/* ----------------------------------------------------------------
* ExecReScanFunctionScan
*
* Rescans the relation.
* ----------------------------------------------------------------
*/
void
ExecReScanFunctionScan(FunctionScanState *node)
{
ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
ExecScanReScan(&node->ss);
/*
* If we haven't materialized yet, just return.
*/
if (!node->tuplestorestate)
return;
/*
* Here we have a choice whether to drop the tuplestore (and recompute the
* function outputs) or just rescan it. We must recompute if the
* expression contains parameters, else we rescan. XXX maybe we should
* recompute if the function is volatile?
*/
if (node->ss.ps.chgParam != NULL)
{
tuplestore_end(node->tuplestorestate);
node->tuplestorestate = NULL;
}
else
tuplestore_rescan(node->tuplestorestate);
}
/* ----------------------------------------------------------------
* ExecMaterialReScan
*
* Rescans the materialized relation.
* ----------------------------------------------------------------
*/
void
ExecMaterialReScan(MaterialState *node, ExprContext *exprCtxt)
{
/*
* If we haven't materialized yet, just return. If outerplan' chgParam is
* not NULL then it will be re-scanned by ExecProcNode, else - no reason
* to re-scan it at all.
*/
if (!node->tuplestorestate)
return;
ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
/*
* If subnode is to be rescanned then we forget previous stored results;
* we have to re-read the subplan and re-store.
*
* Otherwise we can just rewind and rescan the stored output. The state of
* the subnode does not change.
*/
if (((PlanState *) node)->lefttree->chgParam != NULL)
{
tuplestore_end((Tuplestorestate *) node->tuplestorestate);
node->tuplestorestate = NULL;
node->eof_underlying = false;
}
else
tuplestore_rescan((Tuplestorestate *) node->tuplestorestate);
}
/* ----------------------------------------------------------------
* ExecFunctionReScan
*
* Rescans the relation.
* ----------------------------------------------------------------
*/
void
ExecFunctionReScan(FunctionScanState *node, ExprContext *exprCtxt)
{
ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
/*
* If we haven't materialized yet, just return.
*/
if (!node->tuplestorestate)
return;
/*
* Here we have a choice whether to drop the tuplestore (and recompute the
* function outputs) or just rescan it. This should depend on whether the
* function expression contains parameters and/or is marked volatile.
* FIXME soon.
*/
if (node->ss.ps.chgParam != NULL)
{
tuplestore_end(node->tuplestorestate);
node->tuplestorestate = NULL;
}
else
tuplestore_rescan(node->tuplestorestate);
}
/* ----------------------------------------------------------------
* ExecReScanMaterial
*
* Rescans the materialized relation.
* ----------------------------------------------------------------
*/
void
ExecReScanMaterial(MaterialState *node)
{
PlanState *outerPlan = outerPlanState(node);
ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
if (node->eflags != 0)
{
/*
* If we haven't materialized yet, just return. If outerplan's
* chgParam is not NULL then it will be re-scanned by ExecProcNode,
* else no reason to re-scan it at all.
*/
if (!node->tuplestorestate)
return;
/*
* If subnode is to be rescanned then we forget previous stored
* results; we have to re-read the subplan and re-store. Also, if we
* told tuplestore it needn't support rescan, we lose and must
* re-read. (This last should not happen in common cases; else our
* caller lied by not passing EXEC_FLAG_REWIND to us.)
*
* Otherwise we can just rewind and rescan the stored output. The
* state of the subnode does not change.
*/
if (outerPlan->chgParam != NULL ||
(node->eflags & EXEC_FLAG_REWIND) == 0)
{
tuplestore_end(node->tuplestorestate);
node->tuplestorestate = NULL;
if (outerPlan->chgParam == NULL)
ExecReScan(outerPlan);
node->eof_underlying = false;
}
else
tuplestore_rescan(node->tuplestorestate);
}
else
{
/* In this case we are just passing on the subquery's output */
/*
* if chgParam of subnode is not null then plan will be re-scanned by
* first ExecProcNode.
