/third_party/flatbuffers/src/idl_gen_text.cpp
C++ | 378 lines | 310 code | 25 blank | 43 comment | 66 complexity | 1b087a32ea9c573fe6f3c784f455b48c MD5 | raw file
- /*
- * 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 "flatbuffers/flatbuffers.h"
- #include "flatbuffers/flexbuffers.h"
- #include "flatbuffers/idl.h"
- #include "flatbuffers/util.h"
- namespace flatbuffers {
- static bool GenStruct(const StructDef &struct_def, const Table *table,
- int indent, const IDLOptions &opts, std::string *_text);
- // If indentation is less than 0, that indicates we don't want any newlines
- // either.
- const char *NewLine(const IDLOptions &opts) {
- return opts.indent_step >= 0 ? "\n" : "";
- }
- int Indent(const IDLOptions &opts) { return std::max(opts.indent_step, 0); }
- // Output an identifier with or without quotes depending on strictness.
- void OutputIdentifier(const std::string &name, const IDLOptions &opts,
- std::string *_text) {
- std::string &text = *_text;
- if (opts.strict_json) text += "\"";
- text += name;
- if (opts.strict_json) text += "\"";
- }
- // Print (and its template specialization below for pointers) generate text
- // for a single FlatBuffer value into JSON format.
- // The general case for scalars:
- template<typename T>
- bool Print(T val, Type type, int /*indent*/, Type * /*union_type*/,
- const IDLOptions &opts, std::string *_text) {
- std::string &text = *_text;
- if (type.enum_def && opts.output_enum_identifiers) {
- std::vector<EnumVal const *> enum_values;
- if (auto ev = type.enum_def->ReverseLookup(static_cast<int64_t>(val))) {
- enum_values.push_back(ev);
- } else if (val && type.enum_def->attributes.Lookup("bit_flags")) {
- for (auto it = type.enum_def->Vals().begin(),
- e = type.enum_def->Vals().end();
- it != e; ++it) {
- if ((*it)->GetAsUInt64() & static_cast<uint64_t>(val))
- enum_values.push_back(*it);
- }
- }
- if (!enum_values.empty()) {
- text += '\"';
- for (auto it = enum_values.begin(), e = enum_values.end(); it != e; ++it)
- text += (*it)->name + ' ';
- text[text.length() - 1] = '\"';
- return true;
- }
- }
- if (type.base_type == BASE_TYPE_BOOL) {
- text += val != 0 ? "true" : "false";
- } else {
- text += NumToString(val);
- }
- return true;
- }
- // Print a vector or an array of JSON values, comma seperated, wrapped in "[]".
- template<typename T, typename Container>
- bool PrintContainer(const Container &c, size_t size, Type type, int indent,
- const IDLOptions &opts, std::string *_text) {
- std::string &text = *_text;
- text += "[";
- text += NewLine(opts);
- for (uoffset_t i = 0; i < size; i++) {
- if (i) {
- if (!opts.protobuf_ascii_alike) text += ",";
- text += NewLine(opts);
- }
- text.append(indent + Indent(opts), ' ');
- if (IsStruct(type)) {
- if (!Print(reinterpret_cast<const void *>(c.Data() +
- i * type.struct_def->bytesize),
- type, indent + Indent(opts), nullptr, opts, _text)) {
- return false;
- }
- } else {
- if (!Print(c[i], type, indent + Indent(opts), nullptr, opts, _text)) {
- return false;
- }
- }
- }
- text += NewLine(opts);
- text.append(indent, ' ');
- text += "]";
- return true;
- }
- template<typename T>
- bool PrintVector(const Vector<T> &v, Type type, int indent,
- const IDLOptions &opts, std::string *_text) {
- return PrintContainer<T, Vector<T>>(v, v.size(), type, indent, opts, _text);
- }
- // Print an array a sequence of JSON values, comma separated, wrapped in "[]".
- template<typename T>
- bool PrintArray(const Array<T, 0xFFFF> &a, size_t size, Type type, int indent,
- const IDLOptions &opts, std::string *_text) {
- return PrintContainer<T, Array<T, 0xFFFF>>(a, size, type, indent, opts,
- _text);
- }
- // Specialization of Print above for pointer types.
- template<>
- bool Print<const void *>(const void *val, Type type, int indent,
- Type *union_type, const IDLOptions &opts,
- std::string *_text) {
- switch (type.base_type) {
- case BASE_TYPE_UNION:
- // If this assert hits, you have an corrupt buffer, a union type field
- // was not present or was out of range.
