refactor from golang by cursor.

src/walker.rs

@@ -0,0 +1,131 @@
+use std::{
+    ffi::OsStr,
+    fs::{self, DirEntry, ReadDir},
+    io,
+    path::Path,
+};
+
+use crate::{logger::log_error, mac_meta};
+
+pub struct Walker;
+
+impl Walker {
+    pub fn new() -> Self {
+        Self
+    }
+
+    pub fn prune(&self, path: &Path) -> io::Result<bool> {
+        let entries = match self.read_entries(path)? {
+            EntryStream::Entries(entries) => entries,
+            EntryStream::Skip => return Ok(false),
+        };
+
+        let mut is_empty = true;
+
+        for entry_result in entries {
+            if !self.process_entry(path, entry_result) {
+                is_empty = false;
+            }
+        }
+
+        Ok(is_empty)
+    }
+
+    fn read_entries(&self, path: &Path) -> io::Result<EntryStream> {
+        match fs::read_dir(path) {
+            Ok(entries) => Ok(EntryStream::Entries(entries)),
+            Err(err) => {
+                if err.kind() == io::ErrorKind::PermissionDenied {
+                    eprintln!("无法读取 `{}`：{}", path.display(), err);
+                    Ok(EntryStream::Skip)
+                } else {
+                    Err(err)
+                }
+            }
+        }
+    }
+
+    fn process_entry(&self, parent: &Path, entry_result: io::Result<DirEntry>) -> bool {
+        let entry = match entry_result {
+            Ok(entry) => entry,
+            Err(err) => {
+                log_error(parent, &err);
+                return false;
+            }
+        };
+
+        let child_path = entry.path();
+        let file_type = match entry.file_type() {
+            Ok(file_type) => file_type,
+            Err(err) => {
+                log_error(&child_path, &err);
+                return false;
+            }
+        };
+
+        if file_type.is_dir() {
+            return self.handle_directory(&child_path);
+        }
+
+        if file_type.is_file() || file_type.is_symlink() {
+            let name = entry.file_name();
+            return self.handle_metadata_file(&name, &child_path);
+        }
+
+        false
+    }
+
+    fn handle_directory(&self, child_path: &Path) -> bool {
+        match self.prune(child_path) {
+            Ok(true) => match fs::remove_dir(child_path) {
+                Ok(_) => {
+                    println!("删除空目录 `{}`", child_path.display());
+                    true
+                }
+                Err(err) => {
+                    log_error(child_path, &err);
+                    false
+                }
+            },
+            Ok(false) => false,
+            Err(err) => {
+                log_error(child_path, &err);
+                false
+            }
+        }
+    }
+
+    fn handle_metadata_file(&self, name: &OsStr, path: &Path) -> bool {
+        if !should_remove_file(name, path) {
+            return false;
+        }
+
+        println!("删除元数据文件 `{}`", path.display());
+        match fs::remove_file(path) {
+            Ok(_) => true,
+            Err(err) => {
+                log_error(path, &err);
+                false
+            }
+        }
+    }
+}
+
+enum EntryStream {
+    Entries(ReadDir),
+    Skip,
+}
+
+fn should_remove_file(name: &OsStr, path: &Path) -> bool {
+    if name == OsStr::new(".DS_Store") {
+        return true;
+    }
+
+    if let Some(name_str) = name.to_str() {
+        if name_str.starts_with("._") {
+            return mac_meta::is_mac_meta_file(path);
+        }
+    }
+
+    false
+}