| /* |
| * Copyright 2014 Google Inc. All rights reserved. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| // independent from idl_parser, since this code is not needed for most clients |
| |
| #include <cctype> |
| #include <set> |
| #include <string> |
| #include <unordered_set> |
| #include <vector> |
| |
| #include "flatbuffers/code_generators.h" |
| #include "flatbuffers/flatbuffers.h" |
| #include "flatbuffers/idl.h" |
| #include "flatbuffers/util.h" |
| |
| namespace flatbuffers { |
| namespace python { |
| |
| // Hardcode spaces per indentation. |
| const CommentConfig def_comment = { nullptr, "#", nullptr }; |
| const std::string Indent = " "; |
| |
| class PythonGenerator : public BaseGenerator { |
| public: |
| PythonGenerator(const Parser &parser, const std::string &path, |
| const std::string &file_name) |
| : BaseGenerator(parser, path, file_name, "" /* not used */, |
| "" /* not used */, "py"), |
| float_const_gen_("float('nan')", "float('inf')", "float('-inf')") { |
| static const char *const keywords[] = { |
| "False", "None", "True", "and", "as", "assert", "break", |
| "class", "continue", "def", "del", "elif", "else", "except", |
| "finally", "for", "from", "global", "if", "import", "in", |
| "is", "lambda", "nonlocal", "not", "or", "pass", "raise", |
| "return", "try", "while", "with", "yield" |
| }; |
| keywords_.insert(std::begin(keywords), std::end(keywords)); |
| } |
| |
| // Most field accessors need to retrieve and test the field offset first, |
| // this is the prefix code for that. |
| std::string OffsetPrefix(const FieldDef &field) { |
| return "\n" + Indent + Indent + |
| "o = flatbuffers.number_types.UOffsetTFlags.py_type" + |
| "(self._tab.Offset(" + NumToString(field.value.offset) + "))\n" + |
| Indent + Indent + "if o != 0:\n"; |
| } |
| |
| // Begin a class declaration. |
| void BeginClass(const StructDef &struct_def, std::string *code_ptr) { |
| auto &code = *code_ptr; |
| code += "class " + NormalizedName(struct_def) + "(object):\n"; |
| code += Indent + "__slots__ = ['_tab']"; |
| code += "\n\n"; |
| } |
| |
| // Begin enum code with a class declaration. |
| void BeginEnum(const std::string &class_name, std::string *code_ptr) { |
| auto &code = *code_ptr; |
| code += "class " + class_name + "(object):\n"; |
| } |
| |
| std::string EscapeKeyword(const std::string &name) const { |
| return keywords_.find(name) == keywords_.end() ? name : name + "_"; |
| } |
| |
| std::string NormalizedName(const Definition &definition) const { |
| return EscapeKeyword(definition.name); |
| } |
| |
| std::string NormalizedName(const EnumVal &ev) const { |
| return EscapeKeyword(ev.name); |
| } |
| |
| // Converts the name of a definition into upper Camel format. |
| std::string MakeUpperCamel(const Definition &definition) const { |
| return MakeCamel(NormalizedName(definition), true); |
| } |
| |
| // Converts the name of a definition into lower Camel format. |
| std::string MakeLowerCamel(const Definition &definition) const { |
| auto name = MakeCamel(NormalizedName(definition), false); |
| name[0] = char(tolower(name[0])); |
| return name; |
| } |
| |
| // Starts a new line and then indents. |
| std::string GenIndents(int num) { |
| return "\n" + std::string(num * Indent.length(), ' '); |
| } |
| |
| // A single enum member. |
| void EnumMember(const EnumDef &enum_def, const EnumVal &ev, |
| std::string *code_ptr) { |
| auto &code = *code_ptr; |
| code += Indent; |
| code += NormalizedName(ev); |
| code += " = "; |
| code += enum_def.ToString(ev) + "\n"; |
| } |
| |
| // End enum code. |
| void EndEnum(std::string *code_ptr) { |
| auto &code = *code_ptr; |
| code += "\n"; |
| } |
| |
| // Initialize a new struct or table from existing data. |
| void NewRootTypeFromBuffer(const StructDef &struct_def, |
| std::string *code_ptr) { |
| auto &code = *code_ptr; |
| |
| code += Indent + "@classmethod\n"; |
| code += Indent + "def GetRootAs"; |
| code += NormalizedName(struct_def); |
| code += "(cls, buf, offset):"; |
| code += "\n"; |
| code += Indent + Indent; |
| code += "n = flatbuffers.encode.Get"; |
| code += "(flatbuffers.packer.uoffset, buf, offset)\n"; |
| code += Indent + Indent + "x = " + NormalizedName(struct_def) + "()\n"; |
| code += Indent + Indent + "x.Init(buf, n + offset)\n"; |
| code += Indent + Indent + "return x\n"; |
| code += "\n"; |
| } |
| |
| // Initialize an existing object with other data, to avoid an allocation. |
| void InitializeExisting(const StructDef &struct_def, std::string *code_ptr) { |
| auto &code = *code_ptr; |
| |
| GenReceiver(struct_def, code_ptr); |
| code += "Init(self, buf, pos):\n"; |
| code += Indent + Indent + "self._tab = flatbuffers.table.Table(buf, pos)\n"; |
| code += "\n"; |
| } |
| |
| // Get the length of a vector. |
| void GetVectorLen(const StructDef &struct_def, const FieldDef &field, |
| std::string *code_ptr) { |
| auto &code = *code_ptr; |
| |
| GenReceiver(struct_def, code_ptr); |
| code += MakeCamel(NormalizedName(field)) + "Length(self"; |
| code += "):" + OffsetPrefix(field); |
| code += Indent + Indent + Indent + "return self._tab.VectorLen(o)\n"; |
| code += Indent + Indent + "return 0\n\n"; |
| } |
| |
| // Determines whether a vector is none or not. |
| void GetVectorIsNone(const StructDef &struct_def, const FieldDef &field, |
| std::string *code_ptr) { |
| auto &code = *code_ptr; |
| |
| GenReceiver(struct_def, code_ptr); |
| code += MakeCamel(NormalizedName(field)) + "IsNone(self"; |
| code += "):"; |
| code += GenIndents(2) + |
| "o = flatbuffers.number_types.UOffsetTFlags.py_type" + |
| "(self._tab.Offset(" + NumToString(field.value.offset) + "))"; |
| code += GenIndents(2) + "return o == 0"; |
| code += "\n\n"; |
| } |
| |
| // Get the value of a struct's scalar. |
| void GetScalarFieldOfStruct(const StructDef &struct_def, |
| const FieldDef &field, std::string *code_ptr) { |
| auto &code = *code_ptr; |
| std::string getter = GenGetter(field.value.type); |
| GenReceiver(struct_def, code_ptr); |
| code += MakeCamel(NormalizedName(field)); |
| code += "(self): return " + getter; |
