finish 2.7

Signed-off-by: Alex Chi <iskyzh@gmail.com>

mini-lsm/src/table.rs

@@ -146,7 +146,7 @@ impl SsTable {
         let raw_bloom_offset = file.read(len - 4, 4)?;
         let bloom_offset = (&raw_bloom_offset[..]).get_u32() as u64;
         let raw_bloom = file.read(bloom_offset, len - 4 - bloom_offset)?;
-        let bloom_filter = Bloom::decode(&raw_bloom);
+        let bloom_filter = Bloom::decode(&raw_bloom)?;
         let raw_meta_offset = file.read(bloom_offset - 4, 4)?;
         let block_meta_offset = (&raw_meta_offset[..]).get_u32() as u64;
         let raw_meta = file.read(block_meta_offset, bloom_offset - 4 - block_meta_offset)?;

mini-lsm/src/table/bloom.rs

@@ -1,6 +1,7 @@
 // Copyright 2021 TiKV Project Authors. Licensed under Apache-2.0.
 
-use bytes::{BufMut, Bytes, BytesMut};
+use anyhow::{bail, Result};
+use bytes::{Buf, BufMut, Bytes, BytesMut};
 
 /// Implements a bloom filter
 pub struct Bloom {
@@ -45,19 +46,26 @@ impl<T: AsMut<[u8]>> BitSliceMut for T {
 
 impl Bloom {
     /// Decode a bloom filter
-    pub fn decode(buf: &[u8]) -> Self {
-        let filter = &buf[..buf.len() - 1];
-        let k = buf[buf.len() - 1];
-        Self {
+    pub fn decode(buf: &[u8]) -> Result<Self> {
+        let checksum = (&buf[buf.len() - 4..buf.len()]).get_u32();
+        if checksum != crc32fast::hash(&buf[..buf.len() - 4]) {
+            bail!("checksum mismatched for bloom filters");
+        }
+        let filter = &buf[..buf.len() - 5];
+        let k = buf[buf.len() - 5];
+        Ok(Self {
             filter: filter.to_vec().into(),
             k,
-        }
+        })
     }
 
     /// Encode a bloom filter
     pub fn encode(&self, buf: &mut Vec<u8>) {
+        let offset = buf.len();
         buf.extend(&self.filter);
         buf.put_u8(self.k);
+        let checksum = crc32fast::hash(&buf[offset..]);
+        buf.put_u32(checksum);
     }
 
     /// Get bloom filter bits per key from entries count and FPR

mini-lsm/src/wal.rs

@@ -1,6 +1,6 @@
 use std::fs::{File, OpenOptions};
 use std::hash::Hasher;
-use std::io::{Read, Write};
+use std::io::{BufWriter, Read, Write};
 use std::path::Path;
 use std::sync::Arc;
 
@@ -10,20 +10,20 @@ use crossbeam_skiplist::SkipMap;
 use parking_lot::Mutex;
 
 pub struct Wal {
-    file: Arc<Mutex<File>>,
+    file: Arc<Mutex<BufWriter<File>>>,
 }
 
 impl Wal {
     pub fn create(path: impl AsRef<Path>) -> Result<Self> {
         Ok(Self {
-            file: Arc::new(Mutex::new(
+            file: Arc::new(Mutex::new(BufWriter::new(
                 OpenOptions::new()
                     .read(true)
                     .create_new(true)
                     .write(true)
                     .open(path)
                     .context("failed to create WAL")?,
-            )),
+            ))),
         })
     }
 
@@ -56,7 +56,7 @@ impl Wal {
             skiplist.insert(key, value);
         }
         Ok(Self {
-            file: Arc::new(Mutex::new(file)),
+            file: Arc::new(Mutex::new(BufWriter::new(file))),
         })
     }
 
@@ -80,8 +80,9 @@ impl Wal {
     }
 
     pub fn sync(&self) -> Result<()> {
-        let file = self.file.lock();
-        file.sync_all()?;
+        let mut file = self.file.lock();
+        file.flush()?;
+        file.get_mut().sync_all()?;
         Ok(())
     }
 }