*/
if (outerPlan->chgParam == NULL)
ExecReScan(outerPlan);
node->eof_underlying = false;
}
}
/* ----------------------------------------------------------------
* ExecEndRecursiveUnionScan
*
* frees any storage allocated through C routines.
* ----------------------------------------------------------------
*/
void
ExecEndRecursiveUnion(RecursiveUnionState *node)
{
/* Release tuplestores */
tuplestore_end(node->working_table);
tuplestore_end(node->intermediate_table);
/* free subsidiary stuff including hashtable */
if (node->tempContext)
MemoryContextDelete(node->tempContext);
if (node->tableContext)
MemoryContextDelete(node->tableContext);
/*
* clean out the upper tuple table
*/
ExecClearTuple(node->ps.ps_ResultTupleSlot);
/*
* close down subplans
*/
ExecEndNode(outerPlanState(node));
ExecEndNode(innerPlanState(node));
}
/*
* worker_copy_shard_placement implements a internal UDF to copy a table's data from
* a healthy placement into a receiving table on an unhealthy placement. This
* function returns a boolean reflecting success or failure.
*/
Datum
worker_copy_shard_placement(PG_FUNCTION_ARGS)
{
text *shardRelationNameText = PG_GETARG_TEXT_P(0);
text *nodeNameText = PG_GETARG_TEXT_P(1);
int32 nodePort = PG_GETARG_INT32(2);
char *shardRelationName = text_to_cstring(shardRelationNameText);
char *nodeName = text_to_cstring(nodeNameText);
bool fetchSuccessful = false;
Oid shardRelationId = ResolveRelationId(shardRelationNameText);
Relation shardTable = heap_open(shardRelationId, RowExclusiveLock);
TupleDesc tupleDescriptor = RelationGetDescr(shardTable);
Tuplestorestate *tupleStore = tuplestore_begin_heap(false, false, work_mem);
StringInfo selectAllQuery = NULL;
ShardPlacement *placement = NULL;
Task *task = NULL;
selectAllQuery = makeStringInfo();
appendStringInfo(selectAllQuery, SELECT_ALL_QUERY,
quote_identifier(shardRelationName));
placement = (ShardPlacement *) palloc0(sizeof(ShardPlacement));
placement->nodeName = nodeName;
placement->nodePort = nodePort;
task = (Task *) palloc0(sizeof(Task));
task->queryString = selectAllQuery;
task->taskPlacementList = list_make1(placement);
fetchSuccessful = ExecuteTaskAndStoreResults(task, tupleDescriptor, tupleStore);
if (!fetchSuccessful)
{
ereport(ERROR, (errmsg("could not store shard rows from healthy placement"),
errhint("Consult recent messages in the server logs for "
"details.")));
}
CopyDataFromTupleStoreToRelation(tupleStore, shardTable);
tuplestore_end(tupleStore);
heap_close(shardTable, RowExclusiveLock);
PG_RETURN_VOID();
}
/*
* PortalDrop
* Destroy the portal.
*
* isError: if true, we are destroying portals at the end of a failed
* transaction. (This causes PortalCleanup to skip unneeded steps.)
*/
void
PortalDrop(Portal portal, bool isError)
{
AssertArg(PortalIsValid(portal));
/* Not sure if this case can validly happen or not... */
if (portal->portalActive)
elog(ERROR, "cannot drop active portal");
/*
* Remove portal from hash table. Because we do this first, we will
* not come back to try to remove the portal again if there's any
* error in the subsequent steps. Better to leak a little memory than
* to get into an infinite error-recovery loop.
*/
PortalHashTableDelete(portal);
/* let portalcmds.c clean up the state it knows about */
if (PointerIsValid(portal->cleanup))
(*portal->cleanup) (portal, isError);
/*
* Delete tuplestore if present. We should do this even under error
* conditions; since the tuplestore would have been using cross-
* transaction storage, its temp files need to be explicitly deleted.
