steganography_lib/
errors.rs

1use std::{error::Error, fmt::Display};
2
3pub type Result<T> = std::result::Result<T, ErrorKind>;
4
5#[derive(Debug)]
6pub enum ErrorKind {
7    SysIOError(std::io::Error),
8    PngDecodingError(png::DecodingError),
9    PngEncodingError(png::EncodingError),
10
11    DataTooLarge(usize, usize),
12    HashMismatch(u64, u64),
13
14    TransformationError(Box<dyn Error>),
15}
16
17impl Display for ErrorKind {
18    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
19        match self {
20            Self::SysIOError(_) => write!(f, "failed to perform I/O by system"),
21            Self::PngDecodingError(_) => write!(f, "failed to decode PNG image"),
22            Self::PngEncodingError(_) => write!(f, "failed to encode PNG image"),
23            Self::DataTooLarge(actual, available) => write!(
24                f,
25                "cannot fit {} bits in {} bytes available",
26                actual, available
27            ),
28            Self::HashMismatch(expected, actual) => {
29                write!(f, "expecting hash '{}', found '{}'", expected, actual)
30            }
31            Self::TransformationError(e) => write!(f, "{}", e),
32        }
33    }
34}
35
36impl Error for ErrorKind {
37    fn source(&self) -> Option<&(dyn Error + 'static)> {
38        match self {
39            Self::SysIOError(e) => Some(e),
40            Self::PngDecodingError(e) => Some(e),
41            Self::PngEncodingError(e) => Some(e),
42            Self::DataTooLarge(_, _) | Self::HashMismatch(_, _) => None,
43            Self::TransformationError(e) => Some(e.as_ref()),
44        }
45    }
46}
steganography_lib/errors.rs

steganography_lib/
errors.rs