| code += "self._tab.Pos + flatbuffers.number_types.UOffsetTFlags.py_type("; |
| code += NumToString(field.value.offset) + "))\n"; |
| } |
| |
| // Get the value of a table's scalar. |
| void GetScalarFieldOfTable(const StructDef &struct_def, const FieldDef &field, |
| std::string *code_ptr) { |
| auto &code = *code_ptr; |
| std::string getter = GenGetter(field.value.type); |
| GenReceiver(struct_def, code_ptr); |
| code += MakeCamel(NormalizedName(field)); |
| code += "(self):"; |
| code += OffsetPrefix(field); |
| getter += "o + self._tab.Pos)"; |
| auto is_bool = IsBool(field.value.type.base_type); |
| if (is_bool) { getter = "bool(" + getter + ")"; } |
| code += Indent + Indent + Indent + "return " + getter + "\n"; |
| std::string default_value; |
| if (is_bool) { |
| default_value = field.value.constant == "0" ? "False" : "True"; |
| } else { |
| default_value = IsFloat(field.value.type.base_type) |
| ? float_const_gen_.GenFloatConstant(field) |
| : field.value.constant; |
| } |
| code += Indent + Indent + "return " + default_value + "\n\n"; |
| } |
| |
| // Get a struct by initializing an existing struct. |
| // Specific to Struct. |
| void GetStructFieldOfStruct(const StructDef &struct_def, |
| const FieldDef &field, std::string *code_ptr) { |
| auto &code = *code_ptr; |
| GenReceiver(struct_def, code_ptr); |
| code += MakeCamel(NormalizedName(field)); |
| code += "(self, obj):\n"; |
| code += Indent + Indent + "obj.Init(self._tab.Bytes, self._tab.Pos + "; |
| code += NumToString(field.value.offset) + ")"; |
| code += "\n" + Indent + Indent + "return obj\n\n"; |
| } |
| |
| // Get the value of a fixed size array. |
| void GetArrayOfStruct(const StructDef &struct_def, const FieldDef &field, |
| std::string *code_ptr) { |
| auto &code = *code_ptr; |
| const auto vec_type = field.value.type.VectorType(); |
| GenReceiver(struct_def, code_ptr); |
| code += MakeCamel(NormalizedName(field)); |
| if (IsStruct(vec_type)) { |
| code += "(self, obj, i):\n"; |
| code += Indent + Indent + "obj.Init(self._tab.Bytes, self._tab.Pos + "; |
| code += NumToString(field.value.offset) + " + i * "; |
| code += NumToString(InlineSize(vec_type)); |
| code += ")\n" + Indent + Indent + "return obj\n\n"; |
| } else { |
| auto getter = GenGetter(vec_type); |
| code += "(self): return [" + getter; |
| code += "self._tab.Pos + flatbuffers.number_types.UOffsetTFlags.py_type("; |
| code += NumToString(field.value.offset) + " + i * "; |
| code += NumToString(InlineSize(vec_type)); |
| code += ")) for i in range("; |
| code += NumToString(field.value.type.fixed_length) + ")]\n"; |
| } |
| } |
| |
| // Get a struct by initializing an existing struct. |
| // Specific to Table. |
| void GetStructFieldOfTable(const StructDef &struct_def, const FieldDef &field, |
| std::string *code_ptr) { |
| auto &code = *code_ptr; |
| GenReceiver(struct_def, code_ptr); |
| code += MakeCamel(NormalizedName(field)); |
| code += "(self):"; |
| code += OffsetPrefix(field); |
| if (field.value.type.struct_def->fixed) { |
| code += Indent + Indent + Indent + "x = o + self._tab.Pos\n"; |
| } else { |
| code += Indent + Indent + Indent; |
| code += "x = self._tab.Indirect(o + self._tab.Pos)\n"; |
| } |
| if (parser_.opts.include_dependence_headers) { |
| code += Indent + Indent + Indent; |
| code += "from " + GenPackageReference(field.value.type) + " import " + |
| TypeName(field) + "\n"; |
| } |
| code += Indent + Indent + Indent + "obj = " + TypeName(field) + "()\n"; |
| code += Indent + Indent + Indent + "obj.Init(self._tab.Bytes, x)\n"; |
| code += Indent + Indent + Indent + "return obj\n"; |
| code += Indent + Indent + "return None\n\n"; |
| } |
| |
| // Get the value of a string. |
| void GetStringField(const StructDef &struct_def, const FieldDef &field, |
| std::string *code_ptr) { |
| auto &code = *code_ptr; |
| GenReceiver(struct_def, code_ptr); |
| code += MakeCamel(NormalizedName(field)); |
| code += "(self):"; |
| code += OffsetPrefix(field); |
| code += Indent + Indent + Indent + "return " + GenGetter(field.value.type); |
| code += "o + self._tab.Pos)\n"; |
| code += Indent + Indent + "return None\n\n"; |
| } |
| |
| // Get the value of a union from an object. |
| void GetUnionField(const StructDef &struct_def, const FieldDef &field, |
| std::string *code_ptr) { |
| auto &code = *code_ptr; |
| GenReceiver(struct_def, code_ptr); |
| code += MakeCamel(NormalizedName(field)) + "(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 if (parser_.opts.include_dependence_headers) { |
| code += Indent + Indent + Indent; |
| code += "from " + GenPackageReference(field.value.type) + " 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"; |
| } |
| |
| // Generate the package reference when importing a struct or enum from its |
| // module. |
| std::string GenPackageReference(const Type &type) { |
| Namespace *namespaces; |
| if (type.struct_def) { |
| namespaces = type.struct_def->defined_namespace; |
| } else if (type.enum_def) { |
| namespaces = type.enum_def->defined_namespace; |
| } else { |
| return "." + GenTypeGet(type); |
| } |
| |
| return namespaces->GetFullyQualifiedName(GenTypeGet(type)); |
| } |
| |
| // Get the value of a vector's struct member. |
| void GetMemberOfVectorOfStruct(const StructDef &struct_def, |
| const FieldDef &field, std::string *code_ptr) { |
| auto &code = *code_ptr; |
| auto vectortype = field.value.type.VectorType(); |
| |
| GenReceiver(struct_def, code_ptr); |
| code += MakeCamel(NormalizedName(field)); |
| code += "(self, j):" + OffsetPrefix(field); |
| code += Indent + Indent + Indent + "x = self._tab.Vector(o)\n"; |
| code += Indent + Indent + Indent; |
| code += "x += flatbuffers.number_types.UOffsetTFlags.py_type(j) * "; |
| code += NumToString(InlineSize(vectortype)) + "\n"; |
| if (!(vectortype.struct_def->fixed)) { |
| code += Indent + Indent + Indent + "x = self._tab.Indirect(x)\n"; |
| } |
| if (parser_.opts.include_dependence_headers) { |
| code += Indent + Indent + Indent; |
| code += "from " + GenPackageReference(field.value.type) + " import " + |
| TypeName(field) + "\n"; |
| } |
| code += Indent + Indent + Indent + "obj = " + TypeName(field) + "()\n"; |
