// Returns the function name that is able to read a value of the given type.
static std::string GenGetter(const Type &type) {
switch (type.base_type) {
case BASE_TYPE_STRING: return "rcv._tab.ByteVector";
case BASE_TYPE_UNION: return "rcv._tab.Union";
case BASE_TYPE_VECTOR: return GenGetter(type.VectorType());
default:
return "rcv._tab.Get" + MakeCamel(GenTypeGet(type));
}
}
// Get the value of a struct's scalar.
static void GetScalarFieldOfStruct(const StructDef &struct_def,
const FieldDef &field,
std::string *code_ptr) {
std::string &code = *code_ptr;
std::string getter = GenGetter(field.value.type);
GenReceiver(struct_def, code_ptr);
code += " " + MakeCamel(field.name);
code += "() " + TypeName(field) + " { return " + getter;
code += "(rcv._tab.Pos + flatbuffers.UOffsetT(";
code += NumToString(field.value.offset) + ")) }\n";
}
// Get the value of a string.
static void GetStringField(const StructDef &struct_def,
const FieldDef &field,
std::string *code_ptr) {
std::string &code = *code_ptr;
GenReceiver(struct_def, code_ptr);
code += " " + MakeCamel(field.name);
code += "() " + TypeName(field) + " ";
code += OffsetPrefix(field) + "\t\treturn " + GenGetter(field.value.type);
code += "(o + rcv._tab.Pos)\n\t}\n\treturn nil\n";
code += "}\n\n";
}
// Returns the function name that is able to read a value of the given type.
static std::string GenGetter(const Type &type) {
switch (type.base_type) {
case BASE_TYPE_STRING: return "self._tab.String(";
case BASE_TYPE_UNION: return "self._tab.Union(";
case BASE_TYPE_VECTOR: return GenGetter(type.VectorType());
default:
return "self._tab.Get(flatbuffers.number_types." + \
MakeCamel(GenTypeGet(type)) + \
"Flags, ";
}
}
// Get the value of a struct's scalar.
static void GetScalarFieldOfStruct(const StructDef &struct_def,
const FieldDef &field,
std::string *code_ptr) {
std::string &code = *code_ptr;
std::string getter = GenGetter(field.value.type);
GenReceiver(struct_def, code_ptr);
code += MakeCamel(field.name);
code += "(self): return " + getter;
code += "self._tab.Pos + flatbuffers.number_types.UOffsetTFlags.py_type(";
code += NumToString(field.value.offset) + "))\n";
}
// Returns the function name that is able to read a value of the given type.
static std::string GenGetter(const Type &type) {
switch (type.base_type) {
case BASE_TYPE_STRING: return "__string";
case BASE_TYPE_STRUCT: return "__struct";
case BASE_TYPE_UNION: return "__union";
case BASE_TYPE_VECTOR: return GenGetter(type.VectorType());
default:
return "bb.get" + (SizeOf(type.base_type) > 1
? MakeCamel(GenTypeGet(type))
: "");
}
}
// Get the value of a string.
static void GetStringField(const StructDef &struct_def,
const FieldDef &field,
std::string *code_ptr) {
std::string &code = *code_ptr;
GenReceiver(struct_def, code_ptr);
code += MakeCamel(field.name);
code += "(self):";
code += OffsetPrefix(field);
code += Indent + Indent + Indent + "return " + GenGetter(field.value.type);
code += "o + self._tab.Pos)\n";
code += Indent + Indent + "return \"\"\n\n";
}
// Get the value of a union from an object.
static void GetUnionField(const StructDef &struct_def,
const FieldDef &field,
std::string *code_ptr) {
std::string &code = *code_ptr;
GenReceiver(struct_def, code_ptr);
code += " " + MakeCamel(field.name) + "(";
code += "obj " + TypeName(field) + ") bool ";
code += OffsetPrefix(field);
code += "\t\t" + GenGetter(field.value.type);
code += "(obj, o)\n\t\treturn true\n\t}\n";
code += "\treturn false\n";
code += "}\n\n";
}
// Get the value of a union from an object.
