824 lines
30 KiB
C++
824 lines
30 KiB
C++
/*
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* Copyright 2014 Google Inc. All rights reserved.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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// independent from idl_parser, since this code is not needed for most clients
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#include <string>
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#include "flatbuffers/code_generators.h"
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#include "flatbuffers/flatbuffers.h"
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#include "flatbuffers/idl.h"
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#include "flatbuffers/util.h"
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#include <unordered_set>
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namespace flatbuffers {
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namespace python {
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// Hardcode spaces per indentation.
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const CommentConfig def_comment = { nullptr, "#", nullptr };
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const std::string Indent = " ";
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class PythonGenerator : public BaseGenerator {
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public:
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PythonGenerator(const Parser &parser, const std::string &path,
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const std::string &file_name)
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: BaseGenerator(parser, path, file_name, "" /* not used */,
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"" /* not used */),
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float_const_gen_("float('nan')", "float('inf')", "float('-inf')") {
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static const char * const keywords[] = {
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"False",
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"None",
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"True",
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"and",
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"as",
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"assert",
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"break",
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"class",
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"continue",
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"def",
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"del",
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"elif",
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"else",
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"except",
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"finally",
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"for",
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"from",
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"global",
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"if",
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"import",
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"in",
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"is",
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"lambda",
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"nonlocal",
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"not",
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"or",
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"pass",
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"raise",
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"return",
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"try",
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"while",
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"with",
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"yield"
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};
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keywords_.insert(std::begin(keywords), std::end(keywords));
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}
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// Most field accessors need to retrieve and test the field offset first,
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// this is the prefix code for that.
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std::string OffsetPrefix(const FieldDef &field) {
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return "\n" + Indent + Indent +
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"o = flatbuffers.number_types.UOffsetTFlags.py_type" +
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"(self._tab.Offset(" + NumToString(field.value.offset) + "))\n" +
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Indent + Indent + "if o != 0:\n";
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}
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// Begin a class declaration.
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void BeginClass(const StructDef &struct_def, std::string *code_ptr) {
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std::string &code = *code_ptr;
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code += "class " + NormalizedName(struct_def) + "(object):\n";
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code += Indent + "__slots__ = ['_tab']";
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code += "\n\n";
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}
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// Begin enum code with a class declaration.
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void BeginEnum(const std::string &class_name, std::string *code_ptr) {
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std::string &code = *code_ptr;
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code += "class " + class_name + "(object):\n";
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}
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std::string EscapeKeyword(const std::string &name) const {
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return keywords_.find(name) == keywords_.end() ? name : name + "_";
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}
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std::string NormalizedName(const Definition &definition) const {
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return EscapeKeyword(definition.name);
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}
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std::string NormalizedName(const EnumVal &ev) const {
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return EscapeKeyword(ev.name);
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}
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// A single enum member.
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void EnumMember(const EnumDef &enum_def, const EnumVal &ev,
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std::string *code_ptr) {
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std::string &code = *code_ptr;
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code += Indent;
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code += NormalizedName(ev);
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code += " = ";
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code += enum_def.ToString(ev) + "\n";
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}
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// End enum code.
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void EndEnum(std::string *code_ptr) {
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std::string &code = *code_ptr;
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code += "\n";
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}
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// Initialize a new struct or table from existing data.
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void NewRootTypeFromBuffer(const StructDef &struct_def,
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std::string *code_ptr) {
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std::string &code = *code_ptr;
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code += Indent + "@classmethod\n";
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code += Indent + "def GetRootAs";
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code += NormalizedName(struct_def);
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code += "(cls, buf, offset):";
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code += "\n";
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code += Indent + Indent;
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code += "n = flatbuffers.encode.Get";
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code += "(flatbuffers.packer.uoffset, buf, offset)\n";
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code += Indent + Indent + "x = " + NormalizedName(struct_def) + "()\n";
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code += Indent + Indent + "x.Init(buf, n + offset)\n";
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code += Indent + Indent + "return x\n";
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code += "\n";
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}
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// Initialize an existing object with other data, to avoid an allocation.
