Drop copy and clone traits requirement on backend databases

Signed-off-by: Victor Porof <victor.porof@gmail.com>

examples/iterator.rs

@@ -35,7 +35,7 @@ fn main() {
     let k = created_arc.read().unwrap();
     let store = k.open_single("store", StoreOptions::create()).unwrap();
 
-    populate_store(&k, store).unwrap();
+    populate_store(&k, &store).unwrap();
 
     let reader = k.read().unwrap();
 
@@ -64,7 +64,7 @@ fn main() {
     }
 }
 
-fn populate_store(k: &Rkv<LmdbEnvironment>, store: SingleStore<LmdbDatabase>) -> Result<(), StoreError> {
+fn populate_store(k: &Rkv<LmdbEnvironment>, store: &SingleStore<LmdbDatabase>) -> Result<(), StoreError> {
     let mut writer = k.write()?;
     for (country, city) in vec![
         ("Canada", Value::Str("Ottawa")),

examples/simple-store.rs

@@ -27,7 +27,7 @@ use rkv::{
 type MultiStore = rkv::MultiStore<LmdbDatabase>;
 type Writer<'env> = rkv::Writer<LmdbRwTransaction<'env>>;
 
-fn getput<'env, 's>(store: MultiStore, writer: &'env mut Writer, ids: &'s mut Vec<String>) {
+fn getput<'env, 's>(store: &MultiStore, writer: &'env mut Writer, ids: &'s mut Vec<String>) {
     let keys = vec!["str1", "str2", "str3"];
     // we convert the writer into a cursor so that we can safely read
     for k in keys.iter() {
@@ -46,7 +46,7 @@ fn getput<'env, 's>(store: MultiStore, writer: &'env mut Writer, ids: &'s mut Ve
     }
 }
 
-fn delete(store: MultiStore, writer: &mut Writer) {
+fn delete(store: &MultiStore, writer: &mut Writer) {
     let keys = vec!["str1", "str2", "str3"];
     let vals = vec!["string uno", "string quatro", "string siete"];
     // we convert the writer into a cursor so that we can safely read
@@ -96,10 +96,10 @@ fn main() {
         multistore.put(&mut writer, "str3", &Value::Str("string siete")).unwrap();
         multistore.put(&mut writer, "str3", &Value::Str("string ocho")).unwrap();
         multistore.put(&mut writer, "str3", &Value::Str("string nueve")).unwrap();
-        getput(multistore, &mut writer, &mut ids);
+        getput(&multistore, &mut writer, &mut ids);
         writer.commit().unwrap();
         let mut writer = k.write().unwrap();
-        delete(multistore, &mut writer);
+        delete(&multistore, &mut writer);
         writer.commit().unwrap();
     }
 

src/backend/impl_lmdb/database.rs

@@ -10,7 +10,7 @@
 
 use crate::backend::traits::BackendDatabase;
 
-#[derive(Debug, Eq, PartialEq, Copy, Clone)]
+#[derive(Debug, Eq, PartialEq)]
 pub struct DatabaseImpl(pub(crate) lmdb::Database);
 
 impl BackendDatabase for DatabaseImpl {}

src/backend/impl_lmdb/transaction.rs

@@ -31,7 +31,7 @@ impl<'env> BackendRoTransaction for RoTransactionImpl<'env> {
     type Database = DatabaseImpl;
     type Flags = WriteFlagsImpl;
 
-    fn get(&self, db: Self::Database, key: &[u8]) -> Result<&[u8], Self::Error> {
+    fn get(&self, db: &Self::Database, key: &[u8]) -> Result<&[u8], Self::Error> {
         self.0.get(db.0, &key).map_err(ErrorImpl)
     }
 
@@ -43,7 +43,7 @@ impl<'env> BackendRoTransaction for RoTransactionImpl<'env> {
 impl<'env> BackendRoCursorTransaction<'env> for RoTransactionImpl<'env> {
     type RoCursor = RoCursorImpl<'env>;
 
-    fn open_ro_cursor(&'env self, db: Self::Database) -> Result<Self::RoCursor, Self::Error> {
+    fn open_ro_cursor(&'env self, db: &Self::Database) -> Result<Self::RoCursor, Self::Error> {
         self.0.open_ro_cursor(db.0).map(RoCursorImpl).map_err(ErrorImpl)
     }
 }
@@ -56,19 +56,19 @@ impl<'env> BackendRwTransaction for RwTransactionImpl<'env> {
     type Database = DatabaseImpl;
     type Flags = WriteFlagsImpl;
 
