76 lines
1.9 KiB
Rust
76 lines
1.9 KiB
Rust
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use std::ops::Bound;
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use std::path::Path;
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use std::sync::Arc;
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use anyhow::Result;
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use arc_swap::ArcSwap;
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use bytes::Bytes;
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use crate::lsm_iterator::LsmIterator;
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use crate::mem_table::MemTable;
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use crate::table::{SsTable, SsTableIterator};
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pub struct LsmStorageInner {
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memtables: Vec<Arc<MemTable>>,
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sstables: Vec<Arc<SsTable>>,
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}
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impl LsmStorageInner {
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fn create() -> Self {
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Self {
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memtables: vec![Arc::new(MemTable::create())],
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sstables: vec![],
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}
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}
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}
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/// The storage interface of the LSM tree.
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pub struct LsmStorage {
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inner: ArcSwap<LsmStorageInner>,
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}
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impl LsmStorage {
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pub fn open(_path: &Path) -> Result<Self> {
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Ok(Self {
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inner: ArcSwap::from_pointee(LsmStorageInner::create()),
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})
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}
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pub fn get(&self, key: &[u8]) -> Result<Option<Bytes>> {
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let snapshot = self.inner.load();
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for memtable in &snapshot.memtables {
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if let Some(value) = memtable.get(key)? {
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if value.is_empty() {
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// found tomestone, return key not exists
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return Ok(None);
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}
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return Ok(Some(value));
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}
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}
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let mut iters = Vec::new();
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iters.reserve(snapshot.sstables.len());
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for table in snapshot.sstables.iter().rev() {
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iters.push(SsTableIterator::create_and_seek_to_key(table.clone(), key)?);
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}
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Ok(None)
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}
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pub fn put(&mut self, key: &[u8], value: &[u8]) -> Result<()> {
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assert!(!value.is_empty(), "value cannot be empty");
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assert!(!key.is_empty(), "key cannot be empty");
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unimplemented!()
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}
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pub fn delete(&mut self, _key: &[u8]) -> Result<()> {
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unimplemented!()
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}
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pub fn sync(&mut self) -> Result<()> {
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unimplemented!()
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}
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pub fn scan(&self, _lower: Bound<&[u8]>, _upper: Bound<&[u8]>) -> Result<LsmIterator> {
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unimplemented!()
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}
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}
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