more comments, sync check

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

mini-lsm-starter/src/table.rs

@@ -1 +1,85 @@
+#![allow(unused_variables)] // TODO(you): remove this lint after implementing this mod
+#![allow(dead_code)] // TODO(you): remove this lint after implementing this mod
 
+mod builder;
+mod iterator;
+
+use std::{path::Path, sync::Arc};
+
+pub use builder::SsTableBuilder;
+use bytes::{Buf, Bytes};
+pub use iterator::SsTableIterator;
+
+use crate::block::Block;
+use anyhow::Result;
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct BlockMeta {
+    /// Offset of this data block.
+    pub offset: usize,
+    /// The first key of the data block.
+    pub first_key: Bytes,
+}
+
+impl BlockMeta {
+    /// Encode block meta to a buffer.
+    pub fn encode_block_meta(
+        block_meta: &[BlockMeta],
+        #[allow(clippy::ptr_arg)] buf: &mut Vec<u8>,
+    ) {
+        unimplemented!()
+    }
+
+    /// Decode block meta from a buffer.
+    pub fn decode_block_meta(buf: impl Buf) -> Vec<BlockMeta> {
+        unimplemented!()
+    }
+}
+
+/// A file object.
+pub struct FileObject(Bytes);
+
+impl FileObject {
+    pub fn read(&self, offset: u64, len: u64) -> Result<Vec<u8>> {
+        Ok(self.0[offset as usize..(offset + len) as usize].to_vec())
+    }
+
+    pub fn size(&self) -> u64 {
+        self.0.len() as u64
+    }
+
+    pub fn create(path: &Path, data: Vec<u8>) -> Result<Self> {
+        unimplemented!()
+    }
+
+    pub fn open(path: &Path) -> Result<Self> {
+        unimplemented!()
+    }
+}
+
+pub struct SsTable {}
+
+impl SsTable {
+    /// Open SSTable from a file.
+    pub fn open(file: FileObject) -> Result<Self> {
+        unimplemented!()
+    }
+
+    /// Read a block from the disk.
+    pub fn read_block(&self, block_idx: usize) -> Result<Arc<Block>> {
+        unimplemented!()
+    }
+
+    /// Find the block that may contain `key`.
+    pub fn find_block_idx(&self, key: &[u8]) -> usize {
+        unimplemented!()
+    }
+
+    /// Get number of data blocks.
+    pub fn num_of_blocks(&self) -> usize {
+        unimplemented!()
+    }
+}
+
+#[cfg(test)]
+mod tests;