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void InitializeExisting(const StructDef &struct_def,
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std::string *code_ptr) {
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std::string &code = *code_ptr;
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GenReceiver(struct_def, code_ptr);
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code += "Init(self, buf, pos):\n";
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code += Indent + Indent + "self._tab = flatbuffers.table.Table(buf, pos)\n";
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code += "\n";
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}
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// Get the length of a vector.
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void GetVectorLen(const StructDef &struct_def, const FieldDef &field,
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std::string *code_ptr) {
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std::string &code = *code_ptr;
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GenReceiver(struct_def, code_ptr);
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code += MakeCamel(NormalizedName(field)) + "Length(self";
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code += "):" + OffsetPrefix(field);
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code += Indent + Indent + Indent + "return self._tab.VectorLen(o)\n";
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code += Indent + Indent + "return 0\n\n";
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}
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// Get the value of a struct's scalar.
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void GetScalarFieldOfStruct(const StructDef &struct_def,
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const FieldDef &field,
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std::string *code_ptr) {
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std::string &code = *code_ptr;
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std::string getter = GenGetter(field.value.type);
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GenReceiver(struct_def, code_ptr);
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code += MakeCamel(NormalizedName(field));
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code += "(self): return " + getter;
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code += "self._tab.Pos + flatbuffers.number_types.UOffsetTFlags.py_type(";
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code += NumToString(field.value.offset) + "))\n";
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}
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// Get the value of a table's scalar.
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void GetScalarFieldOfTable(const StructDef &struct_def,
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const FieldDef &field,
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std::string *code_ptr) {
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std::string &code = *code_ptr;
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std::string getter = GenGetter(field.value.type);
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GenReceiver(struct_def, code_ptr);
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code += MakeCamel(NormalizedName(field));
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code += "(self):";
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code += OffsetPrefix(field);
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getter += "o + self._tab.Pos)";
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auto is_bool = IsBool(field.value.type.base_type);
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if (is_bool) {
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getter = "bool(" + getter + ")";
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}
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code += Indent + Indent + Indent + "return " + getter + "\n";
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std::string default_value;
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if (is_bool) {
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default_value = field.value.constant == "0" ? "False" : "True";
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} else {
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default_value = IsFloat(field.value.type.base_type)
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? float_const_gen_.GenFloatConstant(field)
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: field.value.constant;
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}
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code += Indent + Indent + "return " + default_value + "\n\n";
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}
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// Get a struct by initializing an existing struct.
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// Specific to Struct.
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void GetStructFieldOfStruct(const StructDef &struct_def,
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const FieldDef &field,
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std::string *code_ptr) {
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std::string &code = *code_ptr;
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GenReceiver(struct_def, code_ptr);
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code += MakeCamel(NormalizedName(field));
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code += "(self, obj):\n";
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code += Indent + Indent + "obj.Init(self._tab.Bytes, self._tab.Pos + ";
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code += NumToString(field.value.offset) + ")";
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code += "\n" + Indent + Indent + "return obj\n\n";
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}
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// Get the value of a fixed size array.
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void GetArrayOfStruct(const StructDef &struct_def, const FieldDef &field,
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std::string *code_ptr) {
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std::string &code = *code_ptr;
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const auto vec_type = field.value.type.VectorType();
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GenReceiver(struct_def, code_ptr);
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code += MakeCamel(NormalizedName(field));
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if (IsStruct(vec_type)) {
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code += "(self, obj, i):\n";
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code += Indent + Indent + "obj.Init(self._tab.Bytes, self._tab.Pos + ";
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code += NumToString(field.value.offset) + " + i * ";
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code += NumToString(InlineSize(vec_type));
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code += ")\n" + Indent + Indent + "return obj\n\n";
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} else {
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auto getter = GenGetter(vec_type);
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code += "(self): return [" + getter;
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code += "self._tab.Pos + flatbuffers.number_types.UOffsetTFlags.py_type(";
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code += NumToString(field.value.offset) + " + i * ";
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code += NumToString(InlineSize(vec_type));
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code += ")) for i in range(";
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code += NumToString(field.value.type.fixed_length) + ")]\n";
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}
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}
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// Get a struct by initializing an existing struct.
