| // Copyright 2019 Google LLC |
| // |
| // 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 |
| // |
| // https://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. |
| |
| use crate::Builder; |
| use serde::ser; |
| use serde::ser::*; |
| use std::fmt::Display; |
| |
| // This struct internally tracks the nested vectors representing |
| // nested structs and such. |
| // TODO: Add an option field names in a map. |
| /// Flexbuffer Serializer. This should be used to serialize structs. |
| #[derive(Debug, Default)] |
| pub struct FlexbufferSerializer { |
| builder: Builder, |
| nesting: Vec<Option<usize>>, |
| } |
| impl FlexbufferSerializer { |
| pub fn new() -> Self { |
| Self::default() |
| } |
| pub fn view(&self) -> &[u8] { |
| self.builder.view() |
| } |
| pub fn take_buffer(&mut self) -> Vec<u8> { |
| self.builder.take_buffer() |
| } |
| fn finish_if_not_nested(&mut self) -> Result<(), Error> { |
| if self.nesting.is_empty() { |
| assert_eq!(self.builder.values.len(), 1); |
| let root = self.builder.values.pop().unwrap(); |
| super::store_root(&mut self.builder.buffer, root); |
| } |
| Ok(()) |
| } |
| fn start_vector(&mut self) { |
| let previous_end = if self.nesting.is_empty() { |
| None |
| } else { |
| Some(self.builder.values.len()) |
| }; |
| self.nesting.push(previous_end); |
| } |
| fn start_map(&mut self) { |
| let previous_end = if self.nesting.is_empty() { |
| None |
| } else { |
| Some(self.builder.values.len()) |
| }; |
| self.nesting.push(previous_end); |
| } |
| fn end_vector(&mut self) -> Result<(), Error> { |
| let previous_end = self.nesting.pop().unwrap(); |
| self.builder.end_map_or_vector(false, previous_end); |
| Ok(()) |
| } |
| fn end_map(&mut self) -> Result<(), Error> { |
| let previous_end = self.nesting.pop().unwrap(); |
| self.builder.end_map_or_vector(true, previous_end); |
| Ok(()) |
| } |
| } |
| |
| #[derive(Debug)] |
| /// Errors that may happen with Serde. |
| pub enum Error { |
| /// Only `str` and `String` can be serialized as keys in serde maps. |
| KeyMustBeString, |
| Serde(String), |
| } |
| |
| impl std::fmt::Display for Error { |
| fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> { |
| write!(f, "{:?}", self) |
| } |
| } |
| impl std::error::Error for Error {} |
| impl ser::Error for Error { |
| fn custom<T>(msg: T) -> Self |
| where |
| T: Display, |
| { |
| Self::Serde(format!("{}", msg)) |
| } |
| } |
| impl<'a> ser::SerializeSeq for &mut FlexbufferSerializer { |
| type Ok = (); |
| type Error = Error; |
| fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error> |
| where |
| T: Serialize, |
| { |
| value.serialize(&mut **self) |
| } |
| fn end(self) -> Result<Self::Ok, Self::Error> { |
| self.end_vector() |
| } |
| } |
| // This is unlike a flexbuffers map which requires CString like keys. |
| // Its implemented as alternating keys and values (hopefully). |
| impl<'a> ser::SerializeMap for &'a mut FlexbufferSerializer { |
| type Ok = (); |
| type Error = Error; |
| fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Self::Error> |
| where |
| T: Serialize, |
| { |
| key.serialize(MapKeySerializer(&mut **self)) |
| } |
| fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error> |
| where |
| T: Serialize, |
| { |
| value.serialize(&mut **self) |
| } |
| fn end(self) -> Result<Self::Ok, Self::Error> { |
| self.end_map() |
| } |
| } |
| impl<'a> ser::SerializeTuple for &mut FlexbufferSerializer { |
| type Ok = (); |
| type Error = Error; |
| fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error> |
