmodes;
        int         n_arg_names;
        bool        isNull;
 
        proargnames = SysCacheGetAttr(PROCNAMEARGSNSP, procedureTuple,
                                      Anum_pg_proc_proargnames,
                                      &isNull);
        if (isNull)
            proargnames = PointerGetDatum(NULL);    /* just to be sure */
 
        proargmodes = SysCacheGetAttr(PROCNAMEARGSNSP, procedureTuple,
                                      Anum_pg_proc_proargmodes,
                                      &isNull);
        if (isNull)
            proargmodes = PointerGetDatum(NULL);    /* just to be sure */
 
        n_arg_names = get_func_input_arg_names(proargnames, proargmodes,
                                               &pinfo->argnames);
 
        /* Paranoia: ignore the result if too few array entries */
        if (n_arg_names < nargs)
            pinfo->argnames = NULL;
    }
    else
        pinfo->argnames = NULL;
 
    return pinfo;
}

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.

{
    pstate->p_pre_columnref_hook = NULL;
    pstate->p_post_columnref_hook = sql_fn_post_column_ref;
    pstate->p_paramref_hook = sql_fn_param_ref;
    /* no need to use p_coerce_param_hook */
    pstate->p_ref_hook_state = (void *) pinfo;
}

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().