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Merged
NinoFloris merged 2 commits into from
Nov 3, 2025
Merged

Add SupportsReading plumbing #5472

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f9c1f87
Add SupportsReading to PgTypeInfo
NinoFloris Dec 4, 2023
192bab0
Force supports reading for the array mappings
NinoFloris Dec 4, 2023
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4 changes: 4 additions & 0 deletions src/Npgsql/Internal/AdoSerializerHelpers.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,8 @@ public static PgTypeInfo GetTypeInfoForReading(Type type, PgTypeId pgTypeId, PgS
try
{
typeInfo = options.GetTypeInfoInternal(type, pgTypeId);
if (typeInfo is { SupportsReading: false })
typeInfo = null;
}
catch (Exception ex)
{
Expand All @@ -41,6 +43,8 @@ public static PgTypeInfo GetTypeInfoForWriting(Type? type, PgTypeId? pgTypeId, P
try
{
typeInfo = options.GetTypeInfoInternal(type, pgTypeId);
if (typeInfo is { SupportsWriting: false })
typeInfo = null;
}
catch (Exception ex)
{
Expand Down
7 changes: 7 additions & 0 deletions src/Npgsql/Internal/PgTypeInfo.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -21,6 +21,7 @@ public class PgTypeInfo
Options = options;
IsBoxing = unboxedType is not null;
Type = unboxedType ?? type;
SupportsReading = GetDefaultSupportsReading(type, unboxedType);
SupportsWriting = true;
}

Expand Down Expand Up @@ -54,6 +55,7 @@ private protected PgTypeInfo(PgSerializerOptions options, Type type, PgConverter
public Type Type { get; }
public PgSerializerOptions Options { get; }

public bool SupportsReading { get; init; }
public bool SupportsWriting { get; init; }
public DataFormat? PreferredFormat { get; init; }

Expand Down Expand Up @@ -240,6 +242,11 @@ DataFormat ResolveFormat(PgConverter converter, out BufferRequirements bufferReq
return default;
}
}

// We assume a boxing type info does not support reading as the converter won't be able to produce the derived type statically.
// Cases like Array converters unboxing to int[], int[,] etc. are the exception and the reason why SupportsReading is a settable property.
internal static bool GetDefaultSupportsReading(Type type, Type? unboxedType)
=> unboxedType is null || unboxedType == type;
}

public sealed class PgResolverTypeInfo(
Expand Down
16 changes: 8 additions & 8 deletions src/Npgsql/Internal/ResolverFactories/AdoTypeInfoResolverFactory.cs
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Expand Up @@ -91,10 +91,10 @@ static TypeInfoMappingCollection AddMappings(TypeInfoMappingCollection mappings)
mapping => mapping with { MatchRequirement = MatchRequirement.DataTypeName, TypeMatchPredicate = type => typeof(Stream).IsAssignableFrom(type) });
//Special mappings, these have no corresponding array mapping.
mappings.AddType<TextReader>(DataTypeNames.Text,
static (options, mapping, _) => mapping.CreateInfo(options, new TextReaderTextConverter(options.TextEncoding), supportsWriting: false, preferredFormat: DataFormat.Text),
static (options, mapping, _) => mapping.CreateInfo(options, new TextReaderTextConverter(options.TextEncoding), preferredFormat: DataFormat.Text, supportsWriting: false),
MatchRequirement.DataTypeName);
mappings.AddStructType<GetChars>(DataTypeNames.Text,
static (options, mapping, _) => mapping.CreateInfo(options, new GetCharsTextConverter(options.TextEncoding), supportsWriting: false, preferredFormat: DataFormat.Text),
static (options, mapping, _) => mapping.CreateInfo(options, new GetCharsTextConverter(options.TextEncoding), preferredFormat: DataFormat.Text, supportsWriting: false),
MatchRequirement.DataTypeName);