-    fn get(&self, db: Self::Database, key: &[u8]) -> Result<&[u8], Self::Error> {
+    fn get(&self, db: &Self::Database, key: &[u8]) -> Result<&[u8], Self::Error> {
         self.0.get(db.0, &key).map_err(ErrorImpl)
     }
 
-    fn put(&mut self, db: Self::Database, key: &[u8], value: &[u8], flags: Self::Flags) -> Result<(), Self::Error> {
+    fn put(&mut self, db: &Self::Database, key: &[u8], value: &[u8], flags: Self::Flags) -> Result<(), Self::Error> {
         self.0.put(db.0, &key, &value, flags.0).map_err(ErrorImpl)
     }
 
-    fn del(&mut self, db: Self::Database, key: &[u8], value: Option<&[u8]>) -> Result<(), Self::Error> {
+    fn del(&mut self, db: &Self::Database, key: &[u8], value: Option<&[u8]>) -> Result<(), Self::Error> {
         self.0.del(db.0, &key, value).map_err(ErrorImpl)
     }
 
-    fn clear_db(&mut self, db: Self::Database) -> Result<(), Self::Error> {
+    fn clear_db(&mut self, db: &Self::Database) -> Result<(), Self::Error> {
         self.0.clear_db(db.0).map_err(ErrorImpl)
     }
 
@@ -84,7 +84,7 @@ impl<'env> BackendRwTransaction for RwTransactionImpl<'env> {
 impl<'env> BackendRwCursorTransaction<'env> for RwTransactionImpl<'env> {
     type RoCursor = RoCursorImpl<'env>;
 
-    fn open_ro_cursor(&'env self, db: Self::Database) -> Result<Self::RoCursor, Self::Error> {
+    fn open_ro_cursor(&'env self, db: &Self::Database) -> Result<Self::RoCursor, Self::Error> {
         self.0.open_ro_cursor(db.0).map(RoCursorImpl).map_err(ErrorImpl)
     }
 }

src/backend/traits.rs

@@ -23,7 +23,7 @@ use crate::error::StoreError;
 
 pub trait BackendError: Debug + Display + Into<StoreError> {}
 
-pub trait BackendDatabase: Debug + Eq + PartialEq + Copy + Clone {}
+pub trait BackendDatabase: Debug + Eq + PartialEq {}
 
 pub trait BackendFlags: Debug + Eq + PartialEq + Copy + Clone + Default {
     fn empty() -> Self;
@@ -120,7 +120,7 @@ pub trait BackendRoTransaction: Debug {
     type Database: BackendDatabase;
     type Flags: BackendWriteFlags;
 
-    fn get(&self, db: Self::Database, key: &[u8]) -> Result<&[u8], Self::Error>;
+    fn get(&self, db: &Self::Database, key: &[u8]) -> Result<&[u8], Self::Error>;
 
     fn abort(self);
 }
@@ -130,13 +130,13 @@ pub trait BackendRwTransaction: Debug {
     type Database: BackendDatabase;
     type Flags: BackendWriteFlags;
 
-    fn get(&self, db: Self::Database, key: &[u8]) -> Result<&[u8], Self::Error>;
+    fn get(&self, db: &Self::Database, key: &[u8]) -> Result<&[u8], Self::Error>;
 
-    fn put(&mut self, db: Self::Database, key: &[u8], value: &[u8], flags: Self::Flags) -> Result<(), Self::Error>;
+    fn put(&mut self, db: &Self::Database, key: &[u8], value: &[u8], flags: Self::Flags) -> Result<(), Self::Error>;
 
-    fn del(&mut self, db: Self::Database, key: &[u8], value: Option<&[u8]>) -> Result<(), Self::Error>;
+    fn del(&mut self, db: &Self::Database, key: &[u8], value: Option<&[u8]>) -> Result<(), Self::Error>;
 
-    fn clear_db(&mut self, db: Self::Database) -> Result<(), Self::Error>;
+    fn clear_db(&mut self, db: &Self::Database) -> Result<(), Self::Error>;
 
     fn commit(self) -> Result<(), Self::Error>;
 
@@ -146,13 +146,13 @@ pub trait BackendRwTransaction: Debug {
 pub trait BackendRoCursorTransaction<'env>: BackendRoTransaction {
     type RoCursor: BackendRoCursor<'env>;
 