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// Specific to Table.
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void GetStructFieldOfTable(const StructDef &struct_def,
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const FieldDef &field,
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std::string *code_ptr) {
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std::string &code = *code_ptr;
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GenReceiver(struct_def, code_ptr);
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code += MakeCamel(NormalizedName(field));
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code += "(self):";
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code += OffsetPrefix(field);
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if (field.value.type.struct_def->fixed) {
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code += Indent + Indent + Indent + "x = o + self._tab.Pos\n";
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} else {
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code += Indent + Indent + Indent;
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code += "x = self._tab.Indirect(o + self._tab.Pos)\n";
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}
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code += Indent + Indent + Indent;
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code += "from ." + TypeName(field) + " import " + TypeName(field) + "\n";
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code += Indent + Indent + Indent + "obj = " + TypeName(field) + "()\n";
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code += Indent + Indent + Indent + "obj.Init(self._tab.Bytes, x)\n";
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code += Indent + Indent + Indent + "return obj\n";
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code += Indent + Indent + "return None\n\n";
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}
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// Get the value of a string.
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void GetStringField(const StructDef &struct_def, const FieldDef &field,
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std::string *code_ptr) {
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std::string &code = *code_ptr;
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GenReceiver(struct_def, code_ptr);
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code += MakeCamel(NormalizedName(field));
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code += "(self):";
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code += OffsetPrefix(field);
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code += Indent + Indent + Indent + "return " + GenGetter(field.value.type);
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code += "o + self._tab.Pos)\n";
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code += Indent + Indent + "return None\n\n";
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}
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// Get the value of a union from an object.
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void GetUnionField(const StructDef &struct_def, const FieldDef &field,
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std::string *code_ptr) {
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std::string &code = *code_ptr;
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GenReceiver(struct_def, code_ptr);
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code += MakeCamel(NormalizedName(field)) + "(self):";
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code += OffsetPrefix(field);
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// TODO(rw): this works and is not the good way to it:
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bool is_native_table = TypeName(field) == "*flatbuffers.Table";
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if (is_native_table) {
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code += Indent + Indent + Indent + "from flatbuffers.table import Table\n";
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} else {
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code += Indent + Indent + Indent;
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code += "from ." + TypeName(field) + " import " + TypeName(field) + "\n";
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}
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code += Indent + Indent + Indent + "obj = Table(bytearray(), 0)\n";
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code += Indent + Indent + Indent + GenGetter(field.value.type);
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code += "obj, o)\n" + Indent + Indent + Indent + "return obj\n";
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code += Indent + Indent + "return None\n\n";
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}
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// Get the value of a vector's struct member.
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void GetMemberOfVectorOfStruct(const StructDef &struct_def,
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const FieldDef &field,
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std::string *code_ptr) {
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std::string &code = *code_ptr;
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auto vectortype = field.value.type.VectorType();
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GenReceiver(struct_def, code_ptr);
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code += MakeCamel(NormalizedName(field));
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code += "(self, j):" + OffsetPrefix(field);
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code += Indent + Indent + Indent + "x = self._tab.Vector(o)\n";
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code += Indent + Indent + Indent;
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code += "x += flatbuffers.number_types.UOffsetTFlags.py_type(j) * ";
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code += NumToString(InlineSize(vectortype)) + "\n";
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if (!(vectortype.struct_def->fixed)) {
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code += Indent + Indent + Indent + "x = self._tab.Indirect(x)\n";
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}
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code += Indent + Indent + Indent;
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code += "from ." + TypeName(field) + " import " + TypeName(field) + "\n";
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code += Indent + Indent + Indent + "obj = " + TypeName(field) + "()\n";
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code += Indent + Indent + Indent + "obj.Init(self._tab.Bytes, x)\n";
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code += Indent + Indent + Indent + "return obj\n";
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code += Indent + Indent + "return None\n\n";
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}
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// Get the value of a vector's non-struct member. Uses a named return
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// argument to conveniently set the zero value for the result.