| code += Indent + Indent + Indent + "obj.Init(self._tab.Bytes, x)\n"; |
| code += 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. |
| void GetMemberOfVectorOfNonStruct(const StructDef &struct_def, |
| const FieldDef &field, |
| std::string *code_ptr) { |
| auto &code = *code_ptr; |
| auto vectortype = field.value.type.VectorType(); |
| |
| GenReceiver(struct_def, code_ptr); |
| code += MakeCamel(NormalizedName(field)); |
| 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"; |
| } |
| |
| // Returns a non-struct vector as a numpy array. Much faster |
| // than iterating over the vector element by element. |
| void GetVectorOfNonStructAsNumpy(const StructDef &struct_def, |
| const FieldDef &field, |
| std::string *code_ptr) { |
| auto &code = *code_ptr; |
| auto vectortype = field.value.type.VectorType(); |
| |
| // Currently, we only support accessing as numpy array if |
| // the vector type is a scalar. |
| if (!(IsScalar(vectortype.base_type))) { return; } |
| |
| GenReceiver(struct_def, code_ptr); |
| code += MakeCamel(NormalizedName(field)) + "AsNumpy(self):"; |
| code += OffsetPrefix(field); |
| |
| code += Indent + Indent + Indent; |
| code += "return "; |
| code += "self._tab.GetVectorAsNumpy(flatbuffers.number_types."; |
| code += MakeCamel(GenTypeGet(field.value.type)); |
| code += "Flags, o)\n"; |
| |
| if (vectortype.base_type == BASE_TYPE_STRING) { |
| code += Indent + Indent + "return \"\"\n"; |
| } else { |
| code += Indent + Indent + "return 0\n"; |
| } |
| code += "\n"; |
| } |
| |
| // Begin the creator function signature. |
| void BeginBuilderArgs(const StructDef &struct_def, std::string *code_ptr) { |
| auto &code = *code_ptr; |
| |
| code += "\n"; |
| code += "def Create" + NormalizedName(struct_def); |
| code += "(builder"; |
| } |
| |
| // Recursively generate arguments for a constructor, to deal with nested |
| // structs. |
| void StructBuilderArgs(const StructDef &struct_def, |
| const std::string nameprefix, |
| const std::string namesuffix, bool has_field_name, |
| const std::string fieldname_suffix, |
| std::string *code_ptr) { |
| for (auto it = struct_def.fields.vec.begin(); |
| it != struct_def.fields.vec.end(); ++it) { |
| auto &field = **it; |
| const auto &field_type = field.value.type; |
| const auto &type = |
| IsArray(field_type) ? field_type.VectorType() : field_type; |
| if (IsStruct(type)) { |
| // Generate arguments for a struct inside a struct. To ensure names |
| // don't clash, and to make it obvious these arguments are constructing |
| // a nested struct, prefix the name with the field name. |
| auto subprefix = nameprefix; |
| if (has_field_name) { |
| subprefix += NormalizedName(field) + fieldname_suffix; |
| } |
| StructBuilderArgs(*field.value.type.struct_def, subprefix, namesuffix, |
| has_field_name, fieldname_suffix, code_ptr); |
| } else { |
| auto &code = *code_ptr; |
| code += std::string(", ") + nameprefix; |
| if (has_field_name) { code += MakeCamel(NormalizedName(field), false); } |
| code += namesuffix; |
| } |
| } |
| } |
| |
| // End the creator function signature. |
| void EndBuilderArgs(std::string *code_ptr) { |
| auto &code = *code_ptr; |
| code += "):\n"; |
| } |
| |
| // Recursively generate struct construction statements and instert manual |
| // padding. |
| void StructBuilderBody(const StructDef &struct_def, const char *nameprefix, |
| std::string *code_ptr, size_t index = 0, |
| bool in_array = false) { |
| auto &code = *code_ptr; |
| std::string indent(index * 4, ' '); |
| code += |
| indent + " builder.Prep(" + NumToString(struct_def.minalign) + ", "; |
| code += NumToString(struct_def.bytesize) + ")\n"; |
| for (auto it = struct_def.fields.vec.rbegin(); |
| it != struct_def.fields.vec.rend(); ++it) { |
| auto &field = **it; |
| const auto &field_type = field.value.type; |
| const auto &type = |
| IsArray(field_type) ? field_type.VectorType() : field_type; |
| if (field.padding) |
| code += |
| indent + " builder.Pad(" + NumToString(field.padding) + ")\n"; |
| if (IsStruct(field_type)) { |
| StructBuilderBody(*field_type.struct_def, |
| (nameprefix + (NormalizedName(field) + "_")).c_str(), |
| code_ptr, index, in_array); |
| } else { |
| const auto index_var = "_idx" + NumToString(index); |
| if (IsArray(field_type)) { |
| code += indent + " for " + index_var + " in range("; |
| code += NumToString(field_type.fixed_length); |
| code += " , 0, -1):\n"; |
| in_array = true; |
| } |
| 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) { |
| auto &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) { |
| auto &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) { |
| auto &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) { |
| auto &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) { |
| auto &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) { |
| auto &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 || |
| field.value.type.base_type == BASE_TYPE_ARRAY) { |
| GetVectorLen(struct_def, field, code_ptr); |
| GetVectorIsNone(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) { |
| auto &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"; |
| } |
| |
| // Generates 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); |
| } |
| } |
| // Generates 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) { |
| // creates a struct constructor function |
| GenStructBuilder(struct_def, code_ptr); |
| } else { |
| // Creates a set of functions that allow table construction. |
| GenTableBuilders(struct_def, code_ptr); |
| } |
| } |
| |
| void GenReceiverForObjectAPI(const StructDef &struct_def, |
| std::string *code_ptr) { |
| auto &code = *code_ptr; |
| code += GenIndents(1) + "# " + NormalizedName(struct_def) + "T"; |
| code += GenIndents(1) + "def "; |
| } |
| |
| void BeginClassForObjectAPI(const StructDef &struct_def, |
| std::string *code_ptr) { |
| auto &code = *code_ptr; |
| code += "\n"; |
| code += "class " + NormalizedName(struct_def) + "T(object):"; |
| code += "\n"; |
| } |
| |
| // Gets the accoresponding python builtin type of a BaseType for scalars and |
