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Merged
merged 1 commit into from
Nov 3, 2024
Merged

Better exceptions #2

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203 changes: 191 additions & 12 deletions packages/sane/lib/src/exceptions.dart
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Original file line number Diff line number Diff line change
@@ -1,23 +1,202 @@
abstract class SaneException implements Exception {}
import 'package:ffi/ffi.dart';
import 'package:meta/meta.dart';
import 'package:sane/src/bindings.g.dart';
import 'package:sane/src/dylib.dart';

class SaneUnsupportedException extends SaneException {}
/// Base class for all possible errors that can occur in the SANE library.
///
/// See also:
///
/// - [SaneEofException]
/// - [SaneJammedException]
/// - [SaneDeviceBusyException]
/// - [SaneInvalidDataException]
/// - [SaneIoException]
/// - [SaneNoDocumentsException]
/// - [SaneCoverOpenException]
/// - [SaneUnsupportedException]
/// - [SaneCancelledException]
/// - [SaneNoMemoryException]
/// - <https://sane-project.gitlab.io/standard/api.html#tab-status>
sealed class SaneException implements Exception {
SANE_Status get _status;

class SaneCancelledException extends SaneException {}
const SaneException._();

class SaneDeviceBusyException extends SaneException {}
factory SaneException(SANE_Status status) {
final exception = switch (status) {
SANE_Status.STATUS_GOOD =>
throw ArgumentError(
'Cannot create SaneException with status STATUS_GOOD',
'status',
),
SANE_Status.STATUS_UNSUPPORTED => SaneUnsupportedException(),
SANE_Status.STATUS_CANCELLED => SaneCancelledException(),
SANE_Status.STATUS_DEVICE_BUSY => SaneDeviceBusyException(),
SANE_Status.STATUS_INVAL => SaneInvalidDataException(),
SANE_Status.STATUS_EOF => SaneEofException(),
SANE_Status.STATUS_JAMMED => SaneJammedException(),
SANE_Status.STATUS_NO_DOCS => SaneNoDocumentsException(),
SANE_Status.STATUS_COVER_OPEN => SaneCoverOpenException(),
SANE_Status.STATUS_IO_ERROR => SaneIoException(),
SANE_Status.STATUS_NO_MEM => SaneNoMemoryException(),
SANE_Status.STATUS_ACCESS_DENIED => SaneAccessDeniedException(),
};

class SaneInvalidException extends SaneException {}
assert(exception._status == status);

class SaneJammedException extends SaneException {}
return exception;
}

class SaneNoDocumentsException extends SaneException {}
String get message {
return dylib.sane_strstatus(_status).cast<Utf8>().toDartString();
}

class SaneCoverOpenException extends SaneException {}
@override
String toString() {
return '$runtimeType: $message';
}
}

class SaneIOErrorException extends SaneException {}
/// No more data available.
///
/// See also:
///
/// - <https://sane-project.gitlab.io/standard/api.html#tab-status>
final class SaneEofException extends SaneException {
const SaneEofException() : super._();

class SaneNoMemoryException extends SaneException {}
@override
SANE_Status get _status => SANE_Status.STATUS_EOF;
}

class SaneAccessDeniedException extends SaneException {}
/// The document feeder is jammed.
///
/// See also:
///
/// - <https://sane-project.gitlab.io/standard/api.html#tab-status>
final class SaneJammedException extends SaneException {
const SaneJammedException() : super._();

class SaneNotFoundOption extends SaneException {}
@override
SANE_Status get _status => SANE_Status.STATUS_JAMMED;
}

/// The document feeder is out of documents.
///
/// See also:
///
/// - <https://sane-project.gitlab.io/standard/api.html#tab-status>
final class SaneNoDocumentsException extends SaneException {
const SaneNoDocumentsException() : super._();

@override
SANE_Status get _status => SANE_Status.STATUS_NO_DOCS;
}

/// The scanner cover is open.
///
/// See also:
///
/// - <https://sane-project.gitlab.io/standard/api.html#tab-status>
final class SaneCoverOpenException extends SaneException {
const SaneCoverOpenException() : super._();

@override
SANE_Status get _status => SANE_Status.STATUS_COVER_OPEN;
}

/// The device is busy.
///
/// See also:
///
/// - <https://sane-project.gitlab.io/standard/api.html#tab-status>
final class SaneDeviceBusyException extends SaneException {
const SaneDeviceBusyException() : super._();

@override
SANE_Status get _status => SANE_Status.STATUS_DEVICE_BUSY;
}

/// Data is invalid.
///
/// See also:
///
/// - <https://sane-project.gitlab.io/standard/api.html#tab-status>
final class SaneInvalidDataException extends SaneException {
const SaneInvalidDataException() : super._();

@override
SANE_Status get _status => SANE_Status.STATUS_INVAL;
}

/// Error during device I/O.
///
/// See also:
///
/// - <https://sane-project.gitlab.io/standard/api.html#tab-status>
final class SaneIoException extends SaneException {
const SaneIoException() : super._();

@override
SANE_Status get _status => SANE_Status.STATUS_IO_ERROR;
}

/// Out of memory.
///
/// See also:
///
/// - <https://sane-project.gitlab.io/standard/api.html#tab-status>
final class SaneNoMemoryException extends SaneException {
const SaneNoMemoryException() : super._();

@override
SANE_Status get _status => SANE_Status.STATUS_NO_MEM;
}

/// Access to resource has been denied.
///
/// See also:
///
/// - <https://sane-project.gitlab.io/standard/api.html#tab-status>
final class SaneAccessDeniedException extends SaneException {
const SaneAccessDeniedException() : super._();

