more comments, sync check

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

mini-lsm-starter/src/table/builder.rs

@@ -0,0 +1,30 @@
+#![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 std::path::Path;
+
+use super::{BlockMeta, SsTable};
+
+/// Builds an SSTable from key-value pairs.
+pub struct SsTableBuilder {
+    pub(super) meta: Vec<BlockMeta>,
+}
+
+impl SsTableBuilder {
+    /// Create a builder based on target SST size and target block size.
+    pub fn new(target_size: usize, block_size: usize) -> Self {
+        unimplemented!()
+    }
+
+    /// Adds a key-value pair to SSTable, return false when SST full.
+    #[must_use]
+    pub fn add(&mut self, key: &[u8], value: &[u8]) -> bool {
+        unimplemented!()
+    }
+
+    /// Builds the SSTable and writes it to the given path. No need to actually write to disk until chapter 4 block cache.
+    pub fn build(self, path: impl AsRef<Path>) -> Result<SsTable> {
+        unimplemented!()
+    }
+}