| // string. |
| std::string GetBasePythonTypeForScalarAndString(const BaseType &base_type) { |
| if (IsBool(base_type)) { |
| return "bool"; |
| } else if (IsFloat(base_type)) { |
| return "float"; |
| } else if (IsInteger(base_type)) { |
| return "int"; |
| } else if (base_type == BASE_TYPE_STRING) { |
| return "str"; |
| } else { |
| FLATBUFFERS_ASSERT(false && "base_type is not a scalar or string type."); |
| return ""; |
| } |
| } |
| |
| std::string GetDefaultValue(const FieldDef &field) { |
| BaseType base_type = field.value.type.base_type; |
| if (IsBool(base_type)) { |
| return field.value.constant == "0" ? "False" : "True"; |
| } else if (IsFloat(base_type)) { |
| return float_const_gen_.GenFloatConstant(field); |
| } else if (IsInteger(base_type)) { |
| return field.value.constant; |
| } else { |
| // For string, struct, and table. |
| return "None"; |
| } |
| } |
| |
| void GenUnionInit(const FieldDef &field, std::string *field_types_ptr, |
| std::set<std::string> *import_list, |
| std::set<std::string> *import_typing_list) { |
| // Gets all possible types in the union. |
| import_typing_list->insert("Union"); |
| auto &field_types = *field_types_ptr; |
| field_types = "Union["; |
| |
| std::string separator_string = ", "; |
| auto enum_def = field.value.type.enum_def; |
| for (auto it = enum_def->Vals().begin(); it != enum_def->Vals().end(); |
| ++it) { |
| auto &ev = **it; |
| // Union only supports string and table. |
| std::string field_type; |
| switch (ev.union_type.base_type) { |
| case BASE_TYPE_STRUCT: |
| field_type = GenTypeGet(ev.union_type) + "T"; |
| if (parser_.opts.include_dependence_headers) { |
| auto package_reference = GenPackageReference(ev.union_type); |
| field_type = package_reference + "." + field_type; |
| import_list->insert("import " + package_reference); |
| } |
| break; |
| case BASE_TYPE_STRING: field_type += "str"; break; |
| case BASE_TYPE_NONE: field_type += "None"; break; |
| default: break; |
| } |
| field_types += field_type + separator_string; |
| } |
| |
| // Removes the last separator_string. |
| field_types.erase(field_types.length() - separator_string.size()); |
| field_types += "]"; |
| |
| // Gets the import lists for the union. |
| if (parser_.opts.include_dependence_headers) { |
| // The package reference is generated based on enum_def, instead |
| // of struct_def in field.type. That's why GenPackageReference() is |
| // not used. |
| Namespace *namespaces = field.value.type.enum_def->defined_namespace; |
| auto package_reference = namespaces->GetFullyQualifiedName( |
| MakeUpperCamel(*(field.value.type.enum_def))); |
| auto union_name = MakeUpperCamel(*(field.value.type.enum_def)); |
| import_list->insert("import " + package_reference); |
| } |
| } |
| |
| void GenStructInit(const FieldDef &field, std::string *field_type_ptr, |
| std::set<std::string> *import_list, |
| std::set<std::string> *import_typing_list) { |
| import_typing_list->insert("Optional"); |
| auto &field_type = *field_type_ptr; |
| if (parser_.opts.include_dependence_headers) { |
| auto package_reference = GenPackageReference(field.value.type); |
| field_type = package_reference + "." + TypeName(field) + "T]"; |
| import_list->insert("import " + package_reference); |
| } else { |
| field_type = TypeName(field) + "T]"; |
| } |
| field_type = "Optional[" + field_type; |
| } |
| |
| void GenVectorInit(const FieldDef &field, std::string *field_type_ptr, |
| std::set<std::string> *import_list, |
| std::set<std::string> *import_typing_list) { |
| import_typing_list->insert("List"); |
| auto &field_type = *field_type_ptr; |
| auto base_type = field.value.type.VectorType().base_type; |
| if (base_type == BASE_TYPE_STRUCT) { |
| field_type = GenTypeGet(field.value.type.VectorType()) + "T]"; |
| if (parser_.opts.include_dependence_headers) { |
| auto package_reference = |
| GenPackageReference(field.value.type.VectorType()); |
| field_type = package_reference + "." + |
| GenTypeGet(field.value.type.VectorType()) + "T]"; |
| import_list->insert("import " + package_reference); |
| } |
| field_type = "List[" + field_type; |
| } else { |
| field_type = |
| "List[" + GetBasePythonTypeForScalarAndString(base_type) + "]"; |
| } |
| } |
| |
| void GenInitialize(const StructDef &struct_def, std::string *code_ptr, |
| std::set<std::string> *import_list) { |
| std::string code; |
| std::set<std::string> import_typing_list; |
| for (auto it = struct_def.fields.vec.begin(); |
| it != struct_def.fields.vec.end(); ++it) { |
| auto &field = **it; |
| if (field.deprecated) continue; |
| |
| // Determines field type, default value, and typing imports. |
| auto base_type = field.value.type.base_type; |
| std::string field_type; |
| switch (base_type) { |
| case BASE_TYPE_UNION: { |
| GenUnionInit(field, &field_type, import_list, &import_typing_list); |
| break; |
| } |
| case BASE_TYPE_STRUCT: { |
| GenStructInit(field, &field_type, import_list, &import_typing_list); |
| break; |
| } |
| case BASE_TYPE_VECTOR: |
| case BASE_TYPE_ARRAY: { |
| GenVectorInit(field, &field_type, import_list, &import_typing_list); |
| break; |
| } |
| default: |
| // Scalar or sting fields. |
| field_type = GetBasePythonTypeForScalarAndString(base_type); |
| break; |
| } |
| |
| auto default_value = GetDefaultValue(field); |
| // Wrties the init statement. |
| auto field_instance_name = MakeLowerCamel(field); |
| code += GenIndents(2) + "self." + field_instance_name + " = " + |
| default_value + " # type: " + field_type; |
| } |
| |
| // Writes __init__ method. |
| auto &code_base = *code_ptr; |
| GenReceiverForObjectAPI(struct_def, code_ptr); |
| code_base += "__init__(self):"; |
| if (code.empty()) { |
| code_base += GenIndents(2) + "pass"; |
| } else { |
| code_base += code; |
| } |
| code_base += "\n"; |
| |
| // Merges the typing imports into import_list. |
| if (!import_typing_list.empty()) { |
| // Adds the try statement. |
| std::string typing_imports = "try:"; |
| typing_imports += GenIndents(1) + "from typing import "; |
| std::string separator_string = ", "; |
| for (auto it = import_typing_list.begin(); it != import_typing_list.end(); |