-    fn open_ro_cursor(&'env self, db: Self::Database) -> Result<Self::RoCursor, Self::Error>;
+    fn open_ro_cursor(&'env self, db: &Self::Database) -> Result<Self::RoCursor, Self::Error>;
 }
 
 pub trait BackendRwCursorTransaction<'env>: BackendRwTransaction {
     type RoCursor: BackendRoCursor<'env>;
 
-    fn open_ro_cursor(&'env self, db: Self::Database) -> Result<Self::RoCursor, Self::Error>;
+    fn open_ro_cursor(&'env self, db: &Self::Database) -> Result<Self::RoCursor, Self::Error>;
 }
 
 pub trait BackendRoCursor<'env>: Debug {

src/env.rs

@@ -734,7 +734,7 @@ mod tests {
         // as the Value::I64 borrows an immutable reference to the Writer.
         // So we extract and copy its primitive value.
 
-        fn get_existing_foo(store: SingleStore<LmdbDatabase>, writer: &Writer<LmdbRwTransaction>) -> Option<i64> {
+        fn get_existing_foo(store: &SingleStore<LmdbDatabase>, writer: &Writer<LmdbRwTransaction>) -> Option<i64> {
             match store.get(writer, "foo").expect("read") {
                 Some(Value::I64(val)) => Some(val),
                 _ => None,
@@ -742,11 +742,11 @@ mod tests {
         }
 
         let mut writer = k.write().expect("writer");
-        let mut existing = get_existing_foo(sk, &writer).unwrap_or(99);
+        let mut existing = get_existing_foo(&sk, &writer).unwrap_or(99);
         existing += 1;
         sk.put(&mut writer, "foo", &Value::I64(existing)).expect("success");
 
-        let updated = get_existing_foo(sk, &writer).unwrap_or(99);
+        let updated = get_existing_foo(&sk, &writer).unwrap_or(99);
         assert_eq!(updated, 100);
         writer.commit().expect("commit");
     }
@@ -1246,7 +1246,7 @@ mod tests {
         let root = Builder::new().prefix("test_multiple_thread").tempdir().expect("tempdir");
         fs::create_dir_all(root.path()).expect("dir created");
         let rkv_arc = Arc::new(RwLock::new(Rkv::new::<backend::Lmdb>(root.path()).expect("new succeeded")));
-        let store = rkv_arc.read().unwrap().open_single("test", StoreOptions::create()).expect("opened");
+        let store_arc = Arc::new(rkv_arc.read().unwrap().open_single("test", StoreOptions::create()).expect("opened"));
 
         let num_threads = 10;
         let mut write_handles = Vec::with_capacity(num_threads as usize);
@@ -1260,10 +1260,11 @@ mod tests {
         // For each KV pair, spawn a thread that writes it to the store.
         for i in 0..num_threads {
             let rkv_arc = rkv_arc.clone();
+            let store_arc = store_arc.clone();
             write_handles.push(thread::spawn(move || {
                 let rkv = rkv_arc.write().expect("rkv");
                 let mut writer = rkv.write().expect("writer");
-                store.put(&mut writer, i.to_string(), &Value::U64(i)).expect("written");
+                store_arc.put(&mut writer, i.to_string(), &Value::U64(i)).expect("written");
                 writer.commit().unwrap();
             }));
         }
@@ -1275,10 +1276,11 @@ mod tests {
         // and returns its value.
         for i in 0..num_threads {
             let rkv_arc = rkv_arc.clone();
+            let store_arc = store_arc.clone();
             read_handles.push(thread::spawn(move || {
                 let rkv = rkv_arc.read().expect("rkv");
                 let reader = rkv.read().expect("reader");
-                let value = match store.get(&reader, i.to_string()) {
+                let value = match store_arc.get(&reader, i.to_string()) {
                     Ok(Some(Value::U64(value))) => value,
                     Ok(Some(_)) => panic!("value type unexpected"),
                     Ok(None) => panic!("value not found"),

src/readwrite.rs

@@ -27,11 +27,11 @@ pub trait Readable<'env> {
     type Database: BackendDatabase;
     type RoCursor: BackendRoCursor<'env>;
 
-    fn get<K>(&'env self, db: Self::Database, k: &K) -> Result<Option<Value<'env>>, StoreError>
+    fn get<K>(&'env self, db: &Self::Database, k: &K) -> Result<Option<Value<'env>>, StoreError>
     where
         K: AsRef<[u8]>;
 
-    fn open_ro_cursor(&'env self, db: Self::Database) -> Result<Self::RoCursor, StoreError>;
+    fn open_ro_cursor(&'env self, db: &Self::Database) -> Result<Self::RoCursor, StoreError>;
 }
 
 impl<'env, T> Readable<'env> for Reader<T>
@@ -41,7 +41,7 @@ where
     type Database = T::Database;
     type RoCursor = T::RoCursor;
 
