kcp_io/core/
error.rs

1//! Error types for KCP operations.
2//!
3//! Defines [`KcpError`] which covers all failure modes of the KCP protocol
4//! engine, and [`KcpResult<T>`] as a convenient type alias.
5
6use thiserror::Error;
7
8/// Error type for KCP protocol operations.
9///
10/// Each variant maps to a specific failure condition when interacting with
11/// the underlying KCP C library through the safe [`Kcp`](super::Kcp) wrapper.
12#[derive(Debug, Error)]
13pub enum KcpError {
14    /// Failed to create a KCP instance (e.g., `ikcp_create` returned null).
15    #[error("failed to create KCP instance")]
16    CreateFailed,
17    /// Failed to send data through KCP. The inner value is the C error code.
18    #[error("send failed (error code: {0})")]
19    SendFailed(i32),
20    /// No data is available to receive right now. This is not a fatal error;
21    /// the caller should retry after feeding more input data and calling `update()`.
22    #[error("no data available to receive (would block)")]
23    RecvWouldBlock,
24    /// The provided receive buffer is too small for the next message.
25    #[error("receive buffer too small (need {need} bytes, got {got} bytes)")]
26    RecvBufferTooSmall {
27        /// The size of the next available message.
28        need: usize,
29        /// The size of the buffer that was provided.
30        got: usize,
31    },
32    /// A generic receive failure with the C error code.
33    #[error("recv failed (error code: {0})")]
34    RecvFailed(i32),
35    /// Failed to feed input data to the KCP engine (e.g., corrupted packet).
36    #[error("input failed (error code: {0})")]
37    InputFailed(i32),
38    /// Failed to set the MTU to the specified value.
39    #[error("failed to set MTU to {mtu} (error code: {code})")]
40    SetMtuFailed {
41        /// The MTU value that was attempted.
42        mtu: u32,
43        /// The C error code returned.
44        code: i32,
45    },
46    /// An invalid configuration parameter was provided.
47    #[error("invalid configuration: {0}")]
48    InvalidConfig(String),
49    /// The conversation ID in the received packet does not match the expected one.
50    #[error("conversation ID mismatch (expected {expected}, got {got})")]
51    ConvMismatch {
52        /// The expected conversation ID.
53        expected: u32,
54        /// The conversation ID found in the packet.
55        got: u32,
56    },
57    /// An I/O error occurred in the output callback.
58    #[error("output callback I/O error: {0}")]
59    OutputError(#[from] std::io::Error),
60}
61
62/// A convenience type alias for `Result<T, KcpError>`.
63pub type KcpResult<T> = Result<T, KcpError>;
kcp_io/core/error.rs

kcp_io/core/
error.rs