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void GetMemberOfVectorOfNonStruct(const StructDef &struct_def,
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const FieldDef &field,
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std::string *code_ptr) {
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std::string &code = *code_ptr;
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auto vectortype = field.value.type.VectorType();
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GenReceiver(struct_def, code_ptr);
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code += MakeCamel(NormalizedName(field));
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code += "(self, j):";
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code += OffsetPrefix(field);
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code += Indent + Indent + Indent + "a = self._tab.Vector(o)\n";
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code += Indent + Indent + Indent;
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code += "return " + GenGetter(field.value.type);
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code += "a + flatbuffers.number_types.UOffsetTFlags.py_type(j * ";
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code += NumToString(InlineSize(vectortype)) + "))\n";
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if (vectortype.base_type == BASE_TYPE_STRING) {
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code += Indent + Indent + "return \"\"\n";
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} else {
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code += Indent + Indent + "return 0\n";
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}
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code += "\n";
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}
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// Returns a non-struct vector as a numpy array. Much faster
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// than iterating over the vector element by element.
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void GetVectorOfNonStructAsNumpy(const StructDef &struct_def,
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const FieldDef &field,
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std::string *code_ptr) {
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std::string &code = *code_ptr;
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auto vectortype = field.value.type.VectorType();
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// Currently, we only support accessing as numpy array if
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// the vector type is a scalar.
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if (!(IsScalar(vectortype.base_type))) { return; }
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GenReceiver(struct_def, code_ptr);
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code += MakeCamel(NormalizedName(field)) + "AsNumpy(self):";
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code += OffsetPrefix(field);
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code += Indent + Indent + Indent;
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code += "return ";
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code += "self._tab.GetVectorAsNumpy(flatbuffers.number_types.";
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code += MakeCamel(GenTypeGet(field.value.type));
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code += "Flags, o)\n";
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if (vectortype.base_type == BASE_TYPE_STRING) {
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code += Indent + Indent + "return \"\"\n";
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} else {
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code += Indent + Indent + "return 0\n";
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}
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code += "\n";
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}
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// Begin the creator function signature.
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void BeginBuilderArgs(const StructDef &struct_def,
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std::string *code_ptr) {
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std::string &code = *code_ptr;
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code += "\n";
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code += "def Create" + NormalizedName(struct_def);
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code += "(builder";
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}
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// Recursively generate arguments for a constructor, to deal with nested
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// structs.
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void StructBuilderArgs(const StructDef &struct_def,
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const char *nameprefix, std::string *code_ptr) {
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for (auto it = struct_def.fields.vec.begin();
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it != struct_def.fields.vec.end(); ++it) {
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auto &field = **it;
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const auto &field_type = field.value.type;
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const auto &type =
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IsArray(field_type) ? field_type.VectorType() : field_type;
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if (IsStruct(type)) {
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// Generate arguments for a struct inside a struct. To ensure names
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// don't clash, and to make it obvious these arguments are constructing
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// a nested struct, prefix the name with the field name.
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StructBuilderArgs(*field_type.struct_def,
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(nameprefix + (NormalizedName(field) + "_")).c_str(),
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code_ptr);
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} else {
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std::string &code = *code_ptr;
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code += std::string(", ") + nameprefix;
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code += MakeCamel(NormalizedName(field), false);
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}
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}
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}
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|
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// End the creator function signature.
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|
void EndBuilderArgs(std::string *code_ptr) {
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std::string &code = *code_ptr;
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code += "):\n";
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}
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|
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// Recursively generate struct construction statements and instert manual
|
|
// padding.
