Files
mini_lsm/mini-lsm-starter/src/lsm_iterator.rs
Alex Chi Z 38c7ef6f2f docs: s/tutorial/course
Signed-off-by: Alex Chi Z <iskyzh@gmail.com>
2025-01-19 19:28:07 -05:00

97 lines
2.5 KiB
Rust

// Copyright (c) 2022-2025 Alex Chi Z
//
// 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 License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// 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.
#![allow(unused_variables)] // TODO(you): remove this lint after implementing this mod
#![allow(dead_code)] // TODO(you): remove this lint after implementing this mod
use anyhow::Result;
use crate::{
iterators::{merge_iterator::MergeIterator, StorageIterator},
mem_table::MemTableIterator,
};
/// Represents the internal type for an LSM iterator. This type will be changed across the course for multiple times.
type LsmIteratorInner = MergeIterator<MemTableIterator>;
pub struct LsmIterator {
inner: LsmIteratorInner,
}
impl LsmIterator {
pub(crate) fn new(iter: LsmIteratorInner) -> Result<Self> {
Ok(Self { inner: iter })
}
}
impl StorageIterator for LsmIterator {
type KeyType<'a> = &'a [u8];
fn is_valid(&self) -> bool {
unimplemented!()
}
fn key(&self) -> &[u8] {
unimplemented!()
}
fn value(&self) -> &[u8] {
unimplemented!()
}
fn next(&mut self) -> Result<()> {
unimplemented!()
}
}
/// A wrapper around existing iterator, will prevent users from calling `next` when the iterator is
/// invalid. If an iterator is already invalid, `next` does not do anything. If `next` returns an error,
/// `is_valid` should return false, and `next` should always return an error.
pub struct FusedIterator<I: StorageIterator> {
iter: I,
has_errored: bool,
}
impl<I: StorageIterator> FusedIterator<I> {
pub fn new(iter: I) -> Self {
Self {
iter,
has_errored: false,
}
}
}
impl<I: StorageIterator> StorageIterator for FusedIterator<I> {
type KeyType<'a>
= I::KeyType<'a>
where
Self: 'a;
fn is_valid(&self) -> bool {
unimplemented!()
}
fn key(&self) -> Self::KeyType<'_> {
unimplemented!()
}
fn value(&self) -> &[u8] {
unimplemented!()
}
fn next(&mut self) -> Result<()> {
unimplemented!()
}
}