use bincode::Options;
use serde::de::DeserializeOwned;
use std::collections::{BTreeMap, Bound, HashMap};
use std::sync::{Arc, RwLock};
use typed_store_error::TypedStoreError;
type InMemoryStoreInternal = Arc<RwLock<HashMap<String, BTreeMap<Vec<u8>, Vec<u8>>>>>;
#[derive(Clone, Debug)]
pub struct InMemoryDB {
data: InMemoryStoreInternal,
}
#[derive(Clone, Debug)]
enum InMemoryChange {
Delete((String, Vec<u8>)),
Put((String, Vec<u8>, Vec<u8>)),
}
#[derive(Clone, Debug, Default)]
pub struct InMemoryBatch {
data: Vec<InMemoryChange>,
}
impl InMemoryBatch {
pub fn delete_cf<K: AsRef<[u8]>>(&mut self, cf_name: &str, key: K) {
self.data.push(InMemoryChange::Delete((
cf_name.to_string(),
key.as_ref().to_vec(),
)));
}
pub fn put_cf<K, V>(&mut self, cf_name: &str, key: K, value: V)
where
K: AsRef<[u8]>,
V: AsRef<[u8]>,
{
self.data.push(InMemoryChange::Put((
cf_name.to_string(),
key.as_ref().to_vec(),
value.as_ref().to_vec(),
)));
}
}
impl InMemoryDB {
pub fn get<K: AsRef<[u8]>>(&self, cf_name: &str, key: K) -> Option<Vec<u8>> {
let data = self.data.read().expect("can't read data");
match data.get(cf_name) {
Some(cf) => cf.get(key.as_ref()).cloned(),
None => None,
}
}
pub fn multi_get<I, K>(&self, cf_name: &str, keys: I) -> Vec<Option<Vec<u8>>>
where
I: IntoIterator<Item = K>,
K: AsRef<[u8]>,
{
let data = self.data.read().expect("can't read data");
match data.get(cf_name) {
Some(cf) => keys
.into_iter()
.map(|k| cf.get(k.as_ref()).cloned())
.collect(),
None => vec![],
}
}
pub fn delete(&self, cf_name: &str, key: &[u8]) {
let mut data = self.data.write().expect("can't write data");
data.entry(cf_name.to_string()).or_default().remove(key);
}
pub fn put(&self, cf_name: &str, key: Vec<u8>, value: Vec<u8>) {
let mut data = self.data.write().expect("can't write data");
data.entry(cf_name.to_string())
.or_default()
.insert(key, value);
}
pub fn write(&self, batch: InMemoryBatch) {
for change in batch.data {
match change {
InMemoryChange::Delete((cf_name, key)) => self.delete(&cf_name, &key),
InMemoryChange::Put((cf_name, key, value)) => self.put(&cf_name, key, value),
}
}
}
pub fn drop_cf(&self, name: &str) {
self.data.write().expect("can't write data").remove(name);
}
pub fn iterator<K, V>(
&self,
cf_name: &str,
lower_bound: Option<Vec<u8>>,
upper_bound: Option<Vec<u8>>,
reverse: bool,
) -> Box<dyn Iterator<Item = Result<(K, V), TypedStoreError>> + '_>
where
K: DeserializeOwned,
V: DeserializeOwned,
{
let config = bincode::DefaultOptions::new()
.with_big_endian()
.with_fixint_encoding();
let lower_bound = lower_bound.map(Bound::Included).unwrap_or(Bound::Unbounded);
let upper_bound = upper_bound.map(Bound::Included).unwrap_or(Bound::Unbounded);
let data = self.data.read().expect("can't read data");
let mut section: Vec<_> = data
.get(cf_name)
.unwrap_or(&BTreeMap::new())
.range((lower_bound, upper_bound))
.map(|(k, v)| (k.clone(), v.clone()))
.collect();
if reverse {
section.reverse();
}
Box::new(section.into_iter().map(move |(raw_key, raw_value)| {
let key = config.deserialize(&raw_key).unwrap();
let value = bcs::from_bytes(&raw_value).unwrap();
Ok((key, value))
}))
}
}