// Do implements plan.Plan Do interface, all records are added into an
// in-memory array, and sorted in ASC/DESC order.
func (r *OrderByDefaultPlan) Do(ctx context.Context, f plan.RowIterFunc) error {
t := &orderByTable{Ascs: r.Ascs}
m := map[interface{}]interface{}{}
err := r.Src.Do(ctx, func(rid interface{}, in []interface{}) (bool, error) {
m[expressions.ExprEvalIdentFunc] = func(name string) (interface{}, error) {
return getIdentValue(name, r.ResultFields, in, field.CheckFieldFlag)
}
m[expressions.ExprEvalPositionFunc] = func(position int) (interface{}, error) {
// position is in [1, len(fields)], so we must decrease 1 to get correct index
// TODO: check position invalidation
return in[position-1], nil
}
row := &orderByRow{
Row: in,
Key: make([]interface{}, 0, len(r.By)),
}
for _, by := range r.By {
// err1 is used for passing `go tool vet --shadow` check.
val, err1 := by.Eval(ctx, m)
if err1 != nil {
return false, err1
}
if val != nil {
var ordered bool
val, ordered, err1 = types.IsOrderedType(val)
if err1 != nil {
return false, err1
}
if !ordered {
return false, errors.Errorf("cannot order by %v (type %T)", val, val)
}
}
row.Key = append(row.Key, val)
}
t.Rows = append(t.Rows, row)
return true, nil
})
if err != nil {
return err
}
sort.Sort(t)
var more bool
for _, row := range t.Rows {
if more, err = f(nil, row.Row); !more || err != nil {
break
}
}
return types.EOFAsNil(err)
}
func (r *OrderByDefaultPlan) fetchAll(ctx context.Context) error {
evalArgs := map[interface{}]interface{}{}
for {
row, err := r.Src.Next(ctx)
if err != nil {
return errors.Trace(err)
}
if row == nil {
break
}
evalArgs[expression.ExprEvalIdentReferFunc] = func(name string, scope int, index int) (interface{}, error) {
if scope == expression.IdentReferFromTable {
return row.FromData[index], nil
} else if scope == expression.IdentReferSelectList {
return row.Data[index], nil
}
// try to find in outer query
return getIdentValueFromOuterQuery(ctx, name)
}
evalArgs[expression.ExprEvalPositionFunc] = func(position int) (interface{}, error) {
// position is in [1, len(fields)], so we must decrease 1 to get correct index
// TODO: check position invalidation
return row.Data[position-1], nil
}
ordRow := &orderByRow{
Row: row,
Key: make([]interface{}, 0, len(r.By)),
}
for _, by := range r.By {
// err1 is used for passing `go tool vet --shadow` check.
val, err1 := by.Eval(ctx, evalArgs)
if err1 != nil {
return err1
}
if val != nil {
if !types.IsOrderedType(val) {
return errors.Errorf("cannot order by %v (type %T)", val, val)
}
}
ordRow.Key = append(ordRow.Key, val)
}
r.ordTable.Rows = append(r.ordTable.Rows, ordRow)
}
sort.Sort(r.ordTable)
return nil
}
func (r *OrderByDefaultPlan) fetchAll(ctx context.Context) error {
evalArgs := map[interface{}]interface{}{}
for {
row, err := r.Src.Next(ctx)
if err != nil {
return errors.Trace(err)
}
if row == nil {
break
}
evalArgs[expressions.ExprEvalIdentFunc] = func(name string) (interface{}, error) {
return getIdentValue(name, r.ResultFields, row.Data, field.CheckFieldFlag)
}
evalArgs[expressions.ExprEvalPositionFunc] = func(position int) (interface{}, error) {
// position is in [1, len(fields)], so we must decrease 1 to get correct index
// TODO: check position invalidation
return row.Data[position-1], nil
}
ordRow := &orderByRow{
Row: row,
Key: make([]interface{}, 0, len(r.By)),
}
for _, by := range r.By {
// err1 is used for passing `go tool vet --shadow` check.
val, err1 := by.Eval(ctx, evalArgs)
if err1 != nil {
return err1
}
if val != nil {
var ordered bool
val, ordered, err1 = types.IsOrderedType(val)
if err1 != nil {
return err1
}
if !ordered {
return errors.Errorf("cannot order by %v (type %T)", val, val)
}
}
ordRow.Key = append(ordRow.Key, val)
}
r.ordTable.Rows = append(r.ordTable.Rows, ordRow)
}
sort.Sort(r.ordTable)
return nil
}
