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use std::io::{self, Write}; use std::fmt; use std::error; use std::{i32, i64}; use byteorder::{LittleEndian, WriteBytesExt}; use chrono::Timelike; use serde::ser::{self, Serialize}; use crate::value::Value; use crate::serde_impl::encode::Encoder; #[derive(Debug)] pub enum EncodeError { IoError(io::Error), InvalidMapKeyType(Value), Unknown(String), UnsupportedUnsignedType } impl From<io::Error> for EncodeError { fn from(err: io::Error) -> EncodeError { EncodeError::IoError(err) } } impl fmt::Display for EncodeError { fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { match *self { EncodeError::IoError(ref inner) => inner.fmt(fmt), EncodeError::InvalidMapKeyType(ref bson) => { write!(fmt, "Invalid map key type: {:?}", bson) } EncodeError::Unknown(ref inner) => inner.fmt(fmt), EncodeError::UnsupportedUnsignedType => write!(fmt, "bson does not support unsigned type"), } } } impl error::Error for EncodeError { fn description(&self) -> &str { match *self { EncodeError::IoError(ref inner) => inner.description(), EncodeError::InvalidMapKeyType(_) => "Invalid map key type", EncodeError::Unknown(ref inner) => inner, EncodeError::UnsupportedUnsignedType => "bson does not support unsigned type", } } fn cause(&self) -> Option<&dyn error::Error> { match *self { EncodeError::IoError(ref inner) => Some(inner), _ => None, } } } impl ser::Error for EncodeError { fn custom<T: fmt::Display>(msg: T) -> EncodeError { EncodeError::Unknown(msg.to_string()) } } pub type EncodeResult<T> = Result<T, EncodeError>; pub(crate) fn write_string(writer: &mut impl Write, s: &str) -> EncodeResult<()> { writer.write_i32::<LittleEndian>(s.len() as i32 + 1)?; writer.write_all(s.as_bytes())?; writer.write_u8(0)?; Ok(()) } pub(crate) fn write_cstring(writer: &mut impl Write, s: &str) -> EncodeResult<()> { writer.write_all(s.as_bytes())?; writer.write_u8(0)?; Ok(()) } #[inline] pub(crate) fn write_i32(writer: &mut impl Write, val: i32) -> EncodeResult<()> { writer.write_i32::<LittleEndian>(val).map_err(From::from) } #[inline] pub(crate) fn write_u32(writer: &mut impl Write, val: u32) -> EncodeResult<()> { writer.write_u32::<LittleEndian>(val).map_err(From::from) } #[inline] pub(crate) fn write_i64(writer: &mut impl Write, val: i64) -> EncodeResult<()> { writer.write_i64::<LittleEndian>(val).map_err(From::from) } #[inline] pub(crate) fn write_u64(writer: &mut impl Write, val: u64) -> EncodeResult<()> { writer.write_u64::<LittleEndian>(val).map_err(From::from) } #[inline] pub(crate) fn write_f32(writer: &mut impl Write, val: f32) -> EncodeResult<()> { writer.write_f32::<LittleEndian>(val).map_err(From::from) } #[inline] pub(crate) fn write_f64(writer: &mut impl Write, val: f64) -> EncodeResult<()> { writer.write_f64::<LittleEndian>(val).map_err(From::from) } fn encode_array(writer: &mut impl Write, arr: &[Value]) -> EncodeResult<()> { let mut buf = Vec::with_capacity(64); write_i32(&mut buf, 0)?; for (key, val) in arr.iter().enumerate() { encode_value(&mut buf, &key.to_string(), val)?; } buf.write_u8(0)?; let len_bytes = (buf.len() as i32).to_le_bytes(); buf[..4].clone_from_slice(&len_bytes); writer.write_all(&buf)?; Ok(()) } pub fn encode_value(writer: &mut impl Write, key: &str, val: &Value) -> EncodeResult<()> { writer.write_u8(val.element_type() as u8)?; write_cstring(writer, key)?; match *val { Value::F32(v) => write_f32(writer, v), Value::F64(v) => write_f64(writer, v), Value::I32(v) => write_i32(writer, v), Value::I64(v) => write_i64(writer, v), Value::U32(v) => write_u32(writer, v), Value::U64(v) => write_u64(writer, v), Value::String(ref s) => write_string(writer, s), Value::Array(ref a) => encode_array(writer, a), Value::Message(ref o) => encode_message(writer, o), Value::Boolean(b) => writer.write_u8(if b { 0x01 } else { 0x00 }).map_err(From::from), Value::Null => Ok(()), Value::Binary(ref data) => { write_i32(writer, data.len() as i32)?; writer.write_all(data).map_err(From::from) } Value::TimeStamp(v) => write_u64(writer, v), Value::UTCDatetime(ref v) => { write_i64( writer, (v.timestamp() * 1000) + i64::from(v.nanosecond() / 1_000_000) ) } Value::MessageId(ref id) => writer.write_all(&id.bytes()).map_err(From::from) } } pub fn encode_message<'a, S, D> (writer: &mut impl Write, message: D) -> EncodeResult<()> where S: AsRef<str> + 'a, D: IntoIterator<Item = (&'a S, &'a Value)> { let mut buf = Vec::with_capacity(64); write_i32(&mut buf, 0)?; for (key, val) in message { encode_value(&mut buf, key.as_ref(), val)?; } buf.write_u8(0)?; let len_bytes = (buf.len() as i32).to_le_bytes(); buf[..4].clone_from_slice(&len_bytes); writer.write_all(&buf)?; Ok(()) } pub fn to_nson<T: ?Sized>(value: &T) -> EncodeResult<Value> where T: Serialize { let ser = Encoder::new(); value.serialize(ser) } pub fn to_vec<T: ?Sized>(value: &T) -> EncodeResult<Vec<u8>> where T: Serialize { let bson = to_nson(value)?; if let Value::Message(msg) = bson { let mut buf: Vec<u8> = Vec::new(); encode_message(&mut buf, &msg)?; return Ok(buf) } Err(EncodeError::InvalidMapKeyType(bson)) } #[cfg(test)] mod test { use std::io::Cursor; use crate::encode::encode_message; use crate::decode::decode_message; use crate::msg; #[test] fn encode() { let msg = msg!{"aa": "bb", "cc": [1, 2, 3, 4]}; let mut buf: Vec<u8> = Vec::new(); encode_message(&mut buf, &msg).unwrap(); let mut reader = Cursor::new(buf); let msg2 = decode_message(&mut reader).unwrap(); assert_eq!(msg, msg2); } }