private (string prepareBlock, string serializeBlock) GetStandardSerializeBlocks(int index, TableMemberModel memberModel)
{
string valueVariableName = $"index{index}Value";
string offsetVariableName = $"index{index}Offset";
string condition = $"if ({valueVariableName} != {CSharpHelpers.GetDefaultValueToken(memberModel)})";
if (memberModel.ItemTypeModel is VectorTypeModel vector && vector.IsMemoryVector)
{
// Memory is a struct and can't be null, and 0-length vectors are valid.
// Therefore, we just need to omit the conditional check entirely.
condition = string.Empty;
}
string prepareBlock =
$@"
var {valueVariableName} = item.{memberModel.PropertyInfo.Name};
int {offsetVariableName} = 0;
{condition}
{{
currentOffset += {CSharpHelpers.GetFullMethodName(ReflectedMethods.SerializationHelpers_GetAlignmentErrorMethod)}(currentOffset, {memberModel.ItemTypeModel.Alignment});
{offsetVariableName} = currentOffset;
vtable.{nameof(VTableBuilder.SetOffset)}({index}, currentOffset - tableStart);
currentOffset += {memberModel.ItemTypeModel.InlineSize};
}}";
string serializeBlock =
$@"
if ({offsetVariableName} != 0)
{{
{this.GetSerializeInvocation(memberModel.ItemTypeModel.ClrType, valueVariableName, offsetVariableName)}
}}";
return(prepareBlock, serializeBlock);
}
/// <summary>
/// Generates a special property getter for union types. This stems from
/// the fact that unions occupy two spots in the table's vtable to deserialize one
/// logical field. This means that the logic to read them must also be special.
/// </summary>
private GeneratedProperty CreateUnionTableGetter(TableMemberModel memberModel, int index)
{
Type propertyType = memberModel.ItemTypeModel.ClrType;
string defaultValue = CSharpHelpers.GetDefaultValueToken(memberModel);
UnionTypeModel unionModel = (UnionTypeModel)memberModel.ItemTypeModel;
GeneratedProperty generatedProperty = new GeneratedProperty(this.options, index, memberModel.PropertyInfo);
// Start by generating switch cases. The codegen'ed union types have
// well-defined constructors for each constituent type, so this .ctor
// will always be available.
List <string> switchCases = new List <string>();
for (int i = 0; i < unionModel.UnionElementTypeModel.Length; ++i)
{
var unionMember = unionModel.UnionElementTypeModel[i];
int unionIndex = i + 1;
string structOffsetAdjustment = string.Empty;
if (unionMember.SchemaType == FlatBufferSchemaType.Struct)
{
structOffsetAdjustment = $"offsetLocation += buffer.{nameof(InputBuffer.ReadUOffset)}(offsetLocation);";
}
string @case =
$@"
case {unionIndex}:
{structOffsetAdjustment}
return new {CSharpHelpers.GetCompilableTypeName(unionModel.ClrType)}({this.GetReadInvocation(unionMember.ClrType, "buffer", "offsetLocation")});
";
switchCases.Add(@case);
}
generatedProperty.ReadValueMethodDefinition =
$@"
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static {CSharpHelpers.GetCompilableTypeName(propertyType)} {generatedProperty.ReadValueMethodName}(InputBuffer buffer, int offset)
{{
int discriminatorLocation = buffer.{nameof(InputBuffer.GetAbsoluteTableFieldLocation)}(offset, {index});
int offsetLocation = buffer.{nameof(InputBuffer.GetAbsoluteTableFieldLocation)}(offset, {index + 1});
if (discriminatorLocation == 0) {{
return {defaultValue};
}}
else {{
byte discriminator = buffer.{nameof(InputBuffer.ReadByte)}(discriminatorLocation);
if (discriminator == 0 && offsetLocation != 0)
throw new System.IO.InvalidDataException(""FlatBuffer union had discriminator set but no offset."");
switch (discriminator)
{{
{string.Join("\r\n", switchCases)}
default:
return {defaultValue};
}}
}}
}}
";
return(generatedProperty);
}
/// <summary>
/// Generates a standard getter for a normal vtable entry.