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|
void StructBuilderBody(const StructDef &struct_def, const char *nameprefix,
|
|
std::string *code_ptr, size_t index = 0,
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bool in_array = false) {
|
|
std::string &code = *code_ptr;
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std::string indent(index * 4, ' ');
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code +=
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indent + " builder.Prep(" + NumToString(struct_def.minalign) + ", ";
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code += NumToString(struct_def.bytesize) + ")\n";
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for (auto it = struct_def.fields.vec.rbegin();
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it != struct_def.fields.vec.rend(); ++it) {
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auto &field = **it;
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const auto &field_type = field.value.type;
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|
const auto &type =
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IsArray(field_type) ? field_type.VectorType() : field_type;
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if (field.padding)
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code +=
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indent + " builder.Pad(" + NumToString(field.padding) + ")\n";
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if (IsStruct(field_type)) {
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StructBuilderBody(*field_type.struct_def,
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(nameprefix + (NormalizedName(field) + "_")).c_str(),
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code_ptr, index, in_array);
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} else {
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const auto index_var = "_idx" + NumToString(index);
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if (IsArray(field_type)) {
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code += indent + " for " + index_var + " in range(";
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code += NumToString(field_type.fixed_length);
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code += " , 0, -1):\n";
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in_array = true;
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}
|
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if (IsStruct(type)) {
|
|
StructBuilderBody(
|
|
*field_type.struct_def,
|
|
(nameprefix + (NormalizedName(field) + "_")).c_str(), code_ptr,
|
|
index + 1, in_array);
|
|
} else {
|
|
code += IsArray(field_type) ? " " : "";
|
|
code += indent + " builder.Prepend" + GenMethod(field) + "(";
|
|
code += nameprefix + MakeCamel(NormalizedName(field), false);
|
|
size_t array_cnt = index + (IsArray(field_type) ? 1 : 0);
|
|
for (size_t i = 0; in_array && i < array_cnt; i++) {
|
|
code += "[_idx" + NumToString(i) + "-1]";
|
|
}
|
|
code += ")\n";
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void EndBuilderBody(std::string *code_ptr) {
|
|
std::string &code = *code_ptr;
|
|
code += " return builder.Offset()\n";
|
|
}
|
|
|
|
// Get the value of a table's starting offset.
|
|
void GetStartOfTable(const StructDef &struct_def,
|
|
std::string *code_ptr) {
|
|
std::string &code = *code_ptr;
|
|
code += "def " + NormalizedName(struct_def) + "Start";
|
|
code += "(builder): ";
|
|
code += "builder.StartObject(";
|
|
code += NumToString(struct_def.fields.vec.size());
|
|
code += ")\n";
|
|
}
|
|
|
|
// Set the value of a table's field.
|
|
void BuildFieldOfTable(const StructDef &struct_def,
|
|
const FieldDef &field, const size_t offset,
|
|
std::string *code_ptr) {
|
|
std::string &code = *code_ptr;
|
|
code += "def " + NormalizedName(struct_def) + "Add" + MakeCamel(NormalizedName(field));
|
|
code += "(builder, ";
|
|
code += MakeCamel(NormalizedName(field), false);
|
|
code += "): ";
|
|
code += "builder.Prepend";
|
|
code += GenMethod(field) + "Slot(";
|
|
code += NumToString(offset) + ", ";
|
|
if (!IsScalar(field.value.type.base_type) && (!struct_def.fixed)) {
|
|
code += "flatbuffers.number_types.UOffsetTFlags.py_type";
|
|
code += "(";
|
|
code += MakeCamel(NormalizedName(field), false) + ")";
|
|
} else {
|
|
code += MakeCamel(NormalizedName(field), false);
|
|
}
|
|
code += ", ";
|
|
code += IsFloat(field.value.type.base_type)
|
|
? float_const_gen_.GenFloatConstant(field)
|
|
: field.value.constant;
|
|
code += ")\n";
|
|
}
|
|
|
|
// Set the value of one of the members of a table's vector.
|
|
void BuildVectorOfTable(const StructDef &struct_def,
|
|
const FieldDef &field, std::string *code_ptr) {
|
|
std::string &code = *code_ptr;
|
|
code += "def " + NormalizedName(struct_def) + "Start";
|
|
code += MakeCamel(NormalizedName(field));
|
|
code += "Vector(builder, numElems): return builder.StartVector(";
|
|
auto vector_type = field.value.type.VectorType();
|
|
auto alignment = InlineAlignment(vector_type);
|
|
auto elem_size = InlineSize(vector_type);
|
|
code += NumToString(elem_size);
|
|
code += ", numElems, " + NumToString(alignment);
|
|
code += ")\n";
|
|
}
|
|
|
|
// Get the offset of the end of a table.
