将Index改为单例模式，防止状态不一致； 注意：测试为单进程，需要reset防止共享单例

Cargo.toml

@@ -15,3 +15,5 @@ serde_json = "1.0.108"
 colored = "2.1.0"
 rand = "0.8.5"
 color-backtrace = "0.6.1"
+once_cell = "1.19.0"
+backtrace = "0.3.69"

src/commands/add.rs

@@ -31,13 +31,12 @@ pub fn add(raw_paths: Vec<String>, all: bool, mut update: bool) {
         println!("{}", "--update 只对已跟踪文件进行操作 不包含new".bright_green());
     }
 
-    let mut index = Index::new();
     for file in &files {
-        add_a_file(file, &mut index);
+        add_a_file(file);
     }
 }
 
-fn add_a_file(file: &Path, index: &mut Index) {
+fn add_a_file(file: &Path) {
     let workdir = util::get_working_dir().unwrap();
     if !util::is_sub_path(file, &workdir) {
         //文件不在工作区内
@@ -50,6 +49,7 @@ fn add_a_file(file: &Path, index: &mut Index) {
         return;
     }
 
+    let index = Index::get_instance();
     let rel_path = util::to_cur_relative_path(file);
     if !file.exists() {
         //文件被删除

src/commands/commit.rs

@@ -3,7 +3,7 @@ use crate::{head, models::*};
 use super::status;
 
 pub fn commit(message: String, allow_empty: bool) {
-    let index = Index::new();
+    let index = Index::get_instance();
     if !allow_empty && status::changes_to_be_committed().is_empty() {
         panic!("工作区没有任何改动，不需要提交");
     }
@@ -13,9 +13,9 @@ pub fn commit(message: String, allow_empty: bool) {
 
     let mut commit = {
         if current_commit_hash.is_empty() {
-            Commit::new(&index, vec![], message.clone())
+            Commit::new(index, vec![], message.clone())
         } else {
-            Commit::new(&index, vec![current_commit_hash.clone()], message.clone())
+            Commit::new(index, vec![current_commit_hash.clone()], message.clone())
         }
     };
     let commit_hash = commit.save();

src/commands/remove.rs

@@ -5,7 +5,7 @@ use std::{fs, io, path::PathBuf};
 /// 从暂存区&|工作区删除文件
 pub fn remove(files: Vec<String>, cached: bool, recursive: bool) -> io::Result<()> {
     util::check_repo_exist();
-    let mut index = Index::new();
+    let index = Index::get_instance();
     for file in files.iter() {
         let path = PathBuf::from(file);
         if !path.exists() {

src/commands/restore.rs

@@ -64,7 +64,7 @@ pub fn restore_worktree(filter: Option<&Vec<PathBuf>>, target_blobs: &Vec<(PathB
     let mut file_paths = util::integrate_paths(&input_paths); //根据用户输入整合存在的文件（绝对路径）
     file_paths.extend(deleted_files); //已删除的文件
 
-    let index = Index::new();
+    let index = Index::get_instance();
     let store = Store::new();
 
     for path in &file_paths {
@@ -103,7 +103,7 @@ pub fn restore_index(filter: Option<&Vec<PathBuf>>, target_blobs: &Vec<(PathBuf,
     let input_paths = preprocess_filters(filter); //预处理filter 将None转化为workdir
     let target_blobs = preprocess_blobs(target_blobs); //预处理target_blobs 转化为绝对路径HashMap
 
-    let mut index = Index::new();
+    let index = Index::get_instance();
     let deleted_files_index = get_index_deleted_files_in_filters(&index, &input_paths, &target_blobs); //统计已删除的文件
 
     //1.获取index中包含于input_path的文件（使用paths进行过滤）
@@ -181,7 +181,7 @@ pub fn restore(paths: Vec<String>, source: Option<String>, worktree: bool, stage
         otherwise from the [index].*/
         if source.is_none() && !staged {
             // 没有指定source，且没有指定--staged，从[index]中恢复到worktree //只有这种情况是从[index]恢复
-            let entries = Index::new().get_tracked_entries();
+            let entries = Index::get_instance().get_tracked_entries();
             entries.into_iter().map(|(p, meta)| (p, meta.hash)).collect()
         } else {
             //从[target_commit]中恢复
@@ -224,7 +224,7 @@ mod test {
         util::ensure_no_file(&path);
         cmd::add(vec![], true, false); //add -A
         cmd::restore(vec![".".to_string()], Some("HEAD".to_string()), false, true);
-        let index = Index::new();
+        let index = Index::get_instance();
         assert!(index.get_tracked_files().is_empty());
     }
 

