Garage works on sqlite, but it's a hack

Cargo.lock

@@ -1017,6 +1017,7 @@ dependencies = [
  "clap 3.1.18",
  "err-derive 0.3.1",
  "hexdump",
+ "log",
  "mktemp",
  "rusqlite",
  "sled",

src/db/Cargo.toml

@@ -19,6 +19,7 @@ required-features = ["cli"]
 [dependencies]
 err-derive = "0.3"
 hexdump = "0.1"
+log = "0.4"
 
 sled = "0.34"
 rusqlite = "0.27"

src/db/bin/convert.rs

@@ -2,7 +2,7 @@ use std::path::PathBuf;
 
 use garage_db::*;
 
-use clap::{Parser};
+use clap::Parser;
 
 /// K2V command line interface
 #[derive(Parser, Debug)]
@@ -41,12 +41,10 @@ fn do_conversion(args: Args) -> Result<()> {
 fn open_db(path: PathBuf, engine: String) -> Result<Db> {
 	match engine.as_str() {
 		"sled" => {
-			let db = sled_adapter::sled::Config::default()
-				.path(&path)
-				.open()?;
+			let db = sled_adapter::sled::Config::default().path(&path).open()?;
 			Ok(sled_adapter::SledDb::init(db))
 		}
-		"sqlite" | "rusqlite" => {
+		"sqlite" | "sqlite3" | "rusqlite" => {
 			let db = sqlite_adapter::rusqlite::Connection::open(&path)?;
 			Ok(sqlite_adapter::SqliteDb::init(db))
 		}

src/db/lib.rs

@@ -180,7 +180,13 @@ impl Db {
 	pub fn import(&self, other: &Db) -> Result<()> {
 		let existing_trees = self.list_trees()?;
 		if !existing_trees.is_empty() {
-			return Err(Error(format!("destination database already contains data: {:?}", existing_trees).into()));
+			return Err(Error(
+				format!(
+					"destination database already contains data: {:?}",
+					existing_trees
+				)
+				.into(),
+			));
 		}
 
 		let tree_names = other.list_trees()?;

src/db/sqlite_adapter.rs

@@ -5,6 +5,8 @@ use std::pin::Pin;
 use std::ptr::NonNull;
 use std::sync::{Arc, Mutex, MutexGuard, RwLock};
 
+use log::trace;
+
 use rusqlite::{params, Connection, Rows, Statement, Transaction};
 
 use crate::{Db, Error, IDb, ITx, ITxFn, Result, TxError, TxFnResult, TxResult, Value, ValueIter};
@@ -53,13 +55,17 @@ impl SqliteDb {
 
 impl IDb for SqliteDb {
 	fn open_tree(&self, name: &str) -> Result<usize> {
-		let name = format!("tree_{}", name.replace(":", "_COLON_"));
+		let name = format!("tree_{}", name.replace(':', "_COLON_"));
 
 		let mut trees = self.trees.write().unwrap();
 		if let Some(i) = trees.iter().position(|x| x == &name) {
 			Ok(i)
 		} else {
-			self.db.lock().unwrap().execute(
+			trace!("open tree {}: lock db", name);
+			let db = self.db.lock().unwrap();
+			trace!("create table {}", name);
+
+			db.execute(
 				&format!(
 					"CREATE TABLE IF NOT EXISTS {} (
 						k BLOB PRIMARY KEY,
@@ -69,6 +75,8 @@ impl IDb for SqliteDb {
 				),
 				[],
 			)?;
+			trace!("table created: {}", name);
+
 			let i = trees.len();
 			trees.push(name.to_string());
 			Ok(i)
@@ -77,7 +85,11 @@ impl IDb for SqliteDb {
 
 	fn list_trees(&self) -> Result<Vec<String>> {
 		let mut trees = vec![];
+
+		trace!("list_trees: lock db");
 		let db = self.db.lock().unwrap();
+		trace!("list_trees: lock acquired");
+
 		let mut stmt = db.prepare(
 			"SELECT name FROM sqlite_schema WHERE type = 'table' AND name LIKE 'tree_%'",
 		)?;
@@ -94,7 +106,11 @@ impl IDb for SqliteDb {
 
