max / balanced_breakfast

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1	//! What a database call can fail with.
2	//!
3	//! Two distinct failures, kept separate rather than flattened: the statement
4	//! itself (rusqlite) and getting a connection to run it on (r2d2). A pool
5	//! timeout says the app is saturated, which is a different thing to diagnose
6	//! than a constraint violation.
7
8	/// Why a repository call failed.
9	#[derive(Debug, thiserror::Error)]
10	pub enum DbError {
11	#[error("database error: {0}")]
12	Sqlite(#[from] rusqlite::Error),
13
14	#[error("could not check out a database connection: {0}")]
15	Pool(#[from] r2d2::Error),
16	}
17
18	impl DbError {
19	/// Whether this is rusqlite's "no rows returned" for a single-row query.
20	///
21	/// Repository methods that can legitimately find nothing return `Option`
22	/// instead, so this is for the callers that go around them.
23	#[must_use]
24	pub fn is_not_found(&self) -> bool {
25	matches!(self, Self::Sqlite(rusqlite::Error::QueryReturnedNoRows))
26	}
27	}
28
29	/// Why a database could not be opened.
30	///
31	/// r2d2's error type is opaque and cannot carry a rusqlite failure, so opening
32	/// the anchor connection and building the pool around it stay separate.
33	#[derive(Debug, thiserror::Error)]
34	pub enum OpenError {
35	#[error("could not open the database: {0}")]
36	Sqlite(#[from] rusqlite::Error),
37
38	#[error("could not build the connection pool: {0}")]
39	Pool(#[from] r2d2::Error),
40	}
41