*/
if (portal->holdStore)
{
MemoryContext oldcontext;
oldcontext = MemoryContextSwitchTo(portal->holdContext);
tuplestore_end(portal->holdStore);
MemoryContextSwitchTo(oldcontext);
portal->holdStore = NULL;
}
/* delete tuplestore storage, if any */
if (portal->holdContext)
MemoryContextDelete(portal->holdContext);
/* release subsidiary storage */
MemoryContextDelete(PortalGetHeapMemory(portal));
/* release portal struct (it's in PortalMemory) */
pfree(portal);
}
/* ----------------------------------------------------------------
* ExecMaterialReScan
*
* Rescans the materialized relation.
* ----------------------------------------------------------------
*/
void
ExecMaterialReScan(MaterialState *node, ExprContext *exprCtxt)
{
ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
if (node->randomAccess)
{
/*
* If we haven't materialized yet, just return. If outerplan' chgParam
* is not NULL then it will be re-scanned by ExecProcNode, else - no
* reason to re-scan it at all.
*/
if (!node->tuplestorestate)
return;
/*
* If subnode is to be rescanned then we forget previous stored
* results; we have to re-read the subplan and re-store.
*
* Otherwise we can just rewind and rescan the stored output. The
* state of the subnode does not change.
*/
if (((PlanState *) node)->lefttree->chgParam != NULL)
{
tuplestore_end((Tuplestorestate *) node->tuplestorestate);
node->tuplestorestate = NULL;
node->eof_underlying = false;
}
else
tuplestore_rescan((Tuplestorestate *) node->tuplestorestate);
}
else
{
/* In this case we are just passing on the subquery's output */
/*
* if chgParam of subnode is not null then plan will be re-scanned by
* first ExecProcNode.
*/
if (((PlanState *) node)->lefttree->chgParam == NULL)
ExecReScan(((PlanState *) node)->lefttree, exprCtxt);
node->eof_underlying = false;
}
}
/* ----------------------------------------------------------------
* ExecEndMaterial
* ----------------------------------------------------------------
*/
void
ExecEndMaterial(MaterialState *node)
{
/*
* clean out the tuple table
*/
ExecClearTuple(node->ss.ss_ScanTupleSlot);
/*
* Release tuplestore resources
*/
if (node->tuplestorestate != NULL)
tuplestore_end((Tuplestorestate *) node->tuplestorestate);
node->tuplestorestate = NULL;
/*
* shut down the subplan
*/
ExecEndNode(outerPlanState(node));
}
/* ----------------------------------------------------------------
* ExecEndCteScan
*
* frees any storage allocated through C routines.
* ----------------------------------------------------------------
*/
void
ExecEndCteScan(CteScanState *node)
{
/*
* Free exprcontext
*/
ExecFreeExprContext(&node->ss.ps);
/*
* clean out the tuple table
*/
ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
ExecClearTuple(node->ss.ss_ScanTupleSlot);
/*
* If I am the leader, free the tuplestore.
*/
if (node->leader == node)
tuplestore_end(node->cte_table);
}
/*
* callback function in case a SetExprState needs to be shut down before it
* has been run to completion
*/
static void
ShutdownSetExpr(Datum arg)
{
SetExprState *sexpr = castNode(SetExprState, DatumGetPointer(arg));
/* If we have a slot, make sure it's let go of any tuplestore pointer */
if (sexpr->funcResultSlot)
ExecClearTuple(sexpr->funcResultSlot);
/* Release any open tuplestore */
if (sexpr->funcResultStore)
tuplestore_end(sexpr->funcResultStore);
sexpr->funcResultStore = NULL;
/* Clear any active set-argument state */
sexpr->setArgsValid = false;
/* execUtils will deregister the callback... */
sexpr->shutdown_reg = false;
}
/* ----------------------------------------------------------------
* ExecEndFunctionScan
*
* frees any storage allocated through C routines.
* ----------------------------------------------------------------
*/
void
ExecEndFunctionScan(FunctionScanState *node)
{
/*
* Free the exprcontext
*/
ExecFreeExprContext(&node->ss.ps);
/*
* clean out the tuple table
*/
ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
ExecClearTuple(node->ss.ss_ScanTupleSlot);
/*
* Release tuplestore resources
*/
if (node->tuplestorestate != NULL)
tuplestore_end(node->tuplestorestate);
node->tuplestorestate = NULL;
}
/*
* PortalDrop
* Destroy the portal.
