Support returning any from callbacks (#1046)

Support returning any from callbacks
This commit is contained in:
Phil Eaton 2022-05-29 21:06:43 -04:00 committed by GitHub
parent b819467576
commit 3ccccfb4c9
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GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 88 additions and 0 deletions

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@ -353,6 +353,20 @@ func callbackRetNil(ctx *C.sqlite3_context, v reflect.Value) error {
return nil
}
func callbackRetGeneric(ctx *C.sqlite3_context, v reflect.Value) error {
if v.IsNil() {
C.sqlite3_result_null(ctx)
return nil
}
cb, err := callbackRet(v.Elem().Type())
if err != nil {
return err
}
return cb(ctx, v.Elem())
}
func callbackRet(typ reflect.Type) (callbackRetConverter, error) {
switch typ.Kind() {
case reflect.Interface:
@ -360,6 +374,11 @@ func callbackRet(typ reflect.Type) (callbackRetConverter, error) {
if typ.Implements(errorInterface) {
return callbackRetNil, nil
}
if typ.NumMethod() == 0 {
return callbackRetGeneric, nil
}
fallthrough
case reflect.Slice:
if typ.Elem().Kind() != reflect.Uint8 {

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@ -102,3 +102,15 @@ func TestCallbackConverters(t *testing.T) {
}
}
}
func TestCallbackReturnAny(t *testing.T) {
udf := func() interface{} {
return 1
}
typ := reflect.TypeOf(udf)
_, err := callbackRet(typ.Out(0))
if err != nil {
t.Errorf("Expected valid callback for any return type, got: %s", err)
}
}

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@ -1449,6 +1449,63 @@ func TestAggregatorRegistration(t *testing.T) {
}
}
type mode struct {
counts map[interface{}]int
top interface{}
topCount int
}
func newMode() *mode {
return &mode{
counts: map[interface{}]int{},
}
}
func (m *mode) Step(x interface{}) {
m.counts[x]++
c := m.counts[x]
if c > m.topCount {
m.top = x
m.topCount = c
}
}
func (m *mode) Done() interface{} {
return m.top
}
func TestAggregatorRegistration_GenericReturn(t *testing.T) {
sql.Register("sqlite3_AggregatorRegistration_GenericReturn", &SQLiteDriver{
ConnectHook: func(conn *SQLiteConn) error {
return conn.RegisterAggregator("mode", newMode, true)
},
})
db, err := sql.Open("sqlite3_AggregatorRegistration_GenericReturn", ":memory:")
if err != nil {
t.Fatal("Failed to open database:", err)
}
defer db.Close()
_, err = db.Exec("create table foo (department integer, profits integer)")
if err != nil {
t.Fatal("Failed to create table:", err)
}
_, err = db.Exec("insert into foo values (1, 10), (1, 20), (1, 45), (2, 42), (2, 115), (2, 20)")
if err != nil {
t.Fatal("Failed to insert records:", err)
}
var mode int
err = db.QueryRow("select mode(profits) from foo").Scan(&mode)
if err != nil {
t.Fatal("MODE query error:", err)
}
if mode != 20 {
t.Fatal("Got incorrect mode. Wanted 20, got: ", mode)
}
}
func rot13(r rune) rune {
switch {
case r >= 'A' && r <= 'Z':