Implement reparenting (depends on 701) (#706)

Signed-off-by: Ron Kuris <[email protected]>

firewood/src/db.rs

@@ -262,7 +262,8 @@ where
             }
         }
         let nodestore = merkle.into_inner();
-        let immutable: Arc<NodeStore<ImmutableProposal, FileBacked>> = Arc::new(nodestore.into());
+        let immutable: Arc<NodeStore<Arc<ImmutableProposal>, FileBacked>> =
+            Arc::new(nodestore.into());
         self.manager
             .write()
             .expect("poisoned lock")
@@ -312,13 +313,13 @@ impl Db {
 
 #[derive(Debug)]
 pub struct Proposal<'p> {
-    nodestore: Arc<NodeStore<ImmutableProposal, FileBacked>>,
+    nodestore: Arc<NodeStore<Arc<ImmutableProposal>, FileBacked>>,
     db: &'p Db,
 }
 
 #[async_trait]
 impl<'a> api::DbView for Proposal<'a> {
-    type Stream<'b> = MerkleKeyValueStream<'b, NodeStore<ImmutableProposal, FileBacked>> where Self: 'b;
+    type Stream<'b> = MerkleKeyValueStream<'b, NodeStore<Arc<ImmutableProposal>, FileBacked>> where Self: 'b;
 
     async fn root_hash(&self) -> Result<Option<api::HashKey>, api::Error> {
         todo!()
@@ -363,7 +364,6 @@ impl<'a> api::Proposal for Proposal<'a> {
         todo!()
     }
 
-    // When committing a proposal, refuse to commit if there are any cloned proposals.
     async fn commit(self: Arc<Self>) -> Result<(), api::Error> {
         match Arc::into_inner(self) {
             Some(proposal) => {

firewood/src/manager.rs

@@ -26,7 +26,7 @@ pub struct RevisionManagerConfig {
 }
 
 type CommittedRevision = Arc<NodeStore<Committed, FileBacked>>;
-type ProposedRevision = Arc<NodeStore<ImmutableProposal, FileBacked>>;
+type ProposedRevision = Arc<NodeStore<Arc<ImmutableProposal>, FileBacked>>;
 
 #[derive(Debug)]
 pub(crate) struct RevisionManager {
@@ -108,7 +108,7 @@ impl RevisionManager {
         let current_revision = self.current_revision();
         if !proposal
             .kind
-            .parent_is(&current_revision.kind.as_nodestore_parent())
+            .parent_hash_is(current_revision.kind.root_hash())
         {
             return Err(RevisionManagerError::NotLatest);
         }
@@ -133,16 +133,16 @@ impl RevisionManager {
         proposal.flush_header()?;
 
         // 7. Proposal Cleanup
-        self.proposals.retain(|p| {
-            // TODO: reparent proposals; this needs a lock on the parent element of immutable proposals
-            // if p
-            //     .kind
-            //     .parent_is(&proposal.kind.as_nodestore_parent())
-            // {
-            //     p.kind.reparent_to(&committed.kind.as_nodestore_parent());
-            // }
-            !Arc::ptr_eq(&proposal, p)
-        });
+        // first remove the committing proposal from the list of outstanding proposals
+        self.proposals.retain(|p| !Arc::ptr_eq(&proposal, p));
+
+        // then reparent any proposals that have this proposal as a parent
+        for p in self.proposals.iter() {
+            proposal.commit_reparent(p);
+        }
+
+        // 8. Revision reaping
+        // TODO
 
         Ok(())
     }

firewood/src/merkle.rs

@@ -385,7 +385,7 @@ impl<T: HashedNodeReader> Merkle<T> {
 }
 
 impl<S: ReadableStorage> From<Merkle<NodeStore<MutableProposal, S>>>
-    for Merkle<NodeStore<ImmutableProposal, S>>
+    for Merkle<NodeStore<Arc<ImmutableProposal>, S>>
 {
     fn from(m: Merkle<NodeStore<MutableProposal, S>>) -> Self {
         Merkle {
@@ -395,7 +395,7 @@ impl<S: ReadableStorage> From<Merkle<NodeStore<MutableProposal, S>>>
 }
 
 impl<S: ReadableStorage> Merkle<NodeStore<MutableProposal, S>> {
-    pub fn hash(self) -> Merkle<NodeStore<ImmutableProposal, S>> {
+    pub fn hash(self) -> Merkle<NodeStore<Arc<ImmutableProposal>, S>> {
         self.into()
     }
 

storage/Cargo.toml

@@ -14,6 +14,7 @@ serde = { version = "1.0.199", features = ["derive"] }
 smallvec = { version = "1.13.2", features = ["serde", "write", "union"] }
 sha2 = "0.10.8"
 integer-encoding = "4.0.0"
+arc-swap = "1.7.1"
 lru = "0.12.4"
 
 [dev-dependencies]