// Alternative text types
Expand All @@ -118,10 +118,10 @@ static TypeInfoMappingCollection AddMappings(TypeInfoMappingCollection mappings)
mapping => mapping with { MatchRequirement = MatchRequirement.DataTypeName, TypeMatchPredicate = type => typeof(Stream).IsAssignableFrom(type) });
//Special mappings, these have no corresponding array mapping.
mappings.AddType<TextReader>(dataTypeName,
static (options, mapping, _) => mapping.CreateInfo(options, new TextReaderTextConverter(options.TextEncoding), supportsWriting: false, preferredFormat: DataFormat.Text),
static (options, mapping, _) => mapping.CreateInfo(options, new TextReaderTextConverter(options.TextEncoding), preferredFormat: DataFormat.Text, supportsWriting: false),
MatchRequirement.DataTypeName);
mappings.AddStructType<GetChars>(dataTypeName,
static (options, mapping, _) => mapping.CreateInfo(options, new GetCharsTextConverter(options.TextEncoding), supportsWriting: false, preferredFormat: DataFormat.Text),
static (options, mapping, _) => mapping.CreateInfo(options, new GetCharsTextConverter(options.TextEncoding), preferredFormat: DataFormat.Text, supportsWriting: false),
MatchRequirement.DataTypeName);
}

Expand All @@ -142,10 +142,10 @@ static TypeInfoMappingCollection AddMappings(TypeInfoMappingCollection mappings)
mapping => mapping with { MatchRequirement = MatchRequirement.DataTypeName, TypeMatchPredicate = type => typeof(Stream).IsAssignableFrom(type) });
//Special mappings, these have no corresponding array mapping.
mappings.AddType<TextReader>(DataTypeNames.Jsonb,
static (options, mapping, _) => mapping.CreateInfo(options, new VersionPrefixedTextConverter<TextReader>(jsonbVersion, new TextReaderTextConverter(options.TextEncoding)), supportsWriting: false, preferredFormat: DataFormat.Text),
static (options, mapping, _) => mapping.CreateInfo(options, new VersionPrefixedTextConverter<TextReader>(jsonbVersion, new TextReaderTextConverter(options.TextEncoding)), preferredFormat: DataFormat.Text, supportsWriting: false),
MatchRequirement.DataTypeName);
mappings.AddStructType<GetChars>(DataTypeNames.Jsonb,
static (options, mapping, _) => mapping.CreateInfo(options, new VersionPrefixedTextConverter<GetChars>(jsonbVersion, new GetCharsTextConverter(options.TextEncoding)), supportsWriting: false, preferredFormat: DataFormat.Text),
static (options, mapping, _) => mapping.CreateInfo(options, new VersionPrefixedTextConverter<GetChars>(jsonbVersion, new GetCharsTextConverter(options.TextEncoding)), preferredFormat: DataFormat.Text, supportsWriting: false),
MatchRequirement.DataTypeName);

// Jsonpath
Expand All @@ -154,10 +154,10 @@ static TypeInfoMappingCollection AddMappings(TypeInfoMappingCollection mappings)
static (options, mapping, _) => mapping.CreateInfo(options, new VersionPrefixedTextConverter<string>(jsonpathVersion, new StringTextConverter(options.TextEncoding))), isDefault: true);
//Special mappings, these have no corresponding array mapping.
mappings.AddType<TextReader>(DataTypeNames.Jsonpath,
static (options, mapping, _) => mapping.CreateInfo(options, new VersionPrefixedTextConverter<TextReader>(jsonpathVersion, new TextReaderTextConverter(options.TextEncoding)), supportsWriting: false, preferredFormat: DataFormat.Text),
static (options, mapping, _) => mapping.CreateInfo(options, new VersionPrefixedTextConverter<TextReader>(jsonpathVersion, new TextReaderTextConverter(options.TextEncoding)), preferredFormat: DataFormat.Text, supportsWriting: false),
MatchRequirement.DataTypeName);
mappings.AddStructType<GetChars>(DataTypeNames.Jsonpath,
static (options, mapping, _) => mapping.CreateInfo(options, new VersionPrefixedTextConverter<GetChars>(jsonpathVersion, new GetCharsTextConverter(options.TextEncoding)), supportsWriting: false, preferredFormat: DataFormat.Text),
static (options, mapping, _) => mapping.CreateInfo(options, new VersionPrefixedTextConverter<GetChars>(jsonpathVersion, new GetCharsTextConverter(options.TextEncoding)), preferredFormat: DataFormat.Text, supportsWriting: false),
MatchRequirement.DataTypeName);