static void GetUnionField(const StructDef &struct_def,
const FieldDef &field,
std::string *code_ptr) {
std::string &code = *code_ptr;
GenReceiver(struct_def, code_ptr);
code += MakeCamel(field.name) + "(self):";
code += OffsetPrefix(field);
// TODO(rw): this works and is not the good way to it:
bool is_native_table = TypeName(field) == "*flatbuffers.Table";
if (is_native_table) {
code += Indent + Indent + Indent + "from flatbuffers.table import Table\n";
} else {
code += Indent + Indent + Indent;
code += "from ." + TypeName(field) + " import " + TypeName(field) + "\n";
}
code += Indent + Indent + Indent + "obj = Table(bytearray(), 0)\n";
code += Indent + Indent + Indent + GenGetter(field.value.type);
code += "obj, o)\n" + Indent + Indent + Indent + "return obj\n";
code += Indent + Indent + "return None\n\n";
}
// Get the value of a vector's non-struct member. Uses a named return
// argument to conveniently set the zero value for the result.
static void GetMemberOfVectorOfNonStruct(const StructDef &struct_def,
const FieldDef &field,
std::string *code_ptr) {
std::string &code = *code_ptr;
auto vectortype = field.value.type.VectorType();
GenReceiver(struct_def, code_ptr);
code += " " + MakeCamel(field.name);
code += "(j int) " + TypeName(field) + " ";
code += OffsetPrefix(field);
code += "\t\ta := rcv._tab.Vector(o)\n";
code += "\t\treturn " + GenGetter(field.value.type) + "(";
code += "a + flatbuffers.UOffsetT(j*";
code += NumToString(InlineSize(vectortype)) + "))\n";
code += "\t}\n";
if (vectortype.base_type == BASE_TYPE_STRING) {
code += "\treturn nil\n";
} else {
code += "\treturn 0\n";
}
code += "}\n\n";
}
// Get the value of a vector's non-struct member. Uses a named return
// argument to conveniently set the zero value for the result.
static void GetMemberOfVectorOfNonStruct(const StructDef &struct_def,
const FieldDef &field,
std::string *code_ptr) {
std::string &code = *code_ptr;
auto vectortype = field.value.type.VectorType();
GenReceiver(struct_def, code_ptr);
code += MakeCamel(field.name);
code += "(self, j):";
code += OffsetPrefix(field);
code += Indent + Indent + Indent + "a = self._tab.Vector(o)\n";
code += Indent + Indent + Indent;
code += "return " + GenGetter(field.value.type);
code += "a + flatbuffers.number_types.UOffsetTFlags.py_type(j * ";
code += NumToString(InlineSize(vectortype)) + "))\n";
if (vectortype.base_type == BASE_TYPE_STRING) {
code += Indent + Indent + "return \"\"\n";
} else {
code += Indent + Indent + "return 0\n";
}
code += "\n";
}
static void GenStruct(StructDef &struct_def,
std::string *code_ptr,
StructDef *root_struct_def) {
if (struct_def.generated) return;
std::string &code = *code_ptr;
// Generate a struct accessor class, with methods of the form:
// public type name() { return bb.getType(i + offset); }
// or for tables of the form:
// public type name() {
// int o = __offset(offset); return o != 0 ? bb.getType(o + i) : default;
// }
GenComment(struct_def.doc_comment, code_ptr);
code += "public class " + struct_def.name + " extends ";
code += struct_def.fixed ? "Struct" : "Table";
code += " {\n";
if (&struct_def == root_struct_def) {
// Generate a special accessor for the table that has been declared as
// the root type.
code += " public static " + struct_def.name + " getRootAs";
code += struct_def.name;
code += "(ByteBuffer _bb, int offset) { ";
code += "_bb.order(ByteOrder.LITTLE_ENDIAN); ";
code += "return (new " + struct_def.name;
code += "()).__init(_bb.getInt(offset) + offset, _bb); }\n";
}
// Generate the __init method that sets the field in a pre-existing
// accessor object. This is to allow object reuse.
code += " public " + struct_def.name;
code += " __init(int _i, ByteBuffer _bb) ";
code += "{ bb_pos = _i; bb = _bb; return this; }\n";
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end();
++it) {
auto &field = **it;
if (field.deprecated) continue;
GenComment(field.doc_comment, code_ptr, " ");
std::string type_name = GenTypeGet(field.value.type);
std::string method_start = " public " + type_name + " " +
MakeCamel(field.name, false);
// Generate the accessors that don't do object reuse.
if (field.value.type.base_type == BASE_TYPE_STRUCT) {
// Calls the accessor that takes an accessor object with a new object.