| ++it) { |
| const std::string &im = *it; |
| typing_imports += im + separator_string; |
| } |
| // Removes the last separator_string. |
| typing_imports.erase(typing_imports.length() - separator_string.size()); |
| |
| // Adds the except statement. |
| typing_imports += "\n"; |
| typing_imports += "except:"; |
| typing_imports += GenIndents(1) + "pass"; |
| import_list->insert(typing_imports); |
| } |
| |
| // Removes the import of the struct itself, if applied. |
| auto package_reference = |
| struct_def.defined_namespace->GetFullyQualifiedName( |
| MakeUpperCamel(struct_def)); |
| auto struct_import = "import " + package_reference; |
| import_list->erase(struct_import); |
| } |
| |
| void InitializeFromBuf(const StructDef &struct_def, std::string *code_ptr) { |
| auto &code = *code_ptr; |
| auto instance_name = MakeLowerCamel(struct_def); |
| auto struct_name = NormalizedName(struct_def); |
| |
| code += GenIndents(1) + "@classmethod"; |
| code += GenIndents(1) + "def InitFromBuf(cls, buf, pos):"; |
| code += GenIndents(2) + instance_name + " = " + struct_name + "()"; |
| code += GenIndents(2) + instance_name + ".Init(buf, pos)"; |
| code += GenIndents(2) + "return cls.InitFromObj(" + instance_name + ")"; |
| code += "\n"; |
| } |
| |
| void InitializeFromObjForObject(const StructDef &struct_def, |
| std::string *code_ptr) { |
| auto &code = *code_ptr; |
| auto instance_name = MakeLowerCamel(struct_def); |
| auto struct_name = NormalizedName(struct_def); |
| |
| code += GenIndents(1) + "@classmethod"; |
| code += GenIndents(1) + "def InitFromObj(cls, " + instance_name + "):"; |
| code += GenIndents(2) + "x = " + struct_name + "T()"; |
| code += GenIndents(2) + "x._UnPack(" + instance_name + ")"; |
| code += GenIndents(2) + "return x"; |
| code += "\n"; |
| } |
| |
| void GenUnPackForStruct(const StructDef &struct_def, const FieldDef &field, |
| std::string *code_ptr) { |
| auto &code = *code_ptr; |
| auto struct_instance_name = MakeLowerCamel(struct_def); |
| auto field_instance_name = MakeLowerCamel(field); |
| auto field_accessor_name = MakeUpperCamel(field); |
| auto field_type = TypeName(field); |
| |
| if (parser_.opts.include_dependence_headers) { |
| auto package_reference = GenPackageReference(field.value.type); |
| field_type = package_reference + "." + TypeName(field); |
| } |
| |
| code += GenIndents(2) + "if " + struct_instance_name + "." + |
| field_accessor_name + "("; |
| // if field is a struct, we need to create an instance for it first. |
| if (struct_def.fixed && field.value.type.base_type == BASE_TYPE_STRUCT) { |
| code += field_type + "()"; |
| } |
| code += ") is not None:"; |
| code += GenIndents(3) + "self." + field_instance_name + " = " + field_type + |
| "T.InitFromObj(" + struct_instance_name + "." + |
| field_accessor_name + "("; |
| // A struct's accessor requires a struct buf instance. |
| if (struct_def.fixed && field.value.type.base_type == BASE_TYPE_STRUCT) { |
| code += field_type + "()"; |
| } |
| code += "))"; |
| } |
| |
| void GenUnPackForUnion(const StructDef &struct_def, const FieldDef &field, |
| std::string *code_ptr) { |
| auto &code = *code_ptr; |
| auto field_instance_name = MakeLowerCamel(field); |
| auto field_accessor_name = MakeUpperCamel(field); |
| auto struct_instance_name = MakeLowerCamel(struct_def); |
| auto union_name = MakeUpperCamel(*(field.value.type.enum_def)); |
| |
| if (parser_.opts.include_dependence_headers) { |
| Namespace *namespaces = field.value.type.enum_def->defined_namespace; |
| auto package_reference = namespaces->GetFullyQualifiedName( |
| MakeUpperCamel(*(field.value.type.enum_def))); |
| union_name = package_reference + "." + union_name; |
| } |
| code += GenIndents(2) + "self." + field_instance_name + " = " + union_name + |
| "Creator(" + "self." + field_instance_name + "Type, " + |
| struct_instance_name + "." + field_accessor_name + "())"; |
| } |
| |
| void GenUnPackForStructVector(const StructDef &struct_def, |
| const FieldDef &field, std::string *code_ptr) { |
| auto &code = *code_ptr; |
| auto field_instance_name = MakeLowerCamel(field); |
| auto field_accessor_name = MakeUpperCamel(field); |
| auto struct_instance_name = MakeLowerCamel(struct_def); |
| |
| code += GenIndents(2) + "if not " + struct_instance_name + "." + |
| field_accessor_name + "IsNone():"; |
| code += GenIndents(3) + "self." + field_instance_name + " = []"; |
| code += GenIndents(3) + "for i in range(" + struct_instance_name + "." + |
| field_accessor_name + "Length()):"; |
| |
| auto field_type_name = TypeName(field); |
| auto one_instance = field_type_name + "_"; |
| one_instance[0] = char(tolower(one_instance[0])); |
| |
| if (parser_.opts.include_dependence_headers) { |
| auto package_reference = GenPackageReference(field.value.type); |
| field_type_name = package_reference + "." + TypeName(field); |
| } |
| |
| code += GenIndents(4) + "if " + struct_instance_name + "." + |
| field_accessor_name + "(i) is None:"; |
| code += GenIndents(5) + "self." + field_instance_name + ".append(None)"; |
| code += GenIndents(4) + "else:"; |
| code += GenIndents(5) + one_instance + " = " + field_type_name + |
| "T.InitFromObj(" + struct_instance_name + "." + |
| field_accessor_name + "(i))"; |
| code += GenIndents(5) + "self." + field_instance_name + ".append(" + |
| one_instance + ")"; |
| } |
| |
| void GenUnpackforScalarVectorHelper(const StructDef &struct_def, |
| const FieldDef &field, |
| std::string *code_ptr, int indents) { |
| auto &code = *code_ptr; |
| auto field_instance_name = MakeLowerCamel(field); |
| auto field_accessor_name = MakeUpperCamel(field); |
| auto struct_instance_name = MakeLowerCamel(struct_def); |
| |
| code += GenIndents(indents) + "self." + field_instance_name + " = []"; |
| code += GenIndents(indents) + "for i in range(" + struct_instance_name + |
| "." + field_accessor_name + "Length()):"; |
| code += GenIndents(indents + 1) + "self." + field_instance_name + |
| ".append(" + struct_instance_name + "." + field_accessor_name + |
| "(i))"; |
| } |
| |
| void GenUnPackForScalarVector(const StructDef &struct_def, |