*/
void
PortalDrop(Portal portal, bool isTopCommit)
{
AssertArg(PortalIsValid(portal));
/* Not sure if this case can validly happen or not... */
if (portal->status == PORTAL_ACTIVE)
elog(ERROR, "cannot drop active portal");
/*
* Remove portal from hash table. Because we do this first, we will not
* come back to try to remove the portal again if there's any error in the
* subsequent steps. Better to leak a little memory than to get into an
* infinite error-recovery loop.
*/
PortalHashTableDelete(portal);
/* let portalcmds.c clean up the state it knows about */
if (PointerIsValid(portal->cleanup))
(*portal->cleanup) (portal);
/*
* Release any resources still attached to the portal. There are several
* cases being covered here:
*
* Top transaction commit (indicated by isTopCommit): normally we should
* do nothing here and let the regular end-of-transaction resource
* releasing mechanism handle these resources too. However, if we have a
* FAILED portal (eg, a cursor that got an error), we'd better clean up
* its resources to avoid resource-leakage warning messages.
*
* Sub transaction commit: never comes here at all, since we don't kill
* any portals in AtSubCommit_Portals().
*
* Main or sub transaction abort: we will do nothing here because
* portal->resowner was already set NULL; the resources were already
* cleaned up in transaction abort.
*
* Ordinary portal drop: must release resources. However, if the portal
* is not FAILED then we do not release its locks. The locks become the
* responsibility of the transaction's ResourceOwner (since it is the
* parent of the portal's owner) and will be released when the transaction
* eventually ends.
*/
if (portal->resowner &&
(!isTopCommit || portal->status == PORTAL_FAILED))
{
bool isCommit = (portal->status != PORTAL_FAILED);
ResourceOwnerRelease(portal->resowner,
RESOURCE_RELEASE_BEFORE_LOCKS,
isCommit, false);
ResourceOwnerRelease(portal->resowner,
RESOURCE_RELEASE_LOCKS,
isCommit, false);
ResourceOwnerRelease(portal->resowner,
RESOURCE_RELEASE_AFTER_LOCKS,
isCommit, false);
ResourceOwnerDelete(portal->resowner);
}
portal->resowner = NULL;
/*
* Delete tuplestore if present. We should do this even under error
* conditions; since the tuplestore would have been using cross-
* transaction storage, its temp files need to be explicitly deleted.
*/
if (portal->holdStore)
{
MemoryContext oldcontext;
oldcontext = MemoryContextSwitchTo(portal->holdContext);
tuplestore_end(portal->holdStore);
MemoryContextSwitchTo(oldcontext);
portal->holdStore = NULL;
}
/* delete tuplestore storage, if any */
if (portal->holdContext)
MemoryContextDelete(portal->holdContext);
/* release subsidiary storage */
MemoryContextDelete(PortalGetHeapMemory(portal));
/* release portal struct (it's in PortalMemory) */
pfree(portal);
}
/*
* ExecMakeFunctionResultSet
*
* Evaluate the arguments to a set-returning function and then call the
* function itself. The argument expressions may not contain set-returning
* functions (the planner is supposed to have separated evaluation for those).
*
* This should be called in a short-lived (per-tuple) context, argContext
* needs to live until all rows have been returned (i.e. *isDone set to
* ExprEndResult or ExprSingleResult).
*
* This is used by nodeProjectSet.c.
*/
Datum
ExecMakeFunctionResultSet(SetExprState *fcache,
ExprContext *econtext,
MemoryContext argContext,
bool *isNull,
ExprDoneCond *isDone)
{
List *arguments;
Datum result;
FunctionCallInfo fcinfo;
PgStat_FunctionCallUsage fcusage;
ReturnSetInfo rsinfo;
bool callit;
int i;
restart:
/* Guard against stack overflow due to overly complex expressions */
check_stack_depth();
/*
* If a previous call of the function returned a set result in the form of
* a tuplestore, continue reading rows from the tuplestore until it's
* empty.
