feat: [#1932] l-s v0.5.1 原子写入保护及文档更新

src/main.rs

@@ -4,10 +4,10 @@ mod head_hash;
 mod meta;
 mod utils;
 
-use std::fs::{self, File};
+use std::fs::{self, File, OpenOptions};
 use std::io::Write;
 use std::path::{Path, PathBuf};
-use std::time::Instant;
+use std::time::{Instant, SystemTime, UNIX_EPOCH};
 
 use anyhow::{Context, Result};
 use clap::Parser;
@@ -57,7 +57,7 @@ fn process_file(path: &Path) -> Result<()> {
         tracker.finish("处理完成");
         let json = meta.to_pretty_json()?;
         println!("{}", json);
-        fs::write(&save_path, json)?;
+        write_atomic(&save_path, &json)?;
         return Ok(());
     }
 
@@ -98,9 +98,7 @@ fn process_dir(path: &Path) -> Result<()> {
     if !meta_path.exists() {
         let snapshot = DirSnapshot::build_root(path)?;
         let json = serde_json::to_string_pretty(&snapshot)?;
-        let mut file = File::create(&meta_path)
-            .with_context(|| format!("无法写入: {}", meta_path.display()))?;
-        file.write_all(json.as_bytes())?;
+        write_atomic(&meta_path, &json)?;
         return Ok(());
     }
 
@@ -151,3 +149,43 @@ fn process_dir(path: &Path) -> Result<()> {
 
     Ok(())
 }
+
+fn write_atomic(path: &Path, contents: &str) -> Result<()> {
+    let parent = path
+        .parent()
+        .map(Path::to_path_buf)
+        .unwrap_or_else(|| PathBuf::from("."));
+    let nanos = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map(|duration| duration.as_nanos())
+        .unwrap_or(0);
+    let tmp_path = parent.join(format!(".l-s-tmp-{}-{nanos}", std::process::id()));
+
+    let result = (|| -> Result<()> {
+        let mut file = OpenOptions::new()
+            .write(true)
+            .create_new(true)
+            .open(&tmp_path)
+            .with_context(|| format!("无法创建临时文件: {}", tmp_path.display()))?;
+        file.write_all(contents.as_bytes())
+            .with_context(|| format!("无法写入临时文件: {}", tmp_path.display()))?;
+        file.sync_all()
+            .with_context(|| format!("无法同步临时文件: {}", tmp_path.display()))?;
+        drop(file);
+
+        fs::rename(&tmp_path, path).with_context(|| {
+            format!(
+                "无法将临时文件重命名为目标文件: {} -> {}",
+                tmp_path.display(),
+                path.display()
+            )
+        })?;
+        Ok(())
+    })();
+
+    if result.is_err() {
+        let _ = fs::remove_file(&tmp_path);
+    }
+
+    result
+}