@override
SANE_Status get _status => SANE_Status.STATUS_ACCESS_DENIED;
}

/// Operation was cancelled.
///
/// See also:
///
/// - <https://sane-project.gitlab.io/standard/api.html#tab-status>
final class SaneCancelledException extends SaneException {
const SaneCancelledException() : super._();

@override
SANE_Status get _status => SANE_Status.STATUS_CANCELLED;
}

/// Operation is not supported.
///
/// See also:
///
/// - <https://sane-project.gitlab.io/standard/api.html#tab-status>
final class SaneUnsupportedException extends SaneException {
const SaneUnsupportedException() : super._();

@override
SANE_Status get _status => SANE_Status.STATUS_UNSUPPORTED;
}

@internal
extension SaneStatusExtension on SANE_Status {
/// Throws [SaneException] if the status is not [SANE_Status.STATUS_GOOD].
@pragma('vm:prefer-inline')
void check() {
if (this != SANE_Status.STATUS_GOOD) {
throw SaneException(this);
}
}
}
48 changes: 11 additions & 37 deletions packages/sane/lib/src/sane.dart
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Original file line number Diff line number Diff line change
Expand Up @@ -49,7 +49,7 @@ class Sane {
final status = dylib.sane_init(versionCodePointer, nativeAuthCallback);
print('sane_init() -> ${status.name}');

_handleSaneStatus(status);
status.check();

final versionCode = versionCodePointer.value;
print('SANE version: ${SaneUtils.version(versionCodePointer.value)}');
Expand Down Expand Up @@ -90,7 +90,7 @@ class Sane {
);
print('sane_get_devices() -> ${status.name}');

_handleSaneStatus(status);
status.check();

final devices = <SaneDevice>[];
for (var i = 0; deviceListPointer.value[i] != ffi.nullptr; i++) {
Expand All @@ -115,7 +115,7 @@ class Sane {
final status = dylib.sane_open(deviceNamePointer, nativeHandlePointer);
print('sane_open() -> ${status.name}');

_handleSaneStatus(status);
status.check();

final handle = SaneHandle(deviceName: deviceName);
_nativeHandles.addAll({
Expand Down Expand Up @@ -230,7 +230,7 @@ class Sane {
valuePointer = ffi.nullptr;

case SaneOptionValueType.group:
throw SaneInvalidException();
throw SaneInvalidDataException();
}

if (action == SaneAction.setValue) {
Expand Down Expand Up @@ -266,7 +266,7 @@ class Sane {

invalid:
default:
throw SaneInvalidException();
throw SaneInvalidDataException();
}
}

Expand All @@ -279,7 +279,7 @@ class Sane {
);
print('sane_control_option($index, $action, $value) -> ${status.name}');

_handleSaneStatus(status);
status.check();

final infos = saneOptionInfoFromNative(infoPointer.value);
late final dynamic result;
Expand All @@ -305,7 +305,7 @@ class Sane {
result = null;

default:
throw SaneInvalidException();
throw SaneInvalidDataException();
}

ffi.calloc.free(valuePointer);
Expand Down Expand Up @@ -397,7 +397,7 @@ class Sane {
_getNativeHandle(handle), nativeParametersPointer);
print('sane_get_parameters() -> ${status.name}');

_handleSaneStatus(status);
status.check();

final parameters = saneParametersFromNative(nativeParametersPointer.ref);

Expand All @@ -416,7 +416,7 @@ class Sane {
final status = dylib.sane_start(_getNativeHandle(handle));
print('sane_start() -> ${status.name}');

_handleSaneStatus(status);
status.check();

completer.complete();
});
Expand All @@ -439,7 +439,7 @@ class Sane {
);
print('sane_read() -> ${status.name}');

_handleSaneStatus(status);
status.check();

final bytes = Uint8List.fromList(
List.generate(
Expand Down Expand Up @@ -480,37 +480,11 @@ class Sane {
);
print('sane_set_io_mode() -> ${status.name}');

_handleSaneStatus(status);
status.check();

completer.complete();
});

return completer.future;
}

void _handleSaneStatus(SANE_Status status) {
switch (status) {
case SANE_Status.STATUS_UNSUPPORTED:
throw SaneUnsupportedException();
case SANE_Status.STATUS_CANCELLED:
throw SaneCancelledException();
case SANE_Status.STATUS_DEVICE_BUSY:
throw SaneDeviceBusyException();
case SANE_Status.STATUS_INVAL:
throw SaneInvalidException();
case SANE_Status.STATUS_JAMMED:
throw SaneJammedException();
case SANE_Status.STATUS_NO_DOCS:
throw SaneNoDocumentsException();
case SANE_Status.STATUS_COVER_OPEN:
throw SaneCoverOpenException();
case SANE_Status.STATUS_IO_ERROR:
throw SaneIOErrorException();
case SANE_Status.STATUS_NO_MEM:
throw SaneNoMemoryException();
case SANE_Status.STATUS_ACCESS_DENIED:
throw SaneAccessDeniedException();
default:
}
}
}
2 changes: 1 addition & 1 deletion packages/sane/pubspec.lock
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Original file line number Diff line number Diff line change
Expand Up @@ -191,7 +191,7 @@ packages:
source: hosted
version: "0.12.16+1"
meta:
dependency: transitive
dependency: "direct main"
description:
name: meta
sha256: e3641ec5d63ebf0d9b41bd43201a66e3fc79a65db5f61fc181f04cd27aab950c
Expand Down
1 change: 1 addition & 0 deletions packages/sane/pubspec.yaml
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Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,7 @@ environment:

dependencies:
ffi: ^2.1.3
meta: ^1.16.0

dev_dependencies:
ffigen: ^14.0.1
Expand Down