|
|
void GetEndOffsetOnTable(const StructDef &struct_def,
|
|
std::string *code_ptr) {
|
|
std::string &code = *code_ptr;
|
|
code += "def " + NormalizedName(struct_def) + "End";
|
|
code += "(builder): ";
|
|
code += "return builder.EndObject()\n";
|
|
}
|
|
|
|
// Generate the receiver for function signatures.
|
|
void GenReceiver(const StructDef &struct_def, std::string *code_ptr) {
|
|
std::string &code = *code_ptr;
|
|
code += Indent + "# " + NormalizedName(struct_def) + "\n";
|
|
code += Indent + "def ";
|
|
}
|
|
|
|
// Generate a struct field, conditioned on its child type(s).
|
|
void GenStructAccessor(const StructDef &struct_def,
|
|
const FieldDef &field, std::string *code_ptr) {
|
|
GenComment(field.doc_comment, code_ptr, &def_comment, Indent.c_str());
|
|
if (IsScalar(field.value.type.base_type)) {
|
|
if (struct_def.fixed) {
|
|
GetScalarFieldOfStruct(struct_def, field, code_ptr);
|
|
} else {
|
|
GetScalarFieldOfTable(struct_def, field, code_ptr);
|
|
}
|
|
} else if (IsArray(field.value.type)) {
|
|
GetArrayOfStruct(struct_def, field, code_ptr);
|
|
} else {
|
|
switch (field.value.type.base_type) {
|
|
case BASE_TYPE_STRUCT:
|
|
if (struct_def.fixed) {
|
|
GetStructFieldOfStruct(struct_def, field, code_ptr);
|
|
} else {
|
|
GetStructFieldOfTable(struct_def, field, code_ptr);
|
|
}
|
|
break;
|
|
case BASE_TYPE_STRING: GetStringField(struct_def, field, code_ptr); break;
|
|
case BASE_TYPE_VECTOR: {
|
|
auto vectortype = field.value.type.VectorType();
|
|
if (vectortype.base_type == BASE_TYPE_STRUCT) {
|
|
GetMemberOfVectorOfStruct(struct_def, field, code_ptr);
|
|
} else {
|
|
GetMemberOfVectorOfNonStruct(struct_def, field, code_ptr);
|
|
GetVectorOfNonStructAsNumpy(struct_def, field, code_ptr);
|
|
}
|
|
break;
|
|
}
|
|
case BASE_TYPE_UNION: GetUnionField(struct_def, field, code_ptr); break;
|
|
default: FLATBUFFERS_ASSERT(0);
|
|
}
|
|
}
|
|
if (field.value.type.base_type == BASE_TYPE_VECTOR) {
|
|
GetVectorLen(struct_def, field, code_ptr);
|
|
}
|
|
}
|
|
|
|
// Generate table constructors, conditioned on its members' types.
|
|
void GenTableBuilders(const StructDef &struct_def,
|
|
std::string *code_ptr) {
|
|
GetStartOfTable(struct_def, code_ptr);
|
|
|
|
for (auto it = struct_def.fields.vec.begin();
|
|
it != struct_def.fields.vec.end(); ++it) {
|
|
auto &field = **it;
|
|
if (field.deprecated) continue;
|
|
|
|
auto offset = it - struct_def.fields.vec.begin();
|
|
BuildFieldOfTable(struct_def, field, offset, code_ptr);
|
|
if (field.value.type.base_type == BASE_TYPE_VECTOR) {
|
|
BuildVectorOfTable(struct_def, field, code_ptr);
|
|
}
|
|
}
|
|
|
|
GetEndOffsetOnTable(struct_def, code_ptr);
|
|
}
|
|
|
|
// Generate function to check for proper file identifier
|
|
void GenHasFileIdentifier(const StructDef &struct_def,
|
|
std::string *code_ptr) {
|
|
std::string &code = *code_ptr;
|
|
std::string escapedID;
|
|
// In the event any of file_identifier characters are special(NULL, \, etc),
|
|
// problems occur. To prevent this, convert all chars to their hex-escaped
|
|
// equivalent.
