| /* |
| * Copyright 2015 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. |
| */ |
| |
| #ifndef FLATBUFFERS_REFLECTION_H_ |
| #define FLATBUFFERS_REFLECTION_H_ |
| |
| // This is somewhat of a circular dependency because flatc (and thus this |
| // file) is needed to generate this header in the first place. |
| // Should normally not be a problem since it can be generated by the |
| // previous version of flatc whenever this code needs to change. |
| // See scripts/generate_code.py for generation. |
| #include "flatbuffers/reflection_generated.h" |
| |
| // Helper functionality for reflection. |
| |
| namespace flatbuffers { |
| |
| // ------------------------- GETTERS ------------------------- |
| |
| inline bool IsScalar(reflection::BaseType t) { |
| return t >= reflection::UType && t <= reflection::Double; |
| } |
| inline bool IsInteger(reflection::BaseType t) { |
| return t >= reflection::UType && t <= reflection::ULong; |
| } |
| inline bool IsFloat(reflection::BaseType t) { |
| return t == reflection::Float || t == reflection::Double; |
| } |
| inline bool IsLong(reflection::BaseType t) { |
| return t == reflection::Long || t == reflection::ULong; |
| } |
| |
| // Size of a basic type, don't use with structs. |
| inline size_t GetTypeSize(reflection::BaseType base_type) { |
| // This needs to correspond to the BaseType enum. |
| static size_t sizes[] = { |
| 0, // None |
| 1, // UType |
| 1, // Bool |
| 1, // Byte |
| 1, // UByte |
| 2, // Short |
| 2, // UShort |
| 4, // Int |
| 4, // UInt |
| 8, // Long |
| 8, // ULong |
| 4, // Float |
| 8, // Double |
| 4, // String |
| 4, // Vector |
| 4, // Obj |
| 4, // Union |
| 0, // Array. Only used in structs. 0 was chosen to prevent out-of-bounds |
| // errors. |
| 8, // Vector64 |
| |
| 0 // MaxBaseType. This must be kept the last entry in this array. |
| }; |
| static_assert(sizeof(sizes) / sizeof(size_t) == reflection::MaxBaseType + 1, |
| "Size of sizes[] array does not match the count of BaseType " |
| "enum values."); |
| return sizes[base_type]; |
| } |
| |
| // Same as above, but now correctly returns the size of a struct if |
| // the field (or vector element) is a struct. |
| inline size_t GetTypeSizeInline(reflection::BaseType base_type, int type_index, |
| const reflection::Schema &schema) { |
| if (base_type == reflection::Obj && |
| schema.objects()->Get(type_index)->is_struct()) { |
| return schema.objects()->Get(type_index)->bytesize(); |
| } else { |
| return GetTypeSize(base_type); |
| } |
| } |
| |
| // Get the root, regardless of what type it is. |
| inline Table *GetAnyRoot(uint8_t *const flatbuf) { |
| return GetMutableRoot<Table>(flatbuf); |
| } |
| |
| inline const Table *GetAnyRoot(const uint8_t *const flatbuf) { |
| return GetRoot<Table>(flatbuf); |
| } |
| |
| inline Table *GetAnySizePrefixedRoot(uint8_t *const flatbuf) { |
| return GetMutableSizePrefixedRoot<Table>(flatbuf); |
| } |
| |
| inline const Table *GetAnySizePrefixedRoot(const uint8_t *const flatbuf) { |
| return GetSizePrefixedRoot<Table>(flatbuf); |
| } |
| |
| // Get a field's default, if you know it's an integer, and its exact type. |
| template<typename T> T GetFieldDefaultI(const reflection::Field &field) { |
| FLATBUFFERS_ASSERT(sizeof(T) == GetTypeSize(field.type()->base_type())); |
| return static_cast<T>(field.default_integer()); |
| } |
| |
| // Get a field's default, if you know it's floating point and its exact type. |
| template<typename T> T GetFieldDefaultF(const reflection::Field &field) { |
| FLATBUFFERS_ASSERT(sizeof(T) == GetTypeSize(field.type()->base_type())); |