*/
if (fcache->funcResultStore)
{
TupleTableSlot *slot = fcache->funcResultSlot;
MemoryContext oldContext;
bool foundTup;
/*
* Have to make sure tuple in slot lives long enough, otherwise
* clearing the slot could end up trying to free something already
* freed.
*/
oldContext = MemoryContextSwitchTo(slot->tts_mcxt);
foundTup = tuplestore_gettupleslot(fcache->funcResultStore, true, false,
fcache->funcResultSlot);
MemoryContextSwitchTo(oldContext);
if (foundTup)
{
*isDone = ExprMultipleResult;
if (fcache->funcReturnsTuple)
{
/* We must return the whole tuple as a Datum. */
*isNull = false;
return ExecFetchSlotTupleDatum(fcache->funcResultSlot);
}
else
{
/* Extract the first column and return it as a scalar. */
return slot_getattr(fcache->funcResultSlot, 1, isNull);
}
}
/* Exhausted the tuplestore, so clean up */
tuplestore_end(fcache->funcResultStore);
fcache->funcResultStore = NULL;
*isDone = ExprEndResult;
*isNull = true;
return (Datum) 0;
}
/*
* arguments is a list of expressions to evaluate before passing to the
* function manager. We skip the evaluation if it was already done in the
* previous call (ie, we are continuing the evaluation of a set-valued
* function). Otherwise, collect the current argument values into fcinfo.
*
* The arguments have to live in a context that lives at least until all
* rows from this SRF have been returned, otherwise ValuePerCall SRFs
* would reference freed memory after the first returned row.
*/
fcinfo = &fcache->fcinfo_data;
arguments = fcache->args;
if (!fcache->setArgsValid)
{
MemoryContext oldContext = MemoryContextSwitchTo(argContext);
ExecEvalFuncArgs(fcinfo, arguments, econtext);
MemoryContextSwitchTo(oldContext);
}
else
{
/* Reset flag (we may set it again below) */
fcache->setArgsValid = false;
}
/*
* Now call the function, passing the evaluated parameter values.
*/
/* Prepare a resultinfo node for communication. */
fcinfo->resultinfo = (Node *) &rsinfo;
rsinfo.type = T_ReturnSetInfo;
rsinfo.econtext = econtext;
rsinfo.expectedDesc = fcache->funcResultDesc;
rsinfo.allowedModes = (int) (SFRM_ValuePerCall | SFRM_Materialize);
/* note we do not set SFRM_Materialize_Random or _Preferred */
rsinfo.returnMode = SFRM_ValuePerCall;
/* isDone is filled below */
rsinfo.setResult = NULL;
rsinfo.setDesc = NULL;
/*
* If function is strict, and there are any NULL arguments, skip calling
* the function.
*/
callit = true;
if (fcache->func.fn_strict)
{
for (i = 0; i < fcinfo->nargs; i++)
{
if (fcinfo->argnull[i])
{
callit = false;
break;
}
}
}
if (callit)
{
pgstat_init_function_usage(fcinfo, &fcusage);
fcinfo->isnull = false;
rsinfo.isDone = ExprSingleResult;
result = FunctionCallInvoke(fcinfo);
*isNull = fcinfo->isnull;
*isDone = rsinfo.isDone;
pgstat_end_function_usage(&fcusage,
rsinfo.isDone != ExprMultipleResult);
}
else
{
/* for a strict SRF, result for NULL is an empty set */
result = (Datum) 0;
*isNull = true;
*isDone = ExprEndResult;
}
/* Which protocol does function want to use? */
if (rsinfo.returnMode == SFRM_ValuePerCall)
{
if (*isDone != ExprEndResult)
{
/*
* Save the current argument values to re-use on the next call.
