Start of all uploads with a rollback

Only if we make it all the way to the git commit should we actually commit all
the way.

Author: alexcrichton

src/db.rs

@@ -100,6 +100,7 @@ impl Transaction {
     }
 
     pub fn rollback(&self) { self.rollback.set(true); }
+    pub fn commit(&self) { self.rollback.set(false); }
 }
 
 impl Middleware for TransactionMiddleware {
@@ -141,6 +142,8 @@ pub trait RequestTransaction<'a> {
 
     /// Do not commit this request's transaction, even if it finishes ok.
     fn rollback(self);
+    /// Flag this transaction to be committed (this is the default)
+    fn commit(self);
 }
 
 impl<'a> RequestTransaction<'a> for &'a Request + 'a {
@@ -161,6 +164,12 @@ impl<'a> RequestTransaction<'a> for &'a Request + 'a {
             .expect("Transaction not present in request")
             .rollback()
     }
+
+    fn commit(self) {
+        self.extensions().find::<Transaction>()
+            .expect("Transaction not present in request")
+            .commit()
+    }
 }
 
 pub trait Connection {

src/krate.rs

@@ -419,6 +419,7 @@ pub fn show(req: &mut Request) -> CargoResult<Response> {
 
 pub fn new(req: &mut Request) -> CargoResult<Response> {
     let app = req.app().clone();
+    req.rollback();
 
     let (new_crate, user) = try!(parse_new_headers(req));
     let name = new_crate.name.as_slice();
@@ -509,6 +510,7 @@ pub fn new(req: &mut Request) -> CargoResult<Response> {
 
     // Now that we've come this far, we're committed!
     bomb.path = None;
+    req.commit();
 
     #[deriving(Encodable)]
     struct R { krate: EncodableCrate }