synthio: Add MidiTrack.error_location to record errors

.. instead of just printing the unraiseable error on the repl

Author: jepler

shared-bindings/synthio/MidiTrack.c

@@ -151,6 +151,23 @@ MP_DEFINE_CONST_FUN_OBJ_1(synthio_miditrack_get_sample_rate_obj, synthio_miditra
 MP_PROPERTY_GETTER(synthio_miditrack_sample_rate_obj,
     (mp_obj_t)&synthio_miditrack_get_sample_rate_obj);
 
+//|     error_location: Optional[int]
+//|     """Offset, in bytes within the midi data, of a decoding error"""
+//|
+STATIC mp_obj_t synthio_miditrack_obj_get_error_location(mp_obj_t self_in) {
+    synthio_miditrack_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    check_for_deinit(self);
+    mp_int_t location = common_hal_synthio_miditrack_get_error_location(self);
+    if (location >= 0) {
+        return MP_OBJ_NEW_SMALL_INT(location);
+    }
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_1(synthio_miditrack_get_error_location_obj, synthio_miditrack_obj_get_error_location);
+
+MP_PROPERTY_GETTER(synthio_miditrack_error_location_obj,
+    (mp_obj_t)&synthio_miditrack_get_error_location_obj);
+
 STATIC const mp_rom_map_elem_t synthio_miditrack_locals_dict_table[] = {
     // Methods
     { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&synthio_miditrack_deinit_obj) },
@@ -159,6 +176,7 @@ STATIC const mp_rom_map_elem_t synthio_miditrack_locals_dict_table[] = {
 
     // Properties
     { MP_ROM_QSTR(MP_QSTR_sample_rate), MP_ROM_PTR(&synthio_miditrack_sample_rate_obj) },
+    { MP_ROM_QSTR(MP_QSTR_error_location), MP_ROM_PTR(&synthio_miditrack_error_location_obj) },
 };
 STATIC MP_DEFINE_CONST_DICT(synthio_miditrack_locals_dict, synthio_miditrack_locals_dict_table);
 

shared-bindings/synthio/MidiTrack.h

@@ -39,3 +39,4 @@ bool common_hal_synthio_miditrack_deinited(synthio_miditrack_obj_t *self);
 uint32_t common_hal_synthio_miditrack_get_sample_rate(synthio_miditrack_obj_t *self);
 uint8_t common_hal_synthio_miditrack_get_bits_per_sample(synthio_miditrack_obj_t *self);
 uint8_t common_hal_synthio_miditrack_get_channel_count(synthio_miditrack_obj_t *self);
+mp_int_t common_hal_synthio_miditrack_get_error_location(synthio_miditrack_obj_t *self);

shared-module/synthio/MidiTrack.c

@@ -29,7 +29,7 @@
 
 
 STATIC void print_midi_stream_error(synthio_miditrack_obj_t *self) {
-    mp_cprintf(&mp_plat_print, translate("Error in MIDI stream at position %d"), self->pos);
+    self->error_location = self->pos;
     self->pos = self->track.len;
 }
 
@@ -106,6 +106,7 @@ static void decode_until_pause(synthio_miditrack_obj_t *self) {
 
 STATIC void start_parse(synthio_miditrack_obj_t *self) {
     self->pos = 0;
+    self->error_location = -1;
     self->synth.span.dur = decode_duration(self);
     if (self->synth.span.dur == 0) {
         // the usual case: the file starts with some MIDI event, not a delay
@@ -135,6 +136,10 @@ bool common_hal_synthio_miditrack_deinited(synthio_miditrack_obj_t *self) {
     return synthio_synth_deinited(&self->synth);
 }
 
+mp_int_t common_hal_synthio_miditrack_get_error_location(synthio_miditrack_obj_t *self) {
+    return self->error_location;
+}
+
 uint32_t common_hal_synthio_miditrack_get_sample_rate(synthio_miditrack_obj_t *self) {
     return self->synth.sample_rate;
 }

shared-module/synthio/MidiTrack.h

@@ -37,6 +37,7 @@ typedef struct {
     mp_buffer_info_t track;
     // invariant: after initial startup, pos always points just after an encoded duration, i.e., at a midi message (or at EOF)
     size_t pos;
+    mp_int_t error_location;
     uint32_t tempo;
 } synthio_miditrack_obj_t;