kevy_store/
error.rs

1//! [`KevyError`] — the single error type of the embeddable stack.
2//!
3//! Defined here because `kevy-store` sits at the bottom of every
4//! consumer's dependency graph (kevy-embedded, kevy-client, kevy-persist,
5//! kevy-rt and the server all already depend on it) and is the source of
6//! the dominant structured error, [`StoreError`]. Hosting the unified
7//! type here adds no dependency edge anywhere; the protocol crate
8//! (`kevy-resp`) hosting it would require a protocol → store edge.
9
10#[cfg(not(feature = "std"))]
11use crate::nostd_prelude::*;
12use crate::StoreError;
13use core::fmt;
14#[cfg(feature = "std")]
15use std::io;
16
17/// Unified result alias over [`KevyError`].
18pub type KevyResult<T> = core::result::Result<T, KevyError>;
19
20/// The error type of the embeddable stack: `kevy_embedded::Store` and
21/// `kevy_client::Connection` surfaces return `Result<_, KevyError>`.
22///
23/// Structured errors stay structured — a wrong-type write arrives as
24/// `KevyError::Store(StoreError::WrongType)`, not as stringly `io::Error`
25/// text. `From<io::Error>` / `From<StoreError>` keep `?` ergonomic at
26/// both the OS boundary and the store boundary.
27#[derive(Debug)]
28pub enum KevyError {
29    /// Structured store-semantic error (wrong type, non-integer,
30    /// overflow, out-of-memory, …).
31    Store(StoreError),
32    /// Operating-system / transport failure (file, socket, AOF).
33    #[cfg(feature = "std")]
34    Io(io::Error),
35    /// RESP-level failure on a client link: a server error reply
36    /// (`-ERR …` text preserved verbatim) or a malformed / unexpected
37    /// reply shape.
38    Protocol(String),
39    /// Write rejected: the target is a read-only replica.
40    ReadOnly,
41    /// Invalid argument to a typed API (bad flag combination, empty
42    /// prefix, malformed URL, …). Rejected before touching any state.
43    InvalidInput(String),
44    /// A named object (index, view, required key) doesn't exist.
45    NotFound(String),
46    /// The operation isn't available on this backend or build.
47    Unsupported(String),
48    /// A bounded blocking call ran out its timeout.
49    TimedOut,
50    /// The connection / in-process bus is gone (EOF).
51    Closed,
52}
53
54impl fmt::Display for KevyError {
55    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
56        match self {
57            Self::Store(e) => write!(f, "store error: {e:?}"),
58            #[cfg(feature = "std")]
59            Self::Io(e) => write!(f, "io error: {e}"),
60            Self::Protocol(msg) => write!(f, "protocol error: {msg}"),
61            Self::ReadOnly => {
62                write!(f, "READONLY You can't write against a read only replica")
63            }
64            Self::InvalidInput(msg) => write!(f, "invalid input: {msg}"),
65            Self::NotFound(what) => write!(f, "not found: {what}"),
66            Self::Unsupported(msg) => write!(f, "unsupported: {msg}"),
67            Self::TimedOut => write!(f, "timed out"),
68            Self::Closed => write!(f, "connection closed"),
69        }
70    }
71}
72
73impl core::error::Error for KevyError {
74    fn source(&self) -> Option<&(dyn core::error::Error + 'static)> {
75        match self {
76            #[cfg(feature = "std")]
77            Self::Io(e) => Some(e),
78            _ => None,
79        }
80    }
81}
82
83impl From<StoreError> for KevyError {
84    fn from(e: StoreError) -> Self {
85        Self::Store(e)
86    }
87}
88
89#[cfg(feature = "std")]
90impl From<io::Error> for KevyError {
91    fn from(e: io::Error) -> Self {
92        Self::Io(e)
93    }
94}
kevy_store/error.rs

kevy_store/
error.rs
