use crate::leb128::{self, read_signed_leb128, write_signed_leb128};
use crate::serialize;
use std::borrow::Cow;
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()
}
}
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, $fun:ident) => {{
let (value, bytes_read) = leb128::$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, read_u128_leb128)
}
#[inline]
fn read_u64(&mut self) -> Result<u64, Self::Error> {
read_uleb128!(self, read_u64_leb128)
}
#[inline]
fn read_u32(&mut self) -> Result<u32, Self::Error> {
read_uleb128!(self, read_u32_leb128)
}
#[inline]
fn read_u16(&mut self) -> Result<u16, Self::Error> {
read_uleb128!(self, 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, 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()
}
}