| const FieldDef &field, std::string *code_ptr) { |
| auto &code = *code_ptr; |
| auto field_instance_name = MakeLowerCamel(field); |
| auto field_accessor_name = MakeUpperCamel(field); |
| auto struct_instance_name = MakeLowerCamel(struct_def); |
| |
| code += GenIndents(2) + "if not " + struct_instance_name + "." + |
| field_accessor_name + "IsNone():"; |
| |
| // String does not have the AsNumpy method. |
| if (!(IsScalar(field.value.type.VectorType().base_type))) { |
| GenUnpackforScalarVectorHelper(struct_def, field, code_ptr, 3); |
| return; |
| } |
| |
| code += GenIndents(3) + "if np is None:"; |
| GenUnpackforScalarVectorHelper(struct_def, field, code_ptr, 4); |
| |
| // If numpy exists, use the AsNumpy method to optimize the unpack speed. |
| code += GenIndents(3) + "else:"; |
| code += GenIndents(4) + "self." + field_instance_name + " = " + |
| struct_instance_name + "." + field_accessor_name + "AsNumpy()"; |
| } |
| |
| void GenUnPackForScalar(const StructDef &struct_def, const FieldDef &field, |
| std::string *code_ptr) { |
| auto &code = *code_ptr; |
| auto field_instance_name = MakeLowerCamel(field); |
| auto field_accessor_name = MakeUpperCamel(field); |
| auto struct_instance_name = MakeLowerCamel(struct_def); |
| |
| code += GenIndents(2) + "self." + field_instance_name + " = " + |
| struct_instance_name + "." + field_accessor_name + "()"; |
| } |
| |
| // Generates the UnPack method for the object class. |
| void GenUnPack(const StructDef &struct_def, std::string *code_ptr) { |
| std::string code; |
| // Items that needs to be imported. No duplicate modules will be imported. |
| std::set<std::string> import_list; |
| |
| for (auto it = struct_def.fields.vec.begin(); |
| it != struct_def.fields.vec.end(); ++it) { |
| auto &field = **it; |
| if (field.deprecated) continue; |
| |
| auto field_type = TypeName(field); |
| switch (field.value.type.base_type) { |
| case BASE_TYPE_STRUCT: { |
| GenUnPackForStruct(struct_def, field, &code); |
| break; |
| } |
| case BASE_TYPE_UNION: { |
| GenUnPackForUnion(struct_def, field, &code); |
| break; |
| } |
| case BASE_TYPE_VECTOR: { |
| auto vectortype = field.value.type.VectorType(); |
| if (vectortype.base_type == BASE_TYPE_STRUCT) { |
| GenUnPackForStructVector(struct_def, field, &code); |
| } else { |
| GenUnPackForScalarVector(struct_def, field, &code); |
| } |
| break; |
| } |
| case BASE_TYPE_ARRAY: { |
| GenUnPackForScalarVector(struct_def, field, &code); |
| break; |
| } |
| default: GenUnPackForScalar(struct_def, field, &code); |
| } |
| } |
| |
| // Writes import statements and code into the generated file. |
| auto &code_base = *code_ptr; |
| auto struct_instance_name = MakeLowerCamel(struct_def); |
| auto struct_name = MakeUpperCamel(struct_def); |
| |
| GenReceiverForObjectAPI(struct_def, code_ptr); |
| code_base += "_UnPack(self, " + struct_instance_name + "):"; |
| code_base += GenIndents(2) + "if " + struct_instance_name + " is None:"; |
| code_base += GenIndents(3) + "return"; |
| |
| // Write the import statements. |
| for (std::set<std::string>::iterator it = import_list.begin(); |
| it != import_list.end(); ++it) { |
| code_base += GenIndents(2) + *it; |
| } |
| |
| // Write the code. |
| code_base += code; |
| code_base += "\n"; |
| } |
| |
| void GenPackForStruct(const StructDef &struct_def, std::string *code_ptr) { |
| auto &code = *code_ptr; |
| auto struct_name = MakeUpperCamel(struct_def); |
| |
| GenReceiverForObjectAPI(struct_def, code_ptr); |
| code += "Pack(self, builder):"; |
| code += GenIndents(2) + "return Create" + struct_name + "(builder"; |
| |
| StructBuilderArgs(struct_def, |
| /* nameprefix = */ "self.", |
| /* namesuffix = */ "", |
| /* has_field_name = */ true, |
| /* fieldname_suffix = */ ".", code_ptr); |
| code += ")\n"; |
| } |
| |
| void GenPackForStructVectorField(const StructDef &struct_def, |
| const FieldDef &field, |
| std::string *code_prefix_ptr, |
| std::string *code_ptr) { |
| auto &code_prefix = *code_prefix_ptr; |
| auto &code = *code_ptr; |
| auto field_instance_name = MakeLowerCamel(field); |
| auto struct_name = NormalizedName(struct_def); |
| auto field_accessor_name = MakeUpperCamel(field); |
| |
| // Creates the field. |
| code_prefix += |
| GenIndents(2) + "if self." + field_instance_name + " is not None:"; |
| if (field.value.type.struct_def->fixed) { |
| code_prefix += GenIndents(3) + struct_name + "Start" + |
| field_accessor_name + "Vector(builder, len(self." + |
| field_instance_name + "))"; |
| code_prefix += GenIndents(3) + "for i in reversed(range(len(self." + |
| field_instance_name + "))):"; |
| code_prefix += |
| GenIndents(4) + "self." + field_instance_name + "[i].Pack(builder)"; |
| code_prefix += GenIndents(3) + field_instance_name + |
| " = builder.EndVector(len(self." + field_instance_name + |
| "))"; |
| } else { |
| // If the vector is a struct vector, we need to first build accessor for |
| // each struct element. |
| code_prefix += GenIndents(3) + field_instance_name + "list = []"; |
| code_prefix += GenIndents(3); |
| code_prefix += "for i in range(len(self." + field_instance_name + ")):"; |
| code_prefix += GenIndents(4) + field_instance_name + "list.append(self." + |
| field_instance_name + "[i].Pack(builder))"; |
| |
| code_prefix += GenIndents(3) + struct_name + "Start" + |
| field_accessor_name + "Vector(builder, len(self." + |
| field_instance_name + "))"; |
| code_prefix += GenIndents(3) + "for i in reversed(range(len(self." + |
| field_instance_name + "))):"; |
| code_prefix += GenIndents(4) + "builder.PrependUOffsetTRelative" + "(" + |
| field_instance_name + "list[i])"; |
| code_prefix += GenIndents(3) + field_instance_name + |
| " = builder.EndVector(len(self." + field_instance_name + |
| "))"; |
| } |
| |
| // Adds the field into the struct. |
| code += GenIndents(2) + "if self." + field_instance_name + " is not None:"; |
| code += GenIndents(3) + struct_name + "Add" + field_accessor_name + |
| "(builder, " + field_instance_name + ")"; |
| } |
| |
| void GenPackForScalarVectorFieldHelper(const StructDef &struct_def, |