-    fn get<K>(&'env self, db: T::Database, k: &K) -> Result<Option<Value<'env>>, StoreError>
+    fn get<K>(&'env self, db: &T::Database, k: &K) -> Result<Option<Value<'env>>, StoreError>
     where
         K: AsRef<[u8]>,
     {
@@ -49,7 +49,7 @@ where
         read_transform(bytes)
     }
 
-    fn open_ro_cursor(&'env self, db: T::Database) -> Result<T::RoCursor, StoreError> {
+    fn open_ro_cursor(&'env self, db: &T::Database) -> Result<T::RoCursor, StoreError> {
         self.0.open_ro_cursor(db).map_err(|e| e.into())
     }
 }
@@ -76,7 +76,7 @@ where
     type Database = T::Database;
     type RoCursor = T::RoCursor;
 
-    fn get<K>(&'env self, db: T::Database, k: &K) -> Result<Option<Value<'env>>, StoreError>
+    fn get<K>(&'env self, db: &T::Database, k: &K) -> Result<Option<Value<'env>>, StoreError>
     where
         K: AsRef<[u8]>,
     {
@@ -84,7 +84,7 @@ where
         read_transform(bytes)
     }
 
-    fn open_ro_cursor(&'env self, db: T::Database) -> Result<T::RoCursor, StoreError> {
+    fn open_ro_cursor(&'env self, db: &T::Database) -> Result<T::RoCursor, StoreError> {
         self.0.open_ro_cursor(db).map_err(|e| e.into())
     }
 }
@@ -107,7 +107,7 @@ where
         self.0.abort();
     }
 
-    pub(crate) fn put<K>(&mut self, db: T::Database, k: &K, v: &Value, flags: T::Flags) -> Result<(), StoreError>
+    pub(crate) fn put<K>(&mut self, db: &T::Database, k: &K, v: &Value, flags: T::Flags) -> Result<(), StoreError>
     where
         K: AsRef<[u8]>,
     {
@@ -115,14 +115,14 @@ where
         self.0.put(db, k.as_ref(), &v.to_bytes()?, flags).map_err(|e| e.into())
     }
 
-    pub(crate) fn delete<K>(&mut self, db: T::Database, k: &K, v: Option<&[u8]>) -> Result<(), StoreError>
+    pub(crate) fn delete<K>(&mut self, db: &T::Database, k: &K, v: Option<&[u8]>) -> Result<(), StoreError>
     where
         K: AsRef<[u8]>,
     {
         self.0.del(db, k.as_ref(), v).map_err(|e| e.into())
     }
 
-    pub(crate) fn clear(&mut self, db: T::Database) -> Result<(), StoreError> {
+    pub(crate) fn clear(&mut self, db: &T::Database) -> Result<(), StoreError> {
         self.0.clear_db(db).map_err(|e| e.into())
     }
 }

src/store/multi.rs

@@ -27,7 +27,6 @@ use crate::value::Value;
 
 type EmptyResult = Result<(), StoreError>;
 
-#[derive(Copy, Clone)]
 pub struct MultiStore<D> {
     db: D,
 }
@@ -49,14 +48,14 @@ where
     }
 
     /// Provides a cursor to all of the values for the duplicate entries that match this key
-    pub fn get<'env, R, I, C, K>(self, reader: &'env R, k: K) -> Result<Iter<'env, I, C>, StoreError>
+    pub fn get<'env, R, I, C, K>(&self, reader: &'env R, k: K) -> Result<Iter<'env, I, C>, StoreError>
     where
         R: Readable<'env, Database = D, RoCursor = C>,
         I: BackendIter<'env>,
         C: BackendRoCursor<'env, Iter = I>,
         K: AsRef<[u8]>,
     {
-        let mut cursor = reader.open_ro_cursor(self.db)?;
+        let mut cursor = reader.open_ro_cursor(&self.db)?;
         let iter = cursor.iter_dup_of(k);
 
         Ok(Iter {
@@ -67,54 +66,54 @@ where
     }
 
     /// Provides the first value that matches this key
-    pub fn get_first<'env, R, K>(self, reader: &'env R, k: K) -> Result<Option<Value<'env>>, StoreError>
+    pub fn get_first<'env, R, K>(&self, reader: &'env R, k: K) -> Result<Option<Value<'env>>, StoreError>
     where
         R: Readable<'env, Database = D>,
         K: AsRef<[u8]>,
     {
-        reader.get(self.db, &k)
+        reader.get(&self.db, &k)
     }
 
