private FieldDef AddFieldCreate(string name, FlatBuffersType type)
{
var fieldOffset = FieldIndexToOffset((ushort)Fields.Count);
var fieldDef = new FieldDef {
Name = name,
Value = new Value {
offset = fieldOffset, type = type
},
TypeBuilder = TypeBuilder,
};
if (Fixed)
{
var size = fieldDef.Value.type.InlineSize;
var alignment = fieldDef.Value.type.InlineAlignment;
// structs_ need to have a predictable format, so we need to align to
// the largest scalar
MinAlign = Math.Max(MinAlign, alignment);
if (Fields.Count > 0)
{
PadLastField(alignment);
}
fieldDef.Value.offset = (ushort)ByteSize;
ByteSize += size;
}
if (Fields.Add(fieldDef.Name, fieldDef))
{
throw new Exception("field already exists!");
}
return(fieldDef);
}
public int ParseEnumDecl(int offset, string schemaStr, bool isUnion)
{
offset = SkipWhitespace(offset, schemaStr);
string name;
offset = ParseIdentifier(offset, schemaStr, out name);
var underlyingType = isUnion ? BaseType.UType : BaseType.Int; // by default
offset = SkipWhitespace(offset, schemaStr);
if (!isUnion && schemaStr[offset] == ':')
{
offset++;
offset = SkipWhitespace(offset, schemaStr);
var tempType = new FlatBuffersType {
BaseType = BaseType.None
};
offset = ParseTypeIdentifier(offset, schemaStr, tempType);
underlyingType = tempType.BaseType;
}
if (!underlyingType.IsScalar())
{
throw new Exception("Enum must be a scalar type");
}
var enumDef = TypeBuilder.AddEnum(name, underlyingType);
if (isUnion)
{
enumDef.UnderlyingType.EnumDef = enumDef;
}
//TODO metadata, again, but as "attributes" on the enumDef
offset = SkipWhitespace(offset, schemaStr);
offset = Consume("{", offset, schemaStr);
offset = ParseEnumValDeclStar(offset, schemaStr, enumDef, isUnion);
return(offset);
}
public int ParseVectorType(int offset, string schemaStr, out FlatBuffersType type)
{
type = new FlatBuffersType();
type.BaseType = BaseType.Vector;
offset = SkipWhitespace(offset, schemaStr);
offset = Consume("[", offset, schemaStr);
offset = ParseTypeIdentifier(offset, schemaStr, type);
offset = SkipWhitespace(offset, schemaStr);
offset = Consume("]", offset, schemaStr);
return(offset);
}
public int ParseType(int offset, string schemaStr, out FlatBuffersType type)
{
type = new FlatBuffersType();
offset = SkipWhitespace(offset, schemaStr);
if (schemaStr[offset] == '[')
{
return(ParseVectorType(offset, schemaStr, out type));
}
else
{
type.BaseType = BaseType.None;
offset = ParseTypeIdentifier(offset, schemaStr, type);
}
return(offset);
}
public FieldDef AddField(string name, FlatBuffersType type, string defaultValue = null,
SymbolTable <Value> attributes = null)
{
if (Fixed && !type.BaseType.IsScalar() && !type.IsStruct)
{
throw new Exception("structs may contain only scalar or struct fields");
}
FieldDef typeField = null;
if (type.BaseType == BaseType.Union)
{
// For union fields, add a second auto-generated field to hold the type
typeField = AddField(name + "_type", type.EnumDef.UnderlyingType);
}
var field = AddFieldCreate(name, type);
field.Attributes = attributes ?? field.Attributes;
if (defaultValue != null)
{
if (!type.BaseType.IsScalar())
{
throw new Exception("default values currently only suppoerted for scalars");
}
field.Value.constant = defaultValue;
}
if (type.EnumDef != null &&
type.BaseType.IsScalar() &&
!Fixed &&
!type.EnumDef.BitFlags &&
field.Value.constant != null &&
type.EnumDef.ReverseLookup(Int32.Parse(field.Value.constant)) != null)
{
throw new Exception("enum " + type.EnumDef.Name +
" does not have a declaration for this field's default of " + field.Value.constant);
}
field.Deprecated = field.Attributes.Lookup("deprecated") != null;
if (field.Deprecated && (Fixed || field.Value.type.BaseType.IsScalar()))
{
throw new Exception("can't deprecate fields in a struct");
}
var nested = field.Attributes.Lookup("nested_flatbuffer");
if (nested != null)
{
if (nested.type.BaseType != BaseType.String)
{
throw new Exception("nested_flatbuffer attribute must be a string (the root type)");
}
if (field.Value.type.BaseType != BaseType.Vector ||
field.Value.type.ElementType != BaseType.UByte)
{
throw new Exception("nested_flatbuffer attribute may only apply to a vector of ubyte");
}
TypeBuilder.LookupOrCreateStruct(nested.constant);
}
// If this field is a union, and it has a manually assigned id, the automatically added type field should have an id as well (of N - 1).
if (typeField != null)
{
var attr = field.Id;
if (attr != null)
{
var id = int.Parse(attr.constant);
var value = new Value();
value.type = field.Id.type;
value.constant = (id - 1).ToString();
typeField.Attributes.Add("id", value);
}
}
return(field);
}
public int ParseTypeIdentifier(int offset, string schemaStr, FlatBuffersType type)
{
offset = SkipWhitespace(offset, schemaStr);
string identifier;
offset = ParseIdentifier(offset, schemaStr, out identifier);
var baseType = BaseType.None;
if (identifier == "bool")
{
baseType = BaseType.Bool;
}
else if (identifier == "byte")
{
baseType = BaseType.Byte;
}
else if (identifier == "ubyte")
{
baseType = BaseType.UByte;
}
else if (identifier == "short")
{
baseType = BaseType.Short;
}
else if (identifier == "ushort")
{
baseType = BaseType.UShort;
}
else if (identifier == "int")
{
baseType = BaseType.Int;
}
else if (identifier == "uint")
{
baseType = BaseType.UInt;
}
else if (identifier == "long")
{
baseType = BaseType.Long;
}
else if (identifier == "ulong")
{
baseType = BaseType.ULong;
}
else if (identifier == "float")
{
baseType = BaseType.Float;
}
else if (identifier == "double")
{
baseType = BaseType.Double;
}
else if (identifier == "string")
{
baseType = BaseType.String;
}
Definition def = null;
if (baseType == BaseType.None)
{
// must be a type defined earlier!
def = TypeBuilder.Enums.Lookup(identifier);
if (def == null)
{
def = TypeBuilder.LookupOrCreateStruct(identifier);
}
}
if (type.BaseType == BaseType.Vector)
{
if (def != null && def is EnumDef)
{
var enumDef = def as EnumDef;
type.ElementType = enumDef.UnderlyingType.BaseType;
type.EnumDef = enumDef;
}
else if (def != null && def is StructDef)
{
type.ElementType = BaseType.Struct;
type.StructDef = def as StructDef;
}
else if (baseType != BaseType.None)
{
type.ElementType = baseType;
}
else
{
throw new Exception("Unexpected type input");
}
}
else if (def != null)
{
if (def is EnumDef)
{
var enumDef = def as EnumDef;
type.BaseType = enumDef.UnderlyingType.BaseType;
type.EnumDef = enumDef;
}
else if (def is StructDef)
{
type.BaseType = BaseType.Struct;
type.StructDef = def as StructDef;
}
else
{
throw new Exception("Unexpected type input");
}
}
else
{
type.BaseType = baseType;
}
return(offset);
}