src/commands/status.rs

@@ -70,7 +70,7 @@ impl Changes {
 */
 pub fn changes_to_be_committed() -> Changes {
     let mut change = Changes::default();
-    let index = Index::new();
+    let index = Index::get_instance();
     let head_hash = head::current_head_commit();
     let tracked_files = index
         .get_tracked_files()
@@ -111,7 +111,7 @@ pub fn changes_to_be_committed() -> Changes {
 /// 比较工作区与暂存区的差异，返回相对路径(to workdir)，不筛选
 pub fn changes_to_be_staged() -> Changes {
     let mut change = Changes::default();
-    let index = Index::new();
+    let index = Index::get_instance();
     for file in index.get_tracked_files() {
         if !file.exists() {
             change.deleted.push(util::to_workdir_relative_path(&file));

src/models/commit.rs

@@ -88,7 +88,7 @@ mod test {
     fn test_commit() {
         util::setup_test_with_clean_mit();
 
-        let index = super::Index::new();
+        let index = super::Index::get_instance();
         let mut commit = super::Commit::new(&index, vec!["123".to_string(), "456".to_string()], "test".to_string());
         assert_eq!(commit.hash.len(), 0);
 

src/models/index.rs

@@ -1,4 +1,5 @@
 use crate::{models::*, utils::util};
+use once_cell::unsync::Lazy;
 use serde::{Deserialize, Serialize};
 use std::{
     collections::HashMap,
@@ -43,7 +44,8 @@ impl FileMetaData {
 }
 
 /** Index
-注意：逻辑处理均为绝对路径，但是存储时为相对路径
+注意：逻辑处理均为绝对路径，但是存储时为相对路径(to workdir)<br>
+<a href="https://wolfsonliu.github.io/archive/2018/li-jie-git-index-wen-jian.html">理解 Git index 文件</a>
  */
 #[derive(Serialize, Deserialize, Debug, Default)]
 pub struct Index {
@@ -53,8 +55,7 @@ pub struct Index {
 
 impl Index {
     /// 从index文件加载
-    pub(crate) fn new() -> Index {
-        //TODO! 设计为单例模式
+    fn new() -> Index {
         let mut index = Index {
             entries: HashMap::new(),
             working_dir: util::get_working_dir().unwrap(),
@@ -63,26 +64,44 @@ impl Index {
         return index;
     }
 
+    /// 单例模式，线程不安全，但是本程序默认单线程
+    pub fn get_instance() -> &'static mut Index {
+        static mut INSTANCE: Lazy<Index> = Lazy::new(Index::new); //延迟初始化，线程不安全
+        unsafe { &mut INSTANCE }
+    }
+
+    /// 重置index，主要用于测试，防止单例模式的影响
+    pub fn reset() {
+        let index = Index::get_instance();
+        index.clear();
+        *index = Index::new(); //drop happened 导致旧数据写入文件
+    }
+
+    fn clear(&mut self) {
+        self.entries.clear();
+        self.working_dir.clear();
+    }
+
     /// 预处理路径，统一形式为绝对路径
-    fn preprocess_path(path: &Path) -> PathBuf {
+    fn preprocess(path: &Path) -> PathBuf {
         util::get_absolute_path(&path)
     }
 
     // 添加文件
     pub fn add(&mut self, mut path: PathBuf, data: FileMetaData) {
-        path = Index::preprocess_path(&path);
+        path = Index::preprocess(&path);
         self.entries.insert(path, data);
     }
 
     // 删除文件
     pub fn remove(&mut self, path: &Path) {
-        let path = Index::preprocess_path(&path);
+        let path = Index::preprocess(&path);
         self.entries.remove(&path);
     }
 
     // 获取文件元数据
     pub fn get(&self, path: &Path) -> Option<FileMetaData> {
-        let path = Index::preprocess_path(path);
+        let path = Index::preprocess(path);
         self.entries.get(&path).cloned()
     }
 
@@ -96,7 +115,7 @@ impl Index {
     }
 
     pub fn contains(&self, path: &Path) -> bool {
-        let path = Index::preprocess_path(path);
+        let path = Index::preprocess(path);
         self.entries.contains_key(&path)
     }
 
@@ -134,7 +153,7 @@ impl Index {
     }
 
     pub fn update(&mut self, mut path: PathBuf, data: FileMetaData) {
-        path = Index::preprocess_path(&path);
+        path = Index::preprocess(&path);
         self.entries.insert(path, data);
     }
 
@@ -151,6 +170,8 @@ impl Index {
                     (abs_path, value)
                 })
                 .collect();
+        } else {
+            // println!("index文件不存在，创建空index");
         }
     }
 