| const FieldDef &field, |
| std::string *code_ptr, int indents) { |
| auto &code = *code_ptr; |
| auto field_instance_name = MakeLowerCamel(field); |
| auto field_accessor_name = MakeUpperCamel(field); |
| auto struct_name = NormalizedName(struct_def); |
| auto vectortype = field.value.type.VectorType(); |
| |
| code += GenIndents(indents) + struct_name + "Start" + field_accessor_name + |
| "Vector(builder, len(self." + field_instance_name + "))"; |
| code += GenIndents(indents) + "for i in reversed(range(len(self." + |
| field_instance_name + "))):"; |
| code += GenIndents(indents + 1) + "builder.Prepend"; |
| |
| std::string type_name; |
| switch (vectortype.base_type) { |
| case BASE_TYPE_BOOL: type_name = "Bool"; break; |
| case BASE_TYPE_CHAR: type_name = "Byte"; break; |
| case BASE_TYPE_UCHAR: type_name = "Uint8"; break; |
| case BASE_TYPE_SHORT: type_name = "Int16"; break; |
| case BASE_TYPE_USHORT: type_name = "Uint16"; break; |
| case BASE_TYPE_INT: type_name = "Int32"; break; |
| case BASE_TYPE_UINT: type_name = "Uint32"; break; |
| case BASE_TYPE_LONG: type_name = "Int64"; break; |
| case BASE_TYPE_ULONG: type_name = "Uint64"; break; |
| case BASE_TYPE_FLOAT: type_name = "Float32"; break; |
| case BASE_TYPE_DOUBLE: type_name = "Float64"; break; |
| case BASE_TYPE_STRING: type_name = "UOffsetTRelative"; break; |
| default: type_name = "VOffsetT"; break; |
| } |
| code += type_name; |
| } |
| |
| void GenPackForScalarVectorField(const StructDef &struct_def, |
| const FieldDef &field, |
| std::string *code_prefix_ptr, |
| std::string *code_ptr) { |
| auto &code = *code_ptr; |
| auto &code_prefix = *code_prefix_ptr; |
| auto field_instance_name = MakeLowerCamel(field); |
| auto field_accessor_name = MakeUpperCamel(field); |
| auto struct_name = NormalizedName(struct_def); |
| |
| // Adds the field into the struct. |
| code += GenIndents(2) + "if self." + field_instance_name + " is not None:"; |
| code += GenIndents(3) + struct_name + "Add" + field_accessor_name + |
| "(builder, " + field_instance_name + ")"; |
| |
| // Creates the field. |
| code_prefix += |
| GenIndents(2) + "if self." + field_instance_name + " is not None:"; |
| // If the vector is a string vector, we need to first build accessor for |
| // each string element. And this generated code, needs to be |
| // placed ahead of code_prefix. |
| auto vectortype = field.value.type.VectorType(); |
| if (vectortype.base_type == BASE_TYPE_STRING) { |
| code_prefix += GenIndents(3) + MakeLowerCamel(field) + "list = []"; |
| code_prefix += GenIndents(3) + "for i in range(len(self." + |
| field_instance_name + ")):"; |
| code_prefix += GenIndents(4) + MakeLowerCamel(field) + |
| "list.append(builder.CreateString(self." + |
| field_instance_name + "[i]))"; |
| GenPackForScalarVectorFieldHelper(struct_def, field, code_prefix_ptr, 3); |
| code_prefix += "(" + MakeLowerCamel(field) + "list[i])"; |
| code_prefix += GenIndents(3) + field_instance_name + |
| " = builder.EndVector(len(self." + field_instance_name + |
| "))"; |
| return; |
| } |
| |
| code_prefix += GenIndents(3) + "if np is not None and type(self." + |
| field_instance_name + ") is np.ndarray:"; |
| code_prefix += GenIndents(4) + field_instance_name + |
| " = builder.CreateNumpyVector(self." + field_instance_name + |
| ")"; |
| code_prefix += GenIndents(3) + "else:"; |
| GenPackForScalarVectorFieldHelper(struct_def, field, code_prefix_ptr, 4); |
| code_prefix += "(self." + field_instance_name + "[i])"; |
| code_prefix += GenIndents(4) + field_instance_name + |
| " = builder.EndVector(len(self." + field_instance_name + |
| "))"; |
| } |
| |
| void GenPackForStructField(const StructDef &struct_def, const FieldDef &field, |
| std::string *code_prefix_ptr, |
| std::string *code_ptr) { |
| auto &code_prefix = *code_prefix_ptr; |
| auto &code = *code_ptr; |
| auto field_instance_name = MakeLowerCamel(field); |
| |
| auto field_accessor_name = MakeUpperCamel(field); |
| auto struct_name = NormalizedName(struct_def); |
| |
| if (field.value.type.struct_def->fixed) { |
| // Pure struct fields need to be created along with their parent |
| // structs. |
| code += |
| GenIndents(2) + "if self." + field_instance_name + " is not None:"; |
| code += GenIndents(3) + field_instance_name + " = self." + |
| field_instance_name + ".Pack(builder)"; |
| } else { |
| // Tables need to be created before their parent structs are created. |
| code_prefix += |
| GenIndents(2) + "if self." + field_instance_name + " is not None:"; |
| code_prefix += GenIndents(3) + field_instance_name + " = self." + |
| field_instance_name + ".Pack(builder)"; |
| code += |
| GenIndents(2) + "if self." + field_instance_name + " is not None:"; |
| } |
| |
| code += GenIndents(3) + struct_name + "Add" + field_accessor_name + |
| "(builder, " + field_instance_name + ")"; |
| } |
| |
| void GenPackForUnionField(const StructDef &struct_def, const FieldDef &field, |
| std::string *code_prefix_ptr, |
| std::string *code_ptr) { |
| auto &code_prefix = *code_prefix_ptr; |
| auto &code = *code_ptr; |
| auto field_instance_name = MakeLowerCamel(field); |
| |
| auto field_accessor_name = MakeUpperCamel(field); |
| auto struct_name = NormalizedName(struct_def); |
| |
| // TODO(luwa): TypeT should be moved under the None check as well. |
| code_prefix += |
| GenIndents(2) + "if self." + field_instance_name + " is not None:"; |
| code_prefix += GenIndents(3) + field_instance_name + " = self." + |
| field_instance_name + ".Pack(builder)"; |
| code += GenIndents(2) + "if self." + field_instance_name + " is not None:"; |
| code += GenIndents(3) + struct_name + "Add" + field_accessor_name + |
| "(builder, " + field_instance_name + ")"; |
| } |
| |
| void GenPackForTable(const StructDef &struct_def, std::string *code_ptr) { |
| auto &code_base = *code_ptr; |
| std::string code, code_prefix; |
| auto struct_instance_name = MakeLowerCamel(struct_def); |
| auto struct_name = NormalizedName(struct_def); |
| |
| GenReceiverForObjectAPI(struct_def, code_ptr); |
| code_base += "Pack(self, builder):"; |
| code += GenIndents(2) + struct_name + "Start(builder)"; |