|
|
for (auto it = parser_.file_identifier_.begin();
|
|
it != parser_.file_identifier_.end(); ++it) {
|
|
escapedID += "\\x" + IntToStringHex(*it, 2);
|
|
}
|
|
|
|
code += Indent + "@classmethod\n";
|
|
code += Indent + "def " + NormalizedName(struct_def);
|
|
code += "BufferHasIdentifier(cls, buf, offset, size_prefixed=False):";
|
|
code += "\n";
|
|
code += Indent + Indent;
|
|
code += "return flatbuffers.util.BufferHasIdentifier(buf, offset, b\"";
|
|
code += escapedID;
|
|
code += "\", size_prefixed=size_prefixed)\n";
|
|
code += "\n";
|
|
}
|
|
|
|
// Generate struct or table methods.
|
|
void GenStruct(const StructDef &struct_def, std::string *code_ptr) {
|
|
if (struct_def.generated) return;
|
|
|
|
GenComment(struct_def.doc_comment, code_ptr, &def_comment);
|
|
BeginClass(struct_def, code_ptr);
|
|
if (!struct_def.fixed) {
|
|
// Generate a special accessor for the table that has been declared as
|
|
// the root type.
|
|
NewRootTypeFromBuffer(struct_def, code_ptr);
|
|
if (parser_.file_identifier_.length()){
|
|
// Generate a special function to test file_identifier
|
|
GenHasFileIdentifier(struct_def, code_ptr);
|
|
}
|
|
}
|
|
// Generate the Init method that sets the field in a pre-existing
|
|
// accessor object. This is to allow object reuse.
|
|
InitializeExisting(struct_def, code_ptr);
|
|
for (auto it = struct_def.fields.vec.begin();
|
|
it != struct_def.fields.vec.end(); ++it) {
|
|
auto &field = **it;
|
|
if (field.deprecated) continue;
|
|
|
|
GenStructAccessor(struct_def, field, code_ptr);
|
|
}
|
|
|
|
if (struct_def.fixed) {
|
|
// create a struct constructor function
|
|
GenStructBuilder(struct_def, code_ptr);
|
|
} else {
|
|
// Create a set of functions that allow table construction.
|
|
GenTableBuilders(struct_def, code_ptr);
|
|
}
|
|
}
|
|
|
|
// Generate enum declarations.
|
|
void GenEnum(const EnumDef &enum_def, std::string *code_ptr) {
|
|
if (enum_def.generated) return;
|
|
|
|
GenComment(enum_def.doc_comment, code_ptr, &def_comment);
|
|
BeginEnum(NormalizedName(enum_def), code_ptr);
|
|
for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end(); ++it) {
|
|
auto &ev = **it;
|
|
GenComment(ev.doc_comment, code_ptr, &def_comment, Indent.c_str());
|
|
EnumMember(enum_def, ev, code_ptr);
|
|
}
|
|
EndEnum(code_ptr);
|
|
}
|
|
|
|
// Returns the function name that is able to read a value of the given type.
|
|
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, ";
|
|
}
|
|
}
|
|
|
|
// Returns the method name for use with add/put calls.
|
|
std::string GenMethod(const FieldDef &field) {
|
|
return (IsScalar(field.value.type.base_type) || IsArray(field.value.type))
|
|
? MakeCamel(GenTypeBasic(field.value.type))
|
|
: (IsStruct(field.value.type) ? "Struct" : "UOffsetTRelative");
|
|
}
|
|
|
|
std::string GenTypeBasic(const Type &type) {
|
|
static const char *ctypename[] = {
|
|
// clang-format off
|
|
#define FLATBUFFERS_TD(ENUM, IDLTYPE, \
|
|
CTYPE, JTYPE, GTYPE, NTYPE, PTYPE, RTYPE, KTYPE) \
|
|
#PTYPE,
|
|
FLATBUFFERS_GEN_TYPES(FLATBUFFERS_TD)
|
|
#undef FLATBUFFERS_TD
|
|
// clang-format on
|
|
};
|
|
return ctypename[IsArray(type) ? type.VectorType().base_type
|
|
: type.base_type];
|
|
}
|
|
|
|
std::string GenTypePointer(const Type &type) {
|
|
switch (type.base_type) {
|
|
case BASE_TYPE_STRING: return "string";
|
|
case BASE_TYPE_VECTOR: return GenTypeGet(type.VectorType());
|
|
case BASE_TYPE_STRUCT: return type.struct_def->name;
|
|
case BASE_TYPE_UNION:
|
|
// fall through
|
|
default: return "*flatbuffers.Table";
|
|
}
|
|
}
|
|
|
|
std::string GenTypeGet(const Type &type) {
|
|
return IsScalar(type.base_type) ? GenTypeBasic(type) : GenTypePointer(type);
|
|
}
|
|
|
|
std::string TypeName(const FieldDef &field) {
|
|
return GenTypeGet(field.value.type);
|
|
}
|
|
|
|
// Create a struct with a builder and the struct's arguments.
