/*
* BeginStreamScan
*/
void
BeginStreamScan(ForeignScanState *node, int eflags)
{
ForeignScan *plan = (ForeignScan *) node->ss.ps.plan;
StreamScanState *state;
ListCell *lc;
List *colnames = (List *) linitial(plan->fdw_private);
List *physical_tlist = (List *) lsecond(plan->fdw_private);
Value *sample_cutoff = (Value *) lthird(plan->fdw_private);
int i = 0;
state = palloc0(sizeof(StreamScanState));
state->pi = palloc(sizeof(StreamProjectionInfo));
state->pi->mcxt = AllocSetContextCreate(CurrentMemoryContext,
"ExecProjectContext",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
state->pi->ecxt = CreateStandaloneExprContext();
state->pi->outdesc = ExecTypeFromTL(physical_tlist, false);
state->pi->indesc = NULL;
state->sample_cutoff = sample_cutoff ? intVal(sample_cutoff) : -1;
Assert(state->pi->outdesc->natts == list_length(colnames));
foreach(lc, colnames)
{
Value *v = (Value *) lfirst(lc);
namestrcpy(&(state->pi->outdesc->attrs[i++]->attname), strVal(v));
}
/*
* makeRangeVarFromNameList
* Utility routine to convert a qualified-name list into RangeVar form.
*
* Copied from backend/catalog/namespace.c
*/
RangeVar *
makeRangeVarFromNameList(List *names)
{
RangeVar *rel = makeRangeVar(NULL, NULL, -1);
switch (list_length(names))
{
case 1:
rel->relname = strVal(linitial(names));
break;
case 2:
rel->schemaname = strVal(linitial(names));
rel->relname = strVal(lsecond(names));
break;
case 3:
rel->catalogname = strVal(linitial(names));
rel->schemaname = strVal(lsecond(names));
rel->relname = strVal(lthird(names));
break;
default:
ereport(WARNING,
(errmsg("invalid relation name, too many indirections, while converting from table name to RangeVar")));
break;
}
return rel;
}
/*
* makeRangeVarFromNameList
* Utility routine to convert a qualified-name list into RangeVar form.
*
* Copied from backend/catalog/namespace.c
*/
RangeVar *
makeRangeVarFromNameList(List *names)
{
RangeVar *rel = makeRangeVar(NULL, NULL, -1);
switch (list_length(names))
{
case 1:
rel->relname = strVal(linitial(names));
break;
case 2:
rel->schemaname = strVal(linitial(names));
rel->relname = strVal(lsecond(names));
break;
case 3:
rel->catalogname = strVal(linitial(names));
rel->schemaname = strVal(lsecond(names));
rel->relname = strVal(lthird(names));
break;
default:
pool_error("improper relation name (too many dotted names)");
break;
}
return rel;
}
/*
* ExtractRangeTblExtraData extracts extra data stored for a range table entry
* that previously has been stored with
* Set/ModifyRangeTblExtraData. Parameters can be NULL if unintersting. It is
* valid to use the function on a RTE without extra data.
*/
void
ExtractRangeTblExtraData(RangeTblEntry *rte, CitusRTEKind *rteKind,
char **fragmentSchemaName, char **fragmentTableName,
List **tableIdList)
{
RangeTblFunction *fauxFunction = NULL;
FuncExpr *fauxFuncExpr = NULL;
Const *tmpConst = NULL;
/* set base rte kind first, so this can be used for 'non-extended' RTEs as well */
if (rteKind != NULL)
{
*rteKind = (CitusRTEKind) rte->rtekind;
}
/* reset values of optionally-present fields, will later be overwritten, if present */
if (fragmentSchemaName != NULL)
{
*fragmentSchemaName = NULL;
}
if (fragmentTableName != NULL)
{
*fragmentTableName = NULL;
}
if (tableIdList != NULL)
{
*tableIdList = NIL;
}
/* only function RTEs have our special extra data */
if (rte->rtekind != RTE_FUNCTION)
{
return;
}
/* we only ever generate one argument */
if (list_length(rte->functions) != 1)
{
return;
}
/* should pretty much always be a FuncExpr, but be liberal in what we expect... */
fauxFunction = linitial(rte->functions);
if (!IsA(fauxFunction->funcexpr, FuncExpr))
{
return;
}
fauxFuncExpr = (FuncExpr *) fauxFunction->funcexpr;
/*
* There will never be a range table entry with this function id, but for
* the purpose of this file.
*/
if (fauxFuncExpr->funcid != CitusExtraDataContainerFuncId())
{
return;
}
/*
* Extra data for rtes is stored in the function arguments. The first
* argument stores the rtekind, second fragmentSchemaName, third
* fragmentTableName, fourth tableIdList.
*/
if (list_length(fauxFuncExpr->args) != 4)
{
ereport(ERROR, (errmsg("unexpected number of function arguments to "
"citus_extradata_container")));
return;
}
/* extract rteKind */
tmpConst = (Const *) linitial(fauxFuncExpr->args);
Assert(IsA(tmpConst, Const));
Assert(tmpConst->consttype == INT4OID);
if (rteKind != NULL)
{
*rteKind = DatumGetInt32(tmpConst->constvalue);
}
/* extract fragmentSchemaName */
tmpConst = (Const *) lsecond(fauxFuncExpr->args);
Assert(IsA(tmpConst, Const));
Assert(tmpConst->consttype == CSTRINGOID);
if (fragmentSchemaName != NULL && !tmpConst->constisnull)
{
*fragmentSchemaName = DatumGetCString(tmpConst->constvalue);
}
/* extract fragmentTableName */
tmpConst = (Const *) lthird(fauxFuncExpr->args);
Assert(IsA(tmpConst, Const));
Assert(tmpConst->consttype == CSTRINGOID);
if (fragmentTableName != NULL && !tmpConst->constisnull)
{
*fragmentTableName = DatumGetCString(tmpConst->constvalue);
}
/* extract tableIdList, stored as a serialized integer list */
tmpConst = (Const *) lfourth(fauxFuncExpr->args);
Assert(IsA(tmpConst, Const));
Assert(tmpConst->consttype == CSTRINGOID);
if (tableIdList != NULL && !tmpConst->constisnull)
{
Node *deserializedList = stringToNode(DatumGetCString(tmpConst->constvalue));
Assert(IsA(deserializedList, IntList));
*tableIdList = (List *) deserializedList;
}
}