// Bytea
Expand Down
9 changes: 2 additions & 7 deletions src/Npgsql/Internal/ResolverFactories/NetworkTypeInfoResolverFactory.cs
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Expand Up @@ -31,14 +31,9 @@ static TypeInfoMappingCollection AddMappings(TypeInfoMappingCollection mappings)

// inet
// There are certain IPAddress values like Loopback or Any that return a *private* derived type (see https://github.com/dotnet/runtime/issues/27870).
// However we still need to be able to resolve some typed converter for those values.
// We do so by returning a boxing info when we deal with a derived type, as a result we don't need an exact typed converter.
// For arrays users can't actually reference the private type so we'll only see some version of ArrayType<IPAddress>.
// For reads we'll only see the public type so we never surface an InvalidCastException trying to cast IPAddress to ReadOnlyIPAddress.
// Finally we add a custom predicate to be able to match any type which values are assignable to IPAddress.
mappings.AddType<IPAddress>(DataTypeNames.Inet,
static (options, mapping, _) => new PgTypeInfo(options, new IPAddressConverter(),
new DataTypeName(mapping.DataTypeName), unboxedType: mapping.Type == typeof(IPAddress) ? null : mapping.Type),
static (options, mapping, _) => new PgTypeInfo(options, new IPAddressConverter(), new DataTypeName(mapping.DataTypeName),
unboxedType: mapping.Type != typeof(IPAddress) ? mapping.Type : null),
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@roji roji Nov 3, 2025

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Super minor nit: FWIW I prefer the the previous ternary to avoid double negation

mapping => mapping with
{
MatchRequirement = MatchRequirement.Single,
Expand Down
31 changes: 17 additions & 14 deletions src/Npgsql/Internal/TypeInfoMapping.cs
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Expand Up @@ -72,7 +72,7 @@ public readonly struct TypeInfoMapping(Type type, string dataTypeName, TypeInfoF

public bool TypeEquals(Type type) => TypeMatchPredicate?.Invoke(type) ?? Type == type;

private bool DataTypeNameEqualsCore(string dataTypeName)
bool DataTypeNameEqualsCore(string dataTypeName)
{
var span = DataTypeName.AsSpan();
return Postgres.DataTypeName.IsFullyQualified(span)
Expand Down Expand Up @@ -196,7 +196,7 @@ TypeInfoMapping GetMapping(Type type, string dataTypeName)
=> TryGetMapping(type, dataTypeName, out var info) ? info : throw new InvalidOperationException($"Could not find mapping for {type} <-> {dataTypeName}");

// Helper to eliminate generic display class duplication.
static TypeInfoFactory CreateComposedFactory(Type mappingType, TypeInfoMapping innerMapping, Func<TypeInfoMapping, PgTypeInfo, PgConverter> mapper, bool copyPreferredFormat = false, bool supportsWriting = true)
static TypeInfoFactory CreateComposedFactory(Type mappingType, TypeInfoMapping innerMapping, Func<TypeInfoMapping, PgTypeInfo, PgConverter> mapper, bool copyPreferredFormat = false, bool? supportsReading = null, bool? supportsWriting = null)
=> (options, mapping, requiresDataTypeName) =>
{
var resolvedInnerMapping = innerMapping;
Expand All @@ -206,18 +206,20 @@ static TypeInfoFactory CreateComposedFactory(Type mappingType, TypeInfoMapping i
var innerInfo = innerMapping.Factory(options, resolvedInnerMapping, requiresDataTypeName);
var converter = mapper(mapping, innerInfo);
var preferredFormat = copyPreferredFormat ? innerInfo.PreferredFormat : null;
var writingSupported = supportsWriting && innerInfo.SupportsWriting;
var unboxedType = ComputeUnboxedType(defaultType: mappingType, converter.TypeToConvert, mapping.Type);
var readingSupported = innerInfo.SupportsReading && (supportsReading ?? PgTypeInfo.GetDefaultSupportsReading(converter.TypeToConvert, unboxedType));
var writingSupported = innerInfo.SupportsWriting && (supportsWriting ?? true);

return new PgTypeInfo(options, converter, options.GetCanonicalTypeId(new DataTypeName(mapping.DataTypeName)), unboxedType)
{
PreferredFormat = preferredFormat,
SupportsReading = readingSupported,
SupportsWriting = writingSupported
};
};