/// </summary>
private GeneratedProperty CreateStandardTableProperty(TableMemberModel memberModel, int index)
{
Type propertyType = memberModel.ItemTypeModel.ClrType;
string defaultValue = CSharpHelpers.GetDefaultValueToken(memberModel);
GeneratedProperty property = new GeneratedProperty(this.options, index, memberModel.PropertyInfo);
property.ReadValueMethodDefinition =
$@"
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static {CSharpHelpers.GetCompilableTypeName(propertyType)} {property.ReadValueMethodName}(InputBuffer buffer, int offset)
{{
int absoluteLocation = buffer.{nameof(InputBuffer.GetAbsoluteTableFieldLocation)}(offset, {index});
if (absoluteLocation == 0) {{
return {defaultValue};
}}
else {{
return {this.GetReadInvocation(propertyType, "buffer", "absoluteLocation")};
}}
}}
";
return(property);
}
private (string prepareBlock, string serializeBlock) GetStandardSerializeBlocks(int index, TableMemberModel memberModel)
{
string valueVariableName = $"index{index}Value";
string offsetVariableName = $"index{index}Offset";
string condition = $"if ({valueVariableName} != {CSharpHelpers.GetDefaultValueToken(memberModel)})";
if ((memberModel.ItemTypeModel is VectorTypeModel vector && vector.IsMemoryVector) || memberModel.IsKey)
{
// 1) Memory is a struct and can't be null, and 0-length vectors are valid.
// Therefore, we just need to omit the conditional check entirely.
// 2) For sorted vector keys, we must include the value since some other
// libraries cannot do binary search with omitted keys.
condition = string.Empty;
}
string keyCheckMethodCall = string.Empty;
if (memberModel.IsKey)
{
keyCheckMethodCall = $"{nameof(SortedVectorHelpers)}.{nameof(SortedVectorHelpers.EnsureKeyNonNull)}({valueVariableName});";
}
string prepareBlock =
$@"
var {valueVariableName} = item.{memberModel.PropertyInfo.Name};
int {offsetVariableName} = 0;
{keyCheckMethodCall}
{condition}
{{
currentOffset += {CSharpHelpers.GetFullMethodName(ReflectedMethods.SerializationHelpers_GetAlignmentErrorMethod)}(currentOffset, {memberModel.ItemTypeModel.Alignment});
{offsetVariableName} = currentOffset;
vtable.{nameof(VTableBuilder.SetOffset)}({index}, currentOffset - tableStart);
currentOffset += {memberModel.ItemTypeModel.InlineSize};
}}";
string sortInvocation = string.Empty;
if (memberModel.IsSortedVector)
{
VectorTypeModel vectorModel = (VectorTypeModel)memberModel.ItemTypeModel;
TableTypeModel tableModel = (TableTypeModel)vectorModel.ItemTypeModel;
TableMemberModel keyMember = tableModel.IndexToMemberMap.Single(x => x.Value.PropertyInfo == tableModel.KeyProperty).Value;
var builtInType = BuiltInType.BuiltInTypes[keyMember.ItemTypeModel.ClrType];
string inlineSize = builtInType.TypeModel.SchemaType == FlatBufferSchemaType.Scalar ? builtInType.TypeModel.InlineSize.ToString() : "null";
sortInvocation = $"{nameof(SortedVectorHelpers)}.{nameof(SortedVectorHelpers.SortVector)}(" +
$"span, {offsetVariableName}, {keyMember.Index}, {inlineSize}, {CSharpHelpers.GetCompilableTypeName(builtInType.SpanComparerType)}.Instance);";
}
string serializeBlock =
$@"
if ({offsetVariableName} != 0)
{{
{this.GetSerializeInvocation(memberModel.ItemTypeModel.ClrType, valueVariableName, offsetVariableName)}
{sortInvocation}
}}";
return(prepareBlock, serializeBlock);
}