use core::ops::Bound; use std::cell::Cell; use std::collections::HashMap; use std::sync::{Arc, RwLock}; use sled::transaction::{ ConflictableTransactionError, TransactionError, Transactional, TransactionalTree, UnabortableTransactionError, }; use crate::{Db, Error, IDb, ITx, ITxFn, Result, TxError, TxFnResult, TxResult, Value, ValueIter}; pub use sled; // -- err impl From for Error { fn from(e: sled::Error) -> Error { Error(format!("Sled: {}", e).into()) } } // -- db pub struct SledDb { db: sled::Db, trees: RwLock<(Vec, HashMap)>, } impl SledDb { pub fn init(db: sled::Db) -> Db { let s = Self { db, trees: RwLock::new((Vec::new(), HashMap::new())), }; Db(Arc::new(s)) } fn get_tree(&self, i: usize) -> Result { self.trees .read() .unwrap() .0 .get(i) .cloned() .ok_or_else(|| Error("invalid tree id".into())) } } impl IDb for SledDb { fn open_tree(&self, name: &str) -> Result { let mut trees = self.trees.write().unwrap(); if let Some(i) = trees.1.get(name) { Ok(*i) } else { let tree = self.db.open_tree(name)?; let i = trees.0.len(); trees.0.push(tree); trees.1.insert(name.to_string(), i); Ok(i) } } fn list_trees(&self) -> Result> { let mut trees = vec![]; for name in self.db.tree_names() { let name = std::str::from_utf8(&name) .map_err(|e| Error(format!("{}", e).into()))? .to_string(); if name != "__sled__default" { trees.push(name); } } Ok(trees) } // ---- fn get(&self, tree: usize, key: &[u8]) -> Result> { let tree = self.get_tree(tree)?; let val = tree.get(key)?; Ok(val.map(|x| x.to_vec())) } fn remove(&self, tree: usize, key: &[u8]) -> Result { let tree = self.get_tree(tree)?; Ok(tree.remove(key)?.is_some()) } fn len(&self, tree: usize) -> Result { let tree = self.get_tree(tree)?; Ok(tree.len()) } fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<()> { let tree = self.get_tree(tree)?; tree.insert(key, value)?; Ok(()) } fn iter(&self, tree: usize) -> Result> { let tree = self.get_tree(tree)?; Ok(Box::new(tree.iter().map(|v| { v.map(|(x, y)| (x.to_vec(), y.to_vec())).map_err(Into::into) }))) } fn iter_rev(&self, tree: usize) -> Result> { let tree = self.get_tree(tree)?; Ok(Box::new(tree.iter().rev().map(|v| { v.map(|(x, y)| (x.to_vec(), y.to_vec())).map_err(Into::into) }))) } fn range<'r>( &self, tree: usize, low: Bound<&'r [u8]>, high: Bound<&'r [u8]>, ) -> Result> { let tree = self.get_tree(tree)?; Ok(Box::new(tree.range::<&'r [u8], _>((low, high)).map(|v| { v.map(|(x, y)| (x.to_vec(), y.to_vec())).map_err(Into::into) }))) } fn range_rev<'r>( &self, tree: usize, low: Bound<&'r [u8]>, high: Bound<&'r [u8]>, ) -> Result> { let tree = self.get_tree(tree)?; Ok(Box::new(tree.range::<&'r [u8], _>((low, high)).rev().map( |v| v.map(|(x, y)| (x.to_vec(), y.to_vec())).map_err(Into::into), ))) } // ---- fn transaction(&self, f: &dyn ITxFn) -> TxResult<(), ()> { let trees = self.trees.read().unwrap(); let res = trees.0.transaction(|txtrees| { let mut tx = SledTx { trees: txtrees, err: Cell::new(None), }; match f.try_on(&mut tx) { TxFnResult::Ok => { assert!(tx.err.into_inner().is_none()); Ok(()) } TxFnResult::Abort => { assert!(tx.err.into_inner().is_none()); Err(ConflictableTransactionError::Abort(())) } TxFnResult::DbErr => { let e = tx.err.into_inner().expect("No DB error"); Err(e.into()) } } }); match res { Ok(()) => Ok(()), Err(TransactionError::Abort(())) => Err(TxError::Abort(())), Err(TransactionError::Storage(s)) => Err(TxError::Db(s.into())), } } } // ---- struct SledTx<'a> { trees: &'a [TransactionalTree], err: Cell>, } impl<'a> SledTx<'a> { fn get_tree(&self, i: usize) -> Result<&TransactionalTree> { self.trees.get(i).ok_or_else(|| { Error( "invalid tree id (it might have been openned after the transaction started)".into(), ) }) } fn save_error(&self, v: std::result::Result) -> Result { match v { Ok(x) => Ok(x), Err(e) => { let txt = format!("{}", e); self.err.set(Some(e)); Err(Error(txt.into())) } } } } impl<'a> ITx for SledTx<'a> { fn get(&self, tree: usize, key: &[u8]) -> Result> { let tree = self.get_tree(tree)?; let tmp = self.save_error(tree.get(key))?; Ok(tmp.map(|x| x.to_vec())) } fn len(&self, _tree: usize) -> Result { unimplemented!(".len() in transaction not supported with Sled backend") } fn insert(&mut self, tree: usize, key: &[u8], value: &[u8]) -> Result<()> { let tree = self.get_tree(tree)?; self.save_error(tree.insert(key, value))?; Ok(()) } fn remove(&mut self, tree: usize, key: &[u8]) -> Result { let tree = self.get_tree(tree)?; Ok(self.save_error(tree.remove(key))?.is_some()) } fn iter(&self, _tree: usize) -> Result> { unimplemented!("Iterators in transactions not supported with Sled backend"); } fn iter_rev(&self, _tree: usize) -> Result> { unimplemented!("Iterators in transactions not supported with Sled backend"); } fn range<'r>( &self, _tree: usize, _low: Bound<&'r [u8]>, _high: Bound<&'r [u8]>, ) -> Result> { unimplemented!("Iterators in transactions not supported with Sled backend"); } fn range_rev<'r>( &self, _tree: usize, _low: Bound<&'r [u8]>, _high: Bound<&'r [u8]>, ) -> Result> { unimplemented!("Iterators in transactions not supported with Sled backend"); } }