// Helper to eliminate generic display class duplication.
static TypeInfoFactory CreateComposedFactory(Type mappingType, TypeInfoMapping innerMapping, Func<TypeInfoMapping, PgResolverTypeInfo, PgConverterResolver> mapper, bool copyPreferredFormat = false, bool supportsWriting = true)
static TypeInfoFactory CreateComposedFactory(Type mappingType, TypeInfoMapping innerMapping, Func<TypeInfoMapping, PgResolverTypeInfo, PgConverterResolver> mapper, bool copyPreferredFormat = false, bool? supportsReading = null, bool? supportsWriting = null)
=> (options, mapping, requiresDataTypeName) =>
{
var resolvedInnerMapping = innerMapping;
Expand All @@ -227,8 +229,9 @@ static TypeInfoFactory CreateComposedFactory(Type mappingType, TypeInfoMapping i
var innerInfo = (PgResolverTypeInfo)innerMapping.Factory(options, resolvedInnerMapping, requiresDataTypeName);
var resolver = mapper(mapping, innerInfo);
var preferredFormat = copyPreferredFormat ? innerInfo.PreferredFormat : null;
var writingSupported = supportsWriting && innerInfo.SupportsWriting;
var unboxedType = ComputeUnboxedType(defaultType: mappingType, resolver.TypeToConvert, mapping.Type);
var readingSupported = innerInfo.SupportsReading && (supportsReading ?? PgTypeInfo.GetDefaultSupportsReading(resolver.TypeToConvert, unboxedType));
var writingSupported = innerInfo.SupportsWriting && (supportsWriting ?? true);
// We include the data type name if the inner info did so as well.
// This way we can rely on its logic around resolvedDataTypeName, including when it ignores that flag.
PgTypeId? pgTypeId = innerInfo.PgTypeId is not null
Expand All @@ -237,6 +240,7 @@ static TypeInfoFactory CreateComposedFactory(Type mappingType, TypeInfoMapping i
return new PgResolverTypeInfo(options, resolver, pgTypeId, unboxedType)
{
PreferredFormat = preferredFormat,
SupportsReading = readingSupported,
SupportsWriting = writingSupported
};
};
Expand Down Expand Up @@ -351,7 +355,7 @@ public void AddArrayType<TElement>(TypeInfoMapping elementMapping, bool suppress

void AddArrayType(TypeInfoMapping elementMapping, Type type, Func<TypeInfoMapping, PgTypeInfo, PgConverter> converter, Func<Type?, bool>? typeMatchPredicate = null, bool suppressObjectMapping = false)
{
var arrayMapping = new TypeInfoMapping(type, arrayDataTypeName, CreateComposedFactory(type, elementMapping, converter))
var arrayMapping = new TypeInfoMapping(type, arrayDataTypeName, CreateComposedFactory(type, elementMapping, converter, supportsReading: true))
{
MatchRequirement = elementMapping.MatchRequirement,
TypeMatchPredicate = typeMatchPredicate
Expand Down Expand Up @@ -391,7 +395,7 @@ public void AddResolverArrayType<TElement>(TypeInfoMapping elementMapping, bool

