Scan for nested files on-demand, not all the time

This does a similar thing that we did with the xattrs, except with the nested files: it removes the 'this' field on File, and replaces it with a method (to_dir) that has the same effect.

This means we get to remove a bunch of 'recurse' fields and parameters that really had no business being there! Now the table doesn't need to know whether it's going to need to list files recursively or not.

src/dir.rs

@@ -37,10 +37,9 @@ impl Dir {
     ///
     /// Passing in `recurse` means that any directories will be scanned for
     /// their contents, as well.
-    pub fn files<'dir>(&'dir self, recurse: bool) -> Files<'dir> {
+    pub fn files<'dir>(&'dir self) -> Files<'dir> {
         Files {
             inner: self.contents.iter(),
-            recurse: recurse,
             dir: &self,
         }
     }
@@ -73,7 +72,6 @@ impl Dir {
 
 pub struct Files<'dir> {
     inner: SliceIter<'dir, PathBuf>,
-    recurse: bool,
     dir: &'dir Dir,
 }
 
@@ -81,6 +79,6 @@ impl<'dir> Iterator for Files<'dir> {
     type Item = Result<File<'dir>, (PathBuf, io::Error)>;
 
     fn next(&mut self) -> Option<Self::Item> {
-        self.inner.next().map(|path| File::from_path(path, Some(self.dir), self.recurse).map_err(|t| (path.clone(), t)))
+        self.inner.next().map(|path| File::from_path(path, Some(self.dir)).map_err(|t| (path.clone(), t)))
     }
 }

src/file.rs

@@ -53,10 +53,6 @@ pub struct File<'dir> {
     /// contain a reference to it, which is used in certain operations (such
     /// as looking up a file's Git status).
     pub dir: Option<&'dir Dir>,
-
-    /// If this `File` is also a directory, then this field is the same file
-    /// as a `Dir`.
-    pub this: Option<io::Result<Dir>>,
 }
 
 impl<'dir> File<'dir> {
@@ -65,31 +61,20 @@ impl<'dir> File<'dir> {
     ///
     /// This uses `symlink_metadata` instead of `metadata`, which doesn't
     /// follow symbolic links.
-    pub fn from_path(path: &Path, parent: Option<&'dir Dir>, recurse: bool) -> io::Result<File<'dir>> {
-        fs::symlink_metadata(path).map(|metadata| File::with_metadata(metadata, path, parent, recurse))
+    pub fn from_path(path: &Path, parent: Option<&'dir Dir>) -> io::Result<File<'dir>> {
+        fs::symlink_metadata(path).map(|metadata| File::with_metadata(metadata, path, parent))
     }
 
     /// Create a new File object from the given metadata result, and other data.
-    pub fn with_metadata(metadata: fs::Metadata, path: &Path, parent: Option<&'dir Dir>, recurse: bool) -> File<'dir> {
+    pub fn with_metadata(metadata: fs::Metadata, path: &Path, parent: Option<&'dir Dir>) -> File<'dir> {
         let filename = path_filename(path);
 
-        // If we are recursing, then the `this` field contains a Dir object
-        // that represents the current File as a directory, if it is a
-        // directory. This is used for the --tree option.
-        let this = if recurse && metadata.is_dir() {
-            Some(Dir::readdir(path, false))
-        }
-        else {
-            None
-        };
-
         File {
             path:   path.to_path_buf(),
             dir:    parent,
             metadata:   metadata,
             ext:    ext(&filename),
             name:   filename.to_string(),
-            this:   this,
         }
     }
 
@@ -98,6 +83,10 @@ impl<'dir> File<'dir> {
         self.metadata.is_dir()
     }
 
+    pub fn to_dir(&self) -> io::Result<Dir> {
+        Dir::readdir(&*self.path, false)
+    }
+
     /// Whether this file is a regular file on the filesystem - that is, not a
     /// directory, a link, or anything else treated specially.
     pub fn is_file(&self) -> bool {
@@ -194,7 +183,6 @@ impl<'dir> File<'dir> {
                 metadata:   metadata,
                 ext:    ext(&filename),
                 name:   filename.to_string(),
-                this:   None,
             })
         }
         else {

src/main.rs

@@ -90,11 +90,8 @@ impl<'dir> Exa<'dir> {
                 let path = Path::new(&*file);
                 let _ = tx.send(match fs::metadata(&path) {
                     Ok(metadata) => {
-                        if !metadata.is_dir() {
-                            StatResult::File(File::with_metadata(metadata, &path, None, false))
-                        }
-                        else if is_tree {
-                            StatResult::File(File::with_metadata(metadata, &path, None, true))
+                        if is_tree || !metadata.is_dir() {
+                            StatResult::File(File::with_metadata(metadata, &path, None))
                         }
                         else {
                             StatResult::Dir(path.to_path_buf())
@@ -149,7 +146,7 @@ impl<'dir> Exa<'dir> {
                 Ok(ref dir) => {
                     let mut files = Vec::new();
 
-                    for file in dir.files(true) {
+                    for file in dir.files() {
                         match file {
                             Ok(file) => files.push(file),
                             Err((path, e))   => println!("[{}: {}]", path.display(), e),

src/output/details.rs

@@ -104,18 +104,18 @@ impl Details {
             // dealt with in the main module. So only actually recurse if we
             // are in tree mode - the other case will be dealt with elsewhere.
             if let Some((r, filter)) = self.recurse {
-                if r.tree == false || r.is_too_deep(depth) {
+                if !file.is_directory() || !r.tree || r.is_too_deep(depth) {
                     continue;
                 }
 
                 // Use the filter to remove unwanted files *before* expanding
                 // them, so we don't examine any directories that wouldn't
                 // have their contents listed anyway.
-                match file.this {
-                    Some(Ok(ref dir)) => {
+                match file.to_dir() {
+                    Ok(ref dir) => {
                         let mut files = Vec::new();
 
-                        let files_to_add = dir.files(true).collect::<Vec<_>>();
+                        let files_to_add = dir.files().collect::<Vec<_>>();
                         let child_count = files_to_add.len();
                         for (index, file_to_add) in files_to_add.into_iter().enumerate() {
                             match file_to_add {
@@ -127,10 +127,9 @@ impl Details {
                         filter.transform_files(&mut files);
                         self.add_files_to_table(table, &files, depth + 1);
                     },
-                    Some(Err(ref e)) => {
+                    Err(ref e) => {
                         table.add_error(e, depth + 1, true, None);
                     },
-                    None => {},
                 }
             }
         }