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use std::{borrow::Cow, error::Error as StdError, fmt, path::Path, sync::Arc};
use futures::lock::{Mutex, MutexGuard};
use rusqlite::{Connection, Row, ToSql};
pub use rusqlite::{Error as RsqlError, params};
#[derive(Clone, Debug)]
pub struct DatabaseHandle {
connection: Arc<Mutex<Connection>>,
}
impl DatabaseHandle {
pub fn new(connection: Connection) -> Self {
Self {
connection: Arc::new(Mutex::new(connection)),
}
}
pub fn open(path: &Path) -> Result<Self, rusqlite::Error> {
Connection::open(path).map(|c| Self {
connection: Arc::new(Mutex::new(c)),
})
}
pub async fn lock<'db>(&'db self) -> DatabaseLock<'db> {
DatabaseLock {
guard: self.connection.lock().await,
}
}
}
pub struct DatabaseLock<'db> {
guard: MutexGuard<'db, Connection>,
}
impl<'db> DatabaseLock<'db> {
pub fn insert<SQL: Into<Cow<'static, str>>>(
&self,
sql: SQL,
params: &[&dyn ToSql],
) -> Result<(), DatabaseError> {
let query = sql.into();
let mut vec = vec![];
for parm in params.iter() {
vec.push(parm as &dyn ToSql);
}
match self.guard.execute(query.as_ref(), vec.as_slice()) {
Err(sqle) => Err(DatabaseError::sqlerror_with_context(sqle, "insert")),
Ok(_) => Ok(()),
}
}
pub fn query_one<SQL: Into<Cow<'static, str>>, T, F>(
&self,
sql: SQL,
params: &[&dyn ToSql],
f: F,
) -> Result<T, DatabaseError>
where
F: Fn(&Row<'_>) -> Result<T, DatabaseError>,
{
let query = sql.into();
let mut stmt = self
.guard
.prepare(&query)
.map_err(|err| DatabaseError::sqlerror_with_context(err, "prepare for select"))?;
match stmt.query(params) {
Ok(mut rows) => {
let mut result: Option<T> = None;
while let Some(row) = rows
.next()
.map_err(|err| DatabaseError::sqlerror_with_context(err, "select"))?
{
if result.is_none() {
result = Some(f(row).map_err(|e| e.with_context("select"))?);
} else {
return Err(DatabaseError::TooManyRows);
}
}
match result {
Some(t) => Ok(t),
None => Err(DatabaseError::NoRows),
}
}
Err(err) => Err(DatabaseError::sqlerror_with_context(err, "select")),
}
}
pub fn create_table<SQL: Into<Cow<'static, str>>>(
&self,
tablename: &'static str,
sql: SQL,
) -> Result<(), DatabaseError> {
let query = sql.into();
match self.guard.execute(query.as_ref(), rusqlite::params![]) {
Err(err) => Err(DatabaseError::CreateTableFailed {
table: tablename,
err,
}),
Ok(_) => Ok(()),
}
}
pub fn execute<SQL: Into<Cow<'static, str>>>(
&self,
sql: SQL,
params: &[&dyn ToSql],
) -> Result<(), DatabaseError> {
let query = sql.into();
self.guard.execute(query.as_ref(), params)?;
Ok(())
}
}
#[derive(Debug)]
pub enum DatabaseError {
CreateTableFailed {
table: &'static str,
err: RsqlError,
},
SqliteError {
context: Option<&'static str>,
err: RsqlError,
},
NoRows,
TooManyRows,
}
impl StdError for DatabaseError {}
impl DatabaseError {
pub fn sqlerror_with_context(sqle: RsqlError, context: &'static str) -> Self {
Self::SqliteError {
context: Some(context),
err: sqle,
}
}
/// Adds context to an SqliteError, or does nothing if it's another variant
pub fn with_context(self, context: &'static str) -> Self {
if let Self::SqliteError { context: None, err } = self {
DatabaseError::SqliteError {
context: Some(context),
err,
}
} else {
self
}
}
}
impl fmt::Display for DatabaseError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
Self::CreateTableFailed { table, err } => {
write!(f, "failed to create table {table}: {err}")
}
Self::SqliteError { context, err } => match context {
None => write!(f, "rusqlite error: {err}"),
Some(ctx) => write!(f, "rusqlite error ({ctx}): {err}"),
},
Self::NoRows => write!(f, "query returned no rows"),
Self::TooManyRows => write!(f, "query returned too many rows"),
}
}
}
impl From<RsqlError> for DatabaseError {
fn from(sqle: RsqlError) -> Self {
DatabaseError::SqliteError {
context: None,
err: sqle,
}
}
}
|