void AddResolverArrayType(TypeInfoMapping elementMapping, Type type, Func<TypeInfoMapping, PgResolverTypeInfo, PgConverterResolver> converter, Func<Type?, bool>? typeMatchPredicate = null, bool suppressObjectMapping = false)
{
var arrayMapping = new TypeInfoMapping(type, arrayDataTypeName, CreateComposedFactory(type, elementMapping, converter))
var arrayMapping = new TypeInfoMapping(type, arrayDataTypeName, CreateComposedFactory(type, elementMapping, converter, supportsReading: true))
{
MatchRequirement = elementMapping.MatchRequirement,
TypeMatchPredicate = typeMatchPredicate
Expand Down Expand Up @@ -483,12 +487,12 @@ void AddStructArrayType(TypeInfoMapping elementMapping, TypeInfoMapping nullable
Func<Type?, bool>? typeMatchPredicate, Func<Type?, bool>? nullableTypeMatchPredicate, bool suppressObjectMapping)
{
var arrayDataTypeName = GetArrayDataTypeName(elementMapping.DataTypeName);
var arrayMapping = new TypeInfoMapping(type, arrayDataTypeName, CreateComposedFactory(type, elementMapping, converter))
var arrayMapping = new TypeInfoMapping(type, arrayDataTypeName, CreateComposedFactory(type, elementMapping, converter, supportsReading: true))
{
MatchRequirement = elementMapping.MatchRequirement,
TypeMatchPredicate = typeMatchPredicate
};
var nullableArrayMapping = new TypeInfoMapping(nullableType, arrayDataTypeName, CreateComposedFactory(nullableType, nullableElementMapping, nullableConverter))
var nullableArrayMapping = new TypeInfoMapping(nullableType, arrayDataTypeName, CreateComposedFactory(nullableType, nullableElementMapping, nullableConverter, supportsReading: true))
{
MatchRequirement = arrayMapping.MatchRequirement,
TypeMatchPredicate = nullableTypeMatchPredicate
Expand Down Expand Up @@ -601,12 +605,12 @@ void AddResolverStructArrayType(TypeInfoMapping elementMapping, TypeInfoMapping
{
var arrayDataTypeName = GetArrayDataTypeName(elementMapping.DataTypeName);

var arrayMapping = new TypeInfoMapping(type, arrayDataTypeName, CreateComposedFactory(type, elementMapping, converter))
var arrayMapping = new TypeInfoMapping(type, arrayDataTypeName, CreateComposedFactory(type, elementMapping, converter, supportsReading: true))
{
MatchRequirement = elementMapping.MatchRequirement,
TypeMatchPredicate = typeMatchPredicate
};
var nullableArrayMapping = new TypeInfoMapping(nullableType, arrayDataTypeName, CreateComposedFactory(nullableType, nullableElementMapping, nullableConverter))
var nullableArrayMapping = new TypeInfoMapping(nullableType, arrayDataTypeName, CreateComposedFactory(nullableType, nullableElementMapping, nullableConverter, supportsReading: true))
{
MatchRequirement = elementMapping.MatchRequirement,
TypeMatchPredicate = nullableTypeMatchPredicate
Expand Down Expand Up @@ -654,7 +658,7 @@ void AddPolymorphicResolverArrayType(TypeInfoMapping elementMapping, Type type,
{
var arrayDataTypeName = GetArrayDataTypeName(elementMapping.DataTypeName);
var mapping = new TypeInfoMapping(type, arrayDataTypeName,
CreateComposedFactory(typeof(Array), elementMapping, converter, supportsWriting: false))
CreateComposedFactory(typeof(Array), elementMapping, converter, supportsReading: true, supportsWriting: false))
{
MatchRequirement = elementMapping.MatchRequirement,
TypeMatchPredicate = typeMatchPredicate
Expand Down Expand Up @@ -811,8 +815,7 @@ public static PgTypeInfo CreateInfo(this TypeInfoMapping mapping, PgSerializerOp
public static PgResolverTypeInfo CreateInfo(this TypeInfoMapping mapping, PgSerializerOptions options, PgConverterResolver resolver, bool includeDataTypeName)
=> new(options, resolver, includeDataTypeName ? new DataTypeName(mapping.DataTypeName) : null)
{
PreferredFormat = null,
SupportsWriting = true
PreferredFormat = null
};

/// <summary>
Expand Down
3 changes: 0 additions & 3 deletions src/Npgsql/NpgsqlParameter.cs
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Expand Up @@ -618,9 +618,6 @@ internal void Bind(out DataFormat format, out Size size, DataFormat? requiredFor
if (TypeInfo is null)
ThrowHelper.ThrowInvalidOperationException($"Missing type info, {nameof(ResolveTypeInfo)} needs to be called before {nameof(Bind)}.");

if (!TypeInfo.SupportsWriting)
ThrowHelper.ThrowNotSupportedException($"Cannot write values for parameters of type '{TypeInfo.Type}' and postgres type '{TypeInfo.Options.DatabaseInfo.GetDataTypeName(PgTypeId).DisplayName}'.");

// We might call this twice, once during validation and once during WriteBind, only compute things once.
if (WriteSize is null)
{
Expand Down
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