| return static_cast<T>(field.default_real()); |
| } |
| |
| // Get a field, if you know it's an integer, and its exact type. |
| template<typename T> |
| T GetFieldI(const Table &table, const reflection::Field &field) { |
| FLATBUFFERS_ASSERT(sizeof(T) == GetTypeSize(field.type()->base_type())); |
| return table.GetField<T>(field.offset(), |
| static_cast<T>(field.default_integer())); |
| } |
| |
| // Get a field, if you know it's floating point and its exact type. |
| template<typename T> |
| T GetFieldF(const Table &table, const reflection::Field &field) { |
| FLATBUFFERS_ASSERT(sizeof(T) == GetTypeSize(field.type()->base_type())); |
| return table.GetField<T>(field.offset(), |
| static_cast<T>(field.default_real())); |
| } |
| |
| // Get a field, if you know it's a string. |
| inline const String *GetFieldS(const Table &table, |
| const reflection::Field &field) { |
| FLATBUFFERS_ASSERT(field.type()->base_type() == reflection::String); |
| return table.GetPointer<const String *>(field.offset()); |
| } |
| |
| // Get a field, if you know it's a vector. |
| template<typename T> |
| Vector<T> *GetFieldV(const Table &table, const reflection::Field &field) { |
| FLATBUFFERS_ASSERT(field.type()->base_type() == reflection::Vector && |
| sizeof(T) == GetTypeSize(field.type()->element())); |
| return table.GetPointer<Vector<T> *>(field.offset()); |
| } |
| |
| // Get a field, if you know it's a vector, generically. |
| // To actually access elements, use the return value together with |
| // field.type()->element() in any of GetAnyVectorElemI below etc. |
| inline VectorOfAny *GetFieldAnyV(const Table &table, |
| const reflection::Field &field) { |
| return table.GetPointer<VectorOfAny *>(field.offset()); |
| } |
| |
| // Get a field, if you know it's a table. |
| inline Table *GetFieldT(const Table &table, const reflection::Field &field) { |
| FLATBUFFERS_ASSERT(field.type()->base_type() == reflection::Obj || |
| field.type()->base_type() == reflection::Union); |
| return table.GetPointer<Table *>(field.offset()); |
| } |
| |
| // Get a field, if you know it's a struct. |
| inline const Struct *GetFieldStruct(const Table &table, |
| const reflection::Field &field) { |
| // TODO: This does NOT check if the field is a table or struct, but we'd need |
| // access to the schema to check the is_struct flag. |
| FLATBUFFERS_ASSERT(field.type()->base_type() == reflection::Obj); |
| return table.GetStruct<const Struct *>(field.offset()); |
| } |
| |
| // Get a structure's field, if you know it's a struct. |
| inline const Struct *GetFieldStruct(const Struct &structure, |
| const reflection::Field &field) { |
| FLATBUFFERS_ASSERT(field.type()->base_type() == reflection::Obj); |
| return structure.GetStruct<const Struct *>(field.offset()); |
| } |
| |
| // Raw helper functions used below: get any value in memory as a 64bit int, a |
| // double or a string. |
| // All scalars get static_cast to an int64_t, strings use strtoull, every other |
| // data type returns 0. |
| int64_t GetAnyValueI(reflection::BaseType type, const uint8_t *data); |
| // All scalars static cast to double, strings use strtod, every other data |
| // type is 0.0. |
| double GetAnyValueF(reflection::BaseType type, const uint8_t *data); |
| // All scalars converted using stringstream, strings as-is, and all other |
| // data types provide some level of debug-pretty-printing. |
| std::string GetAnyValueS(reflection::BaseType type, const uint8_t *data, |
| const reflection::Schema *schema, int type_index); |
| |
| // Get any table field as a 64bit int, regardless of what type it is. |