| where |
| T: Serialize, |
| { |
| value.serialize(&mut **self) |
| } |
| fn end(self) -> Result<Self::Ok, Self::Error> { |
| self.end_vector() |
| } |
| } |
| impl<'a> ser::SerializeTupleStruct for &mut FlexbufferSerializer { |
| type Ok = (); |
| type Error = Error; |
| fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error> |
| where |
| T: Serialize, |
| { |
| value.serialize(&mut **self) |
| } |
| fn end(self) -> Result<Self::Ok, Self::Error> { |
| self.end_vector() |
| } |
| } |
| impl<'a> ser::SerializeStruct for &mut FlexbufferSerializer { |
| type Ok = (); |
| type Error = Error; |
| fn serialize_field<T: ?Sized>( |
| &mut self, |
| key: &'static str, |
| value: &T, |
| ) -> Result<(), Self::Error> |
| where |
| T: Serialize, |
| { |
| self.builder.push_key(key); |
| value.serialize(&mut **self) |
| } |
| fn end(self) -> Result<Self::Ok, Self::Error> { |
| self.end_map() |
| } |
| } |
| impl<'a> ser::SerializeTupleVariant for &mut FlexbufferSerializer { |
| type Ok = (); |
| type Error = Error; |
| fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error> |
| where |
| T: Serialize, |
| { |
| value.serialize(&mut **self) |
| } |
| fn end(self) -> Result<Self::Ok, Self::Error> { |
| self.end_vector()?; |
| self.end_map() |
| } |
| } |
| impl<'a> ser::SerializeStructVariant for &mut FlexbufferSerializer { |
| type Ok = (); |
| type Error = Error; |
| fn serialize_field<T: ?Sized>( |
| &mut self, |
| key: &'static str, |
| value: &T, |
| ) -> Result<(), Self::Error> |
| where |
| T: Serialize, |
| { |
| self.builder.push_key(key); |
| value.serialize(&mut **self) |
| } |
| fn end(self) -> Result<Self::Ok, Self::Error> { |
| self.end_map()?; |
| self.end_map() |
| } |
| // TODO: skip field? |
| } |
| |
| impl<'a> ser::Serializer for &'a mut FlexbufferSerializer { |
| type SerializeSeq = &'a mut FlexbufferSerializer; |
| type SerializeTuple = &'a mut FlexbufferSerializer; |
| type SerializeTupleStruct = &'a mut FlexbufferSerializer; |
| type SerializeTupleVariant = &'a mut FlexbufferSerializer; |
| type SerializeMap = &'a mut FlexbufferSerializer; |
| type SerializeStruct = &'a mut FlexbufferSerializer; |
| type SerializeStructVariant = &'a mut FlexbufferSerializer; |
| type Ok = (); |
| type Error = Error; |
| fn is_human_readable(&self) -> bool { |
| cfg!(serialize_human_readable) |
| } |
| fn serialize_bool(self, v: bool) -> Result<Self::Ok, Self::Error> { |
| self.builder.push(v); |
| self.finish_if_not_nested() |
| } |
| fn serialize_i8(self, v: i8) -> Result<Self::Ok, Self::Error> { |
| self.builder.push(v); |
| self.finish_if_not_nested() |
| } |
| fn serialize_i16(self, v: i16) -> Result<Self::Ok, Self::Error> { |
| self.builder.push(v); |
| self.finish_if_not_nested() |
| } |
| fn serialize_i32(self, v: i32) -> Result<Self::Ok, Self::Error> { |
| self.builder.push(v); |
| self.finish_if_not_nested() |
| } |
| fn serialize_i64(self, v: i64) -> Result<Self::Ok, Self::Error> { |
| self.builder.push(v); |
| self.finish_if_not_nested() |
| } |
| fn serialize_u8(self, v: u8) -> Result<Self::Ok, Self::Error> { |
| self.builder.push(v); |
| self.finish_if_not_nested() |
| } |
| fn serialize_u16(self, v: u16) -> Result<Self::Ok, Self::Error> { |
| self.builder.push(v); |
| self.finish_if_not_nested() |
| } |
| fn serialize_u32(self, v: u32) -> Result<Self::Ok, Self::Error> { |
| self.builder.push(v); |
| self.finish_if_not_nested() |
| } |
| fn serialize_u64(self, v: u64) -> Result<Self::Ok, Self::Error> { |
| self.builder.push(v); |
| self.finish_if_not_nested() |
