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// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
part of protobuf;
/// An object representing a protobuf message field.
class FieldInfo<T> {
/// Cached read-only empty list for this field type. For non-repeated fields
/// this is always `null`. Otherwise it starts as `null` and gets initialized
/// in `readonlyDefault`.
PbList<T>? _emptyList;
/// Name of this field as the `json_name` reported by protoc.
///
/// Example:
///
/// ```proto
/// message Msg {
/// int32 foo_name = 1 [json_name = "barName"];
/// }
/// ```
///
/// Here `name` of the field is `barName`. When `json_name` is not specified
/// in the proto definition, this is the camelCase version of the field name.
/// In the example above, without the `json_name` field option, `name` would
/// be `"fooName"`.
final String name;
/// Name of this field as written in the proto definition.
///
/// Example:
///
/// ```proto
/// message SearchRequest {
/// ...
/// int32 result_per_page = 3;
/// }
/// ```
///
/// `protoName` for the `result_per_page` field above is `"result_per_page"`.
/// The name typically consist of words separated with underscores.
String get protoName {
return _protoName ??= _unCamelCase(name);
}
String? _protoName;
/// Field number as specified in the proto definition.
///
/// Example:
///
/// ```proto
/// message SearchRequest {
/// ...
/// int32 result_per_page = 3;
/// }
/// ```
///
/// `tagNumber` of `result_per_page` field is 3.
final int tagNumber;
/// Index of the field in [_FieldSet._values] list of this field's message.
///
/// The value is `null` for extension fields.
final int? index;
/// Type of this field. See [PbFieldType].
final int type;
/// Constructs the default value of a field.
///
/// For repeated fields, only used when the [check] property is `null`.
final MakeDefaultFunc? makeDefault;
/// Creates an empty message or group when decoding a message.
///
/// Only available in fields with message type.
final CreateBuilderFunc? subBuilder;
/// List of all enum values.
///
/// Only available in enum fields.
final List<ProtobufEnum>? enumValues;
/// Default enum value.
///
/// Only available in enum fields.
final ProtobufEnum? defaultEnumValue;
/// Mapping from enum integer values to enum values.
///
/// Only available in enum fields.
final ValueOfFunc? valueOf;
/// Function to verify items when adding to a repeated field.
///
/// Only available in repeated fields.
final CheckFunc<T>? check;
FieldInfo(this.name, this.tagNumber, this.index, this.type,
{dynamic defaultOrMaker,
this.subBuilder,
this.valueOf,
this.enumValues,
this.defaultEnumValue,
String? protoName})
: makeDefault = findMakeDefault(type, defaultOrMaker),
check = null,
_protoName = protoName,
assert(type != 0),
assert(!_isGroupOrMessage(type) ||
subBuilder != null ||
_isMapField(type)),
assert(!_isEnum(type) || valueOf != null);
// Represents a field that has been removed by a program transformation.
FieldInfo.dummy(this.index)
: name = '<removed field>',
_protoName = '<removed field>',
tagNumber = 0,
type = 0,
makeDefault = null,
valueOf = null,
check = null,
enumValues = null,
defaultEnumValue = null,
subBuilder = null;
FieldInfo.repeated(this.name, this.tagNumber, this.index, this.type,
this.check, this.subBuilder,
{this.valueOf, this.enumValues, this.defaultEnumValue, String? protoName})
: makeDefault = (() => PbList<T>(check: check!)),
_protoName = protoName {
ArgumentError.checkNotNull(name, 'name');
ArgumentError.checkNotNull(tagNumber, 'tagNumber');
assert(_isRepeated(type));
assert(check != null);
assert(!_isEnum(type) || valueOf != null);
}
static MakeDefaultFunc? findMakeDefault(int type, dynamic defaultOrMaker) {
if (defaultOrMaker == null) return PbFieldType._defaultForType(type);
if (defaultOrMaker is MakeDefaultFunc) return defaultOrMaker;
return () => defaultOrMaker;
}
/// Whether this represents a dummy field standing in for a field that has
/// been removed by a program transformation.
bool get _isDummy => tagNumber == 0;
bool get isRequired => _isRequired(type);
bool get isRepeated => _isRepeated(type);
bool get isGroupOrMessage => _isGroupOrMessage(type);
bool get isEnum => _isEnum(type);
bool get isMapField => _isMapField(type);
/// Returns a read-only default value for a field. Unlike
/// [GeneratedMessage.getField], doesn't create a repeated field.
dynamic get readonlyDefault {
if (isRepeated) {
return _emptyList ??= PbList.unmodifiable();
}
return makeDefault!();
}
/// Returns true if the field's value is okay to transmit.
