bump toolchain

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

Cargo.toml

@@ -4,6 +4,7 @@ members = [
   "xtask",
   "mini-lsm-starter",
 ]
+resolver = "2"
 
 [workspace.package]
 version = "0.1.0"

mini-lsm-starter/src/iterators/merge_iterator.rs

@@ -19,6 +19,7 @@ impl<I: StorageIterator> PartialEq for HeapWrapper<I> {
 impl<I: StorageIterator> Eq for HeapWrapper<I> {}
 
 impl<I: StorageIterator> PartialOrd for HeapWrapper<I> {
+    #[allow(clippy::non_canonical_partial_ord_impl)]
     fn partial_cmp(&self, other: &Self) -> Option<cmp::Ordering> {
         match self.1.key().cmp(other.1.key()) {
             cmp::Ordering::Greater => Some(cmp::Ordering::Greater),

mini-lsm/src/block.rs

@@ -27,13 +27,16 @@ impl Block {
     }
 
     pub fn decode(data: &[u8]) -> Self {
+        // get number of elements in the block
         let entry_offsets_len = (&data[data.len() - SIZEOF_U16..]).get_u16() as usize;
         let data_end = data.len() - SIZEOF_U16 - entry_offsets_len * SIZEOF_U16;
         let offsets_raw = &data[data_end..data.len() - SIZEOF_U16];
+        // get offset array
         let offsets = offsets_raw
             .chunks(SIZEOF_U16)
             .map(|mut x| x.get_u16())
             .collect();
+        // retrieve data
         let data = data[0..data_end].to_vec();
         Self { data, offsets }
     }

mini-lsm/src/block/builder.rs

@@ -6,7 +6,7 @@ use super::{Block, SIZEOF_U16};
 pub struct BlockBuilder {
     /// Offsets of each key-value entries.
     offsets: Vec<u16>,
-    /// All key-value pairs in the block.
+    /// All serialized key-value pairs in the block.
     data: Vec<u8>,
     /// The expected block size.
     block_size: usize,
@@ -23,29 +23,33 @@ impl BlockBuilder {
     }
 
     fn estimated_size(&self) -> usize {
-        self.offsets.len() * SIZEOF_U16 + self.data.len() + SIZEOF_U16
+        SIZEOF_U16 /* number of key-value pairs in the block */ +  self.offsets.len() * SIZEOF_U16 /* offsets */ + self.data.len()
+        /* key-value pairs */
     }
 
     /// Adds a key-value pair to the block. Returns false when the block is full.
     #[must_use]
     pub fn add(&mut self, key: &[u8], value: &[u8]) -> bool {
         assert!(!key.is_empty(), "key must not be empty");
-        // The overhead here is `key_len` + `val_len` + `offset`, each is of type `u16`
-        if self.estimated_size() + key.len() + value.len() + SIZEOF_U16 * 3 > self.block_size
+        if self.estimated_size() + key.len() + value.len() + SIZEOF_U16 * 3 /* key_len, value_len and offset */ > self.block_size
             && !self.is_empty()
         {
             return false;
         }
-        // The offsets should be updated at first, to maintain the correct offset
+        // Add the offset of the data into the offset array.
         self.offsets.push(self.data.len() as u16);
+        // Encode key length.
         self.data.put_u16(key.len() as u16);
+        // Encode key content.
         self.data.put(key);
+        // Encode value length.
         self.data.put_u16(value.len() as u16);
+        // Encode value content.
         self.data.put(value);
         true
     }
 
-    /// Check if there is no key-value pair in the block.
+    /// Check if there are no key-value pairs in the block.
     pub fn is_empty(&self) -> bool {
         self.offsets.is_empty()
     }

mini-lsm/src/block/iterator.rs

@@ -6,9 +6,13 @@ use super::Block;
 
 /// Iterates on a block.
 pub struct BlockIterator {
+    /// reference to the block
     block: Arc<Block>,
+    /// the current key at the iterator position
     key: Vec<u8>,
+    /// the current value at the iterator position
     value: Vec<u8>,
+    /// the current index at the iterator position
     idx: usize,
 }
 

mini-lsm/src/iterators/merge_iterator.rs

@@ -17,6 +17,7 @@ impl<I: StorageIterator> PartialEq for HeapWrapper<I> {
 impl<I: StorageIterator> Eq for HeapWrapper<I> {}
 
 impl<I: StorageIterator> PartialOrd for HeapWrapper<I> {
+    #[allow(clippy::non_canonical_partial_ord_impl)]
     fn partial_cmp(&self, other: &Self) -> Option<cmp::Ordering> {
         match self.1.key().cmp(other.1.key()) {
             cmp::Ordering::Greater => Some(cmp::Ordering::Greater),

mini-lsm/src/lsm_storage.rs

@@ -86,8 +86,7 @@ impl LsmStorage {
                 return Ok(Some(value));
             }
         }
-        let mut iters = Vec::new();
-        iters.reserve(snapshot.l0_sstables.len());
+        let mut iters = Vec::with_capacity(snapshot.l0_sstables.len());
         for table in snapshot.l0_sstables.iter().rev() {
             iters.push(Box::new(SsTableIterator::create_and_seek_to_key(
                 table.clone(),
@@ -190,16 +189,14 @@ impl LsmStorage {
             Arc::clone(&guard)
         }; // drop global lock here
 
-        let mut memtable_iters = Vec::new();
-        memtable_iters.reserve(snapshot.imm_memtables.len() + 1);
+        let mut memtable_iters = Vec::with_capacity(snapshot.imm_memtables.len() + 1);
         memtable_iters.push(Box::new(snapshot.memtable.scan(lower, upper)));
         for memtable in snapshot.imm_memtables.iter().rev() {
             memtable_iters.push(Box::new(memtable.scan(lower, upper)));
         }
         let memtable_iter = MergeIterator::create(memtable_iters);
 
-        let mut table_iters = Vec::new();
-        table_iters.reserve(snapshot.l0_sstables.len());
+        let mut table_iters = Vec::with_capacity(snapshot.l0_sstables.len());
         for table in snapshot.l0_sstables.iter().rev() {
             let iter = match lower {
                 Bound::Included(key) => {

rust-toolchain.toml

@@ -1,4 +1,4 @@
 [toolchain]
-channel = "1.70.0"
+channel = "stable"
 components = [ "rustfmt", "clippy" ]
 profile = "minimal"