| inline int64_t GetAnyFieldI(const Table &table, |
| const reflection::Field &field) { |
| auto field_ptr = table.GetAddressOf(field.offset()); |
| return field_ptr ? GetAnyValueI(field.type()->base_type(), field_ptr) |
| : field.default_integer(); |
| } |
| |
| // Get any table field as a double, regardless of what type it is. |
| inline double GetAnyFieldF(const Table &table, const reflection::Field &field) { |
| auto field_ptr = table.GetAddressOf(field.offset()); |
| return field_ptr ? GetAnyValueF(field.type()->base_type(), field_ptr) |
| : field.default_real(); |
| } |
| |
| // Get any table field as a string, regardless of what type it is. |
| // You may pass nullptr for the schema if you don't care to have fields that |
| // are of table type pretty-printed. |
| inline std::string GetAnyFieldS(const Table &table, |
| const reflection::Field &field, |
| const reflection::Schema *schema) { |
| auto field_ptr = table.GetAddressOf(field.offset()); |
| return field_ptr ? GetAnyValueS(field.type()->base_type(), field_ptr, schema, |
| field.type()->index()) |
| : ""; |
| } |
| |
| // Get any struct field as a 64bit int, regardless of what type it is. |
| inline int64_t GetAnyFieldI(const Struct &st, const reflection::Field &field) { |
| return GetAnyValueI(field.type()->base_type(), |
| st.GetAddressOf(field.offset())); |
| } |
| |
| // Get any struct field as a double, regardless of what type it is. |
| inline double GetAnyFieldF(const Struct &st, const reflection::Field &field) { |
| return GetAnyValueF(field.type()->base_type(), |
| st.GetAddressOf(field.offset())); |
| } |
| |
| // Get any struct field as a string, regardless of what type it is. |
| inline std::string GetAnyFieldS(const Struct &st, |
| const reflection::Field &field) { |
| return GetAnyValueS(field.type()->base_type(), |
| st.GetAddressOf(field.offset()), nullptr, -1); |
| } |
| |
| // Get any vector element as a 64bit int, regardless of what type it is. |
| inline int64_t GetAnyVectorElemI(const VectorOfAny *vec, |
| reflection::BaseType elem_type, size_t i) { |
| return GetAnyValueI(elem_type, vec->Data() + GetTypeSize(elem_type) * i); |
| } |
| |
| // Get any vector element as a double, regardless of what type it is. |
| inline double GetAnyVectorElemF(const VectorOfAny *vec, |
| reflection::BaseType elem_type, size_t i) { |
| return GetAnyValueF(elem_type, vec->Data() + GetTypeSize(elem_type) * i); |
| } |
| |
| // Get any vector element as a string, regardless of what type it is. |
| inline std::string GetAnyVectorElemS(const VectorOfAny *vec, |
| reflection::BaseType elem_type, size_t i) { |
| return GetAnyValueS(elem_type, vec->Data() + GetTypeSize(elem_type) * i, |
| nullptr, -1); |
| } |
| |
| // Get a vector element that's a table/string/vector from a generic vector. |
| // Pass Table/String/VectorOfAny as template parameter. |
| // Warning: does no typechecking. |
| template<typename T> |
| T *GetAnyVectorElemPointer(const VectorOfAny *vec, size_t i) { |
| auto elem_ptr = vec->Data() + sizeof(uoffset_t) * i; |
| return reinterpret_cast<T *>(elem_ptr + ReadScalar<uoffset_t>(elem_ptr)); |
| } |
| |
| // Get the inline-address of a vector element. Useful for Structs (pass Struct |
| // as template arg), or being able to address a range of scalars in-line. |
| // Get elem_size from GetTypeSizeInline(). |
| // Note: little-endian data on all platforms, use EndianScalar() instead of |
| // raw pointer access with scalars). |
| template<typename T> |
| T *GetAnyVectorElemAddressOf(const VectorOfAny *vec, size_t i, |
| size_t elem_size) { |
