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use core::ops::Bound;
use std::cell::Cell;
use std::sync::{Arc, Mutex, RwLock, MutexGuard};
use ouroboros::self_referencing;
use rusqlite::{params, Connection, Transaction};
use crate::{
Db, Error, Exporter, IDb, ITx, ITxFn, Result, TxError, TxFnResult, TxResult, Value, ValueIter,
};
pub use rusqlite;
impl From<rusqlite::Error> for Error {
fn from(e: rusqlite::Error) -> Error {
Error(format!("{}", e).into())
}
}
impl<T> From<rusqlite::Error> for TxError<T> {
fn from(e: rusqlite::Error) -> TxError<T> {
TxError::Db(e.into())
}
}
pub struct SqliteDb {
db: Mutex<Connection>,
trees: RwLock<Vec<String>>,
}
impl SqliteDb {
pub fn new(db: rusqlite::Connection) -> Db {
let s = Self {
db: Mutex::new(db),
trees: RwLock::new(Vec::new()),
};
Db(Arc::new(s))
}
fn get_tree(&self, i: usize) -> Result<String> {
self.trees
.read()
.unwrap()
.get(i)
.cloned()
.ok_or(Error("invalid tree id".into()))
}
}
impl IDb for SqliteDb {
fn open_tree(&self, name: &str) -> Result<usize> {
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(
&format!(
"CREATE TABLE IF NOT EXISTS {} (
k BLOB PRIMARY KEY,
v BLOB
)",
name
),
[],
)?;
let i = trees.len();
trees.push(name.to_string());
Ok(i)
}
}
// ----
fn get<'a>(&'a self, tree: usize, key: &[u8]) -> Result<Option<Value<'a>>> {
let tree = self.get_tree(tree)?;
let db = self.db.lock().unwrap();
let mut stmt = db.prepare(&format!("SELECT v FROM {} WHERE k = ?1", tree))?;
let mut res_iter = stmt.query([key])?;
match res_iter.next()? {
None => Ok(None),
Some(v) => Ok(Some(v.get::<_, Vec<u8>>(0)?.into())),
}
}
fn remove(&self, tree: usize, key: &[u8]) -> Result<bool> {
let tree = self.get_tree(tree)?;
let db = self.db.lock().unwrap();
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)?;
let db = self.db.lock().unwrap();
let mut stmt = db.prepare(&format!("SELECT COUNT(*) FROM {}", tree))?;
let mut res_iter = stmt.query([])?;
match res_iter.next()? {
None => Ok(0),
Some(v) => Ok(v.get::<_, usize>(0)?.into()),
}
}
fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<()> {
let tree = self.get_tree(tree)?;
let db = self.db.lock().unwrap();
db.execute(
&format!("INSERT OR REPLACE INTO {} (k, v) VALUES (?1, ?2)", tree),
params![key, value],
)?;
Ok(())
}
fn iter<'a>(&'a self, tree: usize) -> Result<ValueIter<'a>> {
let tree = self.get_tree(tree)?;
let db = self.db.lock().unwrap();
let sql = format!("SELECT k, v FROM {} ORDER BY k ASC", tree);
let mut stmt = db.prepare(&sql)?;
let res = stmt.query([])?;
unimplemented!();
}
fn iter_rev<'a>(&'a self, tree: usize) -> Result<ValueIter<'a>> {
let tree = self.get_tree(tree)?;
unimplemented!();
}
fn range<'a, 'r>(
&'a self,
tree: usize,
low: Bound<&'r [u8]>,
high: Bound<&'r [u8]>,
) -> Result<ValueIter<'a>> {
let tree = self.get_tree(tree)?;
unimplemented!();
}
fn range_rev<'a, 'r>(
&'a self,
tree: usize,
low: Bound<&'r [u8]>,
high: Bound<&'r [u8]>,
) -> Result<ValueIter<'a>> {
let tree = self.get_tree(tree)?;
unimplemented!();
}
// ----
fn transaction(&self, f: &dyn ITxFn) -> TxResult<(), ()> {
let trees = self.trees.read().unwrap();
let mut db = self.db.lock().unwrap();
let tx = SqliteTx {
tx: db.transaction()?,
trees: trees.as_ref(),
};
match f.try_on(&tx) {
TxFnResult::Ok => {
tx.tx.commit()?;
Ok(())
}
TxFnResult::Abort => {
tx.tx.rollback()?;
Err(TxError::Abort(()))
}
TxFnResult::DbErr => {
tx.tx.rollback()?;
Err(TxError::Db(Error(
"(this message will be discarded)".into(),
)))
}
}
}
// ----
fn export<'a>(&'a self) -> Result<Exporter<'a>> {
unimplemented!()
}
fn import<'a>(&self, ex: Exporter<'a>) -> Result<()> {
unimplemented!()
}
// ----
}
// ----
struct SqliteTx<'a> {
tx: Transaction<'a>,
trees: &'a [String],
}
impl<'a> SqliteTx<'a> {
fn get_tree(&self, i: usize) -> Result<String> {
self.trees.get(i).cloned().ok_or(Error(
"invalid tree id (it might have been openned after the transaction started)".into(),
))
}
}
impl<'a> ITx<'a> for SqliteTx<'a> {
fn get(&self, tree: usize, key: &[u8]) -> Result<Option<Value<'a>>> {
let tree = self.get_tree(tree)?;
let mut stmt = self
.tx
.prepare(&format!("SELECT v FROM {} WHERE k = ?1", tree))?;
let mut res_iter = stmt.query([key])?;
match res_iter.next()? {
None => Ok(None),
Some(v) => Ok(Some(v.get::<_, Vec<u8>>(0)?.into())),
}
}
fn len(&self, tree: usize) -> Result<usize> {
let tree = self.get_tree(tree)?;
let mut stmt = self.tx.prepare(&format!("SELECT COUNT(*) FROM {}", tree))?;
let mut res_iter = stmt.query([])?;
match res_iter.next()? {
None => Ok(0),
Some(v) => Ok(v.get::<_, usize>(0)?.into()),
}
}
fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<()> {
let tree = self.get_tree(tree)?;
self.tx.execute(
&format!("INSERT OR REPLACE INTO {} (k, v) VALUES (?1, ?2)", tree),
params![key, value],
)?;
Ok(())
}
fn remove(&self, tree: usize, key: &[u8]) -> Result<bool> {
let tree = self.get_tree(tree)?;
let res = self
.tx
.execute(&format!("DELETE FROM {} WHERE k = ?1", tree), params![key])?;
Ok(res > 0)
}
fn iter(&self, _tree: usize) -> Result<ValueIter<'a>> {
unimplemented!();
}
fn iter_rev(&self, _tree: usize) -> Result<ValueIter<'a>> {
unimplemented!();
}
fn range<'r>(
&self,
_tree: usize,
_low: Bound<&'r [u8]>,
_high: Bound<&'r [u8]>,
) -> Result<ValueIter<'a>> {
unimplemented!();
}
fn range_rev<'r>(
&self,
_tree: usize,
_low: Bound<&'r [u8]>,
_high: Bound<&'r [u8]>,
) -> Result<ValueIter<'a>> {
unimplemented!();
}
}
|
