From 4c0f91ad334f8676a7140aacf93966426e5b2848 Mon Sep 17 00:00:00 2001
From: Yuriy Dupyn <2153100+omedusyo@users.noreply.github.com>
Date: Sun, 4 Feb 2024 18:13:05 +0100
Subject: [PATCH] Fix indexes types

---
 storage_engine/src/cursor.rs         | 14 ++++++------
 storage_engine/src/storage_engine.rs | 34 +++++++++++++++++++---------
 storage_engine/src/store_header.rs   |  6 +++++
 3 files changed, 36 insertions(+), 18 deletions(-)

diff --git a/storage_engine/src/cursor.rs b/storage_engine/src/cursor.rs
index a0c1671..8fefaa6 100644
--- a/storage_engine/src/cursor.rs
+++ b/storage_engine/src/cursor.rs
@@ -21,7 +21,7 @@ use crate::index::Index;
 // ===Concrete Cursors===
 pub struct ReadCursor<'a, T> {
     header: StoreHeader,
-    indexes: Vec<Option<&'a Index<T, FilePosition>>>,
+    indexes: &'a [Option<Index<T, FilePosition>>],
     file: File,
     data_type: PhantomData<T>,
 
@@ -30,7 +30,7 @@ pub struct ReadCursor<'a, T> {
 
 pub struct WriteCursor<'a, T> {
     header: &'a mut StoreHeader,
-    indexes: Vec<Option<&'a Index<T, FilePosition>>>,
+    indexes: &'a mut [Option<Index<T, FilePosition>>],
     file: File,
     data_type: PhantomData<T>,
 
@@ -231,7 +231,7 @@ pub trait CursorWithStoreHeader<T>: PrimitiveCursor<T> {
 
 #[async_trait]
 pub trait CursorWithAccessToIndex<T>: CursorWithStoreHeader<T> {
-    fn indexes(&mut self) -> &[Option<&Index<T, FilePosition>>];
+    fn indexes(&mut self) -> &[Option<Index<T, FilePosition>>];
 
     async fn find_in_index(&mut self, k: &T) -> Result<Option<FilePosition>> 
         where T: Encode + Decode + Ord + Send + Sync
@@ -277,13 +277,13 @@ impl <T>CursorWithStoreHeader<T> for WriteCursor<'_, T> {
 
 // ===CursorWithAccessToIndex===
 impl <T>CursorWithAccessToIndex<T> for ReadCursor<'_, T> {
-    fn indexes(&mut self) -> &[Option<&Index<T, FilePosition>>] {
+    fn indexes(&mut self) -> &[Option<Index<T, FilePosition>>] {
         &self.indexes
     }
 }
 
 impl <T>CursorWithAccessToIndex<T> for WriteCursor<'_, T> {
-    fn indexes(&mut self) -> &[Option<&Index<T, FilePosition>>] {
+    fn indexes(&mut self) -> &[Option<Index<T, FilePosition>>] {
         &self.indexes
     }
 }
@@ -304,7 +304,7 @@ impl <'cursor, T> ReadCursor<'cursor, T> {
                 header: store.header.clone(),
                 file,
                 data_type: store.data_type,
-                indexes: todo!(),
+                indexes: &store.indexes,
 
                 eof_file_position: 0,
             };
@@ -337,7 +337,7 @@ impl <'cursor, T> WriteCursor<'cursor, T>
                 header: &mut store.header,
                 file,
                 data_type: store.data_type,
-                indexes: todo!(),
+                indexes: &mut store.indexes,
 
                 eof_file_position: 0,
             };
diff --git a/storage_engine/src/storage_engine.rs b/storage_engine/src/storage_engine.rs
index 1ff53ad..a753a3d 100644
--- a/storage_engine/src/storage_engine.rs
+++ b/storage_engine/src/storage_engine.rs
@@ -34,7 +34,7 @@ pub struct Store<T> {
     // All 
     pub header: StoreHeader,
     pub data_type: PhantomData<T>,
-    pub primary_index: Index<T, FilePosition>,
+    pub indexes: Vec<Option<Index<T, FilePosition>>>,
 }
 
 pub type PositionOfValue = FilePosition;
@@ -70,14 +70,18 @@ impl <T>Store<T> {
         // We don't need the file right now. Only cursors will later open it.
         Self::create_empty_rows_file(path_to_rows, &header).await?;
 
-        let primary_index: Index<T, FilePosition> = Index::new(
-            &format!("rows_{}", primary_column.to_string()),
-        ).await?;
+        // TODO: I need to construct indexes
+        // let primary_index: Index<T, FilePosition> = Index::new(
+        //     &format!("rows_{}", primary_column.to_string()),
+        // ).await?;
+
+        // TODO
+        let indexes = vec![];
 
         let store = Self {
             header,
             data_type: PhantomData::<T>,
-            primary_index,
+            indexes,
         };
 
         Ok(store)
@@ -118,31 +122,39 @@ impl <T>Store<T> {
         let header = StoreHeader::decode(table_folder, &mut header_bytes).await?;
 
 
-        let primary_index: Index<T, FilePosition> = Index::connect(
-            &format!("rows_{}", header.primary_column.to_string()),
-        ).await?;
+        // let primary_index: Index<T, FilePosition> = Index::connect(
+        //     &format!("rows_{}", header.primary_column.to_string()),
+        // ).await?;
+
+        // TODO
+        let indexes = vec![];
 
         let store = Self {
             header,
             data_type: PhantomData::<T>,
-            primary_index
+            indexes,
         };
         Ok(store)
     }
 
     // ===Cursors===
-    pub async fn read_cursor(&self) -> Result<ReadCursor<T>> 
+    pub async fn read_cursor(&self) -> Result<ReadCursor<T>>
         where T: Send + Sync
     {
         ReadCursor::new(self).await
     }
 
-    pub async fn write_cursor(&mut self) -> Result<WriteCursor<T>> 
+    pub async fn write_cursor(&mut self) -> Result<WriteCursor<T>>
         where T: Send + Sync
     {
         WriteCursor::new(self).await
     }
 
+    pub async fn make_indexable(&mut self, column: Column) -> Result<()> {
+        // Creates an index from scratch at above column
+        todo!()
+    }
+
     // For debugging.
     pub async fn read_all_bytes(&mut self) -> std::result::Result<Vec<u8>, std::io::Error>
         where T: Send + Sync
diff --git a/storage_engine/src/store_header.rs b/storage_engine/src/store_header.rs
index 73cbb55..fc571a4 100644
--- a/storage_engine/src/store_header.rs
+++ b/storage_engine/src/store_header.rs
@@ -11,6 +11,8 @@ pub struct StoreHeader {
     pub deleted_count: usize,
     pub total_count: usize,
     pub primary_column: Column,
+    // TODO
+    // pub indexed_columns: Vec<bool>,
 }
 
 impl StoreHeader {
@@ -25,6 +27,10 @@ impl StoreHeader {
     pub const TOTAL_COUNT_OFFSET: usize = Self::DELETED_COUNT_OFFSET + Self::DELETED_COUNT_SIZE;
     pub const PRIMARY_COLUMN_OFFSET: usize = Self::TOTAL_COUNT_OFFSET + Self::TOTAL_COUNT_SIZE;
 
+    fn indexed_columns_size(&self) -> usize {
+        size_of::<bool>() * self.number_of_columns
+    }
+
     pub fn encode(&self) -> Result<Vec<u8>> {
         let mut result = encode(&self.number_of_columns)?;
         result.append(&mut encode(&self.deleted_count)?);