Add bounded streaming execution kernel

crates/remora-stream/src/progress.rs

@@ -0,0 +1,96 @@
+use crate::integrity::IntegrityState;
+
+/// Monotonic transfer progress observed by the copy loop.
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct TransferProgress {
+    /// Absolute completed bytes, including `initial_completed_bytes`.
+    completed_bytes: u64,
+    /// Bytes written during this copy invocation only.
+    session_bytes: u64,
+    total_bytes: Option<u64>,
+    completed_members: u64,
+    total_members: Option<u64>,
+}
+
+impl TransferProgress {
+    #[must_use]
+    pub fn new(
+        completed_bytes: u64,
+        session_bytes: u64,
+        total_bytes: Option<u64>,
+        completed_members: u64,
+        total_members: Option<u64>,
+    ) -> Self {
+        Self {
+            completed_bytes,
+            session_bytes,
+            total_bytes,
+            completed_members,
+            total_members,
+        }
+    }
+
+    #[must_use]
+    pub fn completed_bytes(&self) -> u64 {
+        self.completed_bytes
+    }
+
+    #[must_use]
+    pub fn session_bytes(&self) -> u64 {
+        self.session_bytes
+    }
+
+    #[must_use]
+    pub fn total_bytes(&self) -> Option<u64> {
+        self.total_bytes
+    }
+
+    #[must_use]
+    pub fn completed_members(&self) -> u64 {
+        self.completed_members
+    }
+
+    #[must_use]
+    pub fn total_members(&self) -> Option<u64> {
+        self.total_members
+    }
+}
+
+/// Checkpoint boundary emitted when retained progress should be durable.
+///
+/// Concrete source and destination proofs are adapter-owned. Integrity covers
+/// every byte hashed by the accountant supplied to the copy (prior seed plus
+/// this session). Absolute digests require a seed whose `bytes_hashed` equals
+/// `initial_completed_bytes`.
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct TransferCheckpoint {
+    completed_bytes: u64,
+    session_bytes: u64,
+    integrity: IntegrityState,
+}
+
+impl TransferCheckpoint {
+    #[must_use]
+    pub fn new(completed_bytes: u64, session_bytes: u64, integrity: IntegrityState) -> Self {
+        Self {
+            completed_bytes,
+            session_bytes,
+            integrity,
+        }
+    }
+
+    #[must_use]
+    pub fn completed_bytes(&self) -> u64 {
+        self.completed_bytes
+    }
+
+    #[must_use]
+    pub fn session_bytes(&self) -> u64 {
+        self.session_bytes
+    }
+
+    #[must_use]
+    pub fn integrity(&self) -> &IntegrityState {
+        &self.integrity
+    }
+}