| use crate::leb128::{self, read_signed_leb128, write_signed_leb128}; |
| use crate::serialize; |
| use std::borrow::Cow; |
| |
| // ----------------------------------------------------------------------------- |
| // Encoder |
| // ----------------------------------------------------------------------------- |
| |
| pub type EncodeResult = Result<(), !>; |
| |
| pub struct Encoder { |
| pub data: Vec<u8>, |
| } |
| |
| impl Encoder { |
| pub fn new(data: Vec<u8>) -> Encoder { |
| Encoder { data } |
| } |
| |
| pub fn into_inner(self) -> Vec<u8> { |
| self.data |
| } |
| |
| #[inline] |
| pub fn emit_raw_bytes(&mut self, s: &[u8]) { |
| self.data.extend_from_slice(s); |
| } |
| } |
| |
| macro_rules! write_uleb128 { |
| ($enc:expr, $value:expr, $fun:ident) => {{ |
| leb128::$fun(&mut $enc.data, $value); |
| Ok(()) |
| }} |
| } |
| |
| macro_rules! write_sleb128 { |
| ($enc:expr, $value:expr) => {{ |
| write_signed_leb128(&mut $enc.data, $value as i128); |
| Ok(()) |
| }} |
| } |
| |
| impl serialize::Encoder for Encoder { |
| type Error = !; |
| |
| #[inline] |
| fn emit_unit(&mut self) -> EncodeResult { |
| Ok(()) |
| } |
| |
| #[inline] |
| fn emit_usize(&mut self, v: usize) -> EncodeResult { |
| write_uleb128!(self, v, write_usize_leb128) |
| } |
| |
| #[inline] |
| fn emit_u128(&mut self, v: u128) -> EncodeResult { |
| write_uleb128!(self, v, write_u128_leb128) |
| } |
| |
| #[inline] |
| fn emit_u64(&mut self, v: u64) -> EncodeResult { |
| write_uleb128!(self, v, write_u64_leb128) |
| } |
| |
| #[inline] |
| fn emit_u32(&mut self, v: u32) -> EncodeResult { |
| write_uleb128!(self, v, write_u32_leb128) |
| } |
| |
| #[inline] |
| fn emit_u16(&mut self, v: u16) -> EncodeResult { |
| write_uleb128!(self, v, write_u16_leb128) |
| } |
| |
| #[inline] |
| fn emit_u8(&mut self, v: u8) -> EncodeResult { |
| self.data.push(v); |
| Ok(()) |
| } |
| |
| #[inline] |
| fn emit_isize(&mut self, v: isize) -> EncodeResult { |
| write_sleb128!(self, v) |
| } |
| |
| #[inline] |
| fn emit_i128(&mut self, v: i128) -> EncodeResult { |
| write_sleb128!(self, v) |
| } |
| |
| #[inline] |
| fn emit_i64(&mut self, v: i64) -> EncodeResult { |
| write_sleb128!(self, v) |
| } |
| |
| #[inline] |
| fn emit_i32(&mut self, v: i32) -> EncodeResult { |
| write_sleb128!(self, v) |
| } |
| |
| #[inline] |
| fn emit_i16(&mut self, v: i16) -> EncodeResult { |
| write_sleb128!(self, v) |
| } |
| |
| #[inline] |
| fn emit_i8(&mut self, v: i8) -> EncodeResult { |
| let as_u8: u8 = unsafe { ::std::mem::transmute(v) }; |
| self.emit_u8(as_u8) |
| } |
| |
| #[inline] |
| fn emit_bool(&mut self, v: bool) -> EncodeResult { |
| self.emit_u8(if v { |
| 1 |
| } else { |
| 0 |
| }) |
| } |
| |
| #[inline] |
| fn emit_f64(&mut self, v: f64) -> EncodeResult { |
| let as_u64: u64 = unsafe { ::std::mem::transmute(v) }; |
| self.emit_u64(as_u64) |
| } |
| |
| #[inline] |
| fn emit_f32(&mut self, v: f32) -> EncodeResult { |
| let as_u32: u32 = unsafe { ::std::mem::transmute(v) }; |
| self.emit_u32(as_u32) |
| } |
| |
| #[inline] |
| fn emit_char(&mut self, v: char) -> EncodeResult { |
| self.emit_u32(v as u32) |
| } |
| |
| #[inline] |
| fn emit_str(&mut self, v: &str) -> EncodeResult { |
| self.emit_usize(v.len())?; |
| self.emit_raw_bytes(v.as_bytes()); |
| Ok(()) |
| } |
| } |
| |
| impl Encoder { |
| #[inline] |
| pub fn position(&self) -> usize { |
| self.data.len() |
| } |
| } |
| |
| // ----------------------------------------------------------------------------- |
| // Decoder |
| // ----------------------------------------------------------------------------- |
| |
| pub struct Decoder<'a> { |
| pub data: &'a [u8], |
| position: usize, |
| } |
| |
| impl<'a> Decoder<'a> { |
| #[inline] |