/// That is, it doesn't contain any required fields that aren't initialized.
bool _hasRequiredValues(value) {
if (value == null) return !isRequired; // missing is okay if optional
if (!_isGroupOrMessage(type)) return true; // primitive and present
if (!isRepeated) {
// A required message: recurse.
final GeneratedMessage message = value;
return message._fieldSet._hasRequiredValues();
}
final List<GeneratedMessage> list = value;
if (list.isEmpty) return true;
// For message types that (recursively) contain no required fields,
// short-circuit the loop.
if (!list[0]._fieldSet._hasRequiredFields) return true;
// Recurse on each item in the list.
return list.every((GeneratedMessage m) => m._fieldSet._hasRequiredValues());
}
/// Appends the dotted path to each required field that's missing a value.
void _appendInvalidFields(List<String> problems, value, String prefix) {
if (value == null) {
if (isRequired) problems.add('$prefix$name');
} else if (!_isGroupOrMessage(type)) {
// primitive and present
} else if (!isRepeated) {
// Required message/group: recurse.
final GeneratedMessage message = value;
message._fieldSet._appendInvalidFields(problems, '$prefix$name.');
} else {
final List<GeneratedMessage> list = value;
if (list.isEmpty) return;
// For message types that (recursively) contain no required fields,
// short-circuit the loop.
if (!list[0]._fieldSet._hasRequiredFields) return;
// Recurse on each item in the list.
var position = 0;
for (final message in list) {
message._fieldSet
._appendInvalidFields(problems, '$prefix$name[$position].');
position++;
}
}
}
/// Creates a repeated field to be attached to the given message.
///
/// Delegates actual list creation to the message, so that it can
/// be overridden by a mixin.
List<T> _createRepeatedField(GeneratedMessage m) {
assert(isRepeated);
return m.createRepeatedField<T>(tagNumber, this);
}
/// Same as above, but allow a tighter typed List to be created.
List<S> _createRepeatedFieldWithType<S extends T>(GeneratedMessage m) {
assert(isRepeated);
return m.createRepeatedField<S>(tagNumber, this as FieldInfo<S>);
}
/// Convenience method to thread this FieldInfo's reified type parameter to
/// _FieldSet._ensureRepeatedField.
List<T> _ensureRepeatedField(BuilderInfo meta, _FieldSet fs) {
return fs._ensureRepeatedField<T>(meta, this);
}
@override
String toString() => name;
}
final RegExp _upperCase = RegExp('[A-Z]');
String _unCamelCase(String name) {
return name.replaceAllMapped(
_upperCase, (match) => '_${match.group(0)!.toLowerCase()}');
}
/// A [FieldInfo] subclass for protobuf `map` fields.
class MapFieldInfo<K, V> extends FieldInfo<PbMap<K, V>?> {
/// Key type of the map. Per proto2 and proto3 specs, this needs to be an
/// integer type or `string`, and the type cannot be `repeated`.
///
/// The `int` value is interpreted the same way as [FieldInfo.type].
final int keyFieldType;
/// Value type of the map. Per proto2 and proto3 specs, this can be any type
/// other than `map`, and the type cannot be `repeated`.
///
/// The `int` value is interpreted the same way as [FieldInfo.type].
final int valueFieldType;
/// Creates a new empty instance of the value type.
///
/// `null` if the value type is not a Message type.
final CreateBuilderFunc? valueCreator;
final BuilderInfo mapEntryBuilderInfo;
MapFieldInfo(
String name,
int tagNumber,
int index,
int type,
this.keyFieldType,
this.valueFieldType,
this.mapEntryBuilderInfo,
this.valueCreator,
{ProtobufEnum? defaultEnumValue,
String? protoName})
: super(name, tagNumber, index, type,
defaultOrMaker: () => PbMap<K, V>(keyFieldType, valueFieldType),
defaultEnumValue: defaultEnumValue,
protoName: protoName) {
ArgumentError.checkNotNull(name, 'name');
ArgumentError.checkNotNull(tagNumber, 'tagNumber');
assert(_isMapField(type));
assert(!_isEnum(type) || valueOf != null);
}
FieldInfo get valueFieldInfo =>
mapEntryBuilderInfo.fieldInfo[PbMap._valueFieldNumber]!;
Map<K, V> _ensureMapField(BuilderInfo meta, _FieldSet fs) {
return fs._ensureMapField<K, V>(meta, this);
}
Map<K, V> _createMapField(GeneratedMessage m) {
assert(isMapField);
return m.createMapField<K, V>(tagNumber, this);
}
}