Add hnsw index

HNSW implementation code from my PR on sdslabs/VortexDB
sdslabs/VortexDB#43

Signed-off-by: Arshdeep54 <balarsh535@gmail.com>

Author: Arshdeep54

Cargo.lock

@@ -5,4 +5,8 @@ edition = "2024"
 
 [dependencies]
 input_handler = "0.1"
+rand = "0.9.2"
+serde = {version = "1.0.228" ,features = ["derive"]}
+serde_json = "1.0.145"
 tempfile = "3.21.0"
+uuid ={version= "1.19.0",features = ["serde","v4","v5"]} 

Cargo.toml

@@ -0,0 +1,25 @@
+use std::{fs, path::PathBuf};
+
+use indexium::parsing::parse_command;
+use indexium::session::IndexSession;
+use input_handler::InputHandler;
+
+fn main() {
+    let mut index_session = IndexSession::new();
+
+    let data_dir = PathBuf::from("data");
+    if !data_dir.exists() {
+        fs::create_dir(&data_dir).expect("Failed to create data directory");
+    }
+    let history_file = data_dir.join("history.txt");
+
+    let mut input_handler =
+        InputHandler::with_history_file(history_file).expect("Failed to initialize input handler");
+
+    while let Ok(line) = input_handler.readline("indexium> ") {
+        if line.eq_ignore_ascii_case("exit") {
+            break;
+        }
+        parse_command(&mut index_session, &line);
+    }
+}

src/bin/indexium.rs

@@ -215,10 +215,10 @@ impl Node {
 
         child.items.insert(0, parent_item);
 
-        if !sibling.is_leaf() {
-            if let Some(last_child) = sibling.children.pop() {
-                child.children.insert(0, last_child);
-            }
+        if !sibling.is_leaf()
+            && let Some(last_child) = sibling.children.pop()
+        {
+            child.children.insert(0, last_child);
         }
 
         sibling.num_items -= 1;
@@ -243,11 +243,11 @@ impl Node {
 
         child.items.push(parent_item);
 
-        if !sibling.is_leaf() {
-            if let Some(first_child) = sibling.children.first().cloned() {
-                child.children.push(Box::new(*first_child));
-                sibling.children.remove(0);
-            }
+        if !sibling.is_leaf()
+            && let Some(first_child) = sibling.children.first().cloned()
+        {
+            child.children.push(Box::new(*first_child));
+            sibling.children.remove(0);
         }
 
         sibling.num_items -= 1;

src/btree/node.rs

@@ -10,10 +10,10 @@ pub struct Visualizer {
 
 impl Visualizer {
     pub fn new(path: &str) -> Self {
-        if let Some(parent) = Path::new(path).parent() {
-            if !parent.exists() {
-                fs::create_dir_all(parent).expect("Failed to create visualization directory");
-            }
+        if let Some(parent) = Path::new(path).parent()
+            && !parent.exists()
+        {
+            fs::create_dir_all(parent).expect("Failed to create visualization directory");
         }
 
         Visualizer {