/*
* pglogIterateForeignScan
* Read next record from the data file and store it into the
* ScanTupleSlot as a virtual tuple
*/
static TupleTableSlot *
pglogIterateForeignScan(ForeignScanState *node)
{
PgLogExecutionState *festate = (PgLogExecutionState *) node->fdw_state;
TupleTableSlot *slot = node->ss.ss_ScanTupleSlot;
bool found;
ErrorContextCallback errcallback;
/* Set up callback to identify error line number. */
errcallback.callback = CopyFromErrorCallback;
errcallback.arg = (void *) festate->cstate;
errcallback.previous = error_context_stack;
error_context_stack = &errcallback;
/*
* The protocol for loading a virtual tuple into a slot is first
* ExecClearTuple, then fill the values/isnull arrays, then
* ExecStoreVirtualTuple. If we don't find another row in the file, we
* just skip the last step, leaving the slot empty as required.
*
* We can pass ExprContext = NULL because we read all columns from the
* file, so no need to evaluate default expressions.
*
* We can also pass tupleOid = NULL because we don't allow oids for
* foreign tables.
*/
ExecClearTuple(slot);
found = GetNextRow(node->ss.ss_currentRelation, festate, slot);
if (found)
ExecStoreVirtualTuple(slot);
else if (! isLastLogFile(festate))
{
/* We could have reached the end of a log file
* We might have to start reading from the next
*/
elog(DEBUG1,"Reached end of file %s",festate->filenames[festate->i]);
festate->i++;
BeginNextCopy(node->ss.ss_currentRelation, festate);
found = GetNextRow(node->ss.ss_currentRelation, festate, slot);
if (found)
ExecStoreVirtualTuple(slot);
}
/* Remove error callback. */
error_context_stack = errcallback.previous;
return slot;
}
/*
* StoreIndexTuple
* Fill the slot with data from the index tuple.
*
* At some point this might be generally-useful functionality, but
* right now we don't need it elsewhere.
*/
static void
StoreIndexTuple(TupleTableSlot *slot, IndexTuple itup, TupleDesc itupdesc)
{
int nindexatts = itupdesc->natts;
Datum *values = slot->tts_values;
bool *isnull = slot->tts_isnull;
int i;
/*
* Note: we must use the tupdesc supplied by the AM in index_getattr, not
* the slot's tupdesc, in case the latter has different datatypes (this
* happens for btree name_ops in particular). They'd better have the same
* number of columns though, as well as being datatype-compatible which is
* something we can't so easily check.
*/
Assert(slot->tts_tupleDescriptor->natts == nindexatts);
ExecClearTuple(slot);
for (i = 0; i < nindexatts; i++)
values[i] = index_getattr(itup, i + 1, itupdesc, &isnull[i]);
ExecStoreVirtualTuple(slot);
}
/* --------------------------------
* ExecStoreAllNullTuple
* Set up the slot to contain a null in every column.
*
* At first glance this might sound just like ExecClearTuple, but it's
* entirely different: the slot ends up full, not empty.
* --------------------------------
*/
TupleTableSlot *
ExecStoreAllNullTuple(TupleTableSlot *slot)
{
/*
* sanity checks
*/
Assert(slot != NULL);
Assert(slot->tts_tupleDescriptor != NULL);
/* Clear any old contents */
ExecClearTuple(slot);
/*
* Fill all the columns of the virtual tuple with nulls
*/
MemSet(slot->tts_values, 0,
slot->tts_tupleDescriptor->natts * sizeof(Datum));
memset(slot->tts_isnull, true,
slot->tts_tupleDescriptor->natts * sizeof(bool));
return ExecStoreVirtualTuple(slot);
}
/* ----------------------------------------------------------------
* ValuesNext
*
* This is a workhorse for ExecValuesScan
* ----------------------------------------------------------------
*/
static TupleTableSlot *
ValuesNext(ValuesScanState *node)
{
TupleTableSlot *slot;
EState *estate;
ExprContext *econtext;
ScanDirection direction;
List *exprlist;
/*
* get information from the estate and scan state
*/
estate = node->ss.ps.state;
direction = estate->es_direction;
slot = node->ss.ss_ScanTupleSlot;
econtext = node->rowcontext;
/*
* Get the next tuple. Return NULL if no more tuples.
