// debugNext is a helper function used by Next() when in explainDebug mode.
func (n *scanNode) debugNext() (bool, error) {
// In debug mode, we output a set of debug values for each key.
n.debugVals.rowIdx = n.rowIndex
var err error
var encRow sqlbase.EncDatumRow
n.debugVals.key, n.debugVals.value, encRow, err = n.fetcher.NextKeyDebug()
if err != nil || n.debugVals.key == "" {
return false, err
}
if encRow == nil {
n.row = nil
n.debugVals.output = debugValuePartial
return true, nil
}
tuple := make(parser.DTuple, len(encRow))
var da sqlbase.DatumAlloc
if err := sqlbase.EncDatumRowToDTuple(tuple, encRow, &da); err != nil {
return false, errors.Errorf("Could not decode row: %v", err)
}
n.row = tuple
passesFilter, err := sqlbase.RunFilter(n.filter, &n.p.evalCtx)
if err != nil {
return false, err
}
if passesFilter {
n.debugVals.output = debugValueRow
} else {
n.debugVals.output = debugValueFiltered
}
n.rowIndex++
return true, nil
}
func (n *scanNode) Next() (bool, error) {
tracing.AnnotateTrace()
if !n.scanInitialized {
if err := n.initScan(); err != nil {
return false, err
}
}
if n.explain == explainDebug {
return n.debugNext()
}
// We fetch one row at a time until we find one that passes the filter.
for {
var err error
n.row, err = n.fetcher.NextRowDecoded()
if err != nil || n.row == nil {
return false, err
}
passesFilter, err := sqlbase.RunFilter(n.filter, &n.p.evalCtx)
if err != nil {
return false, err
}
if passesFilter {
return true, nil
}
}
}
func (s *selectNode) Next() (bool, error) {
for {
if next, err := s.source.plan.Next(); !next {
return false, err
}
if s.explain == explainDebug {
s.debugVals = s.source.plan.DebugValues()
if s.debugVals.output != debugValueRow {
// Let the debug values pass through.
return true, nil
}
}
row := s.source.plan.Values()
s.curSourceRow = row
passesFilter, err := sqlbase.RunFilter(s.filter, &s.planner.evalCtx)
if err != nil {
return false, err
}
if passesFilter {
err := s.renderRow()
return err == nil, err
} else if s.explain == explainDebug {
// Mark the row as filtered out.
s.debugVals.output = debugValueFiltered
return true, nil
}
// Row was filtered out; grab the next row.
}
}
// debugNext is a helper function used by Next() when in explainDebug mode.
func (n *scanNode) debugNext() (bool, error) {
// In debug mode, we output a set of debug values for each key.
n.debugVals.rowIdx = n.rowIndex
var err error
n.debugVals.key, n.debugVals.value, n.row, err = n.fetcher.NextKeyDebug()
if err != nil || n.debugVals.key == "" {
return false, err
}
if n.row != nil {
passesFilter, err := sqlbase.RunFilter(n.filter, &n.p.evalCtx)
if err != nil {
return false, err
}
if passesFilter {
n.debugVals.output = debugValueRow
} else {
n.debugVals.output = debugValueFiltered
}
n.rowIndex++
} else {
n.debugVals.output = debugValuePartial
}
return true, nil
}
// Next implements the planNode interface.
func (f *filterNode) Next() (bool, error) {
for {
if next, err := f.source.plan.Next(); !next {
return false, err
}
if f.explain == explainDebug {
f.debugVals = f.source.plan.DebugValues()
if f.debugVals.output != debugValueRow {
// Let the debug values pass through.
return true, nil
}
}
passesFilter, err := sqlbase.RunFilter(f.filter, &f.p.evalCtx)
if err != nil {
return false, err
}
if passesFilter {
return true, nil
} else if f.explain == explainDebug {
// Mark the row as filtered out.
f.debugVals.output = debugValueFiltered
return true, nil
}
// Row was filtered out; grab the next row.
}
}
// eval for joinPredicate runs the on condition across the columns that do
// not participate in the equality (the equality columns are checked
// in the join algorithm already).
// Returns true if there is no on condition or the on condition accepts the
// row.
func (p *joinPredicate) eval(
ctx *parser.EvalContext, result, leftRow, rightRow parser.DTuple,
) (bool, error) {
if p.onCond != nil {
p.curRow = result
copy(p.curRow[p.numMergedEqualityColumns:p.numMergedEqualityColumns+len(leftRow)], leftRow)
copy(p.curRow[p.numMergedEqualityColumns+len(leftRow):], rightRow)
return sqlbase.RunFilter(p.onCond, ctx)
}
return true, nil
}
// evalFilter is used for filter expressions; it evaluates the expression and
// returns whether the filter passes.
func (eh *exprHelper) evalFilter(row sqlbase.EncDatumRow) (bool, error) {
eh.row = row
return sqlbase.RunFilter(eh.expr, eh.evalCtx)
}