|
|
void GenStructBuilder(const StructDef &struct_def,
|
|
std::string *code_ptr) {
|
|
BeginBuilderArgs(struct_def, code_ptr);
|
|
StructBuilderArgs(struct_def, "", code_ptr);
|
|
EndBuilderArgs(code_ptr);
|
|
|
|
StructBuilderBody(struct_def, "", code_ptr);
|
|
EndBuilderBody(code_ptr);
|
|
}
|
|
|
|
bool generate() {
|
|
if (!generateEnums()) return false;
|
|
if (!generateStructs()) return false;
|
|
return true;
|
|
}
|
|
|
|
private:
|
|
bool generateEnums() {
|
|
for (auto it = parser_.enums_.vec.begin(); it != parser_.enums_.vec.end();
|
|
++it) {
|
|
auto &enum_def = **it;
|
|
std::string enumcode;
|
|
GenEnum(enum_def, &enumcode);
|
|
if (!SaveType(enum_def, enumcode, false)) return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool generateStructs() {
|
|
for (auto it = parser_.structs_.vec.begin();
|
|
it != parser_.structs_.vec.end(); ++it) {
|
|
auto &struct_def = **it;
|
|
std::string declcode;
|
|
GenStruct(struct_def, &declcode);
|
|
if (!SaveType(struct_def, declcode, true)) return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
// Begin by declaring namespace and imports.
|
|
void BeginFile(const std::string &name_space_name, const bool needs_imports,
|
|
std::string *code_ptr) {
|
|
std::string &code = *code_ptr;
|
|
code = code + "# " + FlatBuffersGeneratedWarning() + "\n\n";
|
|
code += "# namespace: " + name_space_name + "\n\n";
|
|
if (needs_imports) { code += "import flatbuffers\n\n"; }
|
|
}
|
|
|
|
// Save out the generated code for a Python Table type.
|
|
bool SaveType(const Definition &def, const std::string &classcode,
|
|
bool needs_imports) {
|
|
if (!classcode.length()) return true;
|
|
|
|
std::string namespace_dir = path_;
|
|
auto &namespaces = def.defined_namespace->components;
|
|
for (auto it = namespaces.begin(); it != namespaces.end(); ++it) {
|
|
if (it != namespaces.begin()) namespace_dir += kPathSeparator;
|
|
namespace_dir += *it;
|
|
std::string init_py_filename = namespace_dir + "/__init__.py";
|
|
SaveFile(init_py_filename.c_str(), "", false);
|
|
}
|
|
|
|
std::string code = "";
|
|
BeginFile(LastNamespacePart(*def.defined_namespace), needs_imports, &code);
|
|
code += classcode;
|
|
std::string filename =
|
|
NamespaceDir(*def.defined_namespace) + NormalizedName(def) + ".py";
|
|
return SaveFile(filename.c_str(), code, false);
|
|
}
|
|
private:
|
|
std::unordered_set<std::string> keywords_;
|
|
const SimpleFloatConstantGenerator float_const_gen_;
|
|
};
|
|
|
|
} // namespace python
|
|
|
|
bool GeneratePython(const Parser &parser, const std::string &path,
|
|
const std::string &file_name) {
|
|
python::PythonGenerator generator(parser, path, file_name);
|
|
return generator.generate();
|
|
}
|
|
|
|
} // namespace flatbuffers
|