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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
use rusqlite::{self, CachedStatement, Connection, Statement};
use std::ops::{Deref, DerefMut};
/// MaybeCached is a type that can be used to help abstract
/// over cached and uncached rusqlite statements in a transparent manner.
pub enum MaybeCached<'conn> {
Uncached(Statement<'conn>),
Cached(CachedStatement<'conn>),
}
impl<'conn> Deref for MaybeCached<'conn> {
type Target = Statement<'conn>;
#[inline]
fn deref(&self) -> &Statement<'conn> {
match self {
MaybeCached::Cached(cached) => Deref::deref(cached),
MaybeCached::Uncached(uncached) => uncached,
}
}
}
impl<'conn> DerefMut for MaybeCached<'conn> {
#[inline]
fn deref_mut(&mut self) -> &mut Statement<'conn> {
match self {
MaybeCached::Cached(cached) => DerefMut::deref_mut(cached),
MaybeCached::Uncached(uncached) => uncached,
}
}
}
impl<'conn> From<Statement<'conn>> for MaybeCached<'conn> {
#[inline]
fn from(stmt: Statement<'conn>) -> Self {
MaybeCached::Uncached(stmt)
}
}
impl<'conn> From<CachedStatement<'conn>> for MaybeCached<'conn> {
#[inline]
fn from(stmt: CachedStatement<'conn>) -> Self {
MaybeCached::Cached(stmt)
}
}
impl<'conn> MaybeCached<'conn> {
#[inline]
pub fn prepare(
conn: &'conn Connection,
sql: &str,
cached: bool,
) -> rusqlite::Result<MaybeCached<'conn>> {
if cached {
Ok(MaybeCached::Cached(conn.prepare_cached(sql)?))
} else {
Ok(MaybeCached::Uncached(conn.prepare(sql)?))
}
}
}
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