 	fn get(&self, tree: usize, key: &[u8]) -> Result<Option<Value<'_>>> {
 		let tree = self.get_tree(tree)?;
+
+		trace!("get: lock db");
 		let db = self.db.lock().unwrap();
+		trace!("get: lock acquired");
+
 		let mut stmt = db.prepare(&format!("SELECT v FROM {} WHERE k = ?1", tree))?;
 		let mut res_iter = stmt.query([key])?;
 		match res_iter.next()? {
@@ -105,14 +121,22 @@ impl IDb for SqliteDb {
 
 	fn remove(&self, tree: usize, key: &[u8]) -> Result<bool> {
 		let tree = self.get_tree(tree)?;
+
+		trace!("remove: lock db");
 		let db = self.db.lock().unwrap();
+		trace!("remove: lock acquired");
+
 		let res = db.execute(&format!("DELETE FROM {} WHERE k = ?1", tree), params![key])?;
 		Ok(res > 0)
 	}
 
 	fn len(&self, tree: usize) -> Result<usize> {
 		let tree = self.get_tree(tree)?;
+
+		trace!("len: lock db");
 		let db = self.db.lock().unwrap();
+		trace!("len: lock acquired");
+
 		let mut stmt = db.prepare(&format!("SELECT COUNT(*) FROM {}", tree))?;
 		let mut res_iter = stmt.query([])?;
 		match res_iter.next()? {
@@ -123,7 +147,11 @@ impl IDb for SqliteDb {
 
 	fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<()> {
 		let tree = self.get_tree(tree)?;
+
+		trace!("insert: lock db");
 		let db = self.db.lock().unwrap();
+		trace!("insert: lock acquired");
+
 		db.execute(
 			&format!("INSERT OR REPLACE INTO {} (k, v) VALUES (?1, ?2)", tree),
 			params![key, value],
@@ -134,13 +162,23 @@ impl IDb for SqliteDb {
 	fn iter(&self, tree: usize) -> Result<ValueIter<'_>> {
 		let tree = self.get_tree(tree)?;
 		let sql = format!("SELECT k, v FROM {} ORDER BY k ASC", tree);
-		DbValueIterator::make(self.db.lock().unwrap(), &sql, [])
+
+		trace!("iter {}: lock db", tree);
+		let db = self.db.lock().unwrap();
+		trace!("iter {}: lock acquired", tree);
+
+		DbValueIterator::make(db, &sql, [])
 	}
 
 	fn iter_rev(&self, tree: usize) -> Result<ValueIter<'_>> {
 		let tree = self.get_tree(tree)?;
 		let sql = format!("SELECT k, v FROM {} ORDER BY k DESC", tree);
-		DbValueIterator::make(self.db.lock().unwrap(), &sql, [])
+
+		trace!("iter_rev {}: lock db", tree);
+		let db = self.db.lock().unwrap();
+		trace!("iter_rev {}: lock acquired", tree);
+
+		DbValueIterator::make(db, &sql, [])
 	}
 
 	fn range<'r>(
@@ -158,11 +196,12 @@ impl IDb for SqliteDb {
 			.iter()
 			.map(|x| x as &dyn rusqlite::ToSql)
 			.collect::<Vec<_>>();
-		DbValueIterator::make::<&[&dyn rusqlite::ToSql]>(
-			self.db.lock().unwrap(),
-			&sql,
-			params.as_ref(),
-		)
+
+		trace!("range {}: lock db", tree);
+		let db = self.db.lock().unwrap();
+		trace!("range {}: lock acquired", tree);
+
+		DbValueIterator::make::<&[&dyn rusqlite::ToSql]>(db, &sql, params.as_ref())
 	}
 	fn range_rev<'r>(
 		&self,
@@ -179,23 +218,28 @@ impl IDb for SqliteDb {
 			.iter()
 			.map(|x| x as &dyn rusqlite::ToSql)
 			.collect::<Vec<_>>();
-		DbValueIterator::make::<&[&dyn rusqlite::ToSql]>(
-			self.db.lock().unwrap(),
-			&sql,
-			params.as_ref(),
-		)
+
+		trace!("range_rev {}: lock db", tree);
+		let db = self.db.lock().unwrap();
+		trace!("range_rev {}: lock acquired", tree);
+
+		DbValueIterator::make::<&[&dyn rusqlite::ToSql]>(db, &sql, params.as_ref())
 	}
 
