[Storage] Add inactivity floor to qmdb::keyless Commit operation (#3624)

Author: danlaine

examples/sync/src/databases/keyless.rs

@@ -1,9 +1,9 @@
 //! Keyless database types and helpers for the sync example.
 //!
 //! A `keyless` database is append-only: operations are stored by location rather than by key.
-//! It supports `Append(value)` and `Commit(metadata)` operations. For sync, the engine targets
-//! the Merkle root over all operations, and the client reconstructs the same state by replaying
-//! the fetched operations.
+//! It supports `Append(value)` and `Commit(metadata, floor)` operations. For sync, the engine
+//! targets the Merkle root over all operations, and the client reconstructs the same state by
+//! replaying the fetched operations.
 
 use crate::{Hasher, Key, Value};
 use commonware_cryptography::{Hasher as CryptoHasher, Sha256};
@@ -28,7 +28,7 @@ use tracing::error;
 pub type Database<E> = fixed::Db<mmr::Family, E, Value, Hasher>;
 
 /// Operation type alias.
-pub type Operation = fixed::Operation<Value>;
+pub type Operation = fixed::Operation<mmr::Family, Value>;
 
 /// Create a database configuration for the keyless variant.
 pub fn create_config(context: &(impl BufferPooler + commonware_runtime::Metrics)) -> fixed::Config {
@@ -56,11 +56,23 @@ pub fn create_config(context: &(impl BufferPooler + commonware_runtime::Metrics)
 }
 
 /// Create deterministic test operations for demonstration purposes.
-/// Generates Append operations and periodic Commit operations.
+///
+/// Generates Append operations and periodic Commit operations, advancing the inactivity
+/// floor at each commit to the *previous* commit's location. This models a realistic
+/// application that declares older commits inactive over time (enabling pruning) while
+/// always keeping the most recent commit readable.
 pub fn create_test_operations(count: usize, seed: u64) -> Vec<Operation> {
     let mut operations = Vec::new();
     let mut hasher = <Hasher as CryptoHasher>::new();
 
+    // The DB's initial commit lands at location 0 before any of these ops are applied.
+    // `op_count` tracks the total ops that will exist on disk (including this initial commit
+    // and everything we push below). `prev_commit_loc` tracks the last commit's location
+    // and is used as the next commit's floor — always <= the next commit's own location, so
+    // the per-commit floor bound is satisfied.
+    let mut op_count: u64 = 1;
+    let mut prev_commit_loc: u64 = 0;
+
     for i in 0..count {
         let value = {
             hasher.update(&i.to_be_bytes());
@@ -69,14 +81,20 @@ pub fn create_test_operations(count: usize, seed: u64) -> Vec<Operation> {
         };
 
         operations.push(Operation::Append(value));
+        op_count += 1;
 
         if (i + 1) % 10 == 0 {
-            operations.push(Operation::Commit(None));
+            operations.push(Operation::Commit(None, Location::new(prev_commit_loc)));
+            prev_commit_loc = op_count;
+            op_count += 1;
         }
     }
 
-    // Always end with a commit
-    operations.push(Operation::Commit(Some(Sha256::fill(1))));
+    // Always end with a commit, floor set to the previous commit's location.
+    operations.push(Operation::Commit(
+        Some(Sha256::fill(1)),
+        Location::new(prev_commit_loc),
+    ));
     operations
 }
 
@@ -107,8 +125,8 @@ where
                 Operation::Append(value) => {
                     batch = batch.append(value);
                 }
-                Operation::Commit(metadata) => {
-                    let merkleized = batch.merkleize(self, metadata);
+                Operation::Commit(metadata, floor) => {
+                    let merkleized = batch.merkleize(self, metadata, floor);
                     self.apply_batch(merkleized).await?;
                     self.commit().await?;
                     batch = self.new_batch();
@@ -127,7 +145,7 @@ where
     }
 
     async fn sync_boundary(&self) -> Location {
-        self.sync_boundary().await
+        self.sync_boundary()
     }
 
     async fn historical_proof(
@@ -161,7 +179,7 @@ mod tests {
         let ops = <KeylessDb as Syncable>::create_test_operations(5, 12345);
         assert_eq!(ops.len(), 6); // 5 operations + 1 commit
 