*/
if (ScanDirectionIsForward(direction))
{
if (node->curr_idx < node->array_len)
node->curr_idx++;
if (node->curr_idx < node->array_len)
exprlist = node->exprlists[node->curr_idx];
else
exprlist = NIL;
}
else
{
if (node->curr_idx >= 0)
node->curr_idx--;
if (node->curr_idx >= 0)
exprlist = node->exprlists[node->curr_idx];
else
exprlist = NIL;
}
/*
* Always clear the result slot; this is appropriate if we are at the end
* of the data, and if we're not, we still need it as the first step of
* the store-virtual-tuple protocol. It seems wise to clear the slot
* before we reset the context it might have pointers into.
*/
ExecClearTuple(slot);
if (exprlist)
{
MemoryContext oldContext;
List *exprstatelist;
Datum *values;
bool *isnull;
ListCell *lc;
int resind;
/*
* Get rid of any prior cycle's leftovers. We use ReScanExprContext
* not just ResetExprContext because we want any registered shutdown
* callbacks to be called.
*/
ReScanExprContext(econtext);
/*
* Build the expression eval state in the econtext's per-tuple memory.
* This is a tad unusual, but we want to delete the eval state again
* when we move to the next row, to avoid growth of memory
* requirements over a long values list.
*/
oldContext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory);
/*
* Pass NULL, not my plan node, because we don't want anything in this
* transient state linking into permanent state. The only possibility
* is a SubPlan, and there shouldn't be any (any subselects in the
* VALUES list should be InitPlans).
*/
exprstatelist = (List *) ExecInitExpr((Expr *) exprlist, NULL);
/* parser should have checked all sublists are the same length */
Assert(list_length(exprstatelist) == slot->tts_tupleDescriptor->natts);
/*
* Compute the expressions and build a virtual result tuple. We
* already did ExecClearTuple(slot).
*/
values = slot->tts_values;
isnull = slot->tts_isnull;
resind = 0;
foreach(lc, exprstatelist)
{
ExprState *estate = (ExprState *) lfirst(lc);
values[resind] = ExecEvalExpr(estate,
econtext,
&isnull[resind],
NULL);
resind++;
}
MemoryContextSwitchTo(oldContext);
/*
* And return the virtual tuple.
*/
ExecStoreVirtualTuple(slot);
}
/*
* Modify slot with user data provided as C strings.
* This is somewhat similar to heap_modify_tuple but also calls the type
* input function on the user data as the input is the text representation
* of the types.
*/
static void
slot_modify_cstrings(TupleTableSlot *slot, LogicalRepRelMapEntry *rel,
char **values, bool *replaces)
{
int natts = slot->tts_tupleDescriptor->natts;
int i;
SlotErrCallbackArg errarg;
ErrorContextCallback errcallback;
slot_getallattrs(slot);
ExecClearTuple(slot);
/* Push callback + info on the error context stack */
errarg.rel = rel;
errarg.local_attnum = -1;
errarg.remote_attnum = -1;
errcallback.callback = slot_store_error_callback;
errcallback.arg = (void *) &errarg;
errcallback.previous = error_context_stack;
error_context_stack = &errcallback;
/* Call the "in" function for each replaced attribute */
for (i = 0; i < natts; i++)
{
Form_pg_attribute att = TupleDescAttr(slot->tts_tupleDescriptor, i);
int remoteattnum = rel->attrmap[i];
if (remoteattnum < 0)
continue;
if (!replaces[remoteattnum])
continue;
if (values[remoteattnum] != NULL)
{
Oid typinput;
Oid typioparam;
errarg.local_attnum = i;
errarg.remote_attnum = remoteattnum;
getTypeInputInfo(att->atttypid, &typinput, &typioparam);
slot->tts_values[i] =
OidInputFunctionCall(typinput, values[remoteattnum],
typioparam, att->atttypmod);
slot->tts_isnull[i] = false;
errarg.local_attnum = -1;
errarg.remote_attnum = -1;
}
else
{
slot->tts_values[i] = (Datum) 0;
slot->tts_isnull[i] = true;
}
}
/* Pop the error context stack */
error_context_stack = errcallback.previous;
ExecStoreVirtualTuple(slot);
}
/*
* Store data in C string form into slot.
* This is similar to BuildTupleFromCStrings but TupleTableSlot fits our
* use better.
