db abstraction: make .insert() and .remove() return the old value
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This commit is contained in:
Alex 2022-06-07 17:05:17 +02:00
parent a9e79f848b
commit a3a01141ec
Signed by: lx
GPG key ID: 0E496D15096376BE
6 changed files with 127 additions and 91 deletions

View file

@ -51,36 +51,26 @@ impl CountedTree {
// ---- writing functions ----
pub fn insert<K, V>(&self, key: K, value: V) -> Result<bool>
pub fn insert<K, V>(&self, key: K, value: V) -> Result<Option<Value>>
where
K: AsRef<[u8]>,
V: AsRef<[u8]>,
{
let inserted = self.0.tree.insert(key, value)?;
if inserted {
let old_val = self.0.tree.insert(key, value)?;
if old_val.is_none() {
self.0.len.fetch_add(1, Ordering::Relaxed);
}
Ok(inserted)
Ok(old_val)
}
pub fn remove<K: AsRef<[u8]>>(&self, key: K) -> Result<bool> {
let removed = self.0.tree.remove(key)?;
if removed {
pub fn remove<K: AsRef<[u8]>>(&self, key: K) -> Result<Option<Value>> {
let old_val = self.0.tree.remove(key)?;
if old_val.is_some() {
self.0.len.fetch_sub(1, Ordering::Relaxed);
}
Ok(removed)
Ok(old_val)
}
/*
pub fn pop_min(&self) -> Result<Option<(Value, Value)>> {
let res = self.0.tree.pop_min();
if let Ok(Some(_)) = &res {
self.0.len.fetch_sub(1, Ordering::Relaxed);
};
res
}
*/
pub fn compare_and_swap<K, OV, NV>(
&self,
key: K,

View file

@ -166,15 +166,18 @@ impl Tree {
.transpose()
}
/// True if item didn't exist before, false if item already existed
/// and was replaced.
/// Returns the old value if there was one
#[inline]
pub fn insert<T: AsRef<[u8]>, U: AsRef<[u8]>>(&self, key: T, value: U) -> Result<bool> {
pub fn insert<T: AsRef<[u8]>, U: AsRef<[u8]>>(
&self,
key: T,
value: U,
) -> Result<Option<Value>> {
self.0.insert(self.1, key.as_ref(), value.as_ref())
}
/// True if item was removed, false if item already didn't exist
/// Returns the old value if there was one
#[inline]
pub fn remove<T: AsRef<[u8]>>(&self, key: T) -> Result<bool> {
pub fn remove<T: AsRef<[u8]>>(&self, key: T) -> Result<Option<Value>> {
self.0.remove(self.1, key.as_ref())
}
@ -220,20 +223,19 @@ impl<'a> Transaction<'a> {
self.0.len(tree.1)
}
/// True if item didn't exist before, false if item already existed
/// and was replaced.
/// Returns the old value if there was one
#[inline]
pub fn insert<T: AsRef<[u8]>, U: AsRef<[u8]>>(
&mut self,
tree: &Tree,
key: T,
value: U,
) -> Result<bool> {
) -> Result<Option<Value>> {
self.0.insert(tree.1, key.as_ref(), value.as_ref())
}
/// True if item was removed, false if item already didn't exist
/// Returns the old value if there was one
#[inline]
pub fn remove<T: AsRef<[u8]>>(&mut self, tree: &Tree, key: T) -> Result<bool> {
pub fn remove<T: AsRef<[u8]>>(&mut self, tree: &Tree, key: T) -> Result<Option<Value>> {
self.0.remove(tree.1, key.as_ref())
}
@ -289,8 +291,8 @@ pub(crate) trait IDb: Send + Sync {
fn get(&self, tree: usize, key: &[u8]) -> Result<Option<Value>>;
fn len(&self, tree: usize) -> Result<usize>;
fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<bool>;
fn remove(&self, tree: usize, key: &[u8]) -> Result<bool>;
fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<Option<Value>>;
fn remove(&self, tree: usize, key: &[u8]) -> Result<Option<Value>>;
fn iter(&self, tree: usize) -> Result<ValueIter<'_>>;
fn iter_rev(&self, tree: usize) -> Result<ValueIter<'_>>;
@ -315,8 +317,8 @@ pub(crate) trait ITx {
fn get(&self, tree: usize, key: &[u8]) -> Result<Option<Value>>;
fn len(&self, tree: usize) -> Result<usize>;
fn insert(&mut self, tree: usize, key: &[u8], value: &[u8]) -> Result<bool>;
fn remove(&mut self, tree: usize, key: &[u8]) -> Result<bool>;
fn insert(&mut self, tree: usize, key: &[u8], value: &[u8]) -> Result<Option<Value>>;
fn remove(&mut self, tree: usize, key: &[u8]) -> Result<Option<Value>>;
fn iter(&self, tree: usize) -> Result<ValueIter<'_>>;
fn iter_rev(&self, tree: usize) -> Result<ValueIter<'_>>;