| return reinterpret_cast<T *>(vec->Data() + elem_size * i); |
| } |
| |
| // Similarly, for elements of tables. |
| template<typename T> |
| T *GetAnyFieldAddressOf(const Table &table, const reflection::Field &field) { |
| return reinterpret_cast<T *>(table.GetAddressOf(field.offset())); |
| } |
| |
| // Similarly, for elements of structs. |
| template<typename T> |
| T *GetAnyFieldAddressOf(const Struct &st, const reflection::Field &field) { |
| return reinterpret_cast<T *>(st.GetAddressOf(field.offset())); |
| } |
| |
| // Loop over all the fields of the provided `object` and call `func` on each one |
| // in increasing order by their field->id(). If `reverse` is true, `func` is |
| // called in descending order |
| void ForAllFields(const reflection::Object *object, bool reverse, |
| std::function<void(const reflection::Field *)> func); |
| |
| // ------------------------- SETTERS ------------------------- |
| |
| // Set any scalar field, if you know its exact type. |
| template<typename T> |
| bool SetField(Table *table, const reflection::Field &field, T val) { |
| reflection::BaseType type = field.type()->base_type(); |
| if (!IsScalar(type)) { return false; } |
| FLATBUFFERS_ASSERT(sizeof(T) == GetTypeSize(type)); |
| T def; |
| if (IsInteger(type)) { |
| def = GetFieldDefaultI<T>(field); |
| } else { |
| FLATBUFFERS_ASSERT(IsFloat(type)); |
| def = GetFieldDefaultF<T>(field); |
| } |
| return table->SetField(field.offset(), val, def); |
| } |
| |
| // Raw helper functions used below: set any value in memory as a 64bit int, a |
| // double or a string. |
| // These work for all scalar values, but do nothing for other data types. |
| // To set a string, see SetString below. |
| void SetAnyValueI(reflection::BaseType type, uint8_t *data, int64_t val); |
| void SetAnyValueF(reflection::BaseType type, uint8_t *data, double val); |
| void SetAnyValueS(reflection::BaseType type, uint8_t *data, const char *val); |
| |
| // Set any table field as a 64bit int, regardless of type what it is. |
| inline bool SetAnyFieldI(Table *table, const reflection::Field &field, |
| int64_t val) { |
| auto field_ptr = table->GetAddressOf(field.offset()); |
| if (!field_ptr) return val == GetFieldDefaultI<int64_t>(field); |
| SetAnyValueI(field.type()->base_type(), field_ptr, val); |
| return true; |
| } |
| |
| // Set any table field as a double, regardless of what type it is. |
| inline bool SetAnyFieldF(Table *table, const reflection::Field &field, |
| double val) { |
| auto field_ptr = table->GetAddressOf(field.offset()); |
| if (!field_ptr) return val == GetFieldDefaultF<double>(field); |
| SetAnyValueF(field.type()->base_type(), field_ptr, val); |
| return true; |
| } |
| |
| // Set any table field as a string, regardless of what type it is. |
| inline bool SetAnyFieldS(Table *table, const reflection::Field &field, |
| const char *val) { |
| auto field_ptr = table->GetAddressOf(field.offset()); |
| if (!field_ptr) return false; |
| SetAnyValueS(field.type()->base_type(), field_ptr, val); |
| return true; |
| } |
| |
| // Set any struct field as a 64bit int, regardless of type what it is. |
| inline void SetAnyFieldI(Struct *st, const reflection::Field &field, |
| int64_t val) { |
| SetAnyValueI(field.type()->base_type(), st->GetAddressOf(field.offset()), |
| val); |
| } |
| |
| // Set any struct field as a double, regardless of type what it is. |
| inline void SetAnyFieldF(Struct *st, const reflection::Field &field, |
| double val) { |
| SetAnyValueF(field.type()->base_type(), st->GetAddressOf(field.offset()), |
| val); |
| } |
| |