*/
static void
slot_store_cstrings(TupleTableSlot *slot, LogicalRepRelMapEntry *rel,
char **values)
{
int natts = slot->tts_tupleDescriptor->natts;
int i;
SlotErrCallbackArg errarg;
ErrorContextCallback errcallback;
ExecClearTuple(slot);
/* Push callback + info on the error context stack */
errarg.rel = rel;
errarg.local_attnum = -1;
errarg.remote_attnum = -1;
errcallback.callback = slot_store_error_callback;
errcallback.arg = (void *) &errarg;
errcallback.previous = error_context_stack;
error_context_stack = &errcallback;
/* Call the "in" function for each non-dropped attribute */
for (i = 0; i < natts; i++)
{
Form_pg_attribute att = TupleDescAttr(slot->tts_tupleDescriptor, i);
int remoteattnum = rel->attrmap[i];
if (!att->attisdropped && remoteattnum >= 0 &&
values[remoteattnum] != NULL)
{
Oid typinput;
Oid typioparam;
errarg.local_attnum = i;
errarg.remote_attnum = remoteattnum;
getTypeInputInfo(att->atttypid, &typinput, &typioparam);
slot->tts_values[i] =
OidInputFunctionCall(typinput, values[remoteattnum],
typioparam, att->atttypmod);
slot->tts_isnull[i] = false;
errarg.local_attnum = -1;
errarg.remote_attnum = -1;
}
else
{
/*
* We assign NULL to dropped attributes, NULL values, and missing
* values (missing values should be later filled using
* slot_fill_defaults).
*/
slot->tts_values[i] = (Datum) 0;
slot->tts_isnull[i] = true;
}
}
/* Pop the error context stack */
error_context_stack = errcallback.previous;
ExecStoreVirtualTuple(slot);
}
/*
* Use the supplied ResultRelInfo to create an appropriately restructured
* version of the tuple in the supplied slot, if necessary.
*
* slot -- slot containing the input tuple
* resultRelInfo -- info pertaining to the target part of an insert
*
* If no restructuring is required, the result is the argument slot, else
* it is the slot from the argument result info updated to hold the
* restructured tuple.
*/
TupleTableSlot *
reconstructMatchingTupleSlot(TupleTableSlot *slot, ResultRelInfo *resultRelInfo)
{
int natts;
Datum *values;
bool *isnull;
AttrMap *map;
TupleTableSlot *partslot;
Datum *partvalues;
bool *partisnull;
map = resultRelInfo->ri_partInsertMap;
TupleDesc inputTupDesc = slot->tts_tupleDescriptor;
TupleDesc resultTupDesc = resultRelInfo->ri_RelationDesc->rd_att;
bool tupleDescMatch = (resultRelInfo->tupdesc_match == 1);
if (resultRelInfo->tupdesc_match == 0)
{
tupleDescMatch = equalTupleDescs(inputTupDesc, resultTupDesc, false);
if (tupleDescMatch)
{
resultRelInfo->tupdesc_match = 1;
}
else
{
resultRelInfo->tupdesc_match = -1;
}
}
/* No map and matching tuple descriptor means no restructuring needed. */
if (map == NULL && tupleDescMatch)
return slot;
/* Put the given tuple into attribute arrays. */
natts = slot->tts_tupleDescriptor->natts;
slot_getallattrs(slot);
values = slot_get_values(slot);
isnull = slot_get_isnull(slot);
/*
* Get the target slot ready. If this is a child partition table,
* set target slot to ri_partSlot. Otherwise, use ri_resultSlot.
*/
if (map != NULL)
{
Assert(resultRelInfo->ri_partSlot != NULL);
partslot = resultRelInfo->ri_partSlot;
}
else
{
if (resultRelInfo->ri_resultSlot == NULL)
{
resultRelInfo->ri_resultSlot = MakeSingleTupleTableSlot(resultTupDesc);
}
partslot = resultRelInfo->ri_resultSlot;
}
partslot = ExecStoreAllNullTuple(partslot);
partvalues = slot_get_values(partslot);
partisnull = slot_get_isnull(partslot);
/* Restructure the input tuple. Non-zero map entries are attribute
* numbers in the target tuple, however, not every attribute
* number of the input tuple need be present. In particular,
* attribute numbers corresponding to dropped attributes will be
* missing.