- FLATBUFFERS_ASSERT(union_type);
- return Print<const void *>(val, *union_type, indent, nullptr, opts,
- _text);
- case BASE_TYPE_STRUCT:
- if (!GenStruct(*type.struct_def, reinterpret_cast<const Table *>(val),
- indent, opts, _text)) {
- return false;
- }
- break;
- case BASE_TYPE_STRING: {
- auto s = reinterpret_cast<const String *>(val);
- if (!EscapeString(s->c_str(), s->size(), _text, opts.allow_non_utf8,
- opts.natural_utf8)) {
- return false;
- }
- break;
- }
- case BASE_TYPE_VECTOR: {
- const auto vec_type = type.VectorType();
- // Call PrintVector above specifically for each element type:
- // clang-format off
- switch (vec_type.base_type) {
- #define FLATBUFFERS_TD(ENUM, IDLTYPE, \
- CTYPE, JTYPE, GTYPE, NTYPE, PTYPE, RTYPE, KTYPE) \
- case BASE_TYPE_ ## ENUM: \
- if (!PrintVector<CTYPE>( \
- *reinterpret_cast<const Vector<CTYPE> *>(val), \
- vec_type, indent, opts, _text)) { \
- return false; \
- } \
- break;
- FLATBUFFERS_GEN_TYPES(FLATBUFFERS_TD)
- #undef FLATBUFFERS_TD
- }
- // clang-format on
- break;
- }
- case BASE_TYPE_ARRAY: {
- const auto vec_type = type.VectorType();
- // Call PrintArray above specifically for each element type:
- // clang-format off
- switch (vec_type.base_type) {
- #define FLATBUFFERS_TD(ENUM, IDLTYPE, \
- CTYPE, JTYPE, GTYPE, NTYPE, PTYPE, RTYPE, KTYPE) \
- case BASE_TYPE_ ## ENUM: \
- if (!PrintArray<CTYPE>( \
- *reinterpret_cast<const Array<CTYPE, 0xFFFF> *>(val), \
- type.fixed_length, \
- vec_type, indent, opts, _text)) { \
- return false; \
- } \
- break;
- FLATBUFFERS_GEN_TYPES_SCALAR(FLATBUFFERS_TD)
- FLATBUFFERS_GEN_TYPES_POINTER(FLATBUFFERS_TD)
- #undef FLATBUFFERS_TD
- case BASE_TYPE_ARRAY: FLATBUFFERS_ASSERT(0);
- }
- // clang-format on
- break;
- }
- default: FLATBUFFERS_ASSERT(0);
- }
- return true;
- }
- template<typename T> static T GetFieldDefault(const FieldDef &fd) {
- T val;
- auto check = StringToNumber(fd.value.constant.c_str(), &val);
- (void)check;
- FLATBUFFERS_ASSERT(check);
- return val;
- }
- // Generate text for a scalar field.
- template<typename T>
- static bool GenField(const FieldDef &fd, const Table *table, bool fixed,
- const IDLOptions &opts, int indent, std::string *_text) {
- return Print(
- fixed ? reinterpret_cast<const Struct *>(table)->GetField<T>(
- fd.value.offset)
- : table->GetField<T>(fd.value.offset, GetFieldDefault<T>(fd)),
- fd.value.type, indent, nullptr, opts, _text);
- }
- static bool GenStruct(const StructDef &struct_def, const Table *table,
- int indent, const IDLOptions &opts, std::string *_text);
- // Generate text for non-scalar field.
- static bool GenFieldOffset(const FieldDef &fd, const Table *table, bool fixed,
- int indent, Type *union_type, const IDLOptions &opts,
- std::string *_text) {
- const void *val = nullptr;
- if (fixed) {
- // The only non-scalar fields in structs are structs or arrays.
- FLATBUFFERS_ASSERT(IsStruct(fd.value.type) || IsArray(fd.value.type));
- val = reinterpret_cast<const Struct *>(table)->GetStruct<const void *>(
- fd.value.offset);
- } else if (fd.flexbuffer) {
- auto vec = table->GetPointer<const Vector<uint8_t> *>(fd.value.offset);
- auto root = flexbuffers::GetRoot(vec->data(), vec->size());
- root.ToString(true, opts.strict_json, *_text);
- return true;
- } else if (fd.nested_flatbuffer) {
- auto vec = table->GetPointer<const Vector<uint8_t> *>(fd.value.offset);
- auto root = GetRoot<Table>(vec->data());
- return GenStruct(*fd.nested_flatbuffer, root, indent, opts, _text);
- } else {
- val = IsStruct(fd.value.type)
- ? table->GetStruct<const void *>(fd.value.offset)
- : table->GetPointer<const void *>(fd.value.offset);
- }
- return Print(val, fd.value.type, indent, union_type, opts, _text);
- }
- // Generate text for a struct or table, values separated by commas, indented,
- // and bracketed by "{}"
- static bool GenStruct(const StructDef &struct_def, const Table *table,
- int indent, const IDLOptions &opts, std::string *_text) {
- std::string &text = *_text;
- text += "{";
- int fieldout = 0;
- Type *union_type = nullptr;
- for (auto it = struct_def.fields.vec.begin();