*/
if (*isDone == ExprMultipleResult)
{
fcache->setArgsValid = true;
/* Register cleanup callback if we didn't already */
if (!fcache->shutdown_reg)
{
RegisterExprContextCallback(econtext,
ShutdownSetExpr,
PointerGetDatum(fcache));
fcache->shutdown_reg = true;
}
}
}
}
else if (rsinfo.returnMode == SFRM_Materialize)
{
/* check we're on the same page as the function author */
if (rsinfo.isDone != ExprSingleResult)
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_SRF_PROTOCOL_VIOLATED),
errmsg("table-function protocol for materialize mode was not followed")));
if (rsinfo.setResult != NULL)
{
/* prepare to return values from the tuplestore */
ExecPrepareTuplestoreResult(fcache, econtext,
rsinfo.setResult,
rsinfo.setDesc);
/* loop back to top to start returning from tuplestore */
goto restart;
}
/* if setResult was left null, treat it as empty set */
*isDone = ExprEndResult;
*isNull = true;
result = (Datum) 0;
}
else
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_SRF_PROTOCOL_VIOLATED),
errmsg("unrecognized table-function returnMode: %d",
(int) rsinfo.returnMode)));
return result;
}
/* ----------------------------------------------------------------
* ExecRecursiveUnion(node)
*
* Scans the recursive query sequentially and returns the next
* qualifying tuple.
*
* 1. evaluate non recursive term and assign the result to RT
*
* 2. execute recursive terms
*
* 2.1 WT := RT
* 2.2 while WT is not empty repeat 2.3 to 2.6. if WT is empty returns RT
* 2.3 replace the name of recursive term with WT
* 2.4 evaluate the recursive term and store into WT
* 2.5 append WT to RT
* 2.6 go back to 2.2
* ----------------------------------------------------------------
*/
TupleTableSlot *
ExecRecursiveUnion(RecursiveUnionState *node)
{
PlanState *outerPlan = outerPlanState(node);
PlanState *innerPlan = innerPlanState(node);
RecursiveUnion *plan = (RecursiveUnion *) node->ps.plan;
TupleTableSlot *slot;
RUHashEntry entry;
bool isnew;
/* 1. Evaluate non-recursive term */
if (!node->recursing)
{
for (;;)
{
slot = ExecProcNode(outerPlan);
if (TupIsNull(slot))
break;
if (plan->numCols > 0)
{
/* Find or build hashtable entry for this tuple's group */
entry = (RUHashEntry)
LookupTupleHashEntry(node->hashtable, slot, &isnew);
/* Must reset temp context after each hashtable lookup */
MemoryContextReset(node->tempContext);
/* Ignore tuple if already seen */
if (!isnew)
continue;
}
/* Each non-duplicate tuple goes to the working table ... */
tuplestore_puttupleslot(node->working_table, slot);
/* ... and to the caller */
return slot;
}
node->recursing = true;
}
/* 2. Execute recursive term */
for (;;)
{
slot = ExecProcNode(innerPlan);
if (TupIsNull(slot))
{
/* Done if there's nothing in the intermediate table */
if (node->intermediate_empty)
break;
/* done with old working table ... */
tuplestore_end(node->working_table);
/* intermediate table becomes working table */
node->working_table = node->intermediate_table;
/* create new empty intermediate table */
node->intermediate_table = tuplestore_begin_heap(false, false,
work_mem);
node->intermediate_empty = true;
/* reset the recursive term */
innerPlan->chgParam = bms_add_member(innerPlan->chgParam,
plan->wtParam);
/* and continue fetching from recursive term */
continue;
}
if (plan->numCols > 0)
{
/* Find or build hashtable entry for this tuple's group */
entry = (RUHashEntry)
LookupTupleHashEntry(node->hashtable, slot, &isnew);
/* Must reset temp context after each hashtable lookup */
MemoryContextReset(node->tempContext);
/* Ignore tuple if already seen */
if (!isnew)
continue;
}
/* Else, tuple is good; stash it in intermediate table ... */
node->intermediate_empty = false;
tuplestore_puttupleslot(node->intermediate_table, slot);
/* ... and return it */
return slot;
}
return NULL;
}