View file

@ -108,27 +108,28 @@ impl IDb for LmdbDb {
}
}
fn remove(&self, tree: usize, key: &[u8]) -> Result<bool> {
let tree = self.get_tree(tree)?;
let mut tx = self.db.write_txn()?;
let deleted = tree.delete(&mut tx, key)?;
tx.commit()?;
Ok(deleted)
}
fn len(&self, tree: usize) -> Result<usize> {
let tree = self.get_tree(tree)?;
let tx = self.db.read_txn()?;
Ok(tree.len(&tx)?.try_into().unwrap())
}
fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<bool> {
fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<Option<Value>> {
let tree = self.get_tree(tree)?;
let mut tx = self.db.write_txn()?;
let old_val = tree.get(&tx, key)?.map(Vec::from);
tree.put(&mut tx, key, value)?;
tx.commit()?;
Ok(old_val.is_none())
Ok(old_val)
}
fn remove(&self, tree: usize, key: &[u8]) -> Result<Option<Value>> {
let tree = self.get_tree(tree)?;
let mut tx = self.db.write_txn()?;
let old_val = tree.get(&tx, key)?.map(Vec::from);
tree.delete(&mut tx, key)?;
tx.commit()?;
Ok(old_val)
}
fn iter(&self, tree: usize) -> Result<ValueIter<'_>> {
@ -222,16 +223,17 @@ impl<'a, 'db> ITx for LmdbTx<'a, 'db> {
unimplemented!(".len() in transaction not supported with LMDB backend")
}
fn insert(&mut self, tree: usize, key: &[u8], value: &[u8]) -> Result<bool> {
fn insert(&mut self, tree: usize, key: &[u8], value: &[u8]) -> Result<Option<Value>> {
let tree = *self.get_tree(tree)?;
let old_val = tree.get(&self.tx, key)?.map(Vec::from);
tree.put(&mut self.tx, key, value)?;
Ok(old_val.is_none())
Ok(old_val)
}
fn remove(&mut self, tree: usize, key: &[u8]) -> Result<bool> {
fn remove(&mut self, tree: usize, key: &[u8]) -> Result<Option<Value>> {
let tree = *self.get_tree(tree)?;
let deleted = tree.delete(&mut self.tx, key)?;
Ok(deleted)
let old_val = tree.get(&self.tx, key)?.map(Vec::from);
tree.delete(&mut self.tx, key)?;
Ok(old_val)
}
fn iter(&self, _tree: usize) -> Result<ValueIter<'_>> {

View file

@ -83,20 +83,21 @@ impl IDb for SledDb {
Ok(val.map(|x| x.to_vec()))
}
fn remove(&self, tree: usize, key: &[u8]) -> Result<bool> {
let tree = self.get_tree(tree)?;
Ok(tree.remove(key)?.is_some())
}
fn len(&self, tree: usize) -> Result<usize> {
let tree = self.get_tree(tree)?;
Ok(tree.len())
}
fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<bool> {
fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<Option<Value>> {
let tree = self.get_tree(tree)?;
let old_val = tree.insert(key, value)?;
Ok(old_val.is_none())
Ok(old_val.map(|x| x.to_vec()))
}
fn remove(&self, tree: usize, key: &[u8]) -> Result<Option<Value>> {
let tree = self.get_tree(tree)?;
let old_val = tree.remove(key)?;
Ok(old_val.map(|x| x.to_vec()))
}
fn iter(&self, tree: usize) -> Result<ValueIter<'_>> {
@ -206,14 +207,15 @@ impl<'a> ITx for SledTx<'a> {
unimplemented!(".len() in transaction not supported with Sled backend")
}
fn insert(&mut self, tree: usize, key: &[u8], value: &[u8]) -> Result<bool> {
fn insert(&mut self, tree: usize, key: &[u8], value: &[u8]) -> Result<Option<Value>> {
let tree = self.get_tree(tree)?;
let old_val = self.save_error(tree.insert(key, value))?;
Ok(old_val.is_none())
Ok(old_val.map(|x| x.to_vec()))
}
fn remove(&mut self, tree: usize, key: &[u8]) -> Result<bool> {
fn remove(&mut self, tree: usize, key: &[u8]) -> Result<Option<Value>> {
let tree = self.get_tree(tree)?;
Ok(self.save_error(tree.remove(key))?.is_some())
let old_val = self.save_error(tree.remove(key))?;
Ok(old_val.map(|x| x.to_vec()))
}
fn iter(&self, _tree: usize) -> Result<ValueIter<'_>> {

