use leb128::{self, read_signed_leb128, write_signed_leb128};
use std::borrow::Cow;
use serialize;
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, $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(unsafe { ::std::mem::transmute(bits) })
}
#[inline]
fn read_f32(&mut self) -> Result<f32, Self::Error> {
let bits = self.read_u32()?;
Ok(unsafe { ::std::mem::transmute(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()
}
}
#[cfg(test)]
mod tests {
use serialize::{Encodable, Decodable};
use std::fmt::Debug;
use super::{Encoder, Decoder};
#[derive(PartialEq, Clone, Debug, RustcEncodable, RustcDecodable)]
struct Struct {
a: (),
b: u8,
c: u16,
d: u32,
e: u64,
f: usize,
g: i8,
h: i16,
i: i32,
j: i64,
k: isize,
l: char,
m: String,
n: f32,
o: f64,
p: bool,
q: Option<u32>,
}
fn check_round_trip<T: Encodable + Decodable + PartialEq + Debug>(values: Vec<T>) {
let mut encoder = Encoder::new(Vec::new());
for value in &values {
Encodable::encode(&value, &mut encoder).unwrap();
}
let data = encoder.into_inner();
let mut decoder = Decoder::new(&data[..], 0);
for value in values {
let decoded = Decodable::decode(&mut decoder).unwrap();
assert_eq!(value, decoded);
}
}
#[test]
fn test_unit() {
check_round_trip(vec![(), (), (), ()]);
}
#[test]
fn test_u8() {
let mut vec = vec![];
for i in ::std::u8::MIN..::std::u8::MAX {
vec.push(i);
}
check_round_trip(vec);
}
#[test]
fn test_u16() {
for i in ::std::u16::MIN..::std::u16::MAX {
check_round_trip(vec![1, 2, 3, i, i, i]);
}
}
#[test]
fn test_u32() {
check_round_trip(vec![1, 2, 3, ::std::u32::MIN, 0, 1, ::std::u32::MAX, 2, 1]);
}
#[test]
fn test_u64() {
check_round_trip(vec![1, 2, 3, ::std::u64::MIN, 0, 1, ::std::u64::MAX, 2, 1]);
}
#[test]
fn test_usize() {
check_round_trip(vec![1, 2, 3, ::std::usize::MIN, 0, 1, ::std::usize::MAX, 2, 1]);
}
#[test]
fn test_i8() {
let mut vec = vec![];
for i in ::std::i8::MIN..::std::i8::MAX {
vec.push(i);
}
check_round_trip(vec);
}
#[test]
fn test_i16() {
for i in ::std::i16::MIN..::std::i16::MAX {
check_round_trip(vec![-1, 2, -3, i, i, i, 2]);
}
}
#[test]
fn test_i32() {
check_round_trip(vec![-1, 2, -3, ::std::i32::MIN, 0, 1, ::std::i32::MAX, 2, 1]);
}
#[test]
fn test_i64() {
check_round_trip(vec![-1, 2, -3, ::std::i64::MIN, 0, 1, ::std::i64::MAX, 2, 1]);
}
#[test]
fn test_isize() {
check_round_trip(vec![-1, 2, -3, ::std::isize::MIN, 0, 1, ::std::isize::MAX, 2, 1]);
}
#[test]
fn test_bool() {
check_round_trip(vec![false, true, true, false, false]);
}
#[test]
fn test_f32() {
let mut vec = vec![];
for i in -100..100 {
vec.push((i as f32) / 3.0);
}
check_round_trip(vec);
}
#[test]
fn test_f64() {
let mut vec = vec![];
for i in -100..100 {
vec.push((i as f64) / 3.0);
}
check_round_trip(vec);
}
#[test]
fn test_char() {
let vec = vec!['a', 'b', 'c', 'd', 'A', 'X', ' ', '#', 'Ö', 'Ä', 'µ', '€'];
check_round_trip(vec);
}
#[test]
fn test_string() {
let vec = vec!["abcbuÖeiovÄnameÜavmpßvmea€µsbpnvapeapmaebn".to_string(),
"abcbuÖganeiovÄnameÜavmpßvmea€µsbpnvapeapmaebn".to_string(),
"abcbuÖganeiovÄnameÜavmpßvmea€µsbpapmaebn".to_string(),
"abcbuÖganeiovÄnameÜavmpßvmeabpnvapeapmaebn".to_string(),
"abcbuÖganeiÄnameÜavmpßvmea€µsbpnvapeapmaebn".to_string(),
"abcbuÖganeiovÄnameÜavmpßvmea€µsbpmaebn".to_string(),
"abcbuÖganeiovÄnameÜavmpßvmea€µnvapeapmaebn".to_string()];
check_round_trip(vec);
}
#[test]
fn test_option() {
check_round_trip(vec![Some(-1i8)]);
check_round_trip(vec![Some(-2i16)]);
check_round_trip(vec![Some(-3i32)]);
check_round_trip(vec![Some(-4i64)]);
check_round_trip(vec![Some(-5isize)]);
let none_i8: Option<i8> = None;
check_round_trip(vec![none_i8]);
let none_i16: Option<i16> = None;
check_round_trip(vec![none_i16]);
let none_i32: Option<i32> = None;
check_round_trip(vec![none_i32]);
let none_i64: Option<i64> = None;
check_round_trip(vec![none_i64]);
let none_isize: Option<isize> = None;
check_round_trip(vec![none_isize]);
}
#[test]
fn test_struct() {
check_round_trip(vec![Struct {
a: (),
b: 10,
c: 11,
d: 12,
e: 13,
f: 14,
g: 15,
h: 16,
i: 17,
j: 18,
k: 19,
l: 'x',
m: "abc".to_string(),
n: 20.5,
o: 21.5,
p: false,
q: None,
}]);
check_round_trip(vec![Struct {
a: (),
b: 101,
c: 111,
d: 121,
e: 131,
f: 141,
g: -15,
h: -16,
i: -17,
j: -18,
k: -19,
l: 'y',
m: "def".to_string(),
n: -20.5,
o: -21.5,
p: true,
q: Some(1234567),
}]);
}
#[derive(PartialEq, Clone, Debug, RustcEncodable, RustcDecodable)]
enum Enum {
Variant1,
Variant2(usize, f32),
Variant3 {
a: i32,
b: char,
c: bool,
},
}
#[test]
fn test_enum() {
check_round_trip(vec![Enum::Variant1,
Enum::Variant2(1, 2.5),
Enum::Variant3 {
a: 3,
b: 'b',
c: false,
},
Enum::Variant3 {
a: -4,
b: 'f',
c: true,
}]);
}
#[test]
fn test_sequence() {
let mut vec = vec![];
for i in -100i64..100i64 {
vec.push(i * 100000);
}
check_round_trip(vec![vec]);
}
#[test]
fn test_hash_map() {
use std::collections::HashMap;
let mut map = HashMap::new();
for i in -100i64..100i64 {
map.insert(i * 100000, i * 10000);
}
check_round_trip(vec![map]);
}
#[test]
fn test_tuples() {
check_round_trip(vec![('x', (), false, 0.5f32)]);
check_round_trip(vec![(9i8, 10u16, 1.5f64)]);
check_round_trip(vec![(-12i16, 11u8, 12usize)]);
check_round_trip(vec![(1234567isize, 100000000000000u64, 99999999999999i64)]);
check_round_trip(vec![(String::new(), "some string".to_string())]);
}
}