read-restrict

Enforce a strict limit on the number of bytes read from a Read with an error when exceeded.

Synopsis

```rust pub trait ReadExt { fn restrict(self, restriction: u64) -> Restrict }

impl ReadExt for R {}

impl Restrict { pub fn restriction(&self) -> u64; pub fn setrestriction(&mut self, restriction: u64); pub fn intoinner(self) -> T; pub fn getref(&self) -> &T; pub fn getmut(&mut self) -> &mut T; }

impl Read for Restrict {} impl BufRead for Restrict {} ```

Description

This is a modified version of Rust's stdlib Read::take implementation which returns an error when its limit is exceeded. Reads operate as normal, bound strictly to the read limit, following which io::ErrorKind::InvalidData will be returned.

Example

```rust use std::io::{self, ErrorKind, Result}; use std::io::prelude::*; use std::fs::File; use read_restrict::ReadExt;

fn main() -> io::Result<()> { let f = File::open("foo.txt")?.restrict(5); let mut handle = f.restrict(5); let mut buf = [0; 8]; asserteq!(5, handle.read(&mut buf)?); // reads at most 5 bytes asserteq!(0, handle.restriction()); // is now exhausted asserteq!(ErrorKind::InvalidData, handle.read(&mut buf).unwraperr().kind()); Ok(()) } ```