Aws s3 support

src/utils/path.rs

@@ -2,7 +2,7 @@
 //!
 //! Path related utilities
 
-use std::path::{Path, PathBuf};
+use std::path::{Component, Path, PathBuf};
 
 /// ### absolutize
 ///
@@ -24,6 +24,64 @@ pub fn absolutize(wrkdir: &Path, target: &Path) -> PathBuf {
     }
 }
 
+/// ### diff_paths
+///
+/// This function will get the difference from path `path` to `base`. Basically will remove `base` from `path`
+///
+/// For example:
+///
+/// ```rust
+/// assert_eq!(diff_paths(&Path::new("/foo/bar"), &Path::new("/")).as_path(), Path::new("foo/bar"));
+/// assert_eq!(diff_paths(&Path::new("/foo/bar"), &Path::new("/foo")).as_path(), Path::new("bar"));
+/// ```
+///
+/// This function has been written by <https://github.com/Manishearth>
+/// and is licensed under the APACHE-2/MIT license <https://github.com/Manishearth/pathdiff>
+pub fn diff_paths<P, B>(path: P, base: B) -> Option<PathBuf>
+where
+    P: AsRef<Path>,
+    B: AsRef<Path>,
+{
+    let path = path.as_ref();
+    let base = base.as_ref();
+
+    if path.is_absolute() != base.is_absolute() {
+        if path.is_absolute() {
+            Some(PathBuf::from(path))
+        } else {
+            None
+        }
+    } else {
+        let mut ita = path.components();
+        let mut itb = base.components();
+        let mut comps: Vec<Component> = vec![];
+        loop {
+            match (ita.next(), itb.next()) {
+                (None, None) => break,
+                (Some(a), None) => {
+                    comps.push(a);
+                    comps.extend(ita.by_ref());
+                    break;
+                }
+                (None, _) => comps.push(Component::ParentDir),
+                (Some(a), Some(b)) if comps.is_empty() && a == b => (),
+                (Some(a), Some(b)) if b == Component::CurDir => comps.push(a),
+                (Some(_), Some(b)) if b == Component::ParentDir => return None,
+                (Some(a), Some(_)) => {
+                    comps.push(Component::ParentDir);
+                    for _ in itb {
+                        comps.push(Component::ParentDir);
+                    }
+                    comps.push(a);
+                    comps.extend(ita.by_ref());
+                    break;
+                }
+            }
+        }
+        Some(comps.iter().map(|c| c.as_os_str()).collect())
+    }
+}
+
 #[cfg(test)]
 mod test {
 
@@ -40,4 +98,26 @@ mod test {
             Path::new("/tmp/readme.txt")
         );
     }
+
+    #[test]
+    fn calc_diff_paths() {
+        assert_eq!(
+            diff_paths(&Path::new("/foo/bar"), &Path::new("/"))
+                .unwrap()
+                .as_path(),
+            Path::new("foo/bar")
+        );
+        assert_eq!(
+            diff_paths(&Path::new("/foo/bar"), &Path::new("/foo"))
+                .unwrap()
+                .as_path(),
+            Path::new("bar")
+        );
+        assert_eq!(
+            diff_paths(&Path::new("/foo/bar/chiedo.gif"), &Path::new("/"))
+                .unwrap()
+                .as_path(),
+            Path::new("foo/bar/chiedo.gif")
+        );
+    }
 }