From c9e14dc8a3be31f7dd4755ebbc94ddbed6e176f0 Mon Sep 17 00:00:00 2001
From: Milosz Muszynski <milosz.muszynski@gmail.com>
Date: Mon, 30 Sep 2024 11:16:43 +0200
Subject: [PATCH] piecrust: write commit performance optimizations

---
 piecrust/CHANGELOG.md         |  2 ++
 piecrust/src/store.rs         | 26 ++++++++++++--------------
 piecrust/src/store/session.rs |  1 -
 3 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/piecrust/CHANGELOG.md b/piecrust/CHANGELOG.md
index 7a73d808..9d59b27c 100644
--- a/piecrust/CHANGELOG.md
+++ b/piecrust/CHANGELOG.md
@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- Improved commit writing time [#388]
 - Changed state representation to improve commit performance [#342]
 
 ## [0.24.0] - 2024-09-04
@@ -465,6 +466,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 <!-- ISSUES -->
 
+[#388]: https://github.com/dusk-network/piecrust/issues/388
 [#371]: https://github.com/dusk-network/piecrust/issues/371
 [#359]: https://github.com/dusk-network/piecrust/issues/359
 [#357]: https://github.com/dusk-network/piecrust/issues/357
diff --git a/piecrust/src/store.rs b/piecrust/src/store.rs
index 295dffd6..df49eb2e 100644
--- a/piecrust/src/store.rs
+++ b/piecrust/src/store.rs
@@ -360,7 +360,7 @@ pub(crate) enum Call {
     Commit {
         contracts: BTreeMap<ContractId, ContractDataEntry>,
         base: Option<Commit>,
-        replier: mpsc::SyncSender<io::Result<Commit>>,
+        replier: mpsc::SyncSender<io::Result<Hash>>,
     },
     GetCommits {
         replier: mpsc::SyncSender<Vec<Hash>>,
@@ -510,7 +510,7 @@ fn write_commit<P: AsRef<Path>>(
     commits: &mut BTreeMap<Hash, Commit>,
     base: Option<Commit>,
     commit_contracts: BTreeMap<ContractId, ContractDataEntry>,
-) -> io::Result<Commit> {
+) -> io::Result<Hash> {
     let root_dir = root_dir.as_ref();
 
     let mut index = base
@@ -530,14 +530,14 @@ fn write_commit<P: AsRef<Path>>(
 
     // Don't write the commit if it already exists on disk. This may happen if
     // the same transactions on the same base commit for example.
-    if let Some(commit) = commits.get(&root) {
-        return Ok(commit.clone());
+    if commits.contains_key(&root) {
+        return Ok(root);
     }
 
     write_commit_inner(root_dir, index, commit_contracts, root_hex, base).map(
         |commit| {
-            commits.insert(root, commit.clone());
-            commit
+            commits.insert(root, commit);
+            root
         },
     )
 }
@@ -622,14 +622,12 @@ fn write_commit_inner<P: AsRef<Path>, S: AsRef<str>>(
     }
 
     let index_main_path = index_path_main(directories.main_dir, commit_id)?;
-    let index_bytes = rkyv::to_bytes::<_, 128>(&index)
-        .map_err(|err| {
-            io::Error::new(
-                io::ErrorKind::InvalidData,
-                format!("Failed serializing index file: {err}"),
-            )
-        })?
-        .to_vec();
+    let index_bytes = rkyv::to_bytes::<_, 128>(&index).map_err(|err| {
+        io::Error::new(
+            io::ErrorKind::InvalidData,
+            format!("Failed serializing index file: {err}"),
+        )
+    })?;
     fs::write(index_main_path.clone(), index_bytes)?;
 
     Ok(Commit { index })
diff --git a/piecrust/src/store/session.rs b/piecrust/src/store/session.rs
index bde49f44..9f86dc1e 100644
--- a/piecrust/src/store/session.rs
+++ b/piecrust/src/store/session.rs
@@ -155,7 +155,6 @@ impl ContractSession {
         receiver
             .recv()
             .expect("The receiver should always receive a reply")
-            .map(|c| *c.index.root())
     }
 
     /// Returns path to a file representing a given commit and page.