| // Set any struct field as a string, regardless of type what it is. |
| inline void SetAnyFieldS(Struct *st, const reflection::Field &field, |
| const char *val) { |
| SetAnyValueS(field.type()->base_type(), st->GetAddressOf(field.offset()), |
| val); |
| } |
| |
| // Set any vector element as a 64bit int, regardless of type what it is. |
| inline void SetAnyVectorElemI(VectorOfAny *vec, reflection::BaseType elem_type, |
| size_t i, int64_t val) { |
| SetAnyValueI(elem_type, vec->Data() + GetTypeSize(elem_type) * i, val); |
| } |
| |
| // Set any vector element as a double, regardless of type what it is. |
| inline void SetAnyVectorElemF(VectorOfAny *vec, reflection::BaseType elem_type, |
| size_t i, double val) { |
| SetAnyValueF(elem_type, vec->Data() + GetTypeSize(elem_type) * i, val); |
| } |
| |
| // Set any vector element as a string, regardless of type what it is. |
| inline void SetAnyVectorElemS(VectorOfAny *vec, reflection::BaseType elem_type, |
| size_t i, const char *val) { |
| SetAnyValueS(elem_type, vec->Data() + GetTypeSize(elem_type) * i, val); |
| } |
| |
| // ------------------------- RESIZING SETTERS ------------------------- |
| |
| // "smart" pointer for use with resizing vectors: turns a pointer inside |
| // a vector into a relative offset, such that it is not affected by resizes. |
| template<typename T, typename U> class pointer_inside_vector { |
| public: |
| pointer_inside_vector(T *ptr, std::vector<U> &vec) |
| : offset_(reinterpret_cast<uint8_t *>(ptr) - |
| reinterpret_cast<uint8_t *>(vec.data())), |
| vec_(vec) {} |
| |
| T *operator*() const { |
| return reinterpret_cast<T *>(reinterpret_cast<uint8_t *>(vec_.data()) + |
| offset_); |
| } |
| T *operator->() const { return operator*(); } |
| |
| private: |
| size_t offset_; |
| std::vector<U> &vec_; |
| }; |
| |
| // Helper to create the above easily without specifying template args. |
| template<typename T, typename U> |
| pointer_inside_vector<T, U> piv(T *ptr, std::vector<U> &vec) { |
| return pointer_inside_vector<T, U>(ptr, vec); |
| } |
| |
| inline const char *UnionTypeFieldSuffix() { return "_type"; } |
| |
| // Helper to figure out the actual table type a union refers to. |
| inline const reflection::Object &GetUnionType( |
| const reflection::Schema &schema, const reflection::Object &parent, |
| const reflection::Field &unionfield, const Table &table) { |
| auto enumdef = schema.enums()->Get(unionfield.type()->index()); |
| // TODO: this is clumsy and slow, but no other way to find it? |
| auto type_field = parent.fields()->LookupByKey( |
| (unionfield.name()->str() + UnionTypeFieldSuffix()).c_str()); |
| FLATBUFFERS_ASSERT(type_field); |
| auto union_type = GetFieldI<uint8_t>(table, *type_field); |
| auto enumval = enumdef->values()->LookupByKey(union_type); |
| return *schema.objects()->Get(enumval->union_type()->index()); |
| } |
| |
| // Changes the contents of a string inside a FlatBuffer. FlatBuffer must |
| // live inside a std::vector so we can resize the buffer if needed. |
| // "str" must live inside "flatbuf" and may be invalidated after this call. |
| // If your FlatBuffer's root table is not the schema's root table, you should |
| // pass in your root_table type as well. |
| void SetString(const reflection::Schema &schema, const std::string &val, |
| const String *str, std::vector<uint8_t> *flatbuf, |
| const reflection::Object *root_table = nullptr); |
| |
| // Resizes a flatbuffers::Vector inside a FlatBuffer. FlatBuffer must |
| // live inside a std::vector so we can resize the buffer if needed. |
