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use tetsy_kvdb::{DBOp, DBTransaction, DBValue, KeyValueDB};
use tetsy_util_mem::MallocSizeOf;
use parking_lot::RwLock;
use std::{
collections::{BTreeMap, HashMap},
io,
};
#[derive(Default, MallocSizeOf)]
pub struct InMemory {
columns: RwLock<HashMap<u32, BTreeMap<Vec<u8>, DBValue>>>,
}
pub fn create(num_cols: u32) -> InMemory {
let mut cols = HashMap::new();
for idx in 0..num_cols {
cols.insert(idx, BTreeMap::new());
}
InMemory { columns: RwLock::new(cols) }
}
impl KeyValueDB for InMemory {
fn get(&self, col: u32, key: &[u8]) -> io::Result<Option<DBValue>> {
let columns = self.columns.read();
match columns.get(&col) {
None => Err(io::Error::new(io::ErrorKind::Other, format!("No such column family: {:?}", col))),
Some(map) => Ok(map.get(key).cloned()),
}
}
fn get_by_prefix(&self, col: u32, prefix: &[u8]) -> Option<Box<[u8]>> {
let columns = self.columns.read();
match columns.get(&col) {
None => None,
Some(map) => {
map.iter().find(|&(ref k, _)| k.starts_with(prefix)).map(|(_, v)| v.to_vec().into_boxed_slice())
}
}
}
fn write_buffered(&self, transaction: DBTransaction) {
let mut columns = self.columns.write();
let ops = transaction.ops;
for op in ops {
match op {
DBOp::Insert { col, key, value } => {
if let Some(col) = columns.get_mut(&col) {
col.insert(key.into_vec(), value);
}
}
DBOp::Delete { col, key } => {
if let Some(col) = columns.get_mut(&col) {
col.remove(&*key);
}
}
}
}
}
fn flush(&self) -> io::Result<()> {
Ok(())
}
fn iter<'a>(&'a self, col: u32) -> Box<dyn Iterator<Item = (Box<[u8]>, Box<[u8]>)> + 'a> {
match self.columns.read().get(&col) {
Some(map) => Box::new(
map.clone().into_iter().map(|(k, v)| (k.into_boxed_slice(), v.into_boxed_slice())),
),
None => Box::new(None.into_iter()),
}
}
fn iter_from_prefix<'a>(
&'a self,
col: u32,
prefix: &'a [u8],
) -> Box<dyn Iterator<Item = (Box<[u8]>, Box<[u8]>)> + 'a> {
match self.columns.read().get(&col) {
Some(map) => Box::new(
map.clone()
.into_iter()
.filter(move |&(ref k, _)| k.starts_with(prefix))
.map(|(k, v)| (k.into_boxed_slice(), v.into_boxed_slice())),
),
None => Box::new(None.into_iter()),
}
}
fn restore(&self, _new_db: &str) -> io::Result<()> {
Err(io::Error::new(io::ErrorKind::Other, "Attempted to restore in-memory database"))
}
}
#[cfg(test)]
mod tests {
use super::create;
use tetsy_kvdb_shared_tests as st;
use std::io;
#[test]
fn get_fails_with_non_existing_column() -> io::Result<()> {
let db = create(1);
st::test_get_fails_with_non_existing_column(&db)
}
#[test]
fn put_and_get() -> io::Result<()> {
let db = create(1);
st::test_put_and_get(&db)
}
#[test]
fn delete_and_get() -> io::Result<()> {
let db = create(1);
st::test_delete_and_get(&db)
}
#[test]
fn iter() -> io::Result<()> {
let db = create(1);
st::test_iter(&db)
}
#[test]
fn iter_from_prefix() -> io::Result<()> {
let db = create(1);
st::test_iter_from_prefix(&db)
}
#[test]
fn complex() -> io::Result<()> {
let db = create(1);
st::test_complex(&db)
}
}