From 8702a29e6f6ff115bb09721502a7303536b64533 Mon Sep 17 00:00:00 2001
From: Robert Habermeier <rphmeier@gmail.com>
Date: Thu, 4 Aug 2016 23:54:26 +0200
Subject: [PATCH] use mutex in dbtransaction (#1843)

---
 util/src/kvdb.rs | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/util/src/kvdb.rs b/util/src/kvdb.rs
index 1b1aa8ead..469a124bb 100644
--- a/util/src/kvdb.rs
+++ b/util/src/kvdb.rs
@@ -28,7 +28,7 @@ const DB_BACKGROUND_COMPACTIONS: i32 = 2;
 
 /// Write transaction. Batches a sequence of put/delete operations for efficiency.
 pub struct DBTransaction {
-	ops: RwLock<Vec<DBOp>>,
+	ops: Mutex<Vec<DBOp>>,
 }
 
 enum DBOp {
@@ -52,7 +52,7 @@ impl DBTransaction {
 	/// Create new transaction.
 	pub fn new(_db: &Database) -> DBTransaction {
 		DBTransaction {
-			ops: RwLock::new(Vec::with_capacity(256)),
+			ops: Mutex::new(Vec::with_capacity(256)),
 		}
 	}
 
@@ -60,7 +60,7 @@ impl DBTransaction {
 	pub fn put(&self, col: Option<u32>, key: &[u8], value: &[u8]) -> Result<(), String> {
 		let mut ekey = ElasticArray32::new();
 		ekey.append_slice(key);
-		self.ops.write().push(DBOp::Insert {
+		self.ops.lock().push(DBOp::Insert {
 			col: col,
 			key: ekey,
 			value: value.to_vec(),
@@ -72,7 +72,7 @@ impl DBTransaction {
 	pub fn put_vec(&self, col: Option<u32>, key: &[u8], value: Bytes) -> Result<(), String> {
 		let mut ekey = ElasticArray32::new();
 		ekey.append_slice(key);
-		self.ops.write().push(DBOp::Insert {
+		self.ops.lock().push(DBOp::Insert {
 			col: col,
 			key: ekey,
 			value: value,
@@ -85,7 +85,7 @@ impl DBTransaction {
 	pub fn put_compressed(&self, col: Option<u32>, key: &[u8], value: Bytes) -> Result<(), String> {
 		let mut ekey = ElasticArray32::new();
 		ekey.append_slice(key);
-		self.ops.write().push(DBOp::InsertCompressed {
+		self.ops.lock().push(DBOp::InsertCompressed {
 			col: col,
 			key: ekey,
 			value: value,
@@ -97,7 +97,7 @@ impl DBTransaction {
 	pub fn delete(&self, col: Option<u32>, key: &[u8]) -> Result<(), String> {
 		let mut ekey = ElasticArray32::new();
 		ekey.append_slice(key);
-		self.ops.write().push(DBOp::Delete {
+		self.ops.lock().push(DBOp::Delete {
 			col: col,
 			key: ekey,
 		});
@@ -290,30 +290,30 @@ impl Database {
 	}
 
 
-	fn to_overly_column(col: Option<u32>) -> usize {
+	fn to_overlay_column(col: Option<u32>) -> usize {
 		col.map_or(0, |c| (c + 1) as usize)
 	}
 
 	/// Commit transaction to database.
 	pub fn write_buffered(&self, tr: DBTransaction) -> Result<(), String> {
 		let mut overlay = self.overlay.write();
-		let ops = mem::replace(&mut *tr.ops.write(), Vec::new());
+		let ops = tr.ops.into_inner();
 		for op in ops {
 			match op {
 				DBOp::Insert { col, key, value } => {
-					let c = Self::to_overly_column(col);
+					let c = Self::to_overlay_column(col);
 					overlay[c].deletions.remove(&key);
 					overlay[c].compressed_insertions.remove(&key);
 					overlay[c].insertions.insert(key, value);
 				},
 				DBOp::InsertCompressed { col, key, value } => {
-					let c = Self::to_overly_column(col);
+					let c = Self::to_overlay_column(col);
 					overlay[c].deletions.remove(&key);
 					overlay[c].insertions.remove(&key);
 					overlay[c].compressed_insertions.insert(key, value);
 				},
 				DBOp::Delete { col, key } => {
-					let c = Self::to_overly_column(col);
+					let c = Self::to_overlay_column(col);
 					overlay[c].insertions.remove(&key);
 					overlay[c].compressed_insertions.remove(&key);
 					overlay[c].deletions.insert(key);
@@ -364,7 +364,7 @@ impl Database {
 	/// Commit transaction to database.
 	pub fn write(&self, tr: DBTransaction) -> Result<(), String> {
 		let batch = WriteBatch::new();
-		let ops = mem::replace(&mut *tr.ops.write(), Vec::new());
+		let ops = tr.ops.into_inner();
 		for op in ops {
 			match op {
 				DBOp::Insert { col, key, value } => {
@@ -384,7 +384,7 @@ impl Database {
 
 	/// Get value by key.
 	pub fn get(&self, col: Option<u32>, key: &[u8]) -> Result<Option<Bytes>, String> {
-		let overlay = &self.overlay.read()[Self::to_overly_column(col)];
+		let overlay = &self.overlay.read()[Self::to_overlay_column(col)];
 		overlay.insertions.get(key).or_else(|| overlay.compressed_insertions.get(key)).map_or_else(||
 			col.map_or_else(
 				|| self.db.get(key).map(|r| r.map(|v| v.to_vec())),