View file

@ -125,18 +125,6 @@ impl IDb for SqliteDb {
this.internal_get(tree, key)
}
fn remove(&self, tree: usize, key: &[u8]) -> Result<bool> {
trace!("remove {}: lock db", tree);
let this = self.0.lock().unwrap();
trace!("remove {}: lock acquired", tree);
let tree = this.get_tree(tree)?;
let res = this
.db
.execute(&format!("DELETE FROM {} WHERE k = ?1", tree), params![key])?;
Ok(res > 0)
}
fn len(&self, tree: usize) -> Result<usize> {
trace!("len {}: lock db", tree);
let this = self.0.lock().unwrap();
@ -151,18 +139,50 @@ impl IDb for SqliteDb {
}
}
fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<bool> {
fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<Option<Value>> {
trace!("insert {}: lock db", tree);
let this = self.0.lock().unwrap();
trace!("insert {}: lock acquired", tree);
let tree = this.get_tree(tree)?;
let old_val = this.internal_get(tree, key)?;
this.db.execute(
&format!("INSERT OR REPLACE INTO {} (k, v) VALUES (?1, ?2)", tree),
match &old_val {
Some(_) => {
let n = this.db.execute(
&format!("UPDATE {} SET v = ?2 WHERE k = ?1", tree),
params![key, value],
)?;
Ok(old_val.is_none())
assert_eq!(n, 1);
}
None => {
let n = this.db.execute(
&format!("INSERT INTO {} (k, v) VALUES (?1, ?2)", tree),
params![key, value],
)?;
assert_eq!(n, 1);
}
}
Ok(old_val)
}
fn remove(&self, tree: usize, key: &[u8]) -> Result<Option<Value>> {
trace!("remove {}: lock db", tree);
let this = self.0.lock().unwrap();
trace!("remove {}: lock acquired", tree);
let tree = this.get_tree(tree)?;
let old_val = this.internal_get(tree, key)?;
if old_val.is_some() {
let n = this
.db
.execute(&format!("DELETE FROM {} WHERE k = ?1", tree), params![key])?;
assert_eq!(n, 1);
}
Ok(old_val)
}
fn iter(&self, tree: usize) -> Result<ValueIter<'_>> {
@ -308,21 +328,41 @@ impl<'a> ITx for SqliteTx<'a> {
}
}
fn insert(&mut self, tree: usize, key: &[u8], value: &[u8]) -> Result<bool> {
fn insert(&mut self, tree: usize, key: &[u8], value: &[u8]) -> Result<Option<Value>> {
let tree = self.get_tree(tree)?;
let old_val = self.internal_get(tree, key)?;
self.tx.execute(
&format!("INSERT OR REPLACE INTO {} (k, v) VALUES (?1, ?2)", tree),
match &old_val {
Some(_) => {
let n = self.tx.execute(
&format!("UPDATE {} SET v = ?2 WHERE k = ?1", tree),
params![key, value],
)?;
Ok(old_val.is_none())
assert_eq!(n, 1);
}
fn remove(&mut self, tree: usize, key: &[u8]) -> Result<bool> {
None => {
let n = self.tx.execute(
&format!("INSERT INTO {} (k, v) VALUES (?1, ?2)", tree),
params![key, value],
)?;
assert_eq!(n, 1);
}
}
Ok(old_val)
}
fn remove(&mut self, tree: usize, key: &[u8]) -> Result<Option<Value>> {
let tree = self.get_tree(tree)?;
let res = self
let old_val = self.internal_get(tree, key)?;
if old_val.is_some() {
let n = self
.tx
.execute(&format!("DELETE FROM {} WHERE k = ?1", tree), params![key])?;
Ok(res > 0)
assert_eq!(n, 1);
}
Ok(old_val)
}
fn iter(&self, _tree: usize) -> Result<ValueIter<'_>> {

View file

@ -14,13 +14,13 @@ fn test_suite(db: Db) {
let vb: &[u8] = &b"plip"[..];
let vc: &[u8] = &b"plup"[..];
tree.insert(ka, va).unwrap();
assert!(tree.insert(ka, va).unwrap().is_none());
assert_eq!(tree.get(ka).unwrap().unwrap(), va);
let res = db.transaction::<_, (), _>(|mut tx| {
assert_eq!(tx.get(&tree, ka).unwrap().unwrap(), va);
tx.insert(&tree, ka, vb).unwrap();
assert_eq!(tx.insert(&tree, ka, vb).unwrap().unwrap(), va);
assert_eq!(tx.get(&tree, ka).unwrap().unwrap(), vb);
@ -32,7 +32,7 @@ fn test_suite(db: Db) {
let res = db.transaction::<(), _, _>(|mut tx| {
assert_eq!(tx.get(&tree, ka).unwrap().unwrap(), vb);
tx.insert(&tree, ka, vc).unwrap();
assert_eq!(tx.insert(&tree, ka, vc).unwrap().unwrap(), vb);
assert_eq!(tx.get(&tree, ka).unwrap().unwrap(), vc);
@ -47,7 +47,7 @@ fn test_suite(db: Db) {
assert!(iter.next().is_none());
drop(iter);
tree.insert(kb, vc).unwrap();
assert!(tree.insert(kb, vc).unwrap().is_none());
assert_eq!(tree.get(kb).unwrap().unwrap(), vc);
let mut iter = tree.iter().unwrap();