qoi/
error.rs

1use core::convert::Infallible;
2use core::fmt::{self, Display};
3
4use crate::consts::QOI_MAGIC;
5
6/// Errors that can occur during encoding or decoding.
7#[derive(Debug)]
8pub enum Error {
9    /// Leading 4 magic bytes don't match when decoding
10    InvalidMagic { magic: u32 },
11    /// Invalid number of channels: expected 3 or 4
12    InvalidChannels { channels: u8 },
13    /// Invalid color space: expected 0 or 1
14    InvalidColorSpace { colorspace: u8 },
15    /// Invalid image dimensions: can't be empty or larger than 400Mp
16    InvalidImageDimensions { width: u32, height: u32 },
17    /// Image dimensions are inconsistent with image buffer length
18    InvalidImageLength { size: usize, width: u32, height: u32 },
19    /// Output buffer is too small to fit encoded/decoded image
20    OutputBufferTooSmall { size: usize, required: usize },
21    /// Input buffer ended unexpectedly before decoding was finished
22    UnexpectedBufferEnd,
23    /// Invalid stream end marker encountered when decoding
24    InvalidPadding,
25    /// Invalid stride
26    InvalidStride { stride: usize },
27    #[cfg(feature = "std")]
28    /// Generic I/O error from the wrapped reader/writer
29    IoError(std::io::Error),
30}
31
32/// Alias for [`Result`](std::result::Result) with the error type of [`Error`].
33pub type Result<T> = core::result::Result<T, Error>;
34
35impl Display for Error {
36    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
37        match *self {
38            Self::InvalidMagic { magic } => {
39                write!(f, "invalid magic: expected {:?}, got {:?}", QOI_MAGIC, magic.to_be_bytes())
40            }
41            Self::InvalidChannels { channels } => {
42                write!(f, "invalid number of channels: {channels}")
43            }
44            Self::InvalidColorSpace { colorspace } => {
45                write!(f, "invalid color space: {colorspace} (expected 0 or 1)")
46            }
47            Self::InvalidImageDimensions { width, height } => {
48                write!(f, "invalid image dimensions: {width}x{height}")
49            }
50            Self::InvalidImageLength { size, width, height } => {
51                write!(f, "invalid image length: {size} bytes for {width}x{height}")
52            }
53            Self::OutputBufferTooSmall { size, required } => {
54                write!(f, "output buffer size too small: {size} (required: {required})")
55            }
56            Self::UnexpectedBufferEnd => {
57                write!(f, "unexpected input buffer end while decoding")
58            }
59            Self::InvalidPadding => {
60                write!(f, "invalid padding (stream end marker mismatch)")
61            }
62            Self::InvalidStride { stride } => {
63                write!(f, "invalid stride: {stride}")
64            }
65            #[cfg(feature = "std")]
66            Self::IoError(ref err) => {
67                write!(f, "i/o error: {err}")
68            }
69        }
70    }
71}
72
73#[cfg(feature = "std")]
74impl std::error::Error for Error {}
75
76impl From<Infallible> for Error {
77    fn from(_: Infallible) -> Self {
78        unreachable!()
79    }
80}
81
82#[cfg(feature = "std")]
83impl From<std::io::Error> for Error {
84    fn from(err: std::io::Error) -> Self {
85        Self::IoError(err)
86    }
87}
qoi/error.rs

qoi/
error.rs