| pub fn new(data: &'a [u8], position: usize) -> Decoder<'a> { |
| Decoder { |
| data, |
| position, |
| } |
| } |
| |
| #[inline] |
| pub fn position(&self) -> usize { |
| self.position |
| } |
| |
| #[inline] |
| pub fn set_position(&mut self, pos: usize) { |
| self.position = pos |
| } |
| |
| #[inline] |
| pub fn advance(&mut self, bytes: usize) { |
| self.position += bytes; |
| } |
| |
| #[inline] |
| pub fn read_raw_bytes(&mut self, s: &mut [u8]) -> Result<(), String> { |
| let start = self.position; |
| let end = start + s.len(); |
| |
| s.copy_from_slice(&self.data[start..end]); |
| |
| self.position = end; |
| |
| Ok(()) |
| } |
| } |
| |
| macro_rules! read_uleb128 { |
| ($dec:expr, $t:ty, $fun:ident) => ({ |
| let (value, bytes_read) = leb128::$fun(&$dec.data[$dec.position ..]); |
| $dec.position += bytes_read; |
| Ok(value) |
| }) |
| } |
| |
| macro_rules! read_sleb128 { |
| ($dec:expr, $t:ty) => ({ |
| let (value, bytes_read) = read_signed_leb128($dec.data, $dec.position); |
| $dec.position += bytes_read; |
| Ok(value as $t) |
| }) |
| } |
| |
| |
| impl<'a> serialize::Decoder for Decoder<'a> { |
| type Error = String; |
| |
| #[inline] |
| fn read_nil(&mut self) -> Result<(), Self::Error> { |
| Ok(()) |
| } |
| |
| #[inline] |
| fn read_u128(&mut self) -> Result<u128, Self::Error> { |
| read_uleb128!(self, u128, read_u128_leb128) |
| } |
| |
| #[inline] |
| fn read_u64(&mut self) -> Result<u64, Self::Error> { |
| read_uleb128!(self, u64, read_u64_leb128) |
| } |
| |
| #[inline] |
| fn read_u32(&mut self) -> Result<u32, Self::Error> { |
| read_uleb128!(self, u32, read_u32_leb128) |
| } |
| |
| #[inline] |
| fn read_u16(&mut self) -> Result<u16, Self::Error> { |
| read_uleb128!(self, u16, read_u16_leb128) |
| } |
| |
| #[inline] |
| fn read_u8(&mut self) -> Result<u8, Self::Error> { |
| let value = self.data[self.position]; |
| self.position += 1; |
| Ok(value) |
| } |
| |
| #[inline] |
| fn read_usize(&mut self) -> Result<usize, Self::Error> { |
| read_uleb128!(self, usize, read_usize_leb128) |
| } |
| |
| #[inline] |
| fn read_i128(&mut self) -> Result<i128, Self::Error> { |
| read_sleb128!(self, i128) |
| } |
| |
| #[inline] |
| fn read_i64(&mut self) -> Result<i64, Self::Error> { |
| read_sleb128!(self, i64) |
| } |
| |
| #[inline] |
| fn read_i32(&mut self) -> Result<i32, Self::Error> { |
| read_sleb128!(self, i32) |
| } |
| |
| #[inline] |
| fn read_i16(&mut self) -> Result<i16, Self::Error> { |
| read_sleb128!(self, i16) |
| } |
| |
| #[inline] |
| fn read_i8(&mut self) -> Result<i8, Self::Error> { |
| let as_u8 = self.data[self.position]; |
| self.position += 1; |
| unsafe { Ok(::std::mem::transmute(as_u8)) } |
| } |
| |
| #[inline] |
| fn read_isize(&mut self) -> Result<isize, Self::Error> { |
| read_sleb128!(self, isize) |
| } |
| |
| #[inline] |
| fn read_bool(&mut self) -> Result<bool, Self::Error> { |
| let value = self.read_u8()?; |
| Ok(value != 0) |
| } |
| |
| #[inline] |
| fn read_f64(&mut self) -> Result<f64, Self::Error> { |
| let bits = self.read_u64()?; |
| Ok(f64::from_bits(bits)) |
| } |
| |
| #[inline] |
| fn read_f32(&mut self) -> Result<f32, Self::Error> { |
| let bits = self.read_u32()?; |
| Ok(f32::from_bits(bits)) |
| } |
| |
| #[inline] |
| fn read_char(&mut self) -> Result<char, Self::Error> { |
| let bits = self.read_u32()?; |
| Ok(::std::char::from_u32(bits).unwrap()) |
| } |
| |
| #[inline] |
| fn read_str(&mut self) -> Result<Cow<'_, str>, Self::Error> { |
| let len = self.read_usize()?; |
| let s = ::std::str::from_utf8(&self.data[self.position..self.position + len]).unwrap(); |
| self.position += len; |
| Ok(Cow::Borrowed(s)) |
| } |
| |
| #[inline] |
| fn error(&mut self, err: &str) -> Self::Error { |
| err.to_string() |
| } |
| } |