 	// ----
 
 	fn transaction(&self, f: &dyn ITxFn) -> TxResult<(), ()> {
 		let trees = self.trees.read().unwrap();
+
+		trace!("transaction: lock db");
 		let mut db = self.db.lock().unwrap();
+		trace!("transaction: lock acquired");
+
 		let tx = SqliteTx {
 			tx: db.transaction()?,
 			trees: trees.as_ref(),
 		};
-		match f.try_on(&tx) {
+		let res = match f.try_on(&tx) {
 			TxFnResult::Ok => {
 				tx.tx.commit()?;
 				Ok(())
@@ -210,7 +254,10 @@ impl IDb for SqliteDb {
 					"(this message will be discarded)".into(),
 				)))
 			}
-		}
+		};
+
+		trace!("transaction done");
+		res
 	}
 }
 
@@ -337,6 +384,7 @@ impl<'a> DbValueIterator<'a> {
 
 impl<'a> Drop for DbValueIterator<'a> {
 	fn drop(&mut self) {
+		trace!("drop iter");
 		drop(self.iter.take());
 		drop(self.stmt.take());
 	}

src/garage/server.rs

@@ -32,15 +32,32 @@ pub async fn run_server(config_file: PathBuf) -> Result<(), Error> {
 	let config = read_config(config_file).expect("Unable to read config file");
 
 	info!("Opening database...");
-	let mut db_path = config.metadata_dir.clone();
-	db_path.push("db");
-	let db = db::sled_adapter::sled::Config::default()
-		.path(&db_path)
-		.cache_capacity(config.sled_cache_capacity)
-		.flush_every_ms(Some(config.sled_flush_every_ms))
-		.open()
-		.expect("Unable to open sled DB");
-	let db = db::sled_adapter::SledDb::init(db);
+	let db = match config.db_engine.as_str() {
+		"sled" => {
+			let mut db_path = config.metadata_dir.clone();
+			db_path.push("db");
+			let db = db::sled_adapter::sled::Config::default()
+				.path(&db_path)
+				.cache_capacity(config.sled_cache_capacity)
+				.flush_every_ms(Some(config.sled_flush_every_ms))
+				.open()
+				.expect("Unable to open sled DB");
+			db::sled_adapter::SledDb::init(db)
+		}
+		"sqlite" => {
+			let mut db_path = config.metadata_dir.clone();
+			db_path.push("db.sqlite");
+			let db = db::sqlite_adapter::rusqlite::Connection::open(db_path)
+				.expect("Unable to open sqlite DB");
+			db::sqlite_adapter::SqliteDb::init(db)
+		}
+		e => {
+			return Err(Error::Message(format!(
+				"Unsupported DB engine: {} (options: sled, sqlite)",
+				e
+			)));
+		}
+	};
 
 	info!("Initializing background runner...");
 	let watch_cancel = netapp::util::watch_ctrl_c();

src/table/merkle.rs

@@ -110,9 +110,14 @@ where
 	}
 
 	fn updater_loop_iter(&self) -> Result<bool, Error> {
-		if let Some(x) = self.data.merkle_todo.iter()?.next() {
+		// TODO undo this iter hack
+		let mut iter = self.data.merkle_todo.iter()?;
+		if let Some(x) = iter.next() {
 			let (key, valhash) = x?;
-			self.update_item(&key[..], &valhash[..])?;
+			let key = key.to_vec();
+			let valhash = valhash.to_vec();
+			drop(iter);
+			self.update_item(&key, &valhash)?;
 			Ok(true)
 		} else {
 			Ok(false)

src/util/config.rs

@@ -64,14 +64,19 @@ pub struct Config {
 	#[serde(default)]
 	pub kubernetes_skip_crd: bool,
 
+	// -- DB
+	/// Database engine to use for metadata (options: sled, sqlite)
+	#[serde(default = "default_db_engine")]
+	pub db_engine: String,
+
 	/// Sled cache size, in bytes
 	#[serde(default = "default_sled_cache_capacity")]
 	pub sled_cache_capacity: u64,
-
 	/// Sled flush interval in milliseconds
 	#[serde(default = "default_sled_flush_every_ms")]
 	pub sled_flush_every_ms: u64,
 
+	// -- APIs
 	/// Configuration for S3 api
 	pub s3_api: S3ApiConfig,
 
@@ -129,6 +134,10 @@ pub struct AdminConfig {
 	pub trace_sink: Option<String>,
 }
 
+fn default_db_engine() -> String {
+	"sled".into()
+}
+
 fn default_sled_cache_capacity() -> u64 {
 	128 * 1024 * 1024
 }