-        if let Operation::Commit(Some(_)) = &ops[5] {
+        if let Operation::Commit(Some(_), _) = &ops[5] {
             // ok
         } else {
             panic!("last operation should be a commit with metadata");

storage/conformance.toml

@@ -220,19 +220,19 @@ hash = "cafbb288de6f8d5c73ddb19df64d2e1429b4f2e273124cb1b20be3026c54d288"
 
 ["commonware_storage::qmdb::conformance::KeylessMmbFixedConf"]
 n_cases = 200
-hash = "41f832011239e8d76ded66ea5e2559a6eaeb6ef65875b9d50db1296a2f26e5f8"
+hash = "d9ad4deb528e8bc514d028efa34e9b31b6642584c8a0c0e98c7a6d9b36f355df"
 
 ["commonware_storage::qmdb::conformance::KeylessMmbVariableConf"]
 n_cases = 200
-hash = "ce612a2c4c3c43db5e797cdeff7df04b872660529ccdfb825feb0efcaaf322a3"
+hash = "c1f535aaa1a4ff8d8594b70d4d121a2ee48c342a68c8549c4b411d299cfa43dc"
 
 ["commonware_storage::qmdb::conformance::KeylessMmrFixedConf"]
 n_cases = 200
-hash = "79ac92e88026d3d73d1cf37edf85fcd82a5fd6824566b05fe04d0ad1fd7ec9e0"
+hash = "49c54ba4ea198f1e5811abfb3a1a077925d1075b006c620cb3e4aa3769c997cb"
 
 ["commonware_storage::qmdb::conformance::KeylessMmrVariableConf"]
 n_cases = 200
-hash = "aa70f866ae6b4104e94c741f46806a430b2ce76e3af5798ba2fb23dff6d1fbd9"
+hash = "aee37bfef687a6855e53f2e4a2ef7190cf9d33cdb67b5e177a7f56f7b44e4b9b"
 
 ["commonware_storage::qmdb::immutable::operation::fixed::tests::conformance::CodecConformance<FixedOp>"]
 n_cases = 65536
@@ -246,13 +246,13 @@ hash = "bdee433c53489ee67a42ad2029081d3f233799bd360d6e5e7f29cbaec87c9064"
 n_cases = 65536
 hash = "7952a9bb3a9cec87a95af6dd96a5b88b535106f0241770e0bfdb8aeaf9421056"
 
-["commonware_storage::qmdb::keyless::operation::tests::conformance::CodecConformance<Operation<FixedEncoding<U64>>>"]
+["commonware_storage::qmdb::keyless::operation::tests::conformance::CodecConformance<Operation<mmr::Family,FixedEncoding<U64>>>"]
 n_cases = 65536
-hash = "c692a20fa40180844888e7a26401f99a45ce3127faeca5f1228a41b454424623"
+hash = "1ad07a5388e328474b353c153617b6a8a3a4713a9895f3f505148f919c49b86d"
 
-["commonware_storage::qmdb::keyless::operation::tests::conformance::CodecConformance<Operation<VariableEncoding<U64>>>"]
+["commonware_storage::qmdb::keyless::operation::tests::conformance::CodecConformance<Operation<mmr::Family,VariableEncoding<U64>>>"]
 n_cases = 65536
-hash = "b41d6c6ec560bde9caf2e206526864c618a0721af367585a1719617ca7ce9291"
+hash = "c6702e8b8d2e96438df00786289df9ee4ec92a767974fa1484766a246ebc71b7"
 
 ["commonware_storage::qmdb::sync::target::tests::conformance::CodecConformance<Target<MmrFamily,sha256::Digest>>"]
 n_cases = 65536