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// Copyright 2018-2019 Mozilla
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use
// this file except in compliance with the License. You may obtain a copy of the
// Unless required by applicable law or agreed to in writing, software distributed
// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
// CONDITIONS OF ANY KIND, either express or implied. See the License for the
// specific language governing permissions and limitations under the License.
use lmdb::Cursor;
use super::IterImpl;
use crate::backend::traits::BackendRoCursor;
#[derive(Debug)]
pub struct RoCursorImpl<'c>(pub(crate) lmdb::RoCursor<'c>);
impl<'c> BackendRoCursor<'c> for RoCursorImpl<'c> {
type Iter = IterImpl<'c, lmdb::RoCursor<'c>>;
fn into_iter(self) -> Self::Iter {
// We call RoCursor.iter() instead of RoCursor.iter_start() because
// the latter panics when there are no items in the store, whereas the
// former returns an iterator that yields no items. And since we create
// the Cursor and don't change its position, we can be sure that a call
// to Cursor.iter() will start at the beginning.
IterImpl::new(self.0, lmdb::RoCursor::iter)
}
fn into_iter_from<K>(self, key: K) -> Self::Iter
where
K: AsRef<[u8]> + 'c,
{
IterImpl::new(self.0, |cursor| cursor.iter_from(key))
}
fn into_iter_dup_of<K>(self, key: K) -> Self::Iter
where
K: AsRef<[u8]> + 'c,
{
IterImpl::new(self.0, |cursor| cursor.iter_dup_of(key))
}
}
#[derive(Debug)]
pub struct RwCursorImpl<'c>(pub(crate) lmdb::RwCursor<'c>);
impl<'c> BackendRoCursor<'c> for RwCursorImpl<'c> {
type Iter = IterImpl<'c, lmdb::RwCursor<'c>>;
fn into_iter(self) -> Self::Iter {
IterImpl::new(self.0, lmdb::RwCursor::iter)
}
fn into_iter_from<K>(self, key: K) -> Self::Iter
where
K: AsRef<[u8]> + 'c,
{
IterImpl::new(self.0, |cursor| cursor.iter_from(key))
}
fn into_iter_dup_of<K>(self, key: K) -> Self::Iter
where
K: AsRef<[u8]> + 'c,
{
IterImpl::new(self.0, |cursor| cursor.iter_dup_of(key))
}
}