- it != struct_def.fields.vec.end(); ++it) {
- FieldDef &fd = **it;
- auto is_present = struct_def.fixed || table->CheckField(fd.value.offset);
- auto output_anyway = opts.output_default_scalars_in_json &&
- IsScalar(fd.value.type.base_type) && !fd.deprecated;
- if (is_present || output_anyway) {
- if (fieldout++) {
- if (!opts.protobuf_ascii_alike) text += ",";
- }
- text += NewLine(opts);
- text.append(indent + Indent(opts), ' ');
- OutputIdentifier(fd.name, opts, _text);
- if (!opts.protobuf_ascii_alike ||
- (fd.value.type.base_type != BASE_TYPE_STRUCT &&
- fd.value.type.base_type != BASE_TYPE_VECTOR))
- text += ":";
- text += " ";
- switch (fd.value.type.base_type) {
- // clang-format off
- #define FLATBUFFERS_TD(ENUM, IDLTYPE, \
- CTYPE, JTYPE, GTYPE, NTYPE, PTYPE, RTYPE, KTYPE) \
- case BASE_TYPE_ ## ENUM: \
- if (!GenField<CTYPE>(fd, table, struct_def.fixed, \
- opts, indent + Indent(opts), _text)) { \
- return false; \
- } \
- break;
- FLATBUFFERS_GEN_TYPES_SCALAR(FLATBUFFERS_TD)
- #undef FLATBUFFERS_TD
- // Generate drop-thru case statements for all pointer types:
- #define FLATBUFFERS_TD(ENUM, IDLTYPE, \
- CTYPE, JTYPE, GTYPE, NTYPE, PTYPE, RTYPE, KTYPE) \
- case BASE_TYPE_ ## ENUM:
- FLATBUFFERS_GEN_TYPES_POINTER(FLATBUFFERS_TD)
- FLATBUFFERS_GEN_TYPE_ARRAY(FLATBUFFERS_TD)
- #undef FLATBUFFERS_TD
- if (!GenFieldOffset(fd, table, struct_def.fixed, indent + Indent(opts),
- union_type, opts, _text)) {
- return false;
- }
- break;
- // clang-format on
- }
- if (fd.value.type.base_type == BASE_TYPE_UTYPE) {
- auto enum_val = fd.value.type.enum_def->ReverseLookup(
- table->GetField<uint8_t>(fd.value.offset, 0), true);
- union_type = enum_val ? &enum_val->union_type : nullptr;
- }
- }
- }
- text += NewLine(opts);
- text.append(indent, ' ');
- text += "}";
- return true;
- }
- // Generate a text representation of a flatbuffer in JSON format.
- bool GenerateTextFromTable(const Parser &parser, const void *table,
- const std::string &table_name, std::string *_text) {
- auto struct_def = parser.LookupStruct(table_name);
- if (struct_def == nullptr) {
- return false;
- }
- auto &text = *_text;
- text.reserve(1024); // Reduce amount of inevitable reallocs.
- auto root = static_cast<const Table *>(table);
- if (!GenStruct(*struct_def, root, 0, parser.opts, &text)) {
- return false;
- }
- text += NewLine(parser.opts);
- return true;
- }
- // Generate a text representation of a flatbuffer in JSON format.
- bool GenerateText(const Parser &parser, const void *flatbuffer,
- std::string *_text) {
- std::string &text = *_text;
- FLATBUFFERS_ASSERT(parser.root_struct_def_); // call SetRootType()
- text.reserve(1024); // Reduce amount of inevitable reallocs.
- auto root = parser.opts.size_prefixed ?
- GetSizePrefixedRoot<Table>(flatbuffer) : GetRoot<Table>(flatbuffer);
- if (!GenStruct(*parser.root_struct_def_, root, 0, parser.opts, _text)) {
- return false;
- }
- text += NewLine(parser.opts);
- return true;
- }
- std::string TextFileName(const std::string &path,
- const std::string &file_name) {
- return path + file_name + ".json";
- }
- bool GenerateTextFile(const Parser &parser, const std::string &path,
- const std::string &file_name) {
- if (!parser.builder_.GetSize() || !parser.root_struct_def_) return true;
- std::string text;
- if (!GenerateText(parser, parser.builder_.GetBufferPointer(), &text)) {
- return false;
- }
- return flatbuffers::SaveFile(TextFileName(path, file_name).c_str(), text,
- false);
- }
- std::string TextMakeRule(const Parser &parser, const std::string &path,
- const std::string &file_name) {
- if (!parser.builder_.GetSize() || !parser.root_struct_def_) return "";
- std::string filebase =
- flatbuffers::StripPath(flatbuffers::StripExtension(file_name));
- std::string make_rule = TextFileName(path, filebase) + ": " + file_name;
- auto included_files =
- parser.GetIncludedFilesRecursive(parser.root_struct_def_->file);
- for (auto it = included_files.begin(); it != included_files.end(); ++it) {
- make_rule += " " + *it;
- }
- return make_rule;
- }
- } // namespace flatbuffers