tor_dirserver/
err.rs

1//! Error module for `tor-dirserver`.
2
3use thiserror::Error;
4
5/// An error while interacting with a database.
6///
7/// This error should be returned by all functions that interact with the
8/// database in one way or another.
9#[derive(Debug, Error)]
10#[non_exhaustive]
11pub(crate) enum DatabaseError {
12    /// A low-level SQLite error has occurred, which can have a bascially
13    /// infinite amount of reasons, all of them outlined in the actual SQLite
14    /// and [`rusqlite`] documentation.
15    #[error("low-level rusqlite error: {0}")]
16    LowLevel(#[from] rusqlite::Error),
17
18    /// This is an application level error meaning that the database can be
19    /// successfully accessed but its content implies it is of a schema version
20    /// we do not support.
21    ///
22    /// Keep in mind that an unrecognized schema is not equal to no schema.
23    /// In the latter case we actually initialize the database, whereas in the
24    /// previous one, we fail early in order to not corrupt an existing database.
25    /// Future versions of this crate should continue with this promise in order
26    /// to ensure forward compatability.
27    #[error("incompatible schema version: {version}")]
28    IncompatibleSchema {
29        /// The incompatible schema version found in the database.
30        version: String,
31    },
32
33    /// Interaction with our database pool, [`r2d2`], has failed.
34    ///
35    /// Unlike other database pools, this error is fairly straightforward and
36    /// may only be obtained in the cases in which we try to obtain a connection
37    /// handle from the pool.  Notably, it does not fail if, for example,
38    /// the low-level [`rusqlite`] has a failure.
39    #[error("pool error: {0}")]
40    Pool(#[from] r2d2::Error),
41
42    /// An internal error.
43    #[error("Internal error")]
44    Bug(#[from] tor_error::Bug),
45}
46
47/// An unrecoverable error during daemon operation.
48///
49/// This error is inteded for functions that generally run forever, unless they
50/// encounter an error that is not recoverable, in which case, they will return
51/// this error type.
52#[derive(Debug, Error)]
53#[non_exhaustive]
54pub(crate) enum FatalError {
55    /// The selection of a consensus from the database has failed.
56    ///
57    /// This most likely indicates that something with the underlying database
58    /// is wrong in a persistent fashion, i.e. retries will not work anymore.
59    #[error("consensus selection error: {0}")]
60    ConsensusSelection(DatabaseError),
61}
tor_dirserver/err.rs

tor_dirserver/
err.rs
