feat(Merkle): Tree and Node IDs for Verify

durable-storage/src/avl/node.rs

@@ -19,6 +19,9 @@ use octez_riscv_data::foldable::Foldable;
 use octez_riscv_data::foldable::NodeFold;
 use octez_riscv_data::hash::Hash;
 use octez_riscv_data::hash::HashFold;
+use octez_riscv_data::merkle_proof::Deserialiser;
+use octez_riscv_data::merkle_proof::DeserialiserNode;
+use octez_riscv_data::merkle_proof::FromProof;
 use octez_riscv_data::mode::Mode;
 use octez_riscv_data::mode::Normal;
 use octez_riscv_data::mode::Prove;
@@ -170,6 +173,31 @@ impl<TreeId, M: BytesMode + AtomMode> Node<TreeId, M> {
         }
     }
 
+    /// Construct a [`Node`] from its branches in a proof, advancing the deserialiser context.
+    pub(super) fn from_branches<D: DeserialiserNode>(
+        ctx: D,
+    ) -> Result<(D, Self), <D::Parent as Deserialiser>::Error>
+    where
+        Atom<Meta, M>: FromProof,
+        Bytes<M>: FromProof,
+        TreeId: FromProof,
+    {
+        let (ctx, meta) = ctx.next_branch::<Atom<Meta, M>>()?;
+        let (ctx, data) = ctx.next_branch::<Bytes<M>>()?;
+        let (ctx, left) = ctx.next_branch::<TreeId>()?;
+        let (ctx, right) = ctx.next_branch::<TreeId>()?;
+
+        let node = Node {
+            meta,
+            data,
+            left,
+            right,
+            hash: Default::default(),
+        };
+
+        Ok((ctx, node))
+    }
+
     /// Converts the [`Node`] to an encoded, serialisable representation,
     /// [`NodeHashRepresentation`], potentially re-hashing uncached [`Node`]s.
     pub(crate) fn to_encode<'a>(&'a self) -> impl Encode + 'a

durable-storage/src/avl/resolver.rs

@@ -36,9 +36,17 @@ use octez_riscv_data::foldable::Fold;
 use octez_riscv_data::foldable::Foldable;
 use octez_riscv_data::hash::Hash;
 use octez_riscv_data::hash::HashFold;
+use octez_riscv_data::merkle_proof::Deserialiser;
+use octez_riscv_data::merkle_proof::DeserialiserNode;
+use octez_riscv_data::merkle_proof::FromProof;
+use octez_riscv_data::merkle_proof::Partial;
+use octez_riscv_data::merkle_proof::Suspended;
+use octez_riscv_data::merkle_proof::SuspendedResult;
 use octez_riscv_data::mode::Mode;
 use octez_riscv_data::mode::Normal;
 use octez_riscv_data::mode::Prove;
+use octez_riscv_data::mode::Verify;
+use octez_riscv_data::mode::utils::not_found;
 use octez_riscv_data::serialisation::deserialise;
 use trait_set::trait_set;
 
@@ -515,6 +523,110 @@ impl<R: Resolver<LazyTreeId, Tree<LazyNodeId>>> Resolver<ProveTreeId, Tree<Prove
     }
 }
 
+/// Identifier for a node resolved in [`Verify`] mode.
+pub enum VerifyNodeId {
+    Present(Node<VerifyTreeId, Verify>),
+    Blind(Hash),
+}
+
+impl FromProof for VerifyNodeId {
+    fn from_proof<Proof: Deserialiser>(proof: Proof) -> SuspendedResult<Proof, Self> {
+        let ctx = proof.into_node()?;
+        match ctx.presence() {
+            Partial::Blinded(hash) => ctx.done(VerifyNodeId::Blind(hash)),
+            Partial::Present(()) => {
+                let (ctx, node) = Node::from_branches(ctx)?;
+                ctx.done(VerifyNodeId::Present(node))
+            }
+            // SAFETY: called only in `Verify` mode
+            Partial::Absent => unsafe { not_found() },
+        }
+    }
+}
+
+/// Identifier for a tree resolved in [`Verify`] mode.
+pub enum VerifyTreeId {
+    Present(Tree<Arc<VerifyNodeId>>),
+    Blind(Hash),
+    Absent,
+}
+
+impl FromProof for VerifyTreeId {
+    fn from_proof<Proof: Deserialiser>(proof: Proof) -> SuspendedResult<Proof, Self> {
+        let ctx = proof.into_node()?;
+        match ctx.presence() {
+            Partial::Absent => ctx.done(VerifyTreeId::Absent),
+            Partial::Blinded(hash) => ctx.done(VerifyTreeId::Blind(hash)),
+            Partial::Present(()) => {
+                let (ctx, present) = ctx.next_branch_with(|proof| proof.into_leaf::<bool>())?;
+                match present {
+                    Partial::Present(true) => {
+                        let (ctx, node_id) = ctx.next_branch_with(|proof| {
+                            let suspended = VerifyNodeId::from_proof(proof)?;
+                            Ok(suspended.map(Arc::new))
+                        })?;
+                        ctx.done(VerifyTreeId::Present(Tree::from(Some(node_id))))
+                    }
+                    Partial::Present(false) => ctx.done(VerifyTreeId::Present(Tree::default())),
+                    // SAFETY: called only in `Verify` mode
+                    Partial::Blinded(_) | Partial::Absent => unsafe { not_found() },
+                }
+            }
+        }
+    }
+}
+
+/// Adapter that projects in-memory AVL identifiers into verify-mode values.
+pub struct VerifyResolver;
+
+impl Resolver<VerifyNodeId, Node<VerifyTreeId, Verify>> for VerifyResolver {
+    fn resolve<'a>(
+        &self,
+        id: &'a VerifyNodeId,
+    ) -> Result<&'a Node<VerifyTreeId, Verify>, OperationalError> {
+        match id {
+            VerifyNodeId::Present(inner) => Ok(inner),
+            // SAFETY: called only in `Verify` mode
+            VerifyNodeId::Blind(_) => unsafe { not_found() },
+        }
+    }
+
+    fn resolve_mut<'a>(
+        &mut self,
+        id: &'a mut VerifyNodeId,
+    ) -> Result<&'a mut Node<VerifyTreeId, Verify>, OperationalError> {
+        match id {
+            VerifyNodeId::Present(inner) => Ok(inner),
+            // SAFETY: called only in `Verify` mode
+            VerifyNodeId::Blind(_) => unsafe { not_found() },
+        }
+    }
+}
+
+impl Resolver<VerifyTreeId, Tree<Arc<VerifyNodeId>>> for VerifyResolver {
+    fn resolve<'a>(
+        &self,
+        id: &'a VerifyTreeId,
+    ) -> Result<&'a Tree<Arc<VerifyNodeId>>, OperationalError> {
+        match id {
+            VerifyTreeId::Present(inner) => Ok(inner),
+            // SAFETY: called only in `Verify` mode
+            VerifyTreeId::Blind(_) | VerifyTreeId::Absent => unsafe { not_found() },
+        }
+    }
+
+    fn resolve_mut<'a>(
+        &mut self,
+        id: &'a mut VerifyTreeId,
+    ) -> Result<&'a mut Tree<Arc<VerifyNodeId>>, OperationalError> {
+        match id {
+            VerifyTreeId::Present(inner) => Ok(inner),
+            // SAFETY: called only in `Verify` mode
+            VerifyTreeId::Blind(_) | VerifyTreeId::Absent => unsafe { not_found() },
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use std::sync::Arc;