| // "vec" must live inside "flatbuf" and may be invalidated after this call. |
| // If your FlatBuffer's root table is not the schema's root table, you should |
| // pass in your root_table type as well. |
| uint8_t *ResizeAnyVector(const reflection::Schema &schema, uoffset_t newsize, |
| const VectorOfAny *vec, uoffset_t num_elems, |
| uoffset_t elem_size, std::vector<uint8_t> *flatbuf, |
| const reflection::Object *root_table = nullptr); |
| |
| template<typename T> |
| void ResizeVector(const reflection::Schema &schema, uoffset_t newsize, T val, |
| const Vector<T> *vec, std::vector<uint8_t> *flatbuf, |
| const reflection::Object *root_table = nullptr) { |
| auto delta_elem = static_cast<int>(newsize) - static_cast<int>(vec->size()); |
| auto newelems = ResizeAnyVector( |
| schema, newsize, reinterpret_cast<const VectorOfAny *>(vec), vec->size(), |
| static_cast<uoffset_t>(sizeof(T)), flatbuf, root_table); |
| // Set new elements to "val". |
| for (int i = 0; i < delta_elem; i++) { |
| auto loc = newelems + i * sizeof(T); |
| auto is_scalar = flatbuffers::is_scalar<T>::value; |
| if (is_scalar) { |
| WriteScalar(loc, val); |
| } else { // struct |
| *reinterpret_cast<T *>(loc) = val; |
| } |
| } |
| } |
| |
| // Adds any new data (in the form of a new FlatBuffer) to an existing |
| // FlatBuffer. This can be used when any of the above methods are not |
| // sufficient, in particular for adding new tables and new fields. |
| // This is potentially slightly less efficient than a FlatBuffer constructed |
| // in one piece, since the new FlatBuffer doesn't share any vtables with the |
| // existing one. |
| // The return value can now be set using Vector::MutateOffset or SetFieldT |
| // below. |
| const uint8_t *AddFlatBuffer(std::vector<uint8_t> &flatbuf, |
| const uint8_t *newbuf, size_t newlen); |
| |
| inline bool SetFieldT(Table *table, const reflection::Field &field, |
| const uint8_t *val) { |
| FLATBUFFERS_ASSERT(sizeof(uoffset_t) == |
| GetTypeSize(field.type()->base_type())); |
| return table->SetPointer(field.offset(), val); |
| } |
| |
| // ------------------------- COPYING ------------------------- |
| |
| // Generic copying of tables from a FlatBuffer into a FlatBuffer builder. |
| // Can be used to do any kind of merging/selecting you may want to do out |
| // of existing buffers. Also useful to reconstruct a whole buffer if the |
| // above resizing functionality has introduced garbage in a buffer you want |
| // to remove. |
| // Note: this does not deal with DAGs correctly. If the table passed forms a |
| // DAG, the copy will be a tree instead (with duplicates). Strings can be |
| // shared however, by passing true for use_string_pooling. |
| |
| Offset<const Table *> CopyTable(FlatBufferBuilder &fbb, |
| const reflection::Schema &schema, |
| const reflection::Object &objectdef, |
| const Table &table, |
| bool use_string_pooling = false); |
| |
| // Verifies the provided flatbuffer using reflection. |
| // root should point to the root type for this flatbuffer. |
| // buf should point to the start of flatbuffer data. |
| // length specifies the size of the flatbuffer data. |
| bool Verify(const reflection::Schema &schema, const reflection::Object &root, |
| const uint8_t *buf, size_t length, uoffset_t max_depth = 64, |
| uoffset_t max_tables = 1000000); |
| |
| bool VerifySizePrefixed(const reflection::Schema &schema, |
| const reflection::Object &root, const uint8_t *buf, |
| size_t length, uoffset_t max_depth = 64, |
| uoffset_t max_tables = 1000000); |
| |
| } // namespace flatbuffers |
| |
| #endif // FLATBUFFERS_REFLECTION_H_ |