| } |
| fn serialize_f32(self, v: f32) -> Result<Self::Ok, Self::Error> { |
| self.builder.push(v); |
| self.finish_if_not_nested() |
| } |
| fn serialize_f64(self, v: f64) -> Result<Self::Ok, Self::Error> { |
| self.builder.push(v); |
| self.finish_if_not_nested() |
| } |
| fn serialize_char(self, v: char) -> Result<Self::Ok, Self::Error> { |
| self.builder.push(v as u8); |
| self.finish_if_not_nested() |
| } |
| fn serialize_str(self, v: &str) -> Result<Self::Ok, Self::Error> { |
| self.builder.push(v); |
| self.finish_if_not_nested() |
| } |
| fn serialize_bytes(self, v: &[u8]) -> Result<Self::Ok, Self::Error> { |
| self.builder.push(crate::Blob(v)); |
| self.finish_if_not_nested() |
| } |
| fn serialize_none(self) -> Result<Self::Ok, Self::Error> { |
| self.builder.push(()); |
| self.finish_if_not_nested() |
| } |
| fn serialize_some<T: ?Sized>(self, t: &T) -> Result<Self::Ok, Self::Error> |
| where |
| T: Serialize, |
| { |
| t.serialize(self) |
| } |
| fn serialize_unit(self) -> Result<Self::Ok, Self::Error> { |
| self.builder.push(()); |
| self.finish_if_not_nested() |
| } |
| fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok, Self::Error> { |
| self.builder.push(()); |
| self.finish_if_not_nested() |
| } |
| fn serialize_unit_variant( |
| self, |
| _name: &'static str, |
| _variant_index: u32, |
| variant: &'static str, |
| ) -> Result<Self::Ok, Self::Error> { |
| self.builder.push(variant); |
| self.finish_if_not_nested() |
| } |
| fn serialize_newtype_struct<T: ?Sized>( |
| self, |
| _name: &'static str, |
| value: &T, |
| ) -> Result<Self::Ok, Self::Error> |
| where |
| T: Serialize, |
| { |
| value.serialize(self) |
| } |
| fn serialize_newtype_variant<T: ?Sized>( |
| self, |
| _name: &'static str, |
| _variant_index: u32, |
| variant: &'static str, |
| value: &T, |
| ) -> Result<Self::Ok, Self::Error> |
| where |
| T: Serialize, |
| { |
| self.start_map(); |
| self.builder.push_key(variant); |
| value.serialize(&mut *self)?; |
| self.end_map() |
| } |
| fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> { |
| self.start_vector(); |
| Ok(self) |
| } |
| fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, Self::Error> { |
| self.start_vector(); |
| Ok(self) |
| } |
| fn serialize_tuple_struct( |
| self, |
| _name: &'static str, |
| _len: usize, |
| ) -> Result<Self::SerializeTupleStruct, Self::Error> { |
| self.start_map(); |
| Ok(self) |
| } |
| fn serialize_tuple_variant( |
| self, |
| _name: &'static str, |
| _variant_index: u32, |
| variant: &'static str, |
| _len: usize, |
| ) -> Result<Self::SerializeTupleVariant, Self::Error> { |
| self.start_map(); |
| self.builder.push_key(variant); |
| self.start_vector(); |
| Ok(self) |
| } |
| fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> { |
| self.start_map(); |
| Ok(self) |
| } |
| fn serialize_struct( |
| self, |
| _name: &'static str, |
| _len: usize, |
| ) -> Result<Self::SerializeStruct, Self::Error> { |
| self.start_map(); |
| Ok(self) |
| } |
| fn serialize_struct_variant( |
| self, |
| _name: &'static str, |
| _variant_index: u32, |
| variant: &'static str, |
| _len: usize, |
| ) -> Result<Self::SerializeStructVariant, Self::Error> { |
| self.start_map(); |
| self.builder.push_key(variant); |
| self.start_map(); |
| Ok(self) |
| } |
| } |
| |
| fn key_must_be_a_string<T>() -> Result<T, Error> { |
| Err(Error::KeyMustBeString) |
| } |
| struct MapKeySerializer<'a>(&'a mut FlexbufferSerializer); |
| impl<'a> Serializer for MapKeySerializer<'a> { |
| type Ok = (); |
| type Error = Error; |