| for (auto it = struct_def.fields.vec.begin(); |
| it != struct_def.fields.vec.end(); ++it) { |
| auto &field = **it; |
| if (field.deprecated) continue; |
| |
| auto field_accessor_name = MakeUpperCamel(field); |
| auto field_instance_name = MakeLowerCamel(field); |
| |
| switch (field.value.type.base_type) { |
| case BASE_TYPE_STRUCT: { |
| GenPackForStructField(struct_def, field, &code_prefix, &code); |
| break; |
| } |
| case BASE_TYPE_UNION: { |
| GenPackForUnionField(struct_def, field, &code_prefix, &code); |
| break; |
| } |
| case BASE_TYPE_VECTOR: { |
| auto vectortype = field.value.type.VectorType(); |
| if (vectortype.base_type == BASE_TYPE_STRUCT) { |
| GenPackForStructVectorField(struct_def, field, &code_prefix, &code); |
| } else { |
| GenPackForScalarVectorField(struct_def, field, &code_prefix, &code); |
| } |
| break; |
| } |
| case BASE_TYPE_ARRAY: { |
| GenPackForScalarVectorField(struct_def, field, &code_prefix, &code); |
| break; |
| } |
| case BASE_TYPE_STRING: { |
| code_prefix += GenIndents(2) + "if self." + field_instance_name + |
| " is not None:"; |
| code_prefix += GenIndents(3) + field_instance_name + |
| " = builder.CreateString(self." + field_instance_name + |
| ")"; |
| code += GenIndents(2) + "if self." + field_instance_name + |
| " is not None:"; |
| code += GenIndents(3) + struct_name + "Add" + field_accessor_name + |
| "(builder, " + field_instance_name + ")"; |
| break; |
| } |
| default: |
| // Generates code for scalar values. If the value equals to the |
| // default value, builder will automatically ignore it. So we don't |
| // need to check the value ahead. |
| code += GenIndents(2) + struct_name + "Add" + field_accessor_name + |
| "(builder, self." + field_instance_name + ")"; |
| break; |
| } |
| } |
| |
| code += GenIndents(2) + struct_instance_name + " = " + struct_name + |
| "End(builder)"; |
| code += GenIndents(2) + "return " + struct_instance_name; |
| |
| code_base += code_prefix + code; |
| code_base += "\n"; |
| } |
| |
| void GenStructForObjectAPI(const StructDef &struct_def, |
| std::string *code_ptr) { |
| if (struct_def.generated) return; |
| |
| std::set<std::string> import_list; |
| std::string code; |
| |
| // Creates an object class for a struct or a table |
| BeginClassForObjectAPI(struct_def, &code); |
| |
| GenInitialize(struct_def, &code, &import_list); |
| |
| InitializeFromBuf(struct_def, &code); |
| |
| InitializeFromObjForObject(struct_def, &code); |
| |
| GenUnPack(struct_def, &code); |
| |
| if (struct_def.fixed) { |
| GenPackForStruct(struct_def, &code); |
| } else { |
| GenPackForTable(struct_def, &code); |
| } |
| |
| // Adds the imports at top. |
| auto &code_base = *code_ptr; |
| code_base += "\n"; |
| for (auto it = import_list.begin(); it != import_list.end(); it++) { |
| auto im = *it; |
| code_base += im + "\n"; |
| } |
| code_base += code; |
| } |
| |
| void GenUnionCreatorForStruct(const EnumDef &enum_def, const EnumVal &ev, |
| std::string *code_ptr) { |
| auto &code = *code_ptr; |
| auto union_name = NormalizedName(enum_def); |
| auto field_name = NormalizedName(ev); |
| auto field_type = GenTypeGet(ev.union_type) + "T"; |
| |
| code += GenIndents(1) + "if unionType == " + union_name + "()." + |
| field_name + ":"; |
| if (parser_.opts.include_dependence_headers) { |
| auto package_reference = GenPackageReference(ev.union_type); |
| code += GenIndents(2) + "import " + package_reference; |
| field_type = package_reference + "." + field_type; |
| } |
| code += GenIndents(2) + "return " + field_type + |
| ".InitFromBuf(table.Bytes, table.Pos)"; |
| } |
| |
| void GenUnionCreatorForString(const EnumDef &enum_def, const EnumVal &ev, |
| std::string *code_ptr) { |
| auto &code = *code_ptr; |
| auto union_name = NormalizedName(enum_def); |
| auto field_name = NormalizedName(ev); |
| |
| code += GenIndents(1) + "if unionType == " + union_name + "()." + |
| field_name + ":"; |
| code += GenIndents(2) + "tab = Table(table.Bytes, table.Pos)"; |
| code += GenIndents(2) + "union = tab.String(table.Pos)"; |
| code += GenIndents(2) + "return union"; |
| } |
| |
| // Creates an union object based on union type. |
| void GenUnionCreator(const EnumDef &enum_def, std::string *code_ptr) { |
| auto &code = *code_ptr; |
| auto union_name = MakeUpperCamel(enum_def); |
| |
| code += "\n"; |
| code += "def " + union_name + "Creator(unionType, table):"; |
| code += GenIndents(1) + "from flatbuffers.table import Table"; |
| code += GenIndents(1) + "if not isinstance(table, Table):"; |
| code += GenIndents(2) + "return None"; |
| |
| for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end(); ++it) { |
| auto &ev = **it; |
| // Union only supports string and table. |
| switch (ev.union_type.base_type) { |
| case BASE_TYPE_STRUCT: |
| GenUnionCreatorForStruct(enum_def, ev, &code); |
| break; |
| case BASE_TYPE_STRING: |
| GenUnionCreatorForString(enum_def, ev, &code); |
| break; |
| default: break; |
| } |
| } |
| code += GenIndents(1) + "return None"; |
| code += "\n"; |
| } |
| |
| // 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) { |
| // clang-format off |
| static const char *ctypename[] = { |
| #define FLATBUFFERS_TD(ENUM, IDLTYPE, \ |
| CTYPE, JTYPE, GTYPE, NTYPE, PTYPE, ...) \ |
| #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, |
| /* nameprefix = */ "", |
| /* namesuffix = */ "", |
| /* has_field_name = */ true, |
| /* fieldname_suffix = */ "_", 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 (parser_.opts.generate_object_based_api & enum_def.is_union) { |
| GenUnionCreator(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 (parser_.opts.generate_object_based_api) { |
| GenStructForObjectAPI(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) { |
| auto &code = *code_ptr; |
| code = code + "# " + FlatBuffersGeneratedWarning() + "\n\n"; |
| code += "# namespace: " + name_space_name + "\n\n"; |
| if (needs_imports) { |
| code += "import flatbuffers\n"; |
| code += "from flatbuffers.compat import import_numpy\n"; |
| code += "np = import_numpy()\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 |