code += method_start + "() { return " + MakeCamel(field.name, false);
code += "(new ";
code += type_name + "()); }\n";
} else if (field.value.type.base_type == BASE_TYPE_VECTOR &&
field.value.type.element == BASE_TYPE_STRUCT) {
// Accessors for vectors of structs also take accessor objects, this
// generates a variant without that argument.
code += method_start + "(int j) { return " + MakeCamel(field.name, false);
code += "(new ";
code += type_name + "(), j); }\n";
}
std::string getter = GenGetter(field.value.type);
code += method_start + "(";
// Most field accessors need to retrieve and test the field offset first,
// this is the prefix code for that:
auto offset_prefix = ") { int o = __offset(" +
NumToString(field.value.offset) +
"); return o != 0 ? ";
if (IsScalar(field.value.type.base_type)) {
if (struct_def.fixed) {
code += ") { return " + getter;
code += "(bb_pos + " + NumToString(field.value.offset) + ")";
} else {
code += offset_prefix + getter;
code += "(o + bb_pos) : " + field.value.constant;
}
} else {
switch (field.value.type.base_type) {
case BASE_TYPE_STRUCT:
code += type_name + " obj";
if (struct_def.fixed) {
code += ") { return obj.__init(bb_pos + ";
code += NumToString(field.value.offset) + ", bb)";
} else {
code += offset_prefix;
code += "obj.__init(";
code += field.value.type.struct_def->fixed
? "o + bb_pos"
: "__indirect(o + bb_pos)";
code += ", bb) : null";
}
break;
case BASE_TYPE_STRING:
code += offset_prefix + getter +"(o) : null";
break;
case BASE_TYPE_VECTOR: {
auto vectortype = field.value.type.VectorType();
if (vectortype.base_type == BASE_TYPE_STRUCT) {
code += type_name + " obj, ";
getter = "obj.__init";
}
code += "int j" + offset_prefix + getter +"(";
auto index = "__vector(o) + j * " +
NumToString(InlineSize(vectortype));
if (vectortype.base_type == BASE_TYPE_STRUCT) {
code += vectortype.struct_def->fixed
? index
: "__indirect(" + index + ")";
code += ", bb";
} else {
code += index;
}
code += ") : ";
code += IsScalar(field.value.type.element) ? "0" : "null";
break;
}
case BASE_TYPE_UNION:
code += type_name + " obj" + offset_prefix + getter;
code += "(obj, o) : null";
break;
default:
assert(0);
}
}
code += "; }\n";
if (field.value.type.base_type == BASE_TYPE_VECTOR) {
code += " public int " + MakeCamel(field.name, false) + "Length(";
code += offset_prefix;
code += "__vector_len(o) : 0; }\n";
}
}
code += "\n";
if (struct_def.fixed) {
// create a struct constructor function
code += " public static int create" + struct_def.name;
code += "(FlatBufferBuilder builder";
GenStructArgs(struct_def, code_ptr, "");
code += ") {\n";
GenStructBody(struct_def, code_ptr, "");
code += " return builder.offset();\n }\n";
} else {
// Create a set of static methods that allow table construction,
// of the form:
// public static void addName(FlatBufferBuilder builder, short name)
// { builder.addShort(id, name, default); }
code += " public static void start" + struct_def.name;
code += "(FlatBufferBuilder builder) { builder.startObject(";
code += NumToString(struct_def.fields.vec.size()) + "); }\n";
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end();
++it) {
auto &field = **it;
if (field.deprecated) continue;
code += " public static void add" + MakeCamel(field.name);
code += "(FlatBufferBuilder builder, " + GenTypeBasic(field.value.type);
auto argname = MakeCamel(field.name, false);
if (!IsScalar(field.value.type.base_type)) argname += "Offset";
code += " " + argname + ") { builder.add";
code += GenMethod(field) + "(";
code += NumToString(it - struct_def.fields.vec.begin()) + ", ";
code += argname + ", " + field.value.constant;
code += "); }\n";
if (field.value.type.base_type == BASE_TYPE_VECTOR) {
code += " public static void start" + MakeCamel(field.name);
code += "Vector(FlatBufferBuilder builder, int numElems) ";
code += "{ builder.startVector(";
code += NumToString(InlineSize(field.value.type.VectorType()));
code += ", numElems); }\n";
}
}
code += " public static int end" + struct_def.name;
code += "(FlatBufferBuilder builder) { return builder.endObject(); }\n";
}
code += "};\n\n";
}