@@ -161,7 +182,7 @@ impl Index {
         path
     }
 
-    /// 二进制序列化
+    /// 保存到文件
     pub fn save(&mut self) {
         //要先转化为相对路径
         let relative_index: HashMap<PathBuf, FileMetaData> = self
@@ -214,14 +235,14 @@ mod tests {
     #[test]
     fn test_load() {
         util::setup_test_with_clean_mit();
-        let index = Index::new();
+        let index = Index::get_instance();
         println!("{:?}", index);
     }
 
     #[test]
     fn test_save() {
         util::setup_test_with_clean_mit();
-        let mut index = Index::new();
+        let index = Index::get_instance();
         let path = PathBuf::from("../mit_test_storage/.mit/HEAD"); //测试../相对路径的处理
         index.add(path.clone(), FileMetaData::new(&Blob::new(&path), &path));
 

src/models/tree.rs

@@ -162,7 +162,7 @@ mod test {
     #[test]
     fn test_new() {
         util::setup_test_with_clean_mit();
-        let mut index = Index::new();
+        let index = Index::get_instance();
         for test_file in vec!["b.txt", "mit_src/a.txt", "test/test.txt"] {
             let test_file = PathBuf::from(test_file);
             util::ensure_test_file(&test_file, None);
@@ -178,7 +178,7 @@ mod test {
     #[test]
     fn test_load() {
         util::setup_test_with_clean_mit();
-        let mut index = Index::new();
+        let index = Index::get_instance();
         let test_files = vec!["b.txt", "mit_src/a.txt"];
         for test_file in test_files.clone() {
             let test_file = PathBuf::from(test_file);
@@ -198,7 +198,7 @@ mod test {
     #[test]
     fn test_get_recursive_file_entries() {
         util::setup_test_with_clean_mit();
-        let mut index = Index::new();
+        let index = Index::get_instance();
         let mut test_files = vec![PathBuf::from("b.txt"), PathBuf::from("mit_src/a.txt")];
         for test_file in test_files.clone() {
             util::ensure_test_file(&test_file, None);
@@ -226,7 +226,7 @@ mod test {
     #[test]
     fn test_get_recursive_blobs() {
         util::setup_test_with_clean_mit();
-        let mut index = Index::new();
+        let index = Index::get_instance();
         let test_files = vec!["b.txt", "mit_src/a.txt"];
         let mut test_blobs = vec![];
         for test_file in test_files.clone() {

src/utils/util.rs

@@ -6,7 +6,7 @@ use std::{
     path::{Path, PathBuf},
 };
 
-use crate::models::{commit::Commit, object::Hash, tree::Tree};
+use crate::models::{commit::Commit, object::Hash, tree::Tree, Index};
 
 pub const ROOT_DIR: &str = ".mit";
 pub const TEST_DIR: &str = "mit_test_storage"; // 执行测试的储存库
@@ -33,26 +33,33 @@ fn find_cargo_dir() -> PathBuf {
     }
 }
 
-fn setup_test_dir() {
+/// 准备测试环境，切换到测试目录
+fn setup_test_env() {
     color_backtrace::install(); // colorize backtrace
+
     let mut path = find_cargo_dir();
     path.push(TEST_DIR);
     if !path.exists() {
         fs::create_dir(&path).unwrap();
     }
-    std::env::set_current_dir(&path).unwrap();
+    std::env::set_current_dir(&path).unwrap(); // 将执行目录切换到测试目录
+}
+
+pub fn init_mit() {
+    let _ = crate::commands::init();
+    Index::reset(); // 重置index, 以防止其他测试修改了index单例
 }
 
 /// with 初始化的干净的mit
 pub fn setup_test_with_clean_mit() {
     setup_test_without_mit();
-    let _ = crate::commands::init::init();
+    init_mit();
 }
 
 pub fn setup_test_without_mit() {
     // 将执行目录切换到测试目录，并清除测试目录下的.mit目录
-    setup_test_dir();
-    let mut path = std::env::current_dir().unwrap();
+    setup_test_env();
+    let mut path = cur_dir();
     path.push(ROOT_DIR);
     if path.exists() {
         fs::remove_dir_all(&path).unwrap();
@@ -632,7 +639,7 @@ mod tests {
         ensure_test_file(Path::new("test.txt"), Some("test"));
         let hash = Blob::new(get_working_dir().unwrap().join("test.txt").as_path()).get_hash();
         assert_eq!(check_object_type(hash), ObjectType::Blob);
-        let mut commit = Commit::new(&Index::new(), vec![], "test".to_string());
+        let mut commit = Commit::new(&Index::get_instance(), vec![], "test".to_string());
         assert_eq!(check_object_type(commit.get_tree_hash()), ObjectType::Tree);
         commit.save();
         assert_eq!(check_object_type(commit.get_hash()), ObjectType::Commit);