From d7bf09ecbdb429e53dca5b88df7aa12acd615891 Mon Sep 17 00:00:00 2001
From: Tyler Neely <t@jujit.su>
Date: Tue, 28 Jul 2020 12:36:15 +0200
Subject: [PATCH 1/3] Cut 0.34.1 with a new TransactionalTrees::flush method

---
 CHANGELOG.md       |  8 ++++++++
 Cargo.toml         |  2 +-
 src/transaction.rs | 29 ++++++++++++++++++++++++++++-
 tests/test_tree.rs | 15 +++++++++++++++
 4 files changed, 52 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b5eaeb3bb..22382f43b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,11 @@
+# 0.34.1
+
+## New Features
+
+* Added the `TransactionalTree::flush` method to
+  flush the underlying database after the transaction
+  commits and before the transaction returns.
+
 # 0.34
 
 ## Improvements
diff --git a/Cargo.toml b/Cargo.toml
index 45cfaf5e7..53685a73e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "sled"
-version = "0.34.0"
+version = "0.34.1"
 authors = ["Tyler Neely <t@jujit.su>"]
 description = "a modern embedded database"
 license = "MIT/Apache-2.0"
diff --git a/src/transaction.rs b/src/transaction.rs
index 492e0d4bf..bd20ecddf 100644
--- a/src/transaction.rs
+++ b/src/transaction.rs
@@ -96,6 +96,7 @@ pub struct TransactionalTree {
     pub(super) tree: Tree,
     pub(super) writes: Rc<RefCell<Map<IVec, Option<IVec>>>>,
     pub(super) read_cache: Rc<RefCell<Map<IVec, Option<IVec>>>>,
+    pub(super) flush_on_commit: Rc<RefCell<bool>>,
 }
 
 /// An error type that is returned from the closure
@@ -329,6 +330,11 @@ impl TransactionalTree {
         Ok(())
     }
 
+    /// Flush the database before returning from the transaction.
+    pub fn flush(&self) {
+        *self.flush_on_commit.borrow_mut() = true;
+    }
+
     fn unstage(&self) {
         unimplemented!()
     }
@@ -352,6 +358,7 @@ impl TransactionalTree {
             tree: tree.clone(),
             writes: Default::default(),
             read_cache: Default::default(),
+            flush_on_commit: Default::default(),
         }
     }
 }
@@ -390,7 +397,25 @@ impl TransactionalTrees {
         // when the peg drops, it ensures all updates
         // written to the log since its creation are
         // recovered atomically
-        peg.seal_batch()
+        let ret = peg.seal_batch();
+
+        ret
+    }
+
+    fn flush_if_configured(&self) -> Result<()> {
+        let mut should_flush = None;
+
+        for tree in &self.inner {
+            if *tree.flush_on_commit.borrow() {
+                should_flush = Some(tree);
+                break;
+            }
+        }
+
+        if let Some(tree) = should_flush {
+            tree.tree.flush()?;
+        }
+        Ok(())
     }
 }
 
@@ -442,6 +467,8 @@ pub trait Transactional<E = ()> {
                 Ok(r) => {
                     let guard = pin();
                     tt.commit(&guard)?;
+                    drop(_locks);
+                    tt.flush_if_configured()?;
                     return Ok(r);
                 }
                 Err(ConflictableTransactionError::Abort(e)) => {
diff --git a/tests/test_tree.rs b/tests/test_tree.rs
index 4afe791ec..3f337b902 100644
--- a/tests/test_tree.rs
+++ b/tests/test_tree.rs
@@ -504,6 +504,21 @@ fn concurrent_tree_transactions() -> TransactionResult<()> {
     Ok(())
 }
 
+#[test]
+fn tree_flush_in_transaction() {
+    let config = sled::Config::new().temporary(true);
+    let db = config.open().unwrap();
+    let tree = db.open_tree(b"a").unwrap();
+
+    tree.transaction::<_, _, sled::transaction::TransactionError>(|tree| {
+        tree.insert(b"k1", b"cats")?;
+        tree.insert(b"k2", b"dogs")?;
+        tree.flush();
+        Ok(())
+    })
+    .unwrap();
+}
+
 #[test]
 fn incorrect_multiple_db_transactions() -> TransactionResult<()> {
     common::setup_logger();

From 3c7312a613caf18ab3ef3c1d72901f2c6cb0ebed Mon Sep 17 00:00:00 2001
From: Tyler Neely <t@jujit.su>
Date: Tue, 28 Jul 2020 12:37:01 +0200
Subject: [PATCH 2/3] Update CHANGELOG.md

---
 CHANGELOG.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 22382f43b..32bc31485 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,7 @@
 
 ## New Features
 
-* Added the `TransactionalTree::flush` method to
+* #1136 Added the `TransactionalTree::flush` method to
   flush the underlying database after the transaction
   commits and before the transaction returns.
 

From 9e566e7a918adeed68edff9c6330cee29941979c Mon Sep 17 00:00:00 2001
From: Tyler Neely <t@jujit.su>
Date: Tue, 28 Jul 2020 12:41:47 +0200
Subject: [PATCH 3/3] Clippy feedback

---
 src/transaction.rs | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/src/transaction.rs b/src/transaction.rs
index bd20ecddf..4f336c3a0 100644
--- a/src/transaction.rs
+++ b/src/transaction.rs
@@ -397,9 +397,7 @@ impl TransactionalTrees {
         // when the peg drops, it ensures all updates
         // written to the log since its creation are
         // recovered atomically
-        let ret = peg.seal_batch();
-
-        ret
+        peg.seal_batch()
     }
 
     fn flush_if_configured(&self) -> Result<()> {
@@ -452,7 +450,7 @@ pub trait Transactional<E = ()> {
             let view = Self::view_overlay(&tt);
 
             // NB locks must exist until this function returns.
-            let _locks = if let Ok(l) = tt.stage() {
+            let locks = if let Ok(l) = tt.stage() {
                 l
             } else {
                 tt.unstage();
@@ -467,7 +465,7 @@ pub trait Transactional<E = ()> {
                 Ok(r) => {
                     let guard = pin();
                     tt.commit(&guard)?;
-                    drop(_locks);
+                    drop(locks);
                     tt.flush_if_configured()?;
                     return Ok(r);
                 }