     /// Insert a value at the specified key.
     /// This put will allow duplicate entries.  If you wish to have duplicate entries
     /// rejected, use the `put_with_flags` function and specify NO_DUP_DATA
-    pub fn put<T, K>(self, writer: &mut Writer<T>, k: K, v: &Value) -> EmptyResult
+    pub fn put<T, K>(&self, writer: &mut Writer<T>, k: K, v: &Value) -> EmptyResult
     where
         T: BackendRwTransaction<Database = D>,
         K: AsRef<[u8]>,
     {
-        writer.put(self.db, &k, v, T::Flags::empty())
+        writer.put(&self.db, &k, v, T::Flags::empty())
     }
 
-    pub fn put_with_flags<T, K>(self, writer: &mut Writer<T>, k: K, v: &Value, flags: T::Flags) -> EmptyResult
+    pub fn put_with_flags<T, K>(&self, writer: &mut Writer<T>, k: K, v: &Value, flags: T::Flags) -> EmptyResult
     where
         T: BackendRwTransaction<Database = D>,
         K: AsRef<[u8]>,
     {
-        writer.put(self.db, &k, v, flags)
+        writer.put(&self.db, &k, v, flags)
     }
 
-    pub fn delete_all<T, K>(self, writer: &mut Writer<T>, k: K) -> EmptyResult
+    pub fn delete_all<T, K>(&self, writer: &mut Writer<T>, k: K) -> EmptyResult
     where
         T: BackendRwTransaction<Database = D>,
         K: AsRef<[u8]>,
     {
-        writer.delete(self.db, &k, None)
+        writer.delete(&self.db, &k, None)
     }
 
-    pub fn delete<T, K>(self, writer: &mut Writer<T>, k: K, v: &Value) -> EmptyResult
+    pub fn delete<T, K>(&self, writer: &mut Writer<T>, k: K, v: &Value) -> EmptyResult
     where
         T: BackendRwTransaction<Database = D>,
         K: AsRef<[u8]>,
     {
-        writer.delete(self.db, &k, Some(&v.to_bytes()?))
+        writer.delete(&self.db, &k, Some(&v.to_bytes()?))
     }
 
-    pub fn clear<T>(self, writer: &mut Writer<T>) -> EmptyResult
+    pub fn clear<T>(&self, writer: &mut Writer<T>) -> EmptyResult
     where
         T: BackendRwTransaction<Database = D>,
     {
-        writer.clear(self.db)
+        writer.clear(&self.db)
     }
 }
 

src/store/single.rs

@@ -27,7 +27,6 @@ use crate::value::Value;
 
 type EmptyResult = Result<(), StoreError>;
 
-#[derive(Copy, Clone)]
 pub struct SingleStore<D> {
     db: D,
 }
@@ -48,38 +47,38 @@ where
         }
     }
 
-    pub fn get<'env, R, K>(self, reader: &'env R, k: K) -> Result<Option<Value<'env>>, StoreError>
+    pub fn get<'env, R, K>(&self, reader: &'env R, k: K) -> Result<Option<Value<'env>>, StoreError>
     where
         R: Readable<'env, Database = D>,
         K: AsRef<[u8]>,
     {
-        reader.get(self.db, &k)
+        reader.get(&self.db, &k)
     }
 
     // TODO: flags
-    pub fn put<T, K>(self, writer: &mut Writer<T>, k: K, v: &Value) -> EmptyResult
+    pub fn put<T, K>(&self, writer: &mut Writer<T>, k: K, v: &Value) -> EmptyResult
     where
         T: BackendRwTransaction<Database = D>,
         K: AsRef<[u8]>,
     {
-        writer.put(self.db, &k, v, T::Flags::empty())
+        writer.put(&self.db, &k, v, T::Flags::empty())
     }
 
-    pub fn delete<T, K>(self, writer: &mut Writer<T>, k: K) -> EmptyResult
+    pub fn delete<T, K>(&self, writer: &mut Writer<T>, k: K) -> EmptyResult
     where
         T: BackendRwTransaction<Database = D>,
         K: AsRef<[u8]>,
     {
-        writer.delete(self.db, &k, None)
+        writer.delete(&self.db, &k, None)
     }
 