*/
reconstructTupleValues(map, values, isnull, natts,
partvalues, partisnull, partslot->tts_tupleDescriptor->natts);
partslot = ExecStoreVirtualTuple(partslot);
return partslot;
}
/* ----------------------------------------------------------------
* ValuesNext
*
* This is a workhorse for ExecValuesScan
* ----------------------------------------------------------------
*/
static TupleTableSlot *
ValuesNext(ValuesScanState *node)
{
TupleTableSlot *slot;
EState *estate;
ExprContext *econtext;
ScanDirection direction;
List *exprlist;
/*
* get information from the estate and scan state
*/
estate = node->ss.ps.state;
direction = estate->es_direction;
slot = node->ss.ss_ScanTupleSlot;
econtext = node->rowcontext;
/*
* Get the next tuple. Return NULL if no more tuples.
*/
if (ScanDirectionIsForward(direction))
{
if (node->curr_idx < node->array_len)
node->curr_idx++;
if (node->curr_idx < node->array_len)
exprlist = node->exprlists[node->curr_idx];
else
exprlist = NIL;
}
else
{
if (node->curr_idx >= 0)
node->curr_idx--;
if (node->curr_idx >= 0)
exprlist = node->exprlists[node->curr_idx];
else
exprlist = NIL;
}
/*
* Always clear the result slot; this is appropriate if we are at the end
* of the data, and if we're not, we still need it as the first step of
* the store-virtual-tuple protocol. It seems wise to clear the slot
* before we reset the context it might have pointers into.
*/
ExecClearTuple(slot);
if (exprlist)
{
MemoryContext oldContext;
List *oldsubplans;
List *exprstatelist;
Datum *values;
bool *isnull;
ListCell *lc;
int resind;
int saved_jit_flags;
/*
* Get rid of any prior cycle's leftovers. We use ReScanExprContext
* not just ResetExprContext because we want any registered shutdown
* callbacks to be called.
*/
ReScanExprContext(econtext);
/*
* Build the expression eval state in the econtext's per-tuple memory.
* This is a tad unusual, but we want to delete the eval state again
* when we move to the next row, to avoid growth of memory
* requirements over a long values list.
*/
oldContext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory);
/*
* The expressions might contain SubPlans (this is currently only
* possible if there's a sub-select containing a LATERAL reference,
* otherwise sub-selects in a VALUES list should be InitPlans). Those
* subplans will want to hook themselves into our subPlan list, which
* would result in a corrupted list after we delete the eval state. We
* can work around this by saving and restoring the subPlan list.
* (There's no need for the functionality that would be enabled by
* having the list entries, since the SubPlans aren't going to be
* re-executed anyway.)
*/
oldsubplans = node->ss.ps.subPlan;
node->ss.ps.subPlan = NIL;
/*
* As the expressions are only ever used once, disable JIT for them.
* This is worthwhile because it's common to insert significant
* amounts of data via VALUES().
*/
saved_jit_flags = econtext->ecxt_estate->es_jit_flags;
econtext->ecxt_estate->es_jit_flags = PGJIT_NONE;
exprstatelist = ExecInitExprList(exprlist, &node->ss.ps);
econtext->ecxt_estate->es_jit_flags = saved_jit_flags;
node->ss.ps.subPlan = oldsubplans;
/* parser should have checked all sublists are the same length */
Assert(list_length(exprstatelist) == slot->tts_tupleDescriptor->natts);
/*
* Compute the expressions and build a virtual result tuple. We
* already did ExecClearTuple(slot).
*/
values = slot->tts_values;
isnull = slot->tts_isnull;
resind = 0;
foreach(lc, exprstatelist)
{
ExprState *estate = (ExprState *) lfirst(lc);
Form_pg_attribute attr = TupleDescAttr(slot->tts_tupleDescriptor,
resind);
values[resind] = ExecEvalExpr(estate,
econtext,
&isnull[resind]);
/*
* We must force any R/W expanded datums to read-only state, in
* case they are multiply referenced in the plan node's output
* expressions, or in case we skip the output projection and the
* output column is multiply referenced in higher plan nodes.
*/
values[resind] = MakeExpandedObjectReadOnly(values[resind],
isnull[resind],
attr->attlen);
resind++;
}
MemoryContextSwitchTo(oldContext);
/*
* And return the virtual tuple.
*/
ExecStoreVirtualTuple(slot);
}
