pub trait Readable: Sized {
// Required method
fn take_from(b: &mut Reader<'_>) -> Result<Self>;
}Expand description
Trait for an object that can be extracted from a Reader.
Implement this trait in order to make an object that can (maybe) be decoded from a reader. Most code won’t need to call this directly, but will instead use it implicitly via the Reader::extract() method.
§Example
use tor_bytes::{Readable,Reader,Result};
#[derive(Debug, Eq, PartialEq)]
struct Message {
flags: u32,
cmd: u8
}
impl Readable for Message {
fn take_from(r: &mut Reader<'_>) -> Result<Self> {
// A "Message" is encoded as flags, then command.
let flags = r.take_u32()?;
let cmd = r.take_u8()?;
Ok(Message{ flags, cmd })
}
}
let encoded = [0x00, 0x00, 0x00, 0x43, 0x07 ];
let mut reader = Reader::from_slice(&encoded);
let m: Message = reader.extract()?;
assert_eq!(m, Message { flags: 0x43, cmd: 0x07 });
reader.should_be_exhausted()?; // make sure there are no bytes left overRequired Methods§
sourcefn take_from(b: &mut Reader<'_>) -> Result<Self>
fn take_from(b: &mut Reader<'_>) -> Result<Self>
Try to extract an object of this type from a Reader.
Implementations should generally try to be efficient: this is not the right place to check signatures or perform expensive operations. If you have an object that must not be used until it is finally validated, consider making this function return a wrapped type that can be unwrapped later on once it gets checked.
Object Safety§
This trait is not object safe.