Interface Table

src/storage/table.rs:104–221

Typed database table.

/// Typed database table.
pub trait Table: RawTable + Sized + From<rocksdb::DB> {
    /// Key format.
    type Key: TableKey;

    /// Value format.
    type Value: rkyv::Archive + rkyv::Serialize<AllocSerializer<4096>> + 'static;

    /// Defines the table's merge behavior.
    const MERGE_OP: MergeOperator<Self> = MergeOperator::Default;

    /// Defines the table's storage optimization.
    const STORAGE_OPT: StorageOpt = StorageOpt::RandomAccess;

    /// LRU cache size for this table. Set to 0 to disable caching.
    const CACHE_SIZE: usize = 16384;

    /// Removes the record with the given key from the table.
    fn remove(&self, key: Self::Key) {
        let key_raw = key.into_raw();

        // Remove from cache
        if Self::CACHE_SIZE > 0 {
            let mut cache = self.cache().lock().unwrap();
            cache.pop(key_raw.as_ref());
        }

        self.raw().delete(key_raw).unwrap();
    }

    /// Inserts the given value at the given key.
    ///
    /// If the record already exists, the previous value is replaced.
    fn insert(&self, key: Self::Key, value: Self::Value) {
        let key_raw = key.into_raw();
        let value_bytes = rkyv::to_bytes(&value).unwrap();

        // Update cache
        if Self::CACHE_SIZE > 0 {
            let mut cache = self.cache().lock().unwrap();
            cache.put(key_raw.as_ref().to_vec(), value_bytes.to_vec());
        }

        match Self::MERGE_OP {
            MergeOperator::Default => self.raw().put(key_raw, value_bytes).unwrap(),
            MergeOperator::Associative(_) => self.raw().merge(key_raw, value_bytes).unwrap(),
        }
    }

    /// Create a new insertion batch.
    fn batched_insert(&self) -> InsertionBatch<'_, Self> {
        InsertionBatch(self, rocksdb::WriteBatch::default())
    }

    /// Get the value at the given key.
    ///
    /// Returns `None` if the key isn't present.
    fn get(&self, key: Self::Key) -> Option<TableValueRef<Self::Value, SmallVec<[u8; 64]>>> {
        let key_raw = key.into_raw();