| #[inline] |
| fn serialize_str(self, value: &str) -> Result<(), Error> { |
| self.0.builder.push_key(value); |
| Ok(()) |
| } |
| #[inline] |
| fn serialize_unit_variant( |
| self, |
| _name: &'static str, |
| _variant_index: u32, |
| variant: &'static str, |
| ) -> Result<(), Error> { |
| self.0.builder.push_key(variant); |
| Ok(()) |
| } |
| #[inline] |
| fn serialize_newtype_struct<T: ?Sized>( |
| self, |
| _name: &'static str, |
| value: &T, |
| ) -> Result<(), Error> |
| where |
| T: Serialize, |
| { |
| value.serialize(self) |
| } |
| type SerializeSeq = Impossible<(), Error>; |
| type SerializeTuple = Impossible<(), Error>; |
| type SerializeTupleStruct = Impossible<(), Error>; |
| type SerializeTupleVariant = Impossible<(), Error>; |
| type SerializeMap = Impossible<(), Error>; |
| type SerializeStruct = Impossible<(), Error>; |
| type SerializeStructVariant = Impossible<(), Error>; |
| |
| fn serialize_bool(self, _value: bool) -> Result<(), Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_i8(self, _value: i8) -> Result<(), Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_i16(self, _value: i16) -> Result<(), Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_i32(self, _value: i32) -> Result<(), Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_i64(self, _value: i64) -> Result<(), Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_u8(self, _value: u8) -> Result<(), Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_u16(self, _value: u16) -> Result<(), Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_u32(self, _value: u32) -> Result<(), Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_u64(self, _value: u64) -> Result<(), Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_f32(self, _value: f32) -> Result<(), Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_f64(self, _value: f64) -> Result<(), Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_char(self, _value: char) -> Result<(), Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_bytes(self, _value: &[u8]) -> Result<(), Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_unit(self) -> Result<(), Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_unit_struct(self, _name: &'static str) -> Result<(), Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_newtype_variant<T: ?Sized>( |
| self, |
| _name: &'static str, |
| _variant_index: u32, |
| _variant: &'static str, |
| _value: &T, |
| ) -> Result<(), Error> |
| where |
| T: Serialize, |
| { |
| key_must_be_a_string() |
| } |
| fn serialize_none(self) -> Result<(), Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_some<T: ?Sized>(self, _value: &T) -> Result<(), Error> |
| where |
| T: Serialize, |
| { |
| key_must_be_a_string() |
| } |
| fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_tuple_struct( |
| self, |
| _name: &'static str, |
| _len: usize, |
| ) -> Result<Self::SerializeTupleStruct, Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_tuple_variant( |
| self, |
| _name: &'static str, |
| _variant_index: u32, |
| _variant: &'static str, |
| _len: usize, |
| ) -> Result<Self::SerializeTupleVariant, Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_struct( |
| self, |
| _name: &'static str, |
| _len: usize, |
| ) -> Result<Self::SerializeStruct, Error> { |
| key_must_be_a_string() |
| } |
| fn serialize_struct_variant( |
| self, |
| _name: &'static str, |
| _variant_index: u32, |
| _variant: &'static str, |
| _len: usize, |
| ) -> Result<Self::SerializeStructVariant, Error> { |
| key_must_be_a_string() |
| } |
| } |