64 lines
1.7 KiB
Rust
64 lines
1.7 KiB
Rust
use super::{Error, Store};
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use parking_lot::RwLock;
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use std::collections::HashMap;
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type DBHashMap = HashMap<Vec<u8>, Vec<u8>>;
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/// A thread-safe `HashMap` wrapper.
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pub struct MemoryStore {
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db: RwLock<DBHashMap>,
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}
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impl MemoryStore {
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/// Create a new, empty database.
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pub fn open() -> Self {
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Self {
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db: RwLock::new(HashMap::new()),
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}
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}
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fn get_key_for_col(col: &str, key: &[u8]) -> Vec<u8> {
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let mut col = col.as_bytes().to_vec();
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col.append(&mut key.to_vec());
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col
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}
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}
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impl Store for MemoryStore {
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/// Get the value of some key from the database. Returns `None` if the key does not exist.
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fn get_bytes(&self, col: &str, key: &[u8]) -> Result<Option<Vec<u8>>, Error> {
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let column_key = MemoryStore::get_key_for_col(col, key);
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Ok(self
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.db
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.read()
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.get(&column_key)
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.and_then(|val| Some(val.clone())))
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}
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/// Puts a key in the database.
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fn put_bytes(&self, col: &str, key: &[u8], val: &[u8]) -> Result<(), Error> {
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let column_key = MemoryStore::get_key_for_col(col, key);
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self.db.write().insert(column_key, val.to_vec());
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Ok(())
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}
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/// Return true if some key exists in some column.
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fn key_exists(&self, col: &str, key: &[u8]) -> Result<bool, Error> {
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let column_key = MemoryStore::get_key_for_col(col, key);
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Ok(self.db.read().contains_key(&column_key))
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}
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/// Delete some key from the database.
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fn key_delete(&self, col: &str, key: &[u8]) -> Result<(), Error> {
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let column_key = MemoryStore::get_key_for_col(col, key);
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self.db.write().remove(&column_key);
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Ok(())
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}
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}
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