octopus: supergit: implement initial tree history mechanism

1 files changed, 38 insertions, 3 deletions

diff --git a/apps/servers/octopus/supergit/src/files/tree_utils.rs b/apps/servers/octopus/supergit/src/files/tree_utils.rs
index 55a6c2e0ffab..f5cb94a4031a 100644
--- a/apps/servers/octopus/supergit/src/files/tree_utils.rs
+++ b/apps/servers/octopus/supergit/src/files/tree_utils.rs
@@ -2,7 +2,33 @@
 
 use crate::HashId;
 use git2::{Repository, Tree};
-use std::{path::PathBuf, sync::Arc};
+use std::{iter::Peekable, path::PathBuf, sync::Arc};
+
+pub(super) trait PairIter<I, K>
+where
+    I: Iterator<Item = K>,
+{
+    /// Step through
+    fn pairs<'i, F: FnMut(K, Option<&K>)>(&'i mut self, cb: F);
+
+    fn next_pair<'i>(&'i mut self) -> (Option<K>, Option<&K>);
+}
+
+impl<I, K> PairIter<I, K> for Peekable<I>
+where
+    I: Iterator<Item = K>,
+{
+    fn pairs<'i, F: FnMut(K, Option<&K>)>(&'i mut self, mut cb: F) {
+        // Iterate until a->None
+        while let (Some(a), b) = self.next_pair() {
+            cb(a, b);
+        }
+    }
+
+    fn next_pair<'i>(&'i mut self) -> (Option<K>, Option<&K>) {
+        (self.next(), self.peek())
+    }
+}
 
 /// Take a vector of path segments, and turn it into a valid offset path
 ///
@@ -32,8 +58,6 @@ pub(super) fn path_cmp(target: &Vec<&str>, path: &str, entry: &str) -> bool {
     let mut buf = path_split(path);
     buf.push(entry);
 
-    eprintln!("{:?}", buf);
-
     target == &buf
 }
 
@@ -59,3 +83,14 @@ fn nested_path() {
         String::from("foo/bar/baz")
     );
 }
+
+#[test]
+fn pair_iterator() {
+    // The pair iterator needs access to `peek()`
+    let mut i = vec![1, 2, 3, 4].into_iter().peekable();
+
+    assert_eq!(i.next_pair(), (Some(1), Some(&2)));
+    assert_eq!(i.next_pair(), (Some(2), Some(&3)));
+    assert_eq!(i.next_pair(), (Some(3), Some(&4)));
+    assert_eq!(i.next_pair(), (Some(4), None));
+}