rust-bitcoin-unsafe-fast/bitcoin/src/consensus/mod.rs

107 lines
3.8 KiB
Rust

// SPDX-License-Identifier: CC0-1.0
//! Bitcoin consensus.
//!
//! This module defines structures, functions, and traits that are needed to
//! conform to Bitcoin consensus.
pub mod encode;
mod error;
#[cfg(feature = "serde")]
pub mod serde;
use core::fmt;
use io::{BufRead, Read};
use crate::consensus;
#[rustfmt::skip] // Keep public re-exports separate.
#[doc(inline)]
pub use self::{
encode::{deserialize, deserialize_partial, serialize, Decodable, Encodable, ReadExt, WriteExt},
error::{Error, FromHexError, DecodeError, ParseError, DeserializeError},
};
pub(crate) use self::error::parse_failed_error;
struct IterReader<E: fmt::Debug, I: Iterator<Item = Result<u8, E>>> {
iterator: core::iter::Fuse<I>,
buf: Option<u8>,
error: Option<E>,
}
impl<E: fmt::Debug, I: Iterator<Item = Result<u8, E>>> IterReader<E, I> {
pub(crate) fn new(iterator: I) -> Self {
IterReader { iterator: iterator.fuse(), buf: None, error: None }
}
fn decode<T: Decodable>(mut self) -> Result<T, DecodeError<E>> {
let result = T::consensus_decode(&mut self);
match (result, self.error) {
(Ok(_), None) if self.iterator.next().is_some() => Err(DecodeError::Unconsumed),
(Ok(value), None) => Ok(value),
(Ok(_), Some(error)) => panic!("{} silently ate the error: {:?}", core::any::type_name::<T>(), error),
(Err(consensus::encode::Error::Io(io_error)), Some(de_error)) if io_error.kind() == io::ErrorKind::Other && io_error.get_ref().is_none() => Err(DecodeError::Other(de_error)),
(Err(consensus::encode::Error::Parse(parse_error)), None) => Err(DecodeError::Parse(parse_error)),
(Err(consensus::encode::Error::Io(io_error)), de_error) => panic!("unexpected IO error {:?} returned from {}::consensus_decode(), deserialization error: {:?}", io_error, core::any::type_name::<T>(), de_error),
(Err(consensus_error), Some(de_error)) => panic!("{} should've returned `Other` IO error because of deserialization error {:?} but it returned consensus error {:?} instead", core::any::type_name::<T>(), de_error, consensus_error),
}
}
}
impl<E: fmt::Debug, I: Iterator<Item = Result<u8, E>>> Read for IterReader<E, I> {
fn read(&mut self, mut buf: &mut [u8]) -> io::Result<usize> {
let mut count = 0;
if buf.is_empty() {
return Ok(0);
}
if let Some(first) = self.buf.take() {
buf[0] = first;
buf = &mut buf[1..];
count += 1;
}
for (dst, src) in buf.iter_mut().zip(&mut self.iterator) {
match src {
Ok(byte) => *dst = byte,
Err(error) => {
self.error = Some(error);
return Err(io::ErrorKind::Other.into());
}
}
// bounded by the length of buf
count += 1;
}
Ok(count)
}
}
impl<E: fmt::Debug, I: Iterator<Item = Result<u8, E>>> BufRead for IterReader<E, I> {
fn fill_buf(&mut self) -> Result<&[u8], io::Error> {
// matching on reference rather than using `ref` confuses borrow checker
if let Some(ref byte) = self.buf {
Ok(core::slice::from_ref(byte))
} else {
match self.iterator.next() {
Some(Ok(byte)) => {
self.buf = Some(byte);
Ok(core::slice::from_ref(self.buf.as_ref().expect("we've just filled it")))
}
Some(Err(error)) => {
self.error = Some(error);
Err(io::ErrorKind::Other.into())
}
None => Ok(&[]),
}
}
}
fn consume(&mut self, len: usize) {
debug_assert!(len <= 1);
if len > 0 {
self.buf = None;
}
}
}