-    pub fn iter_start<'env, R, I, C>(self, reader: &'env R) -> Result<Iter<'env, I, C>, StoreError>
+    pub fn iter_start<'env, R, I, C>(&self, reader: &'env R) -> Result<Iter<'env, I, C>, StoreError>
     where
         R: Readable<'env, Database = D, RoCursor = C>,
         I: BackendIter<'env>,
         C: BackendRoCursor<'env, Iter = I>,
     {
-        let mut cursor = reader.open_ro_cursor(self.db)?;
+        let mut cursor = reader.open_ro_cursor(&self.db)?;
 
         // We call Cursor.iter() instead of Cursor.iter_start() because
         // the latter panics at "called `Result::unwrap()` on an `Err` value:
@@ -98,14 +97,14 @@ where
         })
     }
 
-    pub fn iter_from<'env, R, I, C, K>(self, reader: &'env R, k: K) -> Result<Iter<'env, I, C>, StoreError>
+    pub fn iter_from<'env, R, I, C, K>(&self, reader: &'env R, k: K) -> Result<Iter<'env, I, C>, StoreError>
     where
         R: Readable<'env, Database = D, RoCursor = C>,
         I: BackendIter<'env>,
         C: BackendRoCursor<'env, Iter = I>,
         K: AsRef<[u8]>,
     {
-        let mut cursor = reader.open_ro_cursor(self.db)?;
+        let mut cursor = reader.open_ro_cursor(&self.db)?;
         let iter = cursor.iter_from(k);
 
         Ok(Iter {
@@ -115,12 +114,12 @@ where
         })
     }
 
-    pub fn clear<T>(self, writer: &mut Writer<T>) -> EmptyResult
+    pub fn clear<T>(&self, writer: &mut Writer<T>) -> EmptyResult
     where
         D: BackendDatabase,
         T: BackendRwTransaction<Database = D>,
     {
-        writer.clear(self.db)
+        writer.clear(&self.db)
     }
 }
 

tests/test_txn.rs

@@ -48,9 +48,9 @@ fn read_many() {
     let root = Builder::new().prefix("test_txns").tempdir().expect("tempdir");
     fs::create_dir_all(root.path()).expect("dir created");
     let k = Rkv::new::<Lmdb>(root.path()).expect("new succeeded");
-    let samplestore = k.open_single("s", StoreOptions::create()).expect("open");
-    let datestore = k.open_multi("m", StoreOptions::create()).expect("open");
-    let valuestore = k.open_multi("m", StoreOptions::create()).expect("open");
+    let samplestore = &k.open_single("s", StoreOptions::create()).expect("open");
+    let datestore = &k.open_multi("m", StoreOptions::create()).expect("open");
+    let valuestore = &k.open_multi("m", StoreOptions::create()).expect("open");
 
     {
         let mut writer = k.write().expect("env write lock");
@@ -89,7 +89,7 @@ fn read_many() {
     }
 }
 
-fn get_ids_by_field<'env, T>(txn: &'env T, store: MultiStore, field: &str) -> Vec<u64>
+fn get_ids_by_field<'env, T>(txn: &'env T, store: &MultiStore, field: &str) -> Vec<u64>
 where
     T: Readable<'env, Database = LmdbDatabase, RoCursor = LmdbRoCursor<'env>>,
 {
@@ -103,7 +103,7 @@ where
         .collect::<Vec<u64>>()
 }
 
-fn get_samples<'env, T>(txn: &'env T, samplestore: SingleStore, ids: &[u64]) -> Vec<String>
+fn get_samples<'env, T>(txn: &'env T, samplestore: &SingleStore, ids: &[u64]) -> Vec<String>
 where
     T: Readable<'env, Database = LmdbDatabase, RoCursor = LmdbRoCursor<'env>>,
 {
@@ -119,11 +119,11 @@ where
         .collect::<Vec<String>>()
 }
 
-fn put_sample(txn: &mut Writer<LmdbRwTransaction>, samplestore: SingleStore, id: u64, value: &str) {
+fn put_sample(txn: &mut Writer<LmdbRwTransaction>, samplestore: &SingleStore, id: u64, value: &str) {
     let idbytes = id.to_be_bytes();
     samplestore.put(txn, &idbytes, &Value::Str(value)).expect("put id");
 }
 
-fn put_id_field(txn: &mut Writer<LmdbRwTransaction>, store: MultiStore, field: &str, id: u64) {
+fn put_id_field(txn: &mut Writer<LmdbRwTransaction>, store: &MultiStore, field: &str, id: u64) {
     store.put(